ATTI - | Associazione Italiana Chimica per Ingegneria€¦ · 4 16.30 - 17.00 Coffee Break 17.00 -...
37
ATTI V WORKSHOP NAZIONALE AICIng Tecnologie Chimiche per il Benessere e la Salute dell‘Uomo AICIng 2013 Favignana, Trapani 13-14 Giugno 2013
Transcript of ATTI - | Associazione Italiana Chimica per Ingegneria€¦ · 4 16.30 - 17.00 Coffee Break 17.00 -...
ATTI
V WORKSHOP NAZIONALE AICIng
Tecnologie Chimiche per il Benessere e la Salute dell‘Uomo
AICIng 2013
Favignana, Trapani
13-14 Giugno 2013
2
V WORKSHOP NAZIONALE AICING
Tecnologie Chimiche per il Benessere e la Salute dell‘Uomo
Università degli Studi di Palermo
Favignana, Trapani, 13-14 giugno 2013
Scopo del workshop L’Associazione Italiana di Chimica per l’Ingegneria–AICIng è impegnata, sin dalla sua costituzione, a
favorire contatti tra i propri docenti e giovani ricercatori al fine di promuovere un arricchimento culturale
anche mediante l’organizzazione di incontri biennali su argomenti di carattere trasversale. Dopo gli incontri
di Roma-Villa Mondragone, Messina, Genova e Modena, questo incontro vuole affrontare il tema delle
Tecnologie Chimiche al servizio della salute e, più in generale, del benessere dell’uomo. Scopo del
workshop è fornire un forum per discutere del ruolo e del contributo che la chimica e le tecnologie relative
mettono a disposizione nell’immediato e nel prossimo futuro per la salute dell’uomo e per il miglioramento
della qualità della vita.
La partecipazione è gratuita e AIcing offre 4 premi a giovani ricercatori, autori dei quattro migliori
contributi. Si ringrazia l’Azienda Bracco Imaging per il supporto finanziario all'iniziativa.
Sede del workshop:
Il workshop avrà luogo presso l’Hotel Tempo di Mare, via Frascia 6, Favignana, www.hoteltempodimare.it
Comitato Scientifico
Silvia Licoccia, Università di Roma Tor Vergata
Marta Feroci, Università Sapienza di Roma
Marilena Tolazzi, Università di Udine
Signorino Galvagno, Università di Messina
Salvatore Failla, Università di Catania
Francesco Geobaldo, Politecnico di Torino
Comitato Organizzatore Locale
Clelia Dispenza, DICGIM, Palermo
Sabina Alessi, DICGIM, Palermo
Maria Antonietta Sabatino, DICGIM, Palermo
Natascia Grimaldi, DICGIM, Palermo
Simona Todaro, DICGIM, Palermo
Giuseppe Spadaro, DICGIM, Palermo
Segreteria organizzativa: Maria Antonietta Sabatino
e-mail [email protected]
Simona Todaro
e-mail [email protected]
tel 0039091 23863738
fax 00390917025020
DICGIM - Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica
Università degli Studi di Palermo
Viale delle Scienze
90128 Palermo
3
Programma
Mercoledì 12 giugno
17.00- 19.00 Registrazione e cocktail di benvenuto
Giovedì 13 giugno 2013
08.30 - 09.00 Registrazione
09.00 - 09.20 Apertura dei lavori
09.20 - 10.10 “Healing and regenerating broken hearts: special forces for new battles”
C. Scardulla, ISMETT (Istituto Mediterraneo per i Trapianti e Terapie ad Alta
Specializzazione) Palermo
10.10 - 11.00 “New materials technologies in the Biopharma industry: the path from lab to patients”
C. Lo Presti, Merck SeronoSpA Guidonia Montecelio (Roma)
11.00 - 11.20 “Micro-contact printing of protein patterns on electrospun polymeric matrices”
A. Rainer, Università Campus Bio-Medico di Roma
11.20 - 11.40 Coffee Break
11.40 - 12.00 “Triphenylamine-based dyes for live-cells labeling and imaging of cell’s cytoplasm”
G. Ciccarella, Università del Salento
12.00 - 12.20 “Porphyrin-based chemical sensors and multisensor arrays for the evaluation of food quality”
M.L. Naitana, Università di Roma Tor Vergata
12.20 - 12.40 “Engineered Carbon Nanotubes as Drug Delivery Systems for Antiviral Drugs”
D. Iannazzo, Università di Messina
12.40 - 13.00 “Azahelicenium salts: possible biological applications”
F. Fontana, Università di Bergamo
13.00 - 15.30 Pranzo
15.30 - 15.50 “Applicazioni Della Tecnologia Microonde In Procedure Estrattive Ecocompatibili”
C. Villa, Università di Genova
15.50 - 16.10 “Estrazione a microonde di composti bio-attivi da matrici vegetali”
R. Rosa, Università degli Studi di Modena e Reggio Emilia
16.10 - 16.30 “Studies on Catalytic and catalytic photo-assisted propene hydration in the presence of
H3PW12O40 supported on different oxides”
G. Marcì, Università di Palermo
4
16.30 - 17.00 Coffee Break
17.00 - 17.20 “La0.8Sr0.2Fe0.8Cu0.2O3 as cathodic material for La0.8Sr0.2Ga0.8Mg0.2O3 based SOFCs”
F. Zurlo, Università di Roma Tor Vergata
17.20 - 17.40 “Sintesi via sol-gel dip coating e caratterizzazione di film ibridi organico-inorganici per il
potenziamento delle proprietà biologiche di impianti in lega di Titanio grado 4”
F. Bollino, Seconda Università di Napoli
17.40 - 18.00 “Cost effective electrode materials for energy and environmental applications”
A. Iannaci, Università di Roma Tor Vergata
21.00 Cena sociale
Venerdì 14 giugno
09.00 - 09.50 “La Diagnostica per Immagini Punto di Incontro tra Chimica Sostenibile e Salute”
F. Uggeri, Bracco ImagingSpA, Centro Ricerche Bracco Colleretto Giacosa (Torino)
09.50 - 10.10 “Large-scale manufacturing of radiation sculptured therapeutic nanogels”
C. Dispenza, Università di Palermo
10.10 - 10. 30 “Modelli teorici per idrolisi ed idratazione di complessi antitumorali di platino”
A. Melchior, Università di Udine
10.30 - 10.50 “EIS biochip with integrated microfluidic components and MIP modified-electrodes for POC
analysis of environmental and clinical samples”
M.S. Chiriacò, Università del Salento
10.50 - 11.20 Coffee Break
11.20 - 11.40 “Temperature-responsive degalactosylated xyloglucans as nanocarriers for the sustained release
of hydrophobic drugs”
S. Todaro, Università di Palermo
11.40 - 12.00 “Polyelectrolyte Capsules as Carriers for Insoluble Anticancer Drug”
V. Vergaro, CNR Nano-Istituto Nanoscienze Lecce
12.00 - 12.20 “Periodically nanostructured hydrogels for ethanol vapors sensing”
M.A. Sabatino, Università di Palermo
12.20 - 12.40 “ToF-SIMS Imaging and Depth Profiling for the Characterization of Biomaterials Surfaces”
L. Tortora, Università di Roma Tor Vergata
12.40 Conclusione dei lavori
5
Healing and regenerating broken hearts: special forces for new battles
Cesare Scardulla MD
ISMETT (Istituto Mediterraneo per i Trapianti e le Terapie ad Alta Specializzazione)
UPMC (University of Pittsburgh Medical Center)
Le malattie cardiovascolari costituiscono oggi il principale problema che i sistemi sanitari del mondo
occidentale devono fronteggiare e sono la principale causa di morte. Questo dato epidemiologico può essere
spiegato sia dall’aumento della vita media degli individui nei paesi a maggior sviluppo economico ma anche
dalle caratteristiche dello stile di vita (fumo, obesità, iperalimentazione, stress). E’anche da considerare il
fatto paradossale (ironic failure of success) che l’alta capacità raggiunta nel trattare con successo gli eventi
acuti, fa “sopravvivere” all’infarto pazienti che però non guariscono dalla malattia e che si cronicizzeranno
negli anni successivi gravando sul sistema sanitario a causa delle frequenti ospedalizzazioni. La patologia
cardiaca di maggior impatto è appunto la cardiopatia ischemica: l’infarto miocardico determinando la morte
delle cellule cardiache provoca un disturbo della funzione di pompa dell’organo, che può essere più o meno
grave a seconda dell’estensione dell’area di morte cellulare. L’infarto è seguito da una fase di adattamento
dell’organo che passa attraverso a una serie di trasformazioni che vanno dalla ipertrofia dei cardiomiociti,
alla sostituzione del tessuto danneggiato con tessuto fibroso e assottigliato che, al contrario del muscolo, non
contribuisce all’azione della pompa cardiaca. La sindrome clinica secondaria a questo danno è lo scompenso
cardiaco. Nonostante le conoscenze scientifiche acquisite negli ultimi vent’anni, disponiamo oggi solo di
presidi terapeutici efficaci nel ritardare la progressione della sindrome. Per tale motivo, il gold-standard
terapeutico rimane la sostituzione dell’organo mediante trapianto, trattamento che trova però un grande
limite nel numero esiguo di organi disponibili rispetto al numero di pazienti che ne necessitano. Numerosi
sforzi e studi sperimentali e clinici, possibili anche per lo straordinario contributo di conoscenza offerto dalle
scienze di base, sono stati condotti in questi anni per verificare la possibilità di un trattamento “cellulare” del
miocardio danneggiato che permettesse la rigenerazione del tessuto cardiaco, sostituendo la naturale
riparazione in cicatrice con nuovo tessuto cardiaco “funzionante”. La possibilità che la terapia cellulare possa
divenire un’opzione terapeutica utilizzabile è legata a una serie di non risolti problemi scientifici e anche alle
complessità organizzative nel praticarla. Infatti:
- non è ancora ben chiaro quale sia il migliore tipo di cellule da utilizzare nè quale sia la via migliore di
somministrazione delle stesse
- non è fin oggi definita quale sia la “dose” terapeutica e cioè la quantità minima di cellule da somministrare
per ottenere un risultato apprezzabile in relazione all’area danneggiata;
- è un dato ben documentato il fatto che la somministrazione di preparati cellulari “semplici” sia per via
intracoronarica sia mediante iniezione nel miocardio, è seguita da una grande dispersione cellulare nel
torrente circolatorio e che pertanto è preferibile associare alle cellule sistemi molecolari organizzati
(scaffolds) che le trattengano in situ e le proteggano da un ambiente cellulare ostile perchè caratterizzato da
un processo infiammatorio con sostituzione fibroblastica.
- la terapia cellulare richiede un costo oggi elevato ed un elevato coinvolgimento interdisciplinare (in termini
di operatori e di facilities).
I risultati ottenuti dalla traslazione clinica su pochi pazienti degli esperimenti animali sono poco confortanti
anche perchè difficilmente interpretabili data l’eterogeneità del tipo di cellule impiegate, la diversità delle vie
di somministrazione utilizzate, la diversa selezione di ammalati arruolati alla ricerca. Il dato è che la terapia
cellulare determina un modesto incremento della funzione di pompa cardiaca e un miglioramento anch’esso
lieve della capacità funzionale del paziente (1-3)
. Questo dato associato all’osservazione che le cellule iniettate
difficilmente rimangono nell’area in cui servono, ha fatto ritenere che il seppur lieve effetto positivo sia da
attribuire a una forte componente paracrina associata all’atto rigenerativo. L’identificazione di fattori
paracrini cell-derived ha fatto aprire una nuova possibilità di trattamenti protein-based da usare in luogo della
somministrazione cellulare o insieme ad essa per favorire il meccanismo di riparazione. L’utilizzazione di
scaffolds, soprattutto gli idrogelici, può rispondere all’aspettativa di una crescita cellulare organizzata
soprattutto se gli stessi vengono “funzionalizzati” con proteine specifiche per il recettore espresso da un tipo
cellulare, in modo da garantire la selezione dello stesso e il suo legame che lo vincola al microambiente nel
quale è necessaria la presenza (4)
. Gli scaffolds pertanto trattengono nell’area interessata le cellule e possono
essere “funzionalizzati” anche con fattori di crescita come il VEGF con dimostrazione di angiogenesi,
arteriogenesi e miglioramento della funzione cardiaca dopo infarto miocardico sperimentale (5-8)
. Dati molto
interessanti evidenziano come la somministrazione/applicazione di scaffold sul tessuto danneggiato, senza
6
l’impiego di preparati cellulari, determini lo stesso risultato positivo della somministrazione associata dei
due elementi (9-10)
. Una spiegazione può essere data dal fatto che lo scaffold determina da solo un ambiente
spaziale favorevole che favorisce la colonizzazione dello stesso da parte delle cellule staminali dell’ospite.
La diffusione poi dell’uso degli idrogeli e soprattutto di quelli derivati dal Chitosan, e la possibilità di poterli
ingegnerizzare a seconda delle necessità e funzionalizzare con l’applicazione di molecole nella struttura che
possono avere compiti favorenti l’organizzazione e la crescita cellulare(9)
ha fatto via via crescere l’idea della
creazione e dell’implementazione nel tessuto da riparare di un vero e proprio bioreattore “in situ”,
ingegnerizzato per fornire il migliore supporto alla crescita e alla differenziazione cellulare(11)
.
