Scientific Program

Keynote Talks

Abstract

Cancer, congestive heart failure, diabetes are the leading causes of morbidity and mortality in industrialized nations. The ever-increasing complexity of these diseases, and managing them with highly potent pharmaceutical agents, have also led to serious reduction in an individual’s quality of life. This may largely be attributed to our inability to deliver drugs in sufficient quantities at the diseased site. Polymer therapeutics has evolved as an advantageous platform to address these issues. Despite significant progress, key challenges related to simplifying their synthetic schemes, enabling them to cross biological barriers, and understanding nano-bio interactions, still remain. This has provoked the design of tailor-made macromolecules based nanocarriers that can perform multiple desired tasks with high efficiency. An important parameter for constructing these scaffolds is to develop synthetic tools that can provide desired spatial distribution of different units in these nanostructures. The synthetic methodologies need to be simple and highly versatile, and adaptable to the needs of biology. We shall describe how chemical innovation has given access to a variety of branched and hyperbranched macromolecules and combinations thereof. Functional nanostructures from these macromolecules can be used for monotherapy through physical encapsulation or drug conjugation, or combination therapy using multiple drugs. Their desired structural complexity is ideally suited to perform multiple tasks including targeting and visualizing drug delivery. Kakkar, A.; Traverso, G.; Farokhzad, O.C.; Weissleder, R.; Langer, R. Nat. Rev. Chem. 2017, 1, 0063. Choi, J.; Moquin, A.; Bomal, E.; Li Na; Maysinger, D.; Kakkar, A. Mol. Pharm. 2017, 14, 2607.

Biography

Ashok Kakkar is a Professor in the Department of Chemistry at McGill University in Montreal, Quebec, Canada. He obtained his PhD from University of Waterloo (Canada), and has done Post-doctoral studies at University of Cambridge (UK) and Northwestern University (USA). His research interests include developing methodologies to complex nanostructures for applications in a variety of areas including drug delivery and diagnostics. His group has published extensively in this area, including editing a book (Miktoarm Star Polymers: From Basics of Branched Structure to Synthesis, Self-Assembly and Applications, RSC 2017).

Speaker
Prof. Ashok Kakkar McGill University, Canada

Abstract

Novel magnetic responsive bulk composite biopolymer-based materials have been elaborated by synthezing nanoparticles of maghemite either stabilized by adsoprtion of citrate ions or functionnlized with bifunctional ligands such as dopamine and 3-aminopropyl-triethoxysilane bearing NH2 functional groups and furher introduced in aqueous solutions of sodium alginate. Temperature controlled flow and viscoelastic properties of elaborated bulk composites have been investigated by a new magnetorheological cell specifically designed [1]. Enhancement of viscoelastic moduli and viscosity at low shear rate has been clearly evidenced. This magnetoviscous effect has been explained for the first case by the formation of deformable under magnetic field micron-sized droplets of demixing [2] and for the second case by intramolecular electrostatic interactions between the positively charged NH3+ groups present at the surface of the functionalized nanoparticles and the negatively charged carboxylate groups of sodium alginate chains [3]. This explanation has been supported by microscopic optical observation showing magnetic-induced microstructures in the nanocomposites. [1] C. Galindo-Gonzalez, A. Ponton, A. Bee, J. Chevalet, D. Talbot, R. Perzynski, E. Dubois, Investigation of water-based and oil-based ferrofluids with a new magnetorheological cell: effect of the microstructure, Rheologica Acta 55:67-81 (2016). [2] S. Roger, Y. Yip Cheung Sang, A. Bee, R. Perzynski, J. M. Di Meglio, A. Ponton, Structural and multi-scale rheophysical investigation of diphasic magneto-sensitive materials based on biopolymers, European Physical Journal E, 38, 88 (2015) [3] C. Galindo Gonzalez, S. Gantz, L. Ourry, F. Mammeri, S. Ammar-Merah, A. Ponton, Elaboration and Rheological Investigation of Magnetic Sensitive Nanocomposite Biopolymer Networks, Macromolecules 47, 3136-3144 (2014).