Altro elemento che rappresenta una pietra miliare nell’evoluzione di questa fase della metodologia di
riparazione cellulare è dato dalla’identificazione e quindi dal ruolo svolto da alcuni mi-RNA come
modulatori e regolatori della apoptosi e della morte cellulare. I mi-RNA sono piccole molecole endogene di
RNA non codificante, a singolo filamento, di 20-22 nucleotidi. Fanno parte di una grande rete di geni
regolatori e svolgono diverse funzioni. La più nota, attualmente, è quella di regolazione post-trascrizionale,
in cui vanno a inibire la traduzione di determinati RNA messaggeri (mRNA). Alcuni di essi svolgono un
ruolo cruciale nell’ageing (12)
ma il dato più interessante in questo contesto è il controllo dei processi di
differenziazione cardiovascolare. Il fatto che l’embriogenesi del cuore sia governata nei vari steps di
sviluppo dai miRNA con funzione talvolta inibente e talaltra stimolante un dato processo, fa comprendere
come la conoscenza della rigenerazione e della riparazione del cuore possano ricevere un grande contributo
dai dati di biologia molecolare dell’embriogenesi (13-14)
. Esistono nucleotidi di sintesi con funzione bloccante
alcuni miRNA in grado di modulare la loro espressione apoptotica e inibente la crescita e la differenziazione
cellulare e comincia a diffondersi l’idea di un loro uso terapeutico. È probabile che il futuro della medicina
rigenerativa si basi proprio sulla capacità della chimica di ingegnerizzare scaffolds “funzionalizzati” in modo
da costituire un bioreattore naturale ideale che favorisca il seeding cellulare, l’orientamento spaziale delle
cellule e la loro espansione e differenziazione. Biologi e chimici sulla scorta delle conoscenze provenienti
dalla biologia cellulare e molecolare saranno impegnati a studiare il come modulare
(stimolazione/inibizione) l’ambiente biologico in cui il processo rigenerativo dovrà aver luogo.
Riferimenti
1. Clifford DM, Fisher SA et Al Long-therm effects of Autologous Bone marrow stem Cell Tratment in acute
myocardial infarction: Factors that may influence Outcome PloS ONE, 7,5 2012
2. Fuh E, Brinton TJ. Bone Marrow Stem Cells for the treatment of ischemic Heart Disease: A Clinical Trial
Review J of Cardiovasc Trans Res 2009, 2: 202:218
3. Clifford DM, Fisher SA et Al. Stem cell Treatment for acute myocardial infarction The Cochrane library
2012, Issue 2
4. Aubin H, Nichol JW et Al. Directed 3D cell alignment and elongation in microengineered hydrogels
Biomaterials 31 (2010) 6941-6951
5. Vuniak-Novakovic G, Tandon N et Al. Challenges in Cardiac Tissue Engineering. Tissue Engineering:
Part B, 16,2,2010
6. Li SC, Wang L et Al. Stem cell engineering for treatment of heart diseases: Potentials and challenges.
Cell Biology International 33 (2009)
7. Javad H, Ali NN et AL Myocardial tissue engineering: a review J Tissue Eng Regen Med 2007; 1: 327-
342
8. Lin Y-D, Luo C-Y et Al Instructive Nanofiber Scaffolds with VEGF Create a Microenvironment and
Cardiac Repair Science Translational Medicine 4,146, 2012
9. Seif-Naraghi S, Singelyn JM et Al Safety and Efficacy of an Injectable Extracellular Matrix Hydrogel for
Treating Myocardial Infarction, Science Translational Medicine 5, 173, 2013
10. Burdick JA, Mauck RL et Al, Acellular Biomaterials: An Evolving Alternative to Cell-Based Therapies ,
Science Translational Medicine 5, 176, 2013
11. Sengupta D, Heilshom SC Protein-Engineered Biomaterials: Highly Tunable Tissue engineering
Scaffolds Tissue engineering Part B 16, 3, 2010
12. Dimmeler S, Nicotera P et Al: MicroRNAs in age related diseases. EMBO Mol. Med.
http://dx.doi.org/10.1002/emmm.201201986 (22 January 2013)
13. Xu Q, Seeger FH, Dimmeler S et Al, Micro-RNA-34a Contributes to the Impaired Function of Bone
Marrow derived Mononuclear Cells From Patients with cardiovascular Disease, JACC, 59, 23, 2012 Liu G,
Ding M, Computational analysis of microRNA function in heart development Acta Biochim Biophys Sin
2010, 42: 662–670
14. Obad S, dos Santos CO, Silencing of microRNA families by seed-targeting tiny LNAs , Nature Genetics,
43, April 2011
7
New materials technologies in the Biopharma industry: the path from lab to patients
Caterina Lo Presti*
* Merck SeronoSpA Via L. Einaudi 11 00012 Guidonia Montecelio (Roma) Italy,
In recent years, the advent of therapies based on new biological entities (NBEs) opened several opportunities
for unmet medical needs. NBEs are bio-macromolecules produced via biotechnologies that structurally
mimic compounds naturally found in the body. Compared to traditional drugs, i.e. small molecules produced
via organic chemistry technologies, these NBEs have the potential to cure diseases rather than treat
symptoms, and have more potency and fewer side effects because of their specificity.
Some examples of NBEs are cytokines, enzymes, hormones, vaccines, monoclonal antibodies that
represented a breakthrough in the treatment of many diseases like diabetes, autoimmune disorders,
neurodegenerative diseases, cancer.
On the other hand, NBEs represent a new challenge in the pharmaceutical development field as they are
particularly prone to both physical and chemical degradation outside their native environment. This leads to
a dramatic reduction in biological activity, hence efficacy, that can be overcome only by an accurate and
customized formulation development to enhance protein stability during shelf-life. In addition, patient-
friendly non-invasive routes of administration (oral, transdermal, transmucosal, inhalation) are not feasible
for biologics as such, in that they cannot overcome a number of biological barriers either for size exclusion
or the presence of adverse enzymes. For these reasons, NBE based therapies require the recourse to frequent
injections that increase the number of undesired effects and reduces patient compliance.
Biological effects of therapeutic agents are generally related to their kinetics of absorption in the site of
action. Control in time and space of active ingredients can, then, maximize efficacy and minimize adverse
reactions. Depending on the mechanism of action and the nature of a single protein drug, new technologies
can be used to engineer drug delivery solutions customized as to meet particular therapeutic needs. The
objective may be to prolong the duration of action, target a particular organ or modulate/program the
concentration of a drug in the plasma over time.
Bioinspired engineered vectors are emerging solutions for efficient NBEs delivery in terms of release
kinetics, patient safety and compliance, transport across biological barriers.
The approach of the Biopharma industries in protein drug product development will be discussed as well as
the state of the art in drug delivery solutions for biologics, from modified hydrogels to nanoscopic "trojan
horses", with particular focus on the translation of basic research from lab to patients. The main regulatory
and upscale constraints will be illustrated with the aim of improving the synergies between industry and
academia in the (bio)pharmaceutical technologies field.
8
Micro-contact printing of protein patterns on electrospun polymeric matrices
Rainer A
1, Giannitelli SM
1, Mozetic P
1, Businaro L
2, De Ninno A
2, Gerardino AM
2, Trombetta M
1
1) Tissue Engineering Lab, “Università Campus Bio-Medico di Roma”, Rome, Italy
2) Institute for Photonics and Nanotechnology, National Research Council, Rome, Italy
Surface functionalization of biomaterials represents a promising strategy to obtain biologically instructive
substrates for cell culture. In particular, advances in micro- and nanofabrication technologies allow the
deposition of precise and highly reproducible patterns on biomaterials surfaces.
In less than two decades, micro-contact printing (µCP) has emerged as one of the most straightforward
methods for the preparation of micro- and nanostructured surfaces [1]. µCP relies on a polymeric stamp with
a relief pattern obtained as a replica from a photolithographically structured master. The stamp is ‘‘inked’’
with biomolecules and placed in contact with a substrate. Due to its surface relief structure, the stamp only
contacts the substrate in predefined areas, where the structure protrudes from the stamp. Well-defined protein
patterns with precisely controlled size, shape, and spacing have been successfully obtained by µCP, and used
to study cell adhesion, migration, proliferation, and apoptosis, as well as to perform high-throughput drug
screening and disease diagnosis [2].
However, while most studies have evaluated cell/material interactions on two-dimensional patterned
surfaces, in physiological conditions cells are surrounded by extra-cellular matrix (ECM) and sense similar
cues in a 3D environment. Among 3D substrates, electrospun fibers have been widely used as scaffolds
owing to their dimensional similarity to native ECM. Proposed modifications of electrospun meshes on
length scales comparable to (or smaller than) fiber diameter merely introduce micro/nano-grooves on fibers
surface by imprinting techniques [3].
Aim of this study is to use µCP to transfer protein patterns onto 3D electrospun substrates for tissue
engineering applications. The proposed approach has been successfully pursued for precise and gentle
transfer of different proteins from polydimethylsiloxane (PDMS) stamps onto polymeric electrospun
substrates without loss of biological activity. Fluorescence microscopy has been used to detect successful
patterning, and to determine the fate of inked proteins. Biological in vitro studies confirmed the potential of
this approach to control cell morphology and to modulate cell function.
References:
[1] Kaufmann T, Ravoo BJ. Stamps, inks and substrates: polymers in microcontact printing, Polym Chem
2010;1:371-387.
[2] Bernard A, Renault JP,Michel B, Bosshard HR, Delamarche E.Microcontact Printing of Proteins,
AdvMater 2000;12:1067-1070.
[3] Nandakumar A, Truckenmüller R, Ahmed M, Damanik F, Santos DR, Auffermann N, de Boer J,
Habibovic P, van Blitterswijk C, Moroni L. A fast process for imprinting micro and nano patterns on
electrospun fiber meshes at physiological temperatures. Small 2013 doi: 10.1002/smll.201300220.
9
Triphenylamine-based dyes for live-cells labeling and imaging of cell’s cytoplasm
Angela Scrascia,a, Ilaria Elena Palamà
a, Viviana Vergaro
a, Giuseppe Vasapollo
c,
and Giuseppe Ciccarella*a, b
a Istituto Nanoscienze – CNR, National Nanotechnology Laboratory (NNL), Via Arnesano, 73100 Lecce,
Italy. E-mail: [email protected] b Dipartimento di Ingegneria dell’Innovazione, Università del Salento, Via Monteroni, 73100, Lecce, Italy.
The chemistry of small molecule as fluorophores is exciting and is playing an important role also in
cellular biology research, in particular in cell viability and revealing cytotoxicity, following
proliferation, and monitoring cell adhesion and spreading. Thus, it was developed the idea of applying
new dyes typically studied for DSSC research in biological systems. Novel organic dyes based on TPA
group and the cyanoacetic acid as electron-donor and -acceptor, respectively, whereas a thienyl, phenyl
and thienyl-fluoro-phenyl-substituted as π-linker were synthesized. It was investigated the cytoplasm
labeling of two cell lines (3T3 fibroblasts and C2C12 myoblasts) with conjugated triphenylamine-based
fluorophores. The dyes revealed biocompatible and spontaneously crossing the membrane of living
cells. The obtained results concerning our dyes are the proof that the fluorescent molecules are cell-
permeant and non-toxic and can be used as cell tracing to different component of cellular cytoplasm.
Confirming that our dyes interact with cells we evaluated the opportunity to use them in development of
new optical markers in drug delivery systems. In particular we decided to combine this molecule with
nano calcium carbonate widely studied as nano carrier for anti-cancer drugs.
10
Porphyrin-based chemical sensors and multisensor arrays for the evaluation of food quality
M.L. Naitana
1, F. Mandoj
1, R. Paolesse
1
1Department of Chemical Science and Technologies, University “Tor Vergata”, Rome, Italy
The control of food matrices is an important task nowadays, since it involves from one side nutritional
aspects related to human health safety, and from the other side more hedonic features, such as quality,
freshness, etc, which are also important for commercial aspects. For these reasons in the last few years there
is a strong demand of instrumental methods able to monitor the chemical composition of different matrices.
Recently chemical sensors have been object of interest as a promising solution for the demand of food
freshness control, because they can allow a rapid, non invasive and cheap approach for the control of food
samples.
The complexity of food matrices, where a huge number of analytes are present, makes this field suitable for
the application of sensors arrays, devices that try to mimic the working mechanism of biological senses. For
this reason, these arrays have been called Electronic Nose (EN) and Electronic Tongue (ET), depending if
they are applied for the analysis of gaseous (EN) or liquid (ET) phases.
In recent years we have developed chemical sensors based on porphyrins and related macrocycles as sensing
materials. The richness of properties of such a macrocycle allows the development of a library of sensing
materials to be applied on sensors based on different trasduction mechanisms, ranging from the
nanogravimetric to optical transducers. This versatility of porphyrins allows also the preparation of sensor
arrays based on dual mode transduction systems, where the same sensing materials is used on hyphenated
trasduction platforms, such as, for example, the Computer Screen Photoassisted Technique (CSPT).