Biography

A. Ponton has completed his PhD from Bordeaux University (France) and postdoctoral studies from Trois Rivières University, Canada. He is appointed Research Director at Laboratory Matter and Complex Systems (Paris Diderot University) in which he is the team leader of the research group Dynamics and Organization of Soft Matter. He has published more than 65 papers in reputed journals and has attended more than 80 conferences. A part of his research activities on complex materials from soft matter is carried out in collaboration with partners from industry and within up international collaborations with Spain, Romania, Germany, Algeria, Tunisia.

Speaker
Alain Ponton Université Paris Diderot, France

Abstract

Olefin metathesis provides a versatile synthetic method to produce small, medium and large molecules. Over the past two decades, wide ranges of the molecules have been prepared by various types of olefin metathesis, such as cross metathesis (CM), ring-closing metathesis (RCM), ring-opening metathesis (ROM) reactions. For polymerization, simple polymerization using one of three mechanisms has been a dominant method to produce polymers with rather simple structures. This is because combining more than two different methods into one polymerization fails to give polymers with well-defined structures due to lack of selectivity or control. Here, we demonstrate our recent efforts for developing polymerization methodologies to promote cascade or tandem reactions. This allows us to prepare polymers with more complex structures but still with great selectivity and control. Also, we demonstrate how lessons from organic chemistry can work to improve polymerization.

Biography

Tae-Lim Choi obtained BS from KAIST, Korea in 1999, and Ph. D degree from Caltech under supervision of Bob Grubbs, in 2003. Then he moved to Berkeley as a post-doc under guidance of Jean Frèchet until 2004. Then, he came back to Korea and worked at Cheil Industries, one of Samsung research centers for four years. Since 2008, he is a professor at Department of Chemistry, Seoul National University. His group focuses on developing new methods to synthesize various macromolecules, understanding their catalytic mechanisms and their self-assembly behaviors. Since 2013, he is serving as an editor of Journal of Polymer Science, Part A: Polymer Chemistry.

Speaker
Prof. Tae-Lim Choi Seoul National University, Korea

Abstract

In this presentation, I will discuss several novel strategies to detect biomolecules by utilizing the chromatic and fluorogenic property of polydiacetylene (PDA). First, universal colorimetric methods for the detection of nucleic acids were developed based on ionic interaction and intercalation by the respective amine-modified and intercalator-modified PDA liposomes. Upon applying target nucleic acids, the PDA sensors showed a dramatic color change from blue to red due to the stimuli caused by the corresponding interactions. Second, a micro-patterned PDA chip was constructed to detect pathogen infections utilizing the unique fluorogenic property of PDA and a specific biotin-streptavidin (STA) interaction. The PDA microchip was successfully demonstrated to simultaneously diagnose Chlamydia infections for several real human samples on a single chip. Next, I will describe an aptamer-conjugated PDA imaging probe to detect cancer cells based on its highly specific fluorescence switching upon binding to the tumor biomarker protein EpCAM (epithelial cell adhesion molecule) expressed on their surface. Besides, I will also briefly introduce another interesting application of PDA liposomes, PDA photo-patterning. These strategies should be interesting and could be considered as an important contribution to the advanced application of PDA-based materials.

Biography

Dr. Hyun Gyu Park is a Professor at the department of Chemical and Biomolecular Engineering, KAIST, Korea. He received his Ph.D. in Chemical Engineering from KAIST in 1996. During the past 16 years since he joined KAIST in 2002, he has published about 160 international papers in the prestigious journals including Angewandte, Nucleic Acid Research, Advanced Functional Materials, Small, Nanoscale, ChemComm, and Analytical Chemistry, and holds about 60 international or domestic patents. His research interests include nucleic acid bioengineering, microarray technology, electrochemical technology for biosensing, and nanobiotechnology. Now, he is serving as an editorial board member of Biotechnology Journal.