We have applied the develop systems for the monitoring of different food matrices and the related result1–6
will be presented and discussed.
References
(1) Lvova, L.; Di Natale, C.; Paolesse, R. Sensors and Actuators B: Chemical 2013, 179, 21.
(2) Tortora, L.; Stefanelli, M.; Mastroianni, M.; Lvova, L.; Di Natale, C.; D’Amico, A.; Filippini, D.;
Lundström, I.; Paolesse, R. Sensors and Actuators B: Chemical 2009, 142, 457.
(3) Dini, F.; Paolesse, R.; Filippini, D.; D’Amico, a.; Lundström, I.; Di Natale, C. Procedia Engineering
2010, 5, 1228.
(4) Dini, F.; Filippini, D.; Paolesse, R.; Lundström, I.; Di Natale, C. Sensors and Actuators B: Chemical
2013, 179, 46.
(5) Compagnone, D.; Fusella, G. C.; Del Carlo, M.; Pittia, P.; Martinelli, E.; Tortora, L.; Paolesse, R.; Di
Natale, C. Biosensors & bioelectronics 2013, 42, 618.
(6) Alimelli, A.; Pennazza, G.; Santonico, M.; Paolesse, R.; Filippini, D.; D’Amico, A.; Lundström, I.; Di
Natale, C. Analytica chimica acta 2007, 582, 320.
11
Engineered Carbon Nanotubes as Drug Delivery Systems for Antiviral Drugs
D. Iannazzo,
1 A. Pistone,
1 A. Piperno,
2 G. Grassi,
2A. Mazzaglia,
3 A. Scala,
3 M. Lanza,
4
M. T. Sciortino,5 , M. Prato
6, S. Galvagno
1
1 Università di Messina, Dip. di Ingegneria Elettronica, Chimica e Ing. Industriale, Messina, Italy
2 Università di Messina, Dip Scienze Chimiche, Messina, Italy
3 Consiglio Nazionale delle Ricerche CNR-ISMN, UOS Palermo, Messina, Italy
4 CNR-Istituto per i Processi Chimico F isici, Messina, Italy
5Università di Messina, Dip. di Scienze Biologiche e Ambientali, Messina, Italy 6Università di Trieste, Dip. Scienze Chimiche e Farmaceutiche,Trieste, Italy
E-mail address: [email protected]
Among the different types of nanomaterials, Carbon Nanotubes (CNTs), due to their unique physical,
chemical and physiological properties, have shown great performance in the field of nanomedicine, attracting
particular attention as carriers of biologically relevant molecules. These nanomaterials can be surface
engineered in order to enhance their dispersibility in the aqueous phase or to provide, by multimodal
conjugation, the appropriate functional groups for the synthesis of CNT-based drug delivery system (DDS)
able to bind the desired therapeutic material or the target tissue to obtain a therapeutic effect [1,2]. In the
nanomedicine field, there is a growing considerable demand for new antiviral agents and materials not only
for the increasing worldwide problems caused by harmful viruses infections, but also for the serious side
effects often showed by known antiviral agents [3]. We report here two different approaches for the
conjugation of nucleoside antiviral agents to highly hydrophilic and dispersible MWCNTs which involves
the covalent linkage of the antiviral agent by means of a cleavable linker or the complexation of the drug
with a β-ciclodextrin (β-CD) covalently modified MWCNT nanohybrid (Fig. 1). The obtained compounds
have been fully characterized by XPS, XRD, UV-Vis, SEM, TGA and TEM measurements and their
biological activity against HIV and HSV was tested.
Fig. 1
References
[1] A. Bianco, K. Kostarelos, M. Prato. Chem. Commun., 47 (2011) 10182.
[2] D. Iannazzo, A. Piperno, A. Pistone, G. Grassi, S. Galvagno, Curr Med. Chem, 20 (2013), 1333.
[3] I. Banerjiee, M. P. Douaisi, D. Mondal, R. S. Kane, Nanotechnology, 23 (2012) 105101.
12
Azahelicenium salts: possible biological applications
Francesca Fontana*
,a, Isabella Natali Sora,
a Loredana Latterini
b
a Università di Bergamo, Dipartimento di Ingegneria, viale Marconi 5 24044 Dalmine BG b Università di Perugia, Dipartimento di Chimica, via Elce di Sotto 8, 06153 Perugia PG
Azahelicenes are extensively conjugated heteroaromatic molecules, intrinsically chiral due to helical shape
imparted by steric hindrance. Their extremely long triplet lifetime makes them good phosphorescent
emitters. Their N-alkylated quaternary salts (Fig.1), showing most of the same desirable properties as the
parent helicenes, bear a positive charge, which makes them water-soluble. Some of these derivatives were
characterized for spectroscopic properties, as well as crystal structure.1
Since polycyclic aromatic molecules are known to form complexes with DNA, these particular quaternary
salts have been studied for interaction with cell nuclei.2,3
It was found that intercalation takes place rapidly,
and it has been observed that the nature of the counterion determines the binding parameters (K and the
number of interacting binding sites).2 On the other hand, aggregation phenomena take place, which are
controlled by solvent polarity, and which influence absorption and emission spectra; therefore, their optical
properties can be finely tuned by changing the medium properties. This can be exploited for the
differentiation of different cell compartments, characterized by different medium properties (polarity, ionic
strength, pH etc.): actually, through incubation experiments, it was possible to follow the cell uptake process
and to chromatically differentiate cell compartments.3 In particular, the wavelength emission is shorter when
the salt is located in the nucleus, where it is in monomeric form, while it is longer in the cytoplasm, where
the molecules form aggregates.
Besides, cell labeling through this method has proven to be completely reversible and the molecule is
completely released in about 5 h without alteration of the cell structure.
References
1. T.Caronna, F.Castiglione, F.Fontana, A.Famulari, L. Malpezzi, A.Mele, D.Mendola, I.Natali
Sora “Quantum Mechanics Calculations, Basicity and Crystal Structure: The Route to Transition
Metal Complexes of Azahelicenes” Molecules 2012, 17, 463-479.
2. R. Passeri, G. G. Aloisi, L. Latterini, F. Elisei, T.Caronna, F.Fontana, I.Natali Sora
“Photophysical properties of N-alkylated aza-helicene derivatives as DNA intercalators:
counterion effects” Photochem. Photobiol. Sci., 2009, 8, 1574-1582.
3. L. Latterini, E. Galletti, R. Passeri, A. Barbafina, L. Urbanelli, C. Emiliani, F. Elisei, F. Fontana,
A. Mele, T. Caronna “Fluorescence properties of aza-helicenium derivatives for cell imaging”
J. Photochem. Photobiol. A: Chemistry 2011, 222, 307-313.
Fig.1 - N-methyl-5-aza
[5]helicenium iodide
I
13
Applicazioni della tecnologia microonde in procedure estrattive ecocompatibili
Carla Villa*
DIFAR - Dipartimento di Farmacia, Sezione di Chimica del Farmaco e del Prodotto Cosmetico,
Viale Benedetto XV, 3 – 16132 Genova
L’irraggiamento microonde, quale fonte energetica non convenzionale, può rappresentare un’alternativa
strategicamente vantaggiosa rispetto alle tecniche di riscaldamento classiche, sia per la ricerca in ambito
accademico sia per produzioni a livello industriale. Già da tempo, in campo chimico, farmaceutico e
agroalimentare, le aziende sono orientate verso la necessità di rielaborare il modello industriale tradizionale
verso l’utilizzo di processi eco-compatibili a basso impatto energetico, in una più ampia ottica di
“Responsible Care”1.
In questo contesto il riscaldamento dielettrico microonde può essere considerato una fonte energetica
sostenibile: offre infatti notevoli vantaggi sia in sintesi chimica sia nei processi estrattivi, operando un rapido
riscaldamento omogeneo, volumetrico e selettivo, caratterizzato in particolare da assenza di inerzia dovuta ad
un veloce trasferimento dell’energia in tutta la massa del materiale2. Da ciò deriva una notevole diminuzione
dei tempi di processo con conseguente riduzione della possibile degradazione del materiale sottoposto a
riscaldamento.
L’energia è utilizzata esclusivamente per il riscaldamento del materiale, senza dispersione di calore
all’esterno, con un notevole risparmio energetico e conseguenti vantaggi economici ed ecologici.
In ambito estrattivo, fra le diverse procedure “verdi”, la cui scelta dipende dalla natura del campione, sono
comprese diverse tecniche estrattive che sfruttano il riscaldamento dielettrico sia in presenza che in assenza
di solvente.
Tra le procedure con solvente possiamo citare la MAE (Microwave Assisted Extraction) che utilizza solventi
ad elevata costante dielettrica e la MAP (Microwave Assisted Process) che sfrutta il riscaldamento dell’acqua
presente nella matrice (in genere fresca) per garantire l’estrazione dei principi attivi di interesse con un
solvente apolare3. In molti altri casi, nella MWE (Microwave Water Extraction) in particolare, è possibile
utilizzare l’acqua come estraente verde, in quanto, grazie alla sua elevata costante dielettrica, ha peculiari
proprietà estrattive.
Tra le moderne tecniche estrattive senza solvente le piuutilizate sono la SFME(Solvent Free Microwave
Extraction) e la MHG (Microwave Hydrodiffusion and Gravity): La prima combina il riscaldamento a
microonde alla distillazione a secco ed è ampiamente utilizzata per il recupero di oli essenziali da campioni
botanici freschi. La seconda nuova tecnica, brevettata nel 2008, combina il riscaldamento con microonde e la
gravità. E' stata concepita per l'estrazione di sostanze naturali di varie matrici su scala di laboratorio, ma è
utilizzabile anche su scala industriale4.
Al fine di applicarediversi tipi di estrazione con l’ausilio di unsolofornomicroonde, è statoda noiprogettato,
assemblatoe utilizzatoin diverse procedure, unospecificoprototipomultifunzionededicato.
Consiste di una cavitàmultimodale,dotata di un magnetron operante a 2.45 GHz, duefibreottiche per la
misuradellatemperature di processo e un’unità di controllodedicata, opportunamente interfacciata, che
permette di controllare e modulare diversi parametri di processo, come potenza, tempo e temperature. In base
alla disposizione dei fori presenti sulle pareti della cavità il reattore puo’ essere impiegato per i diversi
processi precedentemente illustrati. Inoltre la presenza dei due fori permette in potenza l’utilizzo del forno
per alcuni tipi di estrazione in continuo5.
Riferimenti
1. Givel, Michael "Motivation of Chemical Industry Social Responsibility Through Responsible Care".
Health Policy 81 (1): 85–92. (2007).
2. Mandal V., Mohan Y., Hemalatha S., “Microwave Assisted Extraction – An Innovative and
Promising Extraction Tool for Medicinal Plant Research”, Pharmacognosy Reviews, Vol 1, Issue 1,
2007
3. C. Leonelli, C. Villa “Applicazioni delle microonde in Chimica Analitica" in "Il riscaldamento a
microonde. Principi ed applicazioni" ISBN: 88-371-1699-3. Pitagora Editrice, Bologna,
(2008)pagg. 205-229.
14
4. F. Chemat, G. CravottoMicrowave-assistedExtraction for Bioactive Compound. ISBN 978-1-
4614-4829-7mSpringer, NewYork, (2013). 238 pages.
5. C Villa. R.Boggia, R Leardi, C. Leonelli, R. Rosa. E. Caponetti, D.Chillura Martino “Ecofriendly
microwave-mediated approach for the extraction of bioactive compounds from waste matrices in the
agro-alimentary sector”Extech 2012 – International Symposium on Advances in Extraction
Technologies.Messina 24-26 Settembre 2012. Book of Abstract pag 102.
15
Estrazione a microonde di composti bio-attivi da matrici vegetali
Roberto Rosa
1, Erika Ferrari
2, Carla Villa
3, Paolo Veronesi
1, Monica Saladini
2, Lorenzo Tassi
2, Cristina
Leonelli1
1Dipartimento di Ingegneria “Enzo Ferrari”, Università degli Studi di Modena e Reggio Emilia, via
Vignolese 905/A, 41125 Modena, [email protected] 2Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, via
Campi 183, 41125 Modena 3Dipartimento di Farmacia, Università degli Studi di Genova, viale Cembrano 4, 16147 Genova
Negli ultimi anni l’utilizzo di composti bio-attivi derivanti da matrici vegetali ha riscosso un interesse
sempre maggiore principalmente a causa della potenziale tossicità e degli eventuali effetti collaterali degli
analoghi sintetici [1, 2]. Inoltre, la possibilità di sfruttare a tale scopo anche i sottoprodotti e gli scarti
derivanti da processi alimentari (eliminandone o comunque riducendone molto i costi di smaltimento),
costituisce un ulteriore vantaggio dell’utilizzo di composti fitochimici [3].
La maggior parte delle convenzionali tecniche estrattive di composti bio-attivi da matrici vegetali (quali ad
esempio la stasi macerativa o l’utilizzo di apparato Soxhlet) presenta numerosi svantaggi tra cui l’utilizzo di
spropositate quantità di solventi organici, un elevato consumo energetico, lunghi tempi di estrazione che in
alcuni casi possono portare alla degradazione dei composti di interesse.