Speaker
Prof. Hyun Gyu Park Korea Advanced Institute of Science & Technology, Korea

Sessions:

General session

Abstract

Infections by pathogenic microorganisms (bacteria, viruses and fungi) are of great concern in many fields, particularly in medical devices, water purification systems, textiles, food packaging and storage, etc. Many efforts have been made by both academic and industrial research in order to struggle infections and polymeric materials are of great interest in this sense thanks to their non-toxicity. There is a multitude of antimicrobial systems, but, among those, polymers exhibiting intrinsic antimicrobial activity are of particular interest. The advantage is the longer-term antimicrobial ability, respect for example to systems containing low molecular weight biocides, which could be released through the polymeric matrix [1]. In this sense, a very interesting polymer is poly(ricinoleic acid) (PRA) (Figure 1), coming from the self-polycondensation of ricinoleic acid (RA), the main constituent of castor oil, which derives from the beans of the castor plant, Ricinus Communis, of the Euphorbiaceae family. PRA is a viscous liquid, with a glass transition temperature of about -67 °C, i.e. significantly low, indicating a very flexible chain. It contains an hydroxyl and carboxyl group, as well as a 9 unsaturation and an aliphatic side chain [2, 3]. The biocidal efficiency of RA is attested by many articles, describing the behaviour of the extract from Ricinus Communis seeds against some human pathogens [2-4]. On the other hand mechanical properties are quite insufficient for whatever application, thus copolymerization is often required. In this work, some polyesters based on 1,3 propandiol (PD), such as poly(propylene terephthalate) (PPT) and poly(propylene isophthalate) (PPI), were chosen to that end. PPT is synthesized starting from terephthalic acid and PD, both derivable from renewable resources [5, 6]. It has become an engineering thermoplastic because many of its properties are between those of poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT). PPT can be used in applications including films, mechanical parts, and mainly fibers. Such fibers combine the advantageous properties of polyesters and polyamides. They are distinguished for their high elasticity, excellent recovery rate, strain resistance, high UV stability, low water absorption, and low electrostatic charging. In addition, PPT films show good barrier properties [7]. On the other hand, a limited number of works have been published about PPI [8, 9]. Unlike PPT, PPI is an amorphous polyester, useful in soft packaging. In order to achieve safe materials, non-cytotoxic, with potent and broad range of antimicrobial activity, long-last response and even reusable, in this work a series of random copolymers based on PRA, PPT and PPI were synthesized starting from monomers (Figure 2-3). Different content of ricinoleic acid have been tested, such as 10 and 25 mol% respect to the comonomer (terephthalic or isophthalic acid), in order to evaluate the lower composition able to confer antibacterial activity. The materials prepared were tested against Staphilococcus aureus and Escherichia coli. Furthermore, thermal properties were investigated. DSC and TGA data of copolymers showed that the thermal properties tended to those of PPT or PPI as a function of composition. All the chemical structures were confirmed by 1H NMR. These materials could be suitable for textile fibers and/or film engineering thermoplastic applications. Figure 1. Poly(ricinoleic acid), PRA. Figure 2. Poly(propylene terephthalate-co-ricinoleic acid), P(PT-co-RA). Figure 3. Poly(propylene isophthalate-co-ricinoleic acid), P(PI-co-RA). References 1) A. Munoz-Bonilla, M. Fernández-García, Prog Polym Sci 37 (2012) 281– 339; 2) G. Totaro, L. Cruciani, M. Vannini, A. Celli, G. Mazzola, D. Di Gioia, L. Sisti, Synthesis of castor oil-derived polyesters with antimicrobial activity, Europ Polym J 56 (2014) 174-184; 3) G. Totaro, L. Paltrinieri, G. Mazzola, M. Vannini, L. Sisti, C. Gualandi, A Ballestrazzi, S. Valeri, A. Pollicino, A. Celli, D. Di Gioia, M. L. Focarete, Macromol Mater Eng 300 (2015) 1085–1095; 4) K. Poonam, S. K. Pratap, Int Res J Pharmacy 3 (2012) 209-210; 5) Y. Tachibana, S. Kimura, Ken-ichi Kasuya, Sci Rep 5 (2015) 8249 (1-4); 6) M. Colonna, C. Berti, M. Fiorini, E. Binassi, M. Mazzacurati, M. Vannini, S Karanam, Green Chem, 13 (2011) 2543-2548; 7) C. P. Roupakias, D. N. Bikiaris, G. P. Karayannidis, Journal of Polymer Science: Part A: Polymer Chemistry 43 (2005) 3998–4011; 8) C. Perez, J. Guzman, E. Riande, J. G. De la Campa, J. De Abajo, Makromol Chem, 189 (1988) 691–699; 9) C. P. Roupakias, G. Z. Papageorgiou, G. P. Karajannidis, J Macromol Sci Part A: Pure Appl Chem, 40 (2003) 791.