Lo scopo di questo lavoro è di proporre innovative tecniche estrattive assistite da microonde (Microwave
Assisted Extraction, MAE) [4], per accelerare le tempistiche di estrazione, ridurre il consumo di solventi
organici ed aumentare le rese estrattive e la qualità dei prodotti ottenuti. In particolare tali tecniche di
estrazione “green” [5] sono state applicate a differenti matrici vegetali quali ad esempio frutti e fiori di noce
bianco (Juglans regia L.), radici di cannella (Cinnamomum Zeylanicum) e vinaccioli allo scopo di
ottimizzare l’estrazione di composti fenolici.
Le tecniche statistiche di disegno sperimentale (Design of Experiments, DoE) sono state in alcuni casi
utilizzate allo scopo di valutare l’effetto dei diversi parametri di processo e ottimizzare il processo estrattivo
assistito da microonde.
Rispetto a metodologie estrattive convenzionali, l’utilizzo di microonde si è dimostrato molto promettente in
termini di rese e di contenuto di composti fenolici. Alcuni estratti sono stati poi caratterizzati in termini di
potere antiossidante e di altri interessanti effetti biologici.
Riferimenti
[1] M. Contini, S. Baccelloni, R. Massantini, G. Anelli, Extraction of natural antioxidants from hazelnut
(Corylus avellana L.) shell and skin wastes by long maceration at room temperature, Food Chem. 110, 2008,
659-669.
[2] I. Oliveira, A. Sousa, I.C.F.R. Ferreira, A. Bento, L. Estevinho, J.A. Pereira, Total phenols, antioxidant
potential and antimicrobial activity of walnut (Juglans regia L.) green husks, Food Chem. Toxicol. 46, 2008,
2326-2331.
[3] H. Wijngaard, M.B. Hossain, D.K. Rai, N. Brunton, Techniques to extract bioactive compounds from
food by-products of plant origin, Food Res. Int. 26, 2012, 505-513.
[4] Microwave-assisted extraction for bioactive compounds, F. Chemat and G. Cravotto Eds., Springer, New
York, 2013.
[5] F. Chemat, M.A. Vian, G. Cravotto, Green extraction of natural products: concept and principles, Int. J.
Mol. Sci. 13, 2012, 8615-8627.
16
Studies on Catalytic and catalytic photo-assisted propene hydration
in the presence of H3PW12O40 supported on different oxides.
G. Marcìa,b
, E. García-Lópeza,b
, M. Bellarditaa,b
, C. Colbeau-Justinc,d
, L.F. Liottae, L. Palmisano
a,b
a“Schiavello-Grillone” Photocatalysis Group. Dipartimento di Energia, Ingegneria dell’informazione e
modelli Matematici (DEIM), Università di Palermo, Viale delle Scienze, 90128 Palermo, Italy bConsorzio Interuniversitario la Chimica per l’Ambiente (INCA),
[email protected]; Fax: +39-091 23860841; Tel: + 39-091 23863737 cUniversité Paris-Sud, Laboratoire de Chimie Physique, UMR8000, Orsay, 91405 France
dCNRS, Laboratoire de Chimie Physique, UMR8000, Orsay, 91405 France
eIstituto per Lo Studio dei Materiali Nanostrutturati (ISMN)-CNR,
via Ugo La Malfa 153, 90146 Palermo, Italy
Propene hydration to obtain 2-propanol is a reaction carried out at moderate temperatures (ca. 150-200°C)
and pressure (2 MPa) in the presence of an acid catalyst [1]; however the realization of this reaction at
ambient conditions is of great interest. The use of heteropolyacids as catalysts for the hydration of propene to
2-propanol in gas-solid regime has been object of several patents [2,3]. Heteropolyacids, a kind of
polyoxometallates (POMs) [4], are very strong Brønsted acids and efficient oxidants that perform fast and
reversible redox multielectronic transformations under mild conditions [5]. Ivanov et al. compared the
catalytic activity of an acidic zeolite with non-supported and SiO2 supported H3PW12O40 (POM) for this
reaction [6]. Supported POM samples resulted much more active than both the bare corresponding sample
and the zeolite, substantially due to their stronger acidity. The POM based materials showed a significant
activity from 100°C with a maximum activity in hydration at 130°C. They have been used also as
homogeneous photocatalysts: absorption of light (λ = 260 nm corresponding to 4.8 eV) by the ground
electronic state of the solubilized POM produces the charge transfer-excited state POM* and it is
qualitatively analogous to the absorption of band gap radiation by a solid semiconducting metal oxide
producing a transient electron-hole pair [7]. Likewise, substrate oxidation by the excited state of the
polyoxometalate, is analogous to the corresponding process in semiconductors [8]. In this manner, the
heteropolyacid can act not only as catalyst but also as a photocatalyst, so the additional effect of irradiation
on the catalytic system can improve its performance. Several studies have been devoted to heterogeneous
photocatalytic processes by using semiconductor oxides. This technology has been applied mainly to degrade
organic and inorganic pollutants both in vapour and in liquid phases [9]. In a previous paper the catalytic and
catalytic photo-assisted activity of the H3PW12O40 POM supported on TiO2 Evonik P25 and SiO2 was studied
and a beneficial role of the photo-catalytically active support on the reaction rate was reported [10]. The
contemporary presence of heat and UV light improved the activity of the POM supported materials for the
propene hydration reaction and the catalytic photo-assisted reaction occurred at a higher rate than the
catalytic one when the solid support was an irradiated semiconductor. In that case, the more significant
increase of reactivity was justified by considering the ability of TiO2 to transfer electrons from the
conduction band to the activated POM* species. In this work catalytic and catalytic photo-assisted hydration
of propene to form 2-propanol in gas-solid regime at atmospheric pressure and 85°C was carried out by using
a heteropolyacid (POM) supported on different oxides. Binary materials have been prepared by impregnation
of H3PW12O40 on different commercial and home prepared supports (TiO2, SiO2, WO3, ZrO2, ZnO, Al2O3).
The POM amount deposited was 50 % in weight with respect to the support. The powders used as catalysts
and photocatalysts are denoted hereafter as POM/oxide support. Some samples containing lower amount of
heteropolyacid were prepared. These amounts were chosen to obtain a theoretical coverage of 2 or 1 layers
on the surface of the support. These materials are labelled hereafter 2L-POM/oxide support or 1L-
POM/oxide support. Some of the composites were active both for catalytic and catalytic photo-assisted
reaction. The Keggin type POM was completely and partially degraded, when supported on ZnO and Al2O3,
respectively, and these binary solids resulted always inactive for both catalytic and catalytic photo-assisted
reactions. XRD characterization of the solid indicates that POM was well dispersed on the supports and that
new picks appeared, with respect to the corresponding bare powders, only in the POM supported samples on
TiO2 Merck, WO3 and ZrO2. These new diffraction peaks do not coincide with those observed for the bare
POM diffraction pattern and they can be explained by considering the occurrence of a strong interaction
POM-support that can introduce distortions within the POM tertiary structure. From the SEM micrographs
observation and FTIR spectra it can be concluded that POM was generally well dispersed on the supports.
17
The NH3-TPD experiments showed that the acid sites strength due to the POM is different for the various
samples and in particular the catalysts that present the strongest acidity are POM/ZrO2, POM/WO3, and
POM/TiO2 Merck. This fact, that is related to the stronger interaction between POM and the support, will be
very useful to explain the higher reactivity observed for these catalyst. The comparison of the catalytic
activity of samples containing different amounts of heteropolyacid was done normalizing the activity for
gram of POM present in the catalyst. These values are reported in Figure 1. From the perusal of Figure 1 the
most active samples are those which have two layers of POM and in particular the best one is 2L-POM/ZrO2
followed by 2L-POM/WO3, 2L-POM/TiO2 Merck and POM/TiO2 Evonik P25. The last two samples show a
very similar catalytic activity. The samples with less POM layers, i.e. POM/TiO2 hp and POM/SiO2, display
reactivity comparable to that of 2L-POM/TiO2 Merck and POM/TiO2 Evonik P25. On the contrary, the
samples in which a higher number of POM layers was present (POM/TiO2 Merck, POM/ZrO2 and
POM/WO3) showed the lowest reactivity. This findings clearly indicates that two factors influence the
reactivity per gram of catalytic species, i. e. the POM dispersion and the nature and physico-chemical
features of the support. All the considerations and trends reported for the catalytic runs are valid for the
catalytic photo-assisted experiments as well; however it is very important to underline that in almost all cases
the reactivity increased in the presence of UV light.
Figure 1: 2-propanol formation rate per gram of POM present in the various POM supported materials for the
catalytic (white bars) and catalytic photoassisted (grey bars) propene hydration reaction.
The supported Keggin POM species played a key role both for the catalytic and the photo-assisted catalytic
reactions, due to their strong acidity and ability to form strong oxidant species under UV irradiation,
respectively. The role of the support should be also considered to explain the different catalytic reactivity of
the various samples. In particular, the SSA of the support and the interaction with POM, that can enhance the
superficial acidity of the samples, play an important role in the catalytic reactivity of the samples. Indeed, it
was observed that the supported samples on the oxides with higher SSA exhibited higher reactivities. This
finding can be related to the better dispersion of the POM on the catalyst surface. Moreover, as evidenced by
comparing the samples reactivity per gram of supported POM, the most active materials were those that
presented the strongest acid sites, i.e. ZrO2, WO3 and TiO2 Merck POM supported samples. The presence of
UV light improved the activity of almost all POM supported materials. Also in this case, the interaction
between POM and the support played a fundamental role for the photo-assisted catalytic reaction. Indeed, a
stronger interaction related also with the acidity of the POM supported samples could give rise to a POM
excitation at lower energy irradiation. Moreover, an electron transfer from the conduction band of the
semiconductor supports (TiO2 or WO3) to the excited POM to form the heteropolyblue species must be also
considered.
223164
225258
217
58
631
123
1041
30
288
188
525
276 258
94
789
123
1166
40
0
200
400
600
800
1000
1200
1400
POM/TiO2
Evonik P25
POM/TiO2
MerckPOM/TiO2
hp
POM/SiO2 POM/WO3 2L-POM/WO3 POM/ZrO2 2L-POM/ZrO2 POM2L-POM/TiO2
Merck
2-p
rop
an
ol
form
ati
on
rate
* 1
07
[ m
ol
min
-1 g
PO
M-1
]
223164
225258
217
58
631
123
1041
30
288
188
525
276 258
94
789
123
1166
40
0
200
400
600
800
1000
1200
1400
POM/TiO2
Evonik P25
POM/TiO2
MerckPOM/TiO2
hp
POM/SiO2 POM/WO3 2L-POM/WO3 POM/ZrO2 2L-POM/ZrO2 POM2L-POM/TiO2
Merck
2-p
rop
an
ol
form
ati
on
rate
* 1
07
[ m
ol
min
-1 g
PO
M-1
]
18
References
1. G. Ertl, H. Knözinger, J. Weitkamp, Handbook of Heterogeneous Catalysis. Wiley, Weinheim, 2008.
2. M.P. Atkins, US Patent 5,616,815 (1997).
3. G.J. Haining, US Patent 5,714,429 (1998).
4. I.V. Kozhevnikov, Catalysis for Fine Chemical Synthesis. Vol. 2: Catalysis by Polyoxometalates. John
Wiley and Sons, Chichester, 2002.
5. V. Kozhevnikov, Chem. Rev., 1998, 98, 171.
6. A.V. Ivanov, E. Zausa, Y. Ben Taarit, N. Essayem, Applied Catal A, 2003, 256, 225.
7. A. Hiskia, A. Mylonas, E. Papaconstantinou, Chem. Soc. Rev., 2001, 30, 62.
8. R.C. Chambers, C.L. Hill, Inorg. Chem., 1991, 30, 2776.
9. A. Fujishima, T.N. Rao, D.A. Tryk, J. Photochem. Photobiol. C, 2000, 1, 1.
10. G. Marcì, E. García-López, L. Palmisano, Applied Catal. A, 2012, 421-422, 70.
19
La0.8Sr0.2Fe0.8Cu0.2O3 as cathodic material for La0.8Sr0.2Ga0.8Mg0.2O3 based SOFCs
Francesca Zurlo1, Alessandra D’Epifanio
1, Elisabetta Di Bartolomeo
1, Valeria Felice
2, Isabella Natali Sora
2
and Silvia Licoccia1
1Department of Chemical Science and Technologies & NAST Center University of Rome “Tor Vergata”,
Via della Ricerca Scientifica, 00133, Italy 2INSTM R.U. and Department of Engineering, University of Bergamo, Dalmine, BG, I-24044 Italy
One of the major goals in the field of solid oxide fuel cells (SOFCs) is to reduce the operating temperature to
700 °C or less (intermediate temperature SOFCs, IT-SOFCs). A viable means to reduce SOFCs operating
temperature is to use electrolytes with high ionic conductivity at relatively low temperature.
La0.8Sr0.2Ga0.8Mg0.2O3 (LSGM) perovskites have very large ionic conductivity (~0.02 Scm-1
at 600 oC, almost
one order of magnitude larger than that of YSZ) [1, 2]. The main drawback of LSGM perovskite is the cation
interdiffusion occurring during the sintering process across the interface between electrolyte and anodic or
cathodic substrates, such as the commonly used GDC/NiO or strontium-doped rare earth cobaltites, with the
consequent formation of insulating phases [3, 4]. Cathode material specifically developed for LSGM
electrolyte with stoichiometric composition La0.8Sr0.2Fe0.8Cu0.2O3 (LSFCu) was prepared by sol-gel synthesis
to achieve chemical purity. Structure, morphology and chemical properties of LSFCu powders were
investigated by several characterization techniques. The chemical compatibility of LSGM electrolyte and
LSFCu cathode materials was investigated by structural and morphological characterization using X-ray
diffraction (XRD) analysis and field emission scanning electron microscopy (FE-SEM).
The electrochemical characteristics of doped perovskite were investigated by electrochemical impedance
spectroscopy (EIS) measurements on dense pellets sintered at 1500 °C for 10 h in the temperature range
500–750 °C.
LSFCu/LSGM/LSFCu symmetric cells were prepared by hand-painting the cathodic powders mixed together
with a commercial printing paste on both sides of LSGM dense pellets, used as electrolytes, then dried and
finally fired at 900 °C for 2 h.
Area Specific Resistance (ASR) values, directly depending on the rate limiting step of the electrochemical
processes involved in the oxygen reduction reaction at the cathode were evaluated. Fuel cells were prepared
using LSFCu as cathode materials and Pt as anode on the LSGM pellet. Fuel cell tests and electrochemical
impedance spectroscopy (EIS) were performed in the 500 – 750°C temperature range and compared to
Pt/LSGM/Pt cells as reported in Fig. 1. The electrochemical investigation has the aim to show that LSFCu is
a potential candidate for cathode application in IT-SOFC.
0 2 4 6 8 10 12 14 16 18 20 22 24
0.0
0.2
0.4
0.6
0.8
1.0 Pt/LSGM/LSCuF
750°C
700°C
650°C
600°C
Po
ten
tia
l (V
)
0
1
2
3
4
5
6
7
Po
we
r D
en
sity (
mW
cm
-2)
0 2 4 6 8 10 12 14 16 18 20 22 24
0.0
0.2
0.4
0.6
0.8
1.0
Current Density (mAcm-2)
0
1
2
3
4
5
6
7
Pt/LSGM/Pt
Fig. 1 Polarization curves measured at different temperatures between 600 and 750 °C with H2 fuel at the
anode and static air at the cathode.
20
References
1. Feng M, Goodenough JB, Huang K, Milliken C. Fuel cells with doped lanthanum gallate electrolyte. J.
Power Sources. 1996;63:47-51.
2. Wan J-H, Yan J-Q, Goodenough JB. LSGM-based Solid Oxide Fuel Cell with 1.4 W/cm2 15 power
density and 30 day long-term stability. J. Electrochem. Soc. 2005;152:A1511-A5.
3. X Hong J-E, Inagaki T, Ida S, Ishihara T. Improved power generation performance of solid oxide fuel
cells using doped LaGaO3 electrolyte films prepared by screen printing method II. Optimization of
Ni–Ce0.8Sm0.2O1.9 cermet anode support. Int. J. Hydrogen Energy. 2011;36:14632-42.
4. Liu B, Guo W, Chen F, Xia C. Ga site doping and concentration variation effects on the conductivities of
melilite-type lanthanum strontium gallate electrolytes. Int. J. Hydrogen Energy. 2012;37:961-6.
Acknowledgments The authors acknowledge the INSTM-Regione Lombardia for the financial support within the program
"Sperimentazione d'iniziative di sviluppo, valorizzazione del capitale umano e trasferimento dei risultati
della ricerca con ricaduta diretta sul territorio lombardo" Project title “Ferriti di Lantanio per Nuove Fonti di
Energia (Ferriti-NFE)" and the Italian Ministry of Research and Education within the program “Programmi
di Ricerca Scientifica di Rilevante Interesse Nazionale-PRIN- Anno 2010-2011–Prot. 2010KHLKFC”.
21
Sintesi via sol-gel dip coating e caratterizzazione di film ibridi organico-inorganici per il
potenziamento delle proprietà biologiche di impianti in lega di Titanio grado 4
Bollino F.1, Roviello G.
2, Ferone C.
2, Papale F.
1, Catauro M.
1
1 Dipartimento di Ingegneria Industriale e dell’Informazione, Seconda Università di Napoli, via Roma 29 –
81031 Aversa (CE); [email protected] 2 Dipartimento per le Tecnologie, Università di Napoli “Parthenope”, Centro Direzionale, Isola C4, 80143
Napoli
Abstract
La modifica di superfici protesiche mediante il rivestimento di film sottili biocompatibili può favorire
notevolmente l’integrazione della protesi nel sito d’impianto. Nel presente lavoro, mediante l’ausilio della
tecnica del dip coating, impianti di Titanio grado 4 (Ti gr. 4) sono stati rivestiti con film sottili, costituiti da
materiali ibridi organico-inorganici sintetizzati utilizzando il metodo sol-gel, al fine di potenziarne le
proprietà biologiche. I materiali e i film sono stati, poi, caratterizzati dal punto di vista chimico e
microstrutturale impiegando numerose tecniche strumentali (FTIR, NMR, AFM, SEM/EDS). Sono inoltre
state studiate le proprietà magnetiche utilizzando un Dispositivo Superconduttore a Interferenza Quantistica
(SQUID) e le proprietà biologiche mediante test in vitro che hanno dimostarto che i film sintetizzati
consentono di potenziare notevolmente la bocomaptibilità e la bioattività degli impiatti di Ti gr. 4.
Introduzione
L’utilizzo pratico di qualsiasi biomateriale comporta la formazione di un’interfaccia tra questo e il sistema
biologico in corrispondenza della quale avvengono le interazioni con i tessuti circostanti. La superficie di
quasi tutti i biomateriali può essere modificata allo scopo di favorirne il processo di integrazione, migliorarne
la biocompatibilità e le complessive prestazioni. In tal modo è possibile ottenere un nuovo materiale che, pur
possedendo diverse caratteristiche superficiali, conservi le medesime proprietà meccaniche e fisiche del
materiale di partenza. La modifica di superfici utilizzando la tecnica del dip coating permette, facilmente, di
rivestire substrati di diversa natura e forma con materiali ottenuti con il processo sol-gel, un metodo per la
produzione di vetri e ceramici a basse temperature. In tale studio ibridi ZrO2/PCL sono stati sintetizzati via
sol-gel ed utilizzati per rivestire, mediante dip coating, substrati di Ti gr. 4 per potenziarne le proprietà
biologiche legate alla superficie.
Materiali e Metodi
I materiali ibridi ZrO2/PCL sono stati sintetizzati utilizzando la tecnica sol-gel. Ad una soluzione idroalcolica
di un precursore metallorganico, il propossido di zirconio Zr(OC3H7)4, è stato aggiunto il policaprolattone
(PCL), previamente solubilizzato in cloroformio, nelle percentuali dello 0, 6, 12, 24 e 50 %p/p. Per regolare
l’elevata attività idrolitica dell’alcossido è stato introdotto l’acetilacetone (CH3COCH2COCH3) come
inibitore. Il sol è stato utilizzato per rivestire impianti di Ti gr. 4 (passivati in HNO3), utilizzando un KSV
LM dip coater. Lo studio delle interazioni presenti tra la fase organica e quella inorganica all’interno
dell’ibrido è stato effettuato utilizzando uno spettrometro FTIR Prestige 21 e uno spettrometro NMR
AMX400WB (Bruker) equipaggiato con sonda MAS da 4 mm. L’analisi microstrutturale dei materiali e dei
film è stata effettuata utilizzando un microscopio a forza atomica AFM Percepition e un microscopio a
scansione elettronica SEM FEI Quanta 200 munito di EDAX per eseguire la microanalisi dei campioni. Per
investigare le proprietà magnetiche dei materiali sintetizzati è stato utilizzato uno SQUID Quantum Design.
Infine, per confermare l’effettivo potenziamento delle proprietà biologiche del substrato, sono stati eseguiti
test di bioattività e biocompatibilità sui supporti rivestiti. La bioattività è stata valutata immergendo i
campioni in una soluzione simulante il plasma sanguigno (SBF o Simulated Body Fluid) tenuta a 37°C. A
diversi intervalli di tempo, i campioni, dopo essere stati asciugati, sono stati osservati al SEM per valutare
l’abilità a promuovere la formazione di uno strato di idrossiapatite sulla loro superficie. Lo studio della
biocompatibilità è stato eseguito effettuando il test di citotossicità o saggio WST-8, un test colorimetrico di
tipo indiretto che fornisce informazioni sulla vitalità delle cellule attraverso la valutazione della loro attività
metabolica, inibita dalla presenza di agenti tossici.
Risultati e discussione
Dall’analisi degli spettri FTIR (Figura 1) dei materiali ibridi si osserva la presenza dei picchi di assorbimento
caratteristici del PCL, a 2928 e a 2840 cm-1
(stretching simmetrico dei gruppi -CH2-) e a 1730 cm-1
22
(stretching del gruppo carbonile -C=O), i quali aumentano di intensità all’aumentare della quantità di
polimero introdotta nella la sintesi. La presenza della banda slargata nella zona tra 3200-3600 cm–1
,
caratteristica dei gruppi O-H, suggerisce la formazione di ponti a idrogeno tra il carbonile del PCL e gli OH
del network inorganico. Tale ipotesi è confermata dallo shift dei picchi di risonanza del PCL puro che si
osserva negli spettri 13C MAS-NMR dei materiali ibridi [1].
Figura 1 Spettri FTIR di: (a) ZrO2; (b) ZrO2+ PCL6 %; (c) ZrO2+ PCL12 %; (d) ZrO2+ PCL24 %; (e) ZrO2+
PCL50 %.
Le topografie AFM dei materiali ibridi e dei film mostrano che la distanza media tra i domini è di circa 20
nm, a conferma che i materiali sintetizzati sono ibridi nanocompositi. Le osservazioni al SEM hanno rilevato
che i film costituiti da sola zirconia sono molto fratturati (Figura 2a) e che la presenza di microcricche
diminuisce all’aumentare della percentuale di polimero inglobata nel film, fino a scomparire quando è
incorporato il 50%p/p di PCL (Figura 2b) [2]. La microanalisi EDAX dei materiali ibridi non ha evidenzia la
presenza di atomi di C in superficie, lasciando ipotizzare che il PCL è all’interno della matrice inorganica.
(a) (b) (c) Figura 2 Micrografie SEM dei substrati in Ti gr. 4 rivestiti con (a) ZrO2 e (b) ZrO2 + PCL 50% e (c) dopo 21
gg in SBF
I materiali, inoltre, immersi nel campo magnetico del dispositivo SQUID hanno manifestato comportamento
diamagnetico. Tale proprietà subisce un incremento proporzionale alla quantità relativa di PCL introdotto.
Ciò lascia intravedere la possibilità di sintetizzare gli ibridi in condizioni di microgravità mediante l’utilizzo
della Levitazione Magnetica allo scopo di comprendere come la forza di gravità influenza il processo che
governa la formazione della microstruttura di tali materiali [1]. Nelle immagini SEM, acquisite dopo
l’immersione dei sistemi rivestiti in SBF(Figura 2c), è evidente la presenza delle formazioni globulari tipiche
dell’idrossiapatite sulla superficie dei materiali. Ciò si traduce come la capacità, di tali sistemi, di
osteointegrarsi una volta impiantati in vivo. Inoltre, il saggio colorimetrico del WST-8 dimostra che i film di
rivestimento rendono i supporti di Ti gr. 4, generalmente bioinerti, biocompatibili [2].
Conclusioni
La tecnica sol-gel dip coating risulta un metodo economico, versatile e molto promettente per la modifica di
superfici. Film organico-inorganici nanocompositi appaiono molto bioattivi e biocompatibili e consentono di
potenziare notevolmente le proprietà biologiche degli impiatti di Ti gr. 4.
Riferimenti 1. Catauro M, Bollino F, Papale F. J Biomed Mater Res Part A. In Press (2013)
2. Catauro M, Bollino F, Mozzati MC, Ferrara C, Mustarelli P. J Solid State Chem. In Press (2013)
23
Cost effective electrode materials for energy and environmental applications
Alessandro Iannaci1, Barbara Mecheri
1, Alessandra D’Epifanio
1, Tommy Pepè Sciarria
2, Fabrizio Adani
2,
and Silvia Licoccia1
1 Dept. Chemical Science and Technology & NAST Center, University of Rome Tor Vergata ,
[email protected] 2 Gruppo Ricicla, DiSAA- Dipartimento di Scienze Agrarie e Ambientali, University of Milan
The increasing price of fossil fuels and of pollution levels in the atmosphere have driven numerous scientific
efforts towards the exploiting of renewable and sustainable energy sources. At present, photovoltaic, wind,
and geothermal sources are most promising both for domestic and industrial aim [1]
. However, for automotive
application and portable electronics, there is the necessity of more practical power sources, with high
efficiency and power output. Fuel cells (FCs) offer a unique combination of benefits that make them a vital
technology ideally suited for all market segments of our energy infrastructures, owing to high-efficiency
conversion of chemical energy to electricity with no or reduced environmental impact [2]
.