Biography

Grazia Totaro, born in 1976, has a degree in Chemistry (University of Ferrara), a Master’s Degree in Science, Technology & Management with a specialization in Environmental Chemistry (University of Ferrara) and a PhD in Materials Engineering (University of Bologna). She worked at the R&D Centre of Basell Polyolefins in Ferrara for 2 years in the frame of a project addressed to the development of a novel methodology for qualitative and quantitative analysis of additives in polymers. She also worked at ARPA, Regional Agency for Environment in Ferrara, division Water Analysis. Then she started working at the school of Engineering of the University of Bologna for a Ph.D. in Materials Engineering (2007-2010). After that, she had a scholarship "Spinner 2013" in cooperation with Reagens spa (San Giorgio di Piano, Bologna) on novel poly(vinyl chloride) nanocomposites. Now she is post-doc fellow at the same school and her research work is related to new polymer-based nanocomposites from renewable sources and inorganic fillers. She also worked at the laboratoire de Chimie et Biochimie Pharmacologique et Toxicologique (Université Réné Descartes) in Paris in 2001 and she was visiting professor at the Ecole Nationale Superieure de Chimie (Université Blaise Pascal, Clermont Ferrand, FR) in 2012 and 2015. Dr. Totaro has about 25 scientific papers and several participations at conferences and scientific schools. She is guest editor for Environmental Engineering and Management Journal and Procedia-Environmental Engineering and Management Journal. She is supervisor of students and referee of several journals. Moreover, she collaborates for Ecomondo from 2013.

Speaker
Grazia Totaro University of Bologna, Italy

Abstract

Nowadays research is paying growing attention to the development of biodegradable polymeric systems to use in several industrial application areas. In particular, according to forecasts, the production of bioplastics is expected to grow exponentially in the near future. The interest in biodegradable materials is driven by the need of a more sustainable economy and a lower dependency on fossil fuels. However, the employment and industrial development of biodegradable polymers is often limited because of their poor chemico-physical properties, unsuitable mechanical performances and difficult processability. Therefore, academic and industrial interests are devoted to realize fully biobased polymer formulations tailored to specific applications, in which the polymeric matrices are associated with natural additives coming from renewable sources and/or wastes of agro-food-paper industry. The use of suitable additives could provide both upgrading of processing and manufacturing performance and the enhancement of biodegradable polymer performances. In this contribution, an overview of fully biobased systems investigated by our group of research with the main scientific goals and applicative outputs in food packaging, agricultural, biomedical areas will be presented. A detailed screening of both polymers and additives investigated will be provided, by highlighting scientific and technological aspects in their applications as hydro-thermoplastic materials. Specifically, as concerning polymeric matrices, the attention will be focused on biodegradable polymers, such as polysaccharides and biopolyesters coming from both renewable sources, such as poly-lactic acid, and from petrochemical products, such as poly-butylene succinate. As far as natural additives are concerned, a screening according to their specific function in modifying polymer properties will be performed. Finally, an emphasis on the current commercially available biobased polymers and additives, and their role in market uptake of environmentally friendly products, will be encompassed too.

Biography

Gabriella Santagata is full-time permanent researcher of the Institute of Polymers, Composites and Biomaterials (IPCB) of the National Council of Research (CNR), Italy, where she works since her graduation in Chemistry. The main research interests concern biobased polymeric systems to be used as eco-sustainable plastics for active food packaging, agricultural activity and biomaterials for biomedical applications. The results of the scientific activity have been reported in about 35 papers in ISI journals, 1 national patent, 6 book chapters with ISSN, dissemination by partecipation at about 40 national and international conferences with relative publications in Proceedings. Scientific leader of IPCB-CNR Research Unity of national projects.