Among the different categories of FCs which are based on power level and end use, direct methanol fuel
cells (DMFCs) are potentially excellent power sources for traction and small portable power sources due to
high energy density of methanol, joint to the ease of storage and transport of this fuel [3]
.
More recently, a different and innovative class of FCs, microbial fuel cells (MFCs), has been developed.
MFCs are based on the ability of bacteria found in waste to digest organic matter through a cascade of redox
reactions. By driving this process, it is possible to produce current, using wastewaters of urban community as
fuel, also eliminating problems linked to waste disposal [4]
.
Figure 1 shows a schematic of the working principle of DMFC (Figure 1a) and MFC (Figure 1b). They both
consist in two electrode compartments separated by a polymer electrolyte membrane (PEM) which enables
the transport of protons from the anode to the cathode. Electrons produced at the anode through the oxidation
reaction of a fuel (methanol and waste, respectively for the two types of cells) flow via the external circuit to
the cathode where they combine with oxygen which is reduced to water.
Figure 1. DMFC (a) and MFC (b) schematics
Although substantial efforts is currently being made to develop both DMFC and MFC devices, their
applicability is still limited due to materials constraints, i.e. cathode catalysts and polymer electrolytes. In
fact, Nafion and platinum and are still the state-of-the-art materials for DMFC and MFC, as electrolyte and
cathode catalyst respectively, despite their cost and limitations.
Nafion suffers from high methanol permeability and its proton conductivity is not sufficiently high at
T<40°C (for MFC applications) and T>80°C (for DMFC applications) [5]
. Besides its cost and limited
abundance, platinum has low selectivity as ORR catalyst and can be easily contaminated with poisoning
elements such as methanol or organic matter [6,7]
.
In this context, our approach is to develop innovative and low cost cathode catalysts for both DMFC and
MFC applications. Our target is the preparation of a catalytic material that has both good selectivity towards
oxygen reaction reduction (ORR) with respect to crossovered methanol (DMFC application) and good
poisoning resistance against organic matter (MFC application). Zirconium oxide (ZrO2) was synthesized via
a sol-gel techniques and used as platinum additive. Catalytic mixtures at different composition were
prepared. Morphology, structure and thermal properties of the composite catalysts were investigated by
SEM-EXD FTIR, TGA/DTA and analysis. Their catalytic activity towards ORR was investigated by
electrochemical techniques, indicating that the presence of ZrO2 increased catalytic activity of Pt towards
24
ORR, due to an homogeneous dispersion of additive which enabled further catalytic sites for ORR .The
effect of surface modification of ZrO2 by introducing sulfate groups (S-ZrO2) was also explored and it was
found to improve stability and selectivity of the catalytic mixtures towards ORR, as evidenced by linear
sweep voltammetry acquired in oxygen saturated electrolyte solution containing also methanol as poisoning
agent. In fact, the parasitic reaction of methanol oxidation (MOR) was hindered by the presence of the
additive, enhancing ORR catalytic activity as well and stability of catalyst.
Pt/S-ZrO2 catalytic mixture was then deposited on carbon cloth gas diffusion electrodes and its performance
as both DMFC and MFC cathode was tested, assembling the cell with a Nafion-based electrolyte membrane.
DMFC tests were carried out, feeding the anode with aqueous methanol and the cathode with oxygen, and
polarization and power density curves were acquired (Figure 2a). Maximum current and power density of
265 mAcm-2
and 158 mWcm-2
, respectively, were recorded at 110 °C. The higher catalytic activity and
selectivity of Pt/S-ZrO2 with respect to bare Pt allowed to eliminate negative effects of crossovered methanol
at the cathode al high temperature. Therefore, Pt/S-ZrO2 catalytic mixture allowed DMFC operation at
temperature higher than that of state of the art DMFCs, achieving higher power output.
MFC tests were also acquired on Pt/S-ZrO2 cathodes, feeding the anode with wastewater from sewage plant
and the cathode with air, the operating temperature being 25 °C to guarantee survival of living
microorganisms. Polarization and power density curves were generated by measuring current at variable
external resistances (0.1 –30 kΩ) and results are shown in Figure 2b. Due to the intrinsic limitation of the
bioelectrocatalytic process and mild operating condition (neutral pH and room temperature) power
generation of MFCs is inherently lower than that achieved for chemical fuel cells, such as DMFC. During the
tests, a maximum power density of 23 µW/cm2 (0.08 mAcm
-2) was achieved, demonstrating the applicability
of Pt/S-ZrO2 cathodes for in situ bioelectricity generation along with wastewater treatment.
Figure 2. Polarization and power density curve of fuel cells assembled with Pt/S-ZrO2 cathode catalysts:
(a) DMFC and (b) MFC functioning
References
[1] N.L. Panwar, S.C. Kaushik, S. Kothari, Renewable and Sustainable Energy Reviews, 15, 1513–1524,
2011
[2] K.D. Kreuer (Editor), Fuel Cells, Selected Entries from the Encyclopedia of Sustainability Science and
Technology, Springer New York, 2013
[3] X. Li, A. Faghri, Journal of Power Sources, 226, 223–240, 2013
[4] B. Logan, D. Call, S. Cheng, H. Hamelers, T. Sleutels, A. Jeremiasse, R. Rozendal, Environmental and
Science Technology, 42, 23, 2008
[5] F. Chen, B. Mecheri, A. D’ Epifanio, E. Traversa, and S. Licoccia, Fuel Cells, 5, 790-797, 2010
[6] H.A. Gasteiger, S.S. Kocha, B. Sompalli, F.T. Wagner, Applied Catalysis B: Environmental, 56, 9–35,
2005
[7] A. Rinaldi, B. Mecheri, V.Garavaglia, S.Licoccia, P. Di Nardo, E.Traversa, Energy and Environmental
Science, 1, 417-429, 2008.
Acknowlegments
The financial support of the Italian Ministry for Environment (MATTM, Project MECH2), and the Ager
Consortium is gratefully acknowledged.
25
La Diagnostica per Immagini Punto di Incontro tra Chimica Sostenibile e Salute
Fulvio Uggeri
Bracco ImagingSpA, Centro Ricerche Bracco – Via Ribes 5, 10100 Colleretto Giacosa (TO)
Le dimensioni del business correlato alla Diagnostica per Immagini hanno fatto di questo settore un’area di
“nicchia” nel mondo della farmaceutica. Storicamente le aziende impegnate nella ricerca, sviluppo e
produzione dei Mezzi di Contrasto (MdC) erano aziende chimiche a elevata tecnologia ma che per nulla
rientravano nei canoni delle cosi dette “big pharma”. Ciò era dovuto alle peculiarità dei MdC che per
definizione non dovevano avere alcuna interazione con i sistemi biologici con cui venivano a contatto ovvero
ogni reazione farmacologica associata alla molecola era considerata un punto di debolezza della stessa. La
peculiarietà di un MdC si accentuava ulteriormente se si consideravano i dosaggi multigrammo di questi
prodotti e la loro formulazione unicamente iniettabile. Queste caratteristiche contraddistinguono ancora oggi
MdC per Raggi X di ultima generazione tuttavia l’evoluzione tecnologica, l’avvento delle nuove modalità
diagnostiche quali la Risonanza Magnetica (MRI), l’uso degli ultrasuoni (US) e dei prodotti radioattivi (NI)
hanno cambiato il paradigma e oggi chi è impegnato in Diagnostica per Immagini fa delle tecnologie
chimiche uno strumento indispensabile di ricerca e innovazione.
Lo scenario è indubbiamente cambiato, in particolare è sempre più compresa l’importanza della diagnostica e
dello slogan“una diagnosi precoce significa, vita” in quanto il conoscere, il vedere, bene e presto ha
ripercussioni drammaticamente importanti sull’approccio al trattamento del paziente, sul follow up
terapeutico, sulla qualità della vita che si viene a generare e conseguentemente anche su come è prodotta e
gestita la spesa sanitaria. In questo ambito saper produrre in modo sostenibile i MdC e le nuove Sonde
Diagnostiche diventa uno snodo ineludibile dove la chimica gioca ancora una volta un ruolo di fondamentale
importanza.
La chimica e le tecnologie associate continuano ad essere l’asse portante della ricerca, dello sviluppo e della
produzione di questi prodotti. Nella ricerca di prodotto partendo dal disegno molecolare fino al processo
dove alle applicazioni chemiometriche si affianca la tecnologia dei processi in continuo vera novità per il
mondo farmaceutico fino alle applicazioni di “green metrics” per la valutazione preventiva di impatto
ambientale delle variazioni di processo o di nuovi processi industriali. Anche i reflui industriali e il loro
trattamento sono oggetto di particolare attenzione in quanto come è vero che un MdC non ha interazione con
i sistemi biologici è altrettanto vero che di conseguenza i tradizionali sistemi di depurazione sono spesso
scarsamente efficienti e quindi nuove soluzioni devono essere adottate. Ultimo aspetto, ma non meno
importante, è la completa valutazione ciclo di vita del prodotto. In un settore industriale dove i prodotti sono
commodities,la cui chimica prevede l’uso di materie prime strategiche quali lo iodio e il gadolinio la cultura
del riciclo sta prendendo sempre più piede e la ricerca deve proporre nuove e adeguate soluzioni.
In conclusione la Diagnostica per Immagini con i suoi prodotti e i suoi processi pur rimanendo una nicchia
nel farmaceutico è certamente oggi un ambito in cui la fantasia del ricercatore unitamente all’abilità del
tecnologo possono dare un vero contributo al progresso. La consapevolezza che è la chimica con la sua
trasversalità che gioca un ruolo fondamentale di scopertainduce di ampliare la prospettiva nella fondata
certezza che i risultati ottenuti e quelli che verranno saranno rilevanti e generalizzabili e quindi fondamentali
per il benessere e la salute dell’uomo.
26
Large-scale manufacturing of radiation sculptured therapeutic nanogels
C. Dispenza
1,2, M.A. Sabatino
1, N. Grimaldi
1, L. Ditta
1, S. Alessi
1, G. Spadaro
1
1Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica, Università degli Studi di
Palermo, Edificio 6, Viale delle Scienze 90128 Palermo, Italy. 2CNR-Istituto di Biofisica U.O.S. di Palermo, via Ugo La Malfa 153 90146, Palermo, Italy.
Nanogels (NGs), or small particles formed by physically or chemically crosslinked polymer networks,
represent a niche in the development of “smart” nanoparticles for drug delivery and diagnostics. Yet, they
offerunique advantages over other systems, including a large and flexible surface for multivalent bio-
conjugation; an internal 3D aqueous environment for incorporation and protection of (bio)molecular drugs;
the possibility to entrap light-activemolecules, metal or mineral nanoparticles for imaging or
phototherapeutic purposes; stimuli-responsiveness to achieve temporal and/or site control of the release
function and biocompatibility.
The availability of inexpensive, robust and versatile synthetic methodologies is at the basis of the
development of effective nanogel-based theragnostic devices. In particular, we have established that
nanogels can be produced with high yields and through-puts by pulsede-beam irradiation of dilute aqueous
solutions of water-soluble biocompatible polymerse.g. poly(N-vinyl pyrrolidone), and functional acrylic
monomers, such as acrylic acid or (3-aminopropyl) methacrylamide hydrochloride, using industrial electron
accelerators and set-ups (see Figure 1). [1-4]
Nanogels are the result of chemical follow-up reactions initiated by a continuous series of electron pulse-
generated hydroxyl radicals in de-aerated water. A number of radical sites are generated on the polymer
chains,which may have a different fate depending onthe system composition and irradiation conditions.Intra-
molecular and inter-molecular radical recombination as well as disproportionation, chain scission and
monomer or short polymer segments grafting may occur up to different extent. As a result, crosslinked-core
nanoparticles with multi-armed surfaces can be generated, with controlled size, crosslinking density, surface
electric charge density, number and nature of functional groups.No recourse to organic solvents, toxic
initiators or catalysts and surfactants is made, therefore expensive or time-consuming purification procedures
are not required. Simultaneous sterilization can be achieved depending on the irradiation doses.
Long-term colloidal stability in the formof aqueous dispersions and redispersability from the freeze-dried
form are advantageous properties especially in the view of a pharmaceutical use.
Nanogels have been decorated with fluorescent probes, peptides, antibodies or oligonucleotides and/or
conjugated to both molecular and macromolecular model drugs to demonstrate their amenability to be
transformed into bio-hybrid, smart drug nanocarriers.
All the base nanogels have been proved to benot cytotoxic or genotoxic at the cellular level. Indeed, they
showed a good affinity for cells, as they rapidly and quantitatively bypass the cellularcompartments, to
accumulate in specific cell portions for the first hours, to bethen completely released from the cells after 24
h.[5] In particular, active targeting features toward specific cell types and smart delivery functions of model
chemotherapeutics of purposely designed bio-hybrid nanogels will be presented.
References 1. Dispenza C, Sabatino MA, Grimaldi N, Spadaro G, Bulone D, Bondì ML, Adamo G, Rigogliuso S.
Large-scale Radiation Manufacturing of Hierarchically Assembled Nanogels. CHEMICAL ENGINEERING
TRANSACTIONS (2012), 27, p. 229-234.