Speaker
Gabriella Santagata National Council of Research Pozzuoli, Italy

Abstract

Pullulan is a natural polysaccharide polymer shown to possess antimicrobial, antioxidant and film forming property. In this study, an attempt has been made to find out whether the anit-oxidant efficacy of pullulan, helps to accelerate wound healing in normal and diabetic rats. A 2cm2 excision wound was made on the dorsum of male Wistar rats weighing between 150 to 200g. The animals were divided into four groups each comprising of 6 animals. Group I and Group III (normal control, Diabetic control respectively) rats were not treated with anything. Group II and Group IV (normal treated and diabetic treated respectively) rats were administered with 500 µl of 10% pullulan hydrogel topically once daily. Wound tissues were removed after 4th and 8th days and the levels of enzymatic and non-enzymatic antioxidants present in the tissues were estimated.Even though there was no significant increase in the levels of enzymes such as catalase and Superoxide dismutase in the normal treated rats for four days (12% and 17%) respectively, a notable increase was observed in Glutathione peroxidase and Glutathione-S-transferase (45% and 101%) respectively when compared to the control. A significant increase in all the enzymes except Glutathione-S-transferase was noticed in diabetic rats when compared to their respective diabetic controls. Similarly, a substantial increase in the levels of nonenzymatic antioxidants like ascorbic acid and vitamin E was observed except reduced glutathione.The inflammatory phase which is normally prolonged in diabetic conditions was controlled by pullulan by its anti-oxidant activity and helped the wounds to heal faster.

Biography

Lonchin Suguna has completed her Ph.D at 27 from the University of Madras. She did her postdoctoral studies at ETH-Zentrum, Switzerland. She is working as a Scientist in the Department of Biochemistry, Central Leather Research Institute, India. She has published 60 papers in reputed journals and serving as a reviewer, Editorial board member for many journals. She was awarded Mr.V.V.Swaminathan Diamond Jubilee Research Endowment award for the outstanding contribution in the scientific evaluation of medicinal properties of plants, by Indian Association of Biomedical Scientists, 2012 (Gold Medal). She received Fellow of International Medical Sciences Academy (FIMSA) in the year 2014.

Speaker
LONCHIN SUGUNA CENTRAL LEATHER RESEARCH INSTITUTE Session, India

Abstract

Inert biological polymers can have unexpected activities when cut into smaller units of oligomers. For example, polypeptides fragmented into short (10-50 amino acids) peptides can possess strong antimicrobial activities. We have identified a new role for oligomers of polyhydroxybutyrate (PHB) from the endosymbiont Methylobacterium extorquens. Our studies have concentrated on the interaction between M. extorquens and Scots pine, where the bacterium produces antioxidants having a capacity to improve viability of the pine tissue. These antioxidants were identified as oligomers of PHB. We found that during colonization of pine surface by M. extorquens, the bacterium consumes the plant-produced methanol as a carbon source to biosynthesize PHB. Upon tissue infection, the bacterium degrades the endogenous PHB storages to yield oligomers. These oligomers protect the endosymbiont from host-induced oxidative stress, enabling it to avoid the host defenses and to colonize further tissues. This discovery yielded a completely new mechanism of antioxidative defenses in bacteria. The PHB-based cellular protection from oxidative stress is widespread among bacteria, providing an explanation on the persistence of PHB-carrying bacteria in extreme conditions. Whereas PHB is mainly found in microorganisms, its monomeric unit 3-hydroxybutyrate exists in all living organisms, being actively studied for various applications in human health. Therefore, we have tested if the structurally similar oligomers have a cytoprotective effect on human cells. In vitro-based stress assays on human retinal pigment epithelium cells (ARPE-19) have shown that the oligomers significantly reduce effects of oxidative stress, increasing the integrity of retinal cells. Our results suggest that the PHB oligomers represent a potential novel therapeutic agent for oxidative stress-induced ocular diseases.

Biography

Speaker
Anna Maria Pirttilä University of Oulu, Finland

Abstract

Lithium-based batteries are a key technology for successfully transitioning from depleting fossil fuels to renewable energy sources, particularly in meeting the demands of a highly mobile society. Nevertheless, the commonly employed liquid organic electrolytes are highly flammable and release toxic degradation products[1]. Solid electrolytes are a promising alternative, since they offer an improved safety and potentially suppress dendritic lithium deposition[2]. Among them, due to their flexibility and modularity, solid polymer electrolytes (SPEs) are excellent candidates. For their commercial implementation, however, one must simultaneously ensure acceptable ionic conductivity (>10-4 S cm-1 at 25 °C), high mechanical strength, and an electrochemical stability window of at least 45 V. Conventional polymer electrolytes based on poly(ethylene oxide) (PEO) consist of a lithium salt dissolved in the polymer. Frequently, also a plasticizer is added to enhance the segmental relaxation-dependent charge transport by lowering the glass transition temperature (Tg)[3]. The need for a conducting salt, however, results in transference numbers (t+) far below 0.5. This leads to charge concentration gradient and reversed cell polarization issues, which worsen the long-term cycling stability[4]. SPEs with t+ = 1, also known as ‘single-ion polymer electrolytes’ (SIPEs), might overcome these issues. The simplest approach to achieve single-ion conductivity is to covalently tether the anion to the polymer backbone (so-called ‘ionomers’), thus ensuring that the only mobile species is the cation. Nevertheless, the conductivity of these systems is typically very low (10−8 to 10−7 S cm−1 at 25 °C)[5] and despite the ten-fold increase achieved through optimizing the ionomer structure by introducing weakly coordinating anionic species (∼10−6 S cm−1 at 25 °C)[6] or designing block or grafted copolymers[7], their employment remains unfeasibl. Moreover, for most block copolymer-based SIPEs, the anion is tethered to the rigid block, while the Li+ conduction occurs in the microphase-separated PEO block[8]. Consequently, adequate conductivities are achievable only in the disordered state above the melting point of the PEO phase, so that the phase separation and, accordingly, the mechanical properties provided by the rigid block vanish. In this presentation we give SIPE that we recently synthetized[9] with very efficient charge transport pathways, high electrochemical stability and an ionic conductivity approaching that of liquid organic electrolytes. Moreover, these SIPEs allowed for lithium stripping/plating for more than 1000 h with a remarkably low overpotential. These are very remarkable and original results, since the materials’ properties are nicely tailorable with regard to the ionomer structure, charge carrier density, phase separation, and morphological appearance. References 1. Hammami, A., Raymond, N. & Armand, M. Nature 424, 635–636 (2003). 2. Aricò, A. S., Bruce, P., Scrosati, B., Tarascon, J.-M. & Van Schalkwijk, W. Nat. Mater. 4, 366–377 (2005). 3. Osada, I., De Vries, H., Scrosati, B. & Passerini, S. Angew. Chemie - Int. Ed. 55, 500–513 (2016). 4. Tikekar, M. D., Choudhury, S., Tu, Z. & Archer, L. A. Nat. Energy 1, 16114 (2016). 5. Shaplov, A. S., Marcilla, R. & Mecerreyes, D. Electrochim. Acta 175, 18–34 (2015). 6. Xu, K. Chem. Rev. 114, 11503–11618 (2014). 7. Bouchet, R. et al. Nat. Mater. 12, 452–457 (2013). 8. Zhang, H. et al. Chem. Soc. Rev. 46, 797–815 (2017). 9. Iojoiu I. et al Patent under submission