2. Sabatino MA, Bulone D, Veres M, Spinella A, Spadaro G, Dispenza C. Structure of e-beam sculptured poly(N-
vinylpyrrolidone) networks across different length-scales, from macro to nano. POLYMER (2013), 54 (1), p. 54-64.
3. Dispenza C, Sabatino MA, Grimaldi N, Bulone D, Bondi ML, Casaletto MP, Rigogliuso S, Adamo G, Ghersi G.
Minimalism in Radiation Synthesis of Biomedical Functional Nanogels. BIOMACROMOLECULES (2012), 13, 1805-
1817.
4. N. Grimaldi, M.A. Sabatino, G. Przybytniak, I. Kaluska, M.L. Bondì, D. Bulone, S. Alessi, G. Spadaro, C. Dispenza,
High-energy radiation processing, a smart approach to obtain PVP-graft-AA nanogels. Radiation Physics and
Chemistry, http://dx.doi.org/10.1016/j.radphyschem.2013.04.012
5. Rigogliuso S, Sabatino MA, Adamo G, Grimaldi N, Dispenza C, Ghersi G. Polymeric nanogels: Nanocarriers for
drug delivery application. CHEMICAL ENGINEERING TRANSACTIONS (2012), 27, p. 247-252.
27
(a)
(b)
Figure 1: Amino-functionalised, radiationcrosslinked PVP nanogelvariants, decorated with fluoresceine
isothiocyanate (FITC) probe, BovinSerum Albumine (BSA) and ratmonoclonal Anti-human CD44 Antibody
C37 labeled with TRITC (Antibody)(a); Caboxyl-functionalised, radiationcrosslinked PVP nanogelvariants,
decorated with amino fluorescein (AmFluor) probe, folic acid, doxorubicin (DOXO) and a single
strandoligonucleotideFAM-FW-N (FAM-5’-AAA ACT GCA GCC AAT GTA ATC GAA-3’-
NH2)(OligoFAM) (b).
28
Modelli teorici per idrolisi ed idratazione di complessi
antitumorali di platino.
Andrea Melchior
Dipartimento di Chimica Fisica e Ambiente, Università di Udine, Udine, Italy
I complessi metallici a base di platino (Figura 1), sono tra i principali farmaci efficaci nella chemioterapia di
una grande varietà di tumori. In particolare, il cisplatin (Fig. 1) viene impiegato da oltre 30 anni nel
trattamento dei tumori umani. Il meccanismo d’azione del cisplatin procede attraverso due stadi
fondamentali: i) l’attivazione intracellulare per idrolisi di un cloruro dovuta alla minore concentrazione di
questo anione all’interno delle cellule (~3-20mM) rispetto al plasma (~100mM); ii) formazione di legami
covalenti con le basi puriniche del DNA.
La formazione degli addotti causa una deformazione
della doppia elica del DNA che provoca una produzione
di proteine difettose all’interno della cellula e la sua
successiva morte. Le cellule sane possiedono svariati
meccanismi di riparazione del DNA che possono
correggere una varietà di difetti. Tali meccanismi sono
malfunzionanti nelle cellule appartenenti a svariati tipi di
tumori, per cui non sono in grado di correggere i difetti
prodotti dal farmaco.
Nonostante i risultati positivi raggiunti nell’applicazione
clinica, esistono numerosi svantaggi: pesanti effetti
collaterali (tossicità), chemio-resistenza, limitato numero
di tumori che possono essere trattati. Al fine di superare
tali limiti, numerosi complessi di platino sono stati studiati nelle ultime decadi, per poter ottenere farmaci
equivalenti o migliori del cisplatin, e con una minore tossicità. Tuttavia solo pochi sono i composti che
effettivamente sono utilizzati clinicamente (Fig. 1), mentre svariati altri sono presenti in test clinici.
L’obbiettivo di un miglioramento delle caratteristiche di efficacia e tollerabilità di tali metallo-farmaci ha
mantenuto viva negli ultimi decenni sia la ricerca sperimentale sia teorica.
In questa comunicazione saranno presentati alcuni esempi di metodi teorici per la definizione dei fondamenti
chimici del funzionamento di metallo-farmaci a base di platino. Infatti, numerosi studi di modellizzazione
molecolare basati su approcci ab initio (per esempio DFT) si sono rivelati utili per chiarire i meccanismi
d’azione a livello molecolare, in particolare per l’idrolisi dei leganti e la coordinazione del complesso al
DNA. L’applicazione di metodi teorici allo studio della reazioni di idrolisi dei leganti al platino è utile alla
descrizione a livello molecolare di quello che gli esperimenti dimostrano essere il rate-determining step
precedente la coordinazione al DNA. Informazioni dettagliate su tale processo possono quindi supportare la
progettazione razionale di nuovi composti con cinetica controllata e possibilmente con una buona inerzia
rispetto a reazioni competitive con altre biomolecole (es. glutatione). Un ulteriore aspetto fondamentale ed
importante da chiarire è la struttura dell’acqua che interagisce con il complesso. Infatti, una descrizione della
struttura di idratazione del complesso e dell’effetto dei leganti al platino su di essa (es. diverso ingombro
sterico) possono portare a una migliore comprensione dei meccanismi di reazione. Per questo scopo, l’analisi
delle traiettorie ottenute da simulazioni di dinamica molecolare fornisce informazioni strutturali sulla
distribuzione delle molecole d’acqua attorno al complesso di platino e sulla diversa interazione con i vari
leganti.
NH3
NH3
PtO
OO
O
NH3
NH3
Pt
O
O
O
Pt
Cl
Cl
NH3
NH3
NH2
NH2 O
Pt
O
O
O
cisplatin
nedaplatin
carboplatin
oxaliplatin
Figura 1
29
EIS biochip with integrated microfluidic components and MIP modified-electrodes for POC
analysis of environmental and clinical samples
Maria Serena Chiriacò
*1,2, Elisabetta Primiceri
2, Anna Grazia Monteduro
3, Francesco De Feo
2, Alessandro
Montanaro1, Ross Rinaldi
1,2, Giuseppe Maruccio
1,2
1 Dept. of Mathematics and Physics “E. de Giorgi”, Università del Salento, Via per Arnesano, Lecce, Italy.
2 NNL CNR-Istituto Nanoscienze, Via per Arnesano, Lecce, Italy
3. Dept. of Innovation Engineering, Università del Salento, Via per Arnesano, Lecce, Italy.
* Corresponding author: [email protected]
Biochips for environmental and clinical analysis represent a very attracting research field and many R&D
efforts are today directed in this direction where integration of smart platforms for automatic handling of
biological fluids is a further challenge towards a saving-cost and label-free analysis. In this respect
Electrochemical Impedance Spectroscopy (EIS) biosensors based on the immobilization of molecules on
electrodes surface could be used as a powerful tool to investigate interactions between molecules [1]. Our
EIS device has been produced by optical lithography and it includes some sensing chambers in each of which
there are four couples of interdigitated electrodes made of gold on a glass substrate. The device includes also
an inlet/outlet microfluidic system for the delivery of functionalization and sample solutions into the
chambers. This system could be implemented with the presence of flow control valves for automatic sample
handling (Fig. 1d). In our case, we have chosen poly-N-isopropylacrylamide (poly- NIPAAm) as
thermoresponsive polymer. This material belongs to a class of temperature sensitive polymers characterized
by a lower critical solution temperature (LCST) of 32-34°C. Transitions in open/closed conformation are
possible on chip because of the presence of two integrated couples of heaters. With our biochip we provided
an accurate functionalization of electrodes in a multi-step process to form a homogeneous surface protected
from unspecific binding events. Characterization of each single step necessary to obtain a surface modified
to hold antibodies or peptides and to allow the detection of Cholera toxin from waters [3], PSA (Prostate
Specific Antigen) forms from serum samples or antibodies against a tumor-specific phosphorilated isoform
of an enzyme (α-enolase) found in the most of pancreatic cancer serum from affected people [4]. An
increasing number of molecules adsorbed onto the electrode surface modulates the rate of electron transfer
(Fig. 1 a,b.c). Specifically, the antigens or antibodies in solutions are captured on the electrode surface,
according to the specific functionalization thus providing a smart and sensitive POC tool for clinical practice.
Biochip results are in agreement with those from traditional techniques, such as ELISA and Western Blot,
but measurements are faster, more reproducible and specific making the developed biochips ideal for a
quick, cost-saving and label-free analysis of serum samples. In a near future, integration of multi-biomarker
assays within the same biochip can be envisioned to provide more appropriate tests for early diagnosis, case
management and treatment monitoring of patients and a POC tool in environmental monitoring. Moreover
continuous implementation of the device led to the realization of nanostructured electrodes thanks to the
presence of immobilized MIP (Molecularly Imprinted Polymers) [5] on gold surface. This tool represents a
kind of artificial antibodies and allows to avoid problems of stability of antibodies layer since this materials
have highly stability toward temperature conditions, so that MIP based biosensors could become a tool of
large interest in the field of POC analysis.
30
Fig.1(a) Nyquist plot related to the detection of Cholera Toxin decreasing concentration of Cholera Toxin
until 1 ng/ml.
(b) Linear plot of Impedance values in function of concentration of PSA in serum samples. Current limit of
detection on
chip is 0.3 ng/ml. (c) Antibody against phosphorilated α-enolase detection from pancreatic cancer serum
sample. (d)
Cross-sectional SEM images of PNIPAAm monolith in a microchannel
References
[1] Katz E., Willner I. Probing Biomolecular Interactions at Conductive and Semiconductive Surfaces by
Impedance Spectroscopy. Electroanalysis 15 11, pages 913–947 (2003)
[2] Luo et al. Monolithic valves for microfluidic chips based on thermoresponsive polymer gels
Electrophoresis 24 21, pages 3694-702 (2003)
[3] Chiriacò et al. EIS microfluidic chips for flow immunoassay and ultrasensitive cholera toxin detection
Lab on a chip 11, pages 658–663 (2011)
[4] Chiriacò et al. Towards pancreatic cancer diagnosis by EIS biochips Lab on a chip 13 Issue: 4 Pages:730-
4 (2012)
[5] Ho et al. Amperometric detection of morphine based on poly(3,4-ethylenedioxythiophene) immobilized
molecularly imprinted polymer particles prepared by precipitation polymerization. Analytica Chimica
Acta542 90–96 (2005)
31
Temperature-responsive degalactosylated xyloglucans as nanocarriers for the sustained
release of hydrophobic drugs
S. Todaro
(1,2), M.A. Sabatino
(1), M.R. Mangione
(2), D. Bulone
(2), C. Dispenza
(1,2)
1 Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica.
Università degli Studi di Palermo, Viale delle Scienze Ed. 6, 90128 Palermo, Italy. 2CNR - Istituto di Biofisica (Palermo unit), Via U. La Malfa 153, 90146 Palermo, Italy.
Xyloglucans are a major class of structural polysaccharides found in the primary cell walls of higher plants.
In the native form they are film-forming polymers [1], but they can undergo gelation in the presence of
moderate amounts of alcohol [2]. When they have been partially degalactosylated via an enzymatic
treatment, they can form physical, thermo-reversible gels at body temperature [3]. Degalactosylated
xyloglucan (Deg-XG) has been already proposed as in situ, macroscopic gelling system for tissue
engineering applications [4] and for drug delivery [5]. However, there are few studies concerning its use in
the pharmaceutical field in the form of micro/nano-aggregates [6,7].
A Deg-XG variant, with the 44% of galactose removal ratio, has been here employed for the production of
nanoparticles, which incorporate and release hydrophobic drugs. Due to Deg-XG poor solubility in water,
different purification and dispersion protocols were developed and compared with the purpose of obtaining
colloidally stable polymer suspensions, which were fully characterized by multi-angle static and dynamic
light scattering and gel filtration chromatography. Thermally-induced mesoscopic gelation of Deg-XG in
water was investigated by dynamic light scattering measurements as function of time and temperature. This
phenomenon was exploited to incorporate hydrophobic model molecules and drugs, such as 1-
anilinonaphthalene-8-sulphonic acid (1,8-ANS) and theophylline, respectively a fluorescence probe whose
fluorescence intensity increases when it is surrounded by a nonpolar environment and a bronchus-dilator
drug that presents anti-inflammatory effects [8, 9].
References
[1] Kochumalayil J., Houssine S., Qi Z., Berglund L., “Xyloglucan films”, Patent application number
20120216706 (2012).
[2] Yuguchi Y., Kumagai T., Wu M., Hirotsu T., Hosokawa J., “Gelation of xyloglucan in water/alcohol
systems”. Cellulose 11 (2004), 203-208.
[3] Shirakawa M., Yamatoya K., Nishinari K., “Tailoring of xyloglucan properties using an enzyme”. Food
Hydrocolloids 12 (1998), 25-28.
[4] Nisbet D. R., Moses D., Gengenbach T. R., Forsythe J. S., Finkelstein D. I., Horne M. K., “Enhancing
neurite outgrowth from primary neurons and neural stem cells using thermoresponsive hydrogel
scaffolds for the repair of spinal cord injury”. J. Biomed. Mater. Res. A, 89(A), 1 (2008), 24-35.