Biography

Speaker
Iojoiu Cristina LEPMI CNRS, France

Abstract

Pectin is a natural biopolymer extracted mostly from citrus peel, sugar beet and apple pomace. In order to improve its functional properties and then to enlarge the field of its potential applications, pectin was functionalized according to two approaches. The first one consisted in an oxidative reaction between pectin and Ferulic Acid (FA) catalysed by laccase leading to pectin-F. The second one was based on the physical adsorption of FA-oxidation products (POX) on pectin leading to pectin-POX. The POX were previously obtained through oxidative reaction of FA catalysed by laccase. A comparative study was performed aiming to determine the impact of each functionalization pathway on the properties of pectin. As a result of this study, a significant improvement of the antioxidant properties of pectin after functionalization was observed. In the colorometric test, the ∆E showed clear color difference between pectin-F (26.25 +/- 0.62) and pectin-POX (15,01 +/- 1,38) in comparison to native pectin, due to the grafting of oxidized phenols. This trend was even more pronounced in the case of pectin-F. In addition, the functionalized pectin powders were less hygroscopic and viscous than the native pectin and presented different gelation properties in the presence of calcium ions. Finally the thermal properties and the structural characteristics of the different pectin samples were shown to be also affected by the functionalization performed. As a conclusion, both approaches led to derivatives with improved properties that could widen the field of applications of pectin. Image Recent Publications 1- Aljawish, A., Muniglia, L., Klouj, A., Jasniewski, J., Scher, J., Desobry, S., 2016. Characterization of films based on enzymatically modified chitosan derivatives with phenol compounds. Food Hydrocol 60, 551–558 2- Hajj Ali, H., Michaux, F., Bouelet Ntsama, I.S., Durand, P., Jasniewski, J., Linder, M., 2016. Shea butter solid nanoparticles for curcumin encapsulation: Influence of nanoparticles size on drug loading. Eur. J. Lipid Sci. Technol. 118, 1168–1178 3- Karaki, N., Aljawish, A., Humeau, C., Muniglia, L., Jasniewski, J., 2016a. Enzymatic modification of polysaccharides: Mechanisms, properties, and potential applications: A review. Enzyme Microb. Technol. 90, 1–18. 4- Karaki, N., Aljawish, A., Muniglia, L., Humeau, C., Jasniewski, J., 2016b. Physicochemical characterization of pectin grafted with exogenous phenols. Food Hydrocol 60, 486–493. 5- Pirestani, S., Nasirpour, A., Keramat, J., Desobry, S., Jasniewski, J., 2017. Effect of glycosylation with gum Arabic by Maillard reaction in a liquid system on the emulsifying properties of canola protein isolate. Carbohydrate Polymers 157, 1620–1627.

Biography

Work on the fundamental study of the mechanism of complexation and coacervation between biopolymers of a protein and / or polysaccharide nature. The main objective of this work is to better understand the energetic mechanisms that are at the origin of the various formed entities such as macromolecular complexes, complex aggregates and coacervats. These different types of architectures are studied from the molecular scale to the mesoscopic scale. This work focuses on the relative contribution of entropy and enthalpy during the different structural transitions as well as on the low-energy interactions that dominate at each stage of the structuring mechanism. Finally, the functionalization of the biopolymers by enzymatic means is carried out to modify their structure and thus to determine the relationship between the structure of a biopolymer and its ability to self-assembly by simple or complex coacervation. All these approaches are used for structuring vectors and matrices.

Speaker
Jordane Jasniewski Université de Lorraine_LIBio, France

Abstract

When we think of polymers, we probably think of plastics and polyester, and all sorts of modern stuff? If we think again…we will find that years ago, before there were plastics and synthetic polymers, in fact, all the way back to the beginning of the earth, nature was using natural polymers to make life possible. We don't think of natural polymers in the same way as synthetic polymers because we can't take credit for them as marvels of our own ingenuity, and chemical companies can't sell them for profit. However, that doesn't make natural polymers less important; it turns out in fact, that they are more important in many ways. Natural polymers include the RNA and DNA which are so important in genes and life processes. In fact, messenger RNA is what makes possible proteins, peptides, and enzymes. Enzymes help do the chemistry inside living organisms and peptides make up some of the more interesting structural components of skin, hair, and even the horns of rhinos. Other natural polymers include polysaccharides and polypeptides like silk, keratin, and hair. Natural rubber is, naturally a natural polymer too, made from just carbon and hydrogen. Naturally occurring polymers show no adverse effects on the environment or human being. In contrary, synthetic polymers, being prepared by the help of chemicals have side effect on environment as well as on the human health.

Biography

Prof. Hala Aleasa has completed his PhD from Reading University, UK and postdoctoral studies from Ludwig Maximillian University, Germany. She served as the head of chemistry and Earth Sciences Department and as the Associated Dean for Research and Graduate Studies at the cillege of Arts and Sciences at Qatar University. She has published more than 30 papers in reputed journals mainly on Natural Products and co-authored two books on the chemistry of Natural Products.