[5] Miyazaki S., Suisha F., Kawasaki N., Shirakawa M., Yamatoya K., Attwood D., “Thermally reversible
xyloglucan gels as vehicles for rectal drug delivery”. J. Control. Release 56 (1998), 75-83.
[6] Jò T. A., Petri D. F. S., Beltramini L. M., Lucyszyn N., Sierakowski M. R., “Xyloglucan nano-
aggregates: physico-chemical characterisation in buffer solution and potential application as a carrier for
camptothecin, an anti-cancer drug”. Carbohyd. Polym. 82 (2010), 355-362.
[7] Cao Y., Gu Y., Ma H., Bai J., Liu L., Zhao P., He H., “Self-assembled nanoparticle drug delivery systems
from galactosylated polysaccharide-doxorubicin conjugate loaded doxorubicin”. Int. J. Biol. Macromol
46 (2010), 245-249.
[8] Slavik J., “Anilinonaphthalene sulfonate as a probe of membrane composition and function”. Biochim.
Biophys. Acta 694 (1982), 1-25.
[9] Al-Kahtani A. A., Sherigara B. S., “Controlled release of theophylline through semi-interpenetrating
network microspheres of chitosan –(dextran-g-acrylamide)”. J. Mater. Sci. Mater. Med. 20(7) (2009),
1437-1445.
32
Polyelectrolyte Capsules as Carriers for Insoluble Anticancer Drug
Viviana Vergaro
1*, Francesca Baldassarre
2, Stefano Leporatti
1 and Giuseppe Ciccarrella
1,3
1CNR Nano-Istituto Nanoscienze, via Arnesano 16, 73100 Lecce, Italy
e-mail*[email protected] 2Department of Internal Medicine, Immunology and Infectious Diseases, Section of Internal Medicine,
University of Bari, Medical School, Bari, Italy 3Department of Innovation Engineering, Università del Salento,c\o Technological District Via Arnesano 16,
73100 Lecce, Italy
The requested features of pharmaceutical drug delivery (such as biodegradability or targeting) for
intravenous administration are reasonably well met by liposomes, microcapsules, and nanoparticles for
water-soluble drugs. Low solubility in water, however, tends to be an intrinsic property of many drugs,
including some powerful anti-cancer agents. Intravenous administration of relatively large aggregates of an
insoluble drug may result in embolisation of these particles into small blood capillaries and may cause
unwanted effects like tissue ischemia. So is necessary encapsulate these drugs into a carrier. In this work we
used as drug carrier a biocompatible colloidal CaCO3cores coated with Layer-by-Layer (LbL) self-assembled
oppositely charged polyelectrolytes. Microparticles and hollow capsules, obtained after removal of carbonate
cores by EDTA, were characterised by ζ-Potential, Scanning Electron microscopy (SEM) and Scanning
Force Microscopy (SFM). Fuorescently-labelled polymer layers coated onto carbonate cores were employed
for evaluating cell uptake efficiency, and confocal laser scanning microscopy (CLSM) confirmed the
dissolution of pre-formed biodegradable multilayers with entrapped drug. We have performed cytotoxicity
tests by using this type of carrier, using different neoplastic cell lines.
In particular we tested the efficiency of LY-loaded microcapsules in epatocellular carcinoma. Hepatocellular
carcinoma (HCC) is the third most frequent cause of tumor-related death in the United States and Europe. In
standard therapies, prognosis and survival are not satisfactory. Ideally, a drug needs to be able to modulate
the different biological characteristics of the tumor, such as growth, metastatic spread, vascular invasion, etc.
LY is a selective inhibitor of TGF-beta, inhibits the invasive and migratory ability of constitutively invasive
HCC cells. LY has no effect on liver cancer cell viability at concentrations ranging from 0.001 to 1mM so
the biological effects of the molecule are not related to cytotoxicity. LY strongly inhibited the migration of
HCC cells in a dose dependent manner. As a proof of concept, the migration of HLF cells was assayed. We
observed an enhanced inhibition of HLF migration with LY-loaded biodegradable capsules with respect to
free LY. Compared to untreated cells, LY-treated cells decrease their migration power from 29% (lower
concentration, 0.5 nM) up to 54% (higher concentration, 10 nM).
Migration assays further showed an enhancement of drug efficiency (e.g., a significant migration inhibition
increase) of encapsulated drug with respect to free administration upon increasing drug concentration.
Keeping in mind a future clinical application of these polymeric particles/capsules, our data here can be
regarded as an essential step towards developing new nanotechnology- based strategies against HCC.
33
34
Periodically nanostructured hydrogels for ethanol vapors sensing
M.A. Sabatino
1, D. Spigolon
1, L. D’Acquisto
1, C. Dispenza
1
R. Pernice2, G.Adamo
2, S. Stivala
2, A. Parisi
2, A.C. Busacca
2
1Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica (DICGIM), Università di
Palermo, Viale delle Scienze, Bldg. 6, 90128 Palermo, Italy 2 Dipartimento di Energia, Ingegneria dell'Informazione e Modelli Matematici (DEIM), Università di
Palermo, Viale delle Scienze, Bldg. 9, 90128 Palermo, Italy
Chemical sensing using optics has been under extensive research all over the world during last decades and
many optical chemical sensors are nowadays finding increasing applications in industry, environmental
monitoring, medicine, biomedicine and chemical analysis. These optical sensors can be based on various
optical principles, such as absorbance, reflectance or transmittance, luminescence and fluorescence, covering
different regions of the spectrum (UV, visible, IR, NIR). Optical chemical sensors have several advantages
over conventional electricity-based sensors, in terms of selectivity, immunity to electromagnetic interference,
higher sensitivity, and they are also relatively inexpensive and minimally invasive. A wide class of optical
chemical sensors is based on Photonic Crystals (PCs), i.e. regular arrays of materials with different refractive
indices. In particular, they are artificial structures with a periodic dielectric function.
In this paper, we present the optical characterization of a polystyrene opal, infiltrated with a stimuli
responsive hydrogel specifically formulated to be sensitive to ethanol (EtOH), also in the presence of water.
Stimuli-responsive hydrogels are interesting materials for sensing applications due to thefact that they can
change their volume significantly in response to small alterations of certain environmental parameters. In
fact, hydrogels are increasingly considered as responsive materials to generate active inverse opals fortheir
ability to exhibit significant reversible diffraction shifts as a response of a variety of stimuli, such
astemperature, pH and ionic strength, single molecules binding and mechanical forces.The stimuli-
responsiveness must be accompanied by adequate elasticity and chemical stability forthe inverse opal to be
able to survive, without collapsing, to the template removal process byorganic solvents (for polymer
colloids) during preparation and to withstand repeated swelling/deswelling cycles when in use, as well as
erosion due to prolonged exposure to the swelling medium.
While there are interesting studies which report diffraction shifts in a wide region of the visible spectral
region when e.g. a crosslinked 2-hydroxyethyl methacrylate (HEMA) hydrogel is exposed either to pure
liquid water or to concentrated ethanol/water liquid solutions, at the best of our knowledge there are no
equivalent studies which report on the ability of hydrogel inverse opals tospecifically respond to ethanol
vapors when already swollen by water.The hydrogel network should be designed so that it can uptake and
retain water, when exposed towater vapor-rich atmospheres, and further swell when the atmosphere which is
exposed to isprogressively concentrated of ethanol vapors. For this purpose, 2-hydroxyethyl methacrylate
(HEMA) was used as main building block for the network, for its known favorable Flory-Huggins mixing
parameter with ethanol; acrylic acid (AA) at two different ratios was also considered as co-monomer for its
affinity toward water and its contribution to hydrogel network mechanical properties, due to establishment of
further crosslinking through strong secondary interactions; finally poly-ethylene glycol-200dimethacrylate
(PEG200DMA) was used as crosslinking agent. The polymerization process combined a “cold” UV-photo-
crosslinking step and a thermal post-cure. Preliminary swelling studies in the presence of both liquid ethanol
and ethanol vapors were carried out on the macrogel analogue as well as a dynamic mechanical thermal
analysis to withdraw useful information on the hydrogels mechanical spectra and validate both the
formulation and curing process. The most promising of the two formulations was selected to infiltrate a
polystyrene (PS)opal structure, which was generated onto pre-etched silica through self-assembly of PS
nanoparticles. The periodically nanostructured hydrogel film (Fig.1) was then evaluated as active component
of an ethanol vapor optical sensor by means of UV-Vis transmission measurements atthe variance of ethanol
vapor concentration (Fig.2).
35
Fig.1. (a) Photograph of the fabricated bare polystyrene opal. (b) Scanning electron micrograph of the
periodic structure of the bare polystyrene opal. (c) Scanning electron micrograph of the periodically
nanostructured hydrogel film after removal of the polystyrene template.
Fig.2. Transmission spectra at varying ethanol vapor concentrations after that the steady value has been
reached.
References
1. A Lobnik, M. Turel, and Š. KorentUrek, Optical Chemical Sensors: Design and Applications, in
Advances in Chemical Sensors, W. Wang, ed. (In-Tech, 2012).
2. J. Y. Wang, Y. Cao, Y. Feng, F. Yin, and J.P. Gao, Multiresponsive Inverse-Opal Hydrogels, Adv.
Mater.19(22), 3865–3871 (2007).
3. A. Pasquazi, S. Stivala, G. Assanto, V. Amendola, M. Meneghetti, M. Cucini, and D. Comoretto, In situ
tuning of a photonic band gap with laser pulses, Appl. Phys. Lett. 93(9),091111 - 091111-3 (2008).
4. J. Shin, P. V. Braun, and W. Lee, Fast response photonic crystal pH sensor based on templated photo-
polymerized hydrogel inverse opal, Sensor. Actuat. B - Chem. 150, 183–190 (2010).
5. M. Allard, E.H. Sargent, E. Kumacheva, and O. Kalinina, Characterization of internal order of colloidal
crystals by optical diffraction, Opt. Quant. Electron. 34(1-3), 27-36 (2002).
6. S. Achelle, Á. Blanco, M. López-García, R. Sapienza, M. Ibisate, C. López, and J. Rodríguez-López,
New Poly(phenylene-vinylene)-Methyl Methacrylate-Based Photonic Crystals, J. Polym. Sci. Part A: Polym.
Chem.48(12),2659–2665 (2010).
7. X. Xu, A. V. Goponenko, and S. A. Asher, Polymerized PolyHEMA Photonic Crystals: pH and Ethanol
Sensor Materials, J. Am. Chem. Soc.130(10), 3113-3119 (2008).
8. A. Bearzotti, A. Macagnano, S. Pantalei, E. Zampetti, I. Venditti, I. Fratoddi, and M. V. Russo, Alcohol
vapor sensory properties of nanostructured conjugated polymers, J. Phys.: Condens. Matter 20 (47), 474207-
474213 (2008).
9. R. Pernice, G. Adamo,
S. Stivala, A. Parisi,A.C. Busacca, D. Spigolon, M.A. Sabatino, L. D’Acquisto C.
Dispenza, Optical ensors for ethanol vapor based on polystyrene opals infiltrated with a stimuli-responsive
hydrogel, submitted
36
ToF-SIMS Imaging and Depth Profiling for the Characterization of Biomaterials Surfaces
Luca Tortora1,2
and Alberto Rainer3
1 Industrial Engineering Department, University of Rome "Tor Vergata", Via del Politecnico 1, 00133 Rome,
Italy 2 Surface Analysis Laboratory, Department of Physics "E. Amaldi", University of Rome "ROMA TRE", Via
della Vasca Navale 84, 00146 Rome, Italy 3
Tissue Engineering Laboratory, CIR—Center for Integrated Research, Università Campus Bio-Medico di
Roma, via Álvaro del Portillo 21, 00128 Rome, Italy
Functionalization of biomaterials surfaces with bioactive molecules represents a key issue in the field of
biomaterials science. Indeed, the biological response to biomaterials depends upon biomaterial/cell
interactions at the molecular scale. Therefore, morphology and surface chemistry of biomaterials have a deep
influence on their compatibility and performance within the body. The successful tailoring of the surface
chemistry requires a detailed surface characterization, including the ability to determine the composition,
structure, orientation, and spatial distribution of the molecules and chemical structures on the surface. Time
of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is a powerful surface characterization technique
that is able to address these requirements through both spectral analysis and direct chemical state imaging.
The flexibility of ToF-SIMS technique and the wealth of data produced have generated much interest for
applications in biomaterials characterization. Recently, we have focused on ToF-SIMS imaging and depth
profiling of bioactive glasses and polymers for tissue engineering. We will present preliminary results on the
characterization of polymeric surfaces functionalized by covalent grafting of bioactive peptides, showing the
power of imaging and depth profiling data from SIMS to determine the characteristics of protein release. We
will also report on the 3D-mapping of sol–gel derived bioactive glass films in the SiO2–CaO–SrO–P2O5
system.
References
[1] Schumacher M, Henß A, Rohnke M, Gelinsky M., Acta Biomater. (2013) in press
[2] H. Sun, S. Onneby, Polym. Int. (2006) 55; 1336–1340.
37
Il Workshop è stato patrocinato e sponsorizzato da:
Università degli Studi di Palermo
Bracco ImagingSpA
EdiSES