Speaker
Hala Sultan Saif Al-Easa Chemistry and Earth Sciences Department, College of Arts and Sciences, Qatar University

Abstract

One-dimensional polyaniline nanomaterials (1-D PANI-nano) have great promise applications in supercapacitors, sensors and actuators, electrochromic devices, anticorrosive coatings and other nanometer devices. Consequently, production of 1-D PANI-nano at commercial-scale needs to be developed to meet the requirement of the widespread usage of this material. Here, some important issues dealing with commercial production of 1-D PANI-nano were discussed based on the approaches including hard template methods, soft template methods, interfacial polymerization, rapid mixing polymerization, dilute polymerization, and electrochemical polymerization. Their advantages and disadvantages, particularly in the aspects of waste treatment and yields are mainly focused. In addition, potential solutions to these important issues are also proposed.

Biography

Speaker
Jixiao Wang Tianjin University, China

Abstract

A fundamental issue in biomedical sciences is the development of sensitive and robust sensors that are able to continuously monitor biological events in situ. For instance, pH is an important control parameter for the maintenance of cellular viability and for improving tissue functions. Many evidences show that an acidic microenvironment regulates cellular phenotype and, notably, acidic extracellular pH (pHe) is a major feature of tumor tissues.[1] The design of novel methods to probe changes in ions concentrations is greatly desired for fully understanding both physiological and pathological processes. Herein, the synthesis, characterization and applications of fluorescent ratiometric sensors based on multilayer polymer capsules will be described. Examples will be given in which (i) ion-sensitive probes are encapsulated within capsules for assembly of ratiometric fluorescent capsule-based sensors,[2] (ii) colloidal quantum dots are used to tag the walls of the capsules with unique optical bar codes for multiplex read-out of analytes,[3] (iii) capsule- based pH sensors are applied in vitro to detect intracellular pH changes in complex cell lines,[4] and (iv) capsule-in-fiber mats are produced for sensing pH changes in the local environment.[5] Finally, the synthesis and properties of recently developed multilayered magnetic nanobeads as delivery systems with multimodal imaging and therapy features, will be presented.[6] The results show the concrete applications of multifunctional stimuli-responsive systems for sensing, imaging and therapy, and highlight their potential in medicine.[7] [1] Y. Kato, S. Ozawa, C. Miyamoto, Y. Maehata, A. Suzuki, T. Maeda, Y. Baba, Cancer Cell Int 2013, 13, 89. [2] L. L. del Mercato, A. Z. Abbasi, W. J. Parak, Small 2011, 7, 351. [3] L. L. del Mercato, A. Z. Abbasi, M. Ochs, W. J. Parak, ACS Nano 2011, 5, 9668. [4] M. De Luca, M. Ferraro, R. Hartmann, P. Rivera-Gil, A. Klingl, M. Nazarenus, A. Ramirez, W. J. Parak, C. Bucci, R. Rinaldi, L. L. del Mercato, ACS Appl Mater Interfaces 2015, 15, 15052. [5] L. L. del Mercato, M. Moffa, R. Rinaldi, D. Pisignano, Small 2015, 11, 6417. [6] A. Quarta, M. Rodio, M. Cassani, G. Gigli, T. Pellegrino, L. L. del Mercato, ACS Appl Mater Interfaces 2017, 11, 35095. [7] M. Turetta, F. Del Ben, G. Brisotto, E. Biscontin, M. Bulfoni, D. Cesselli, A. Colombatti, G. Scoles, G. Gigli, L.L. del Mercato, Curr Med Chem. 2018, doi: 10.2174/0929867325666180605122633.

Biography

Speaker
Loretta L. del Mercato Nanotechnology Institute of CNR, Italy

Abstract

Poly (3-hydroxybutyrate) or (P3HB) is a thermoplastic polyester of the family of the polyhydroxyalkanoates (PHAs) produced by different kinds of microorganisms under stress conditions. It has very interesting mechanical and physicochemical characteristics that allow it to be used for packaging applications. However, it’s necessary to improve some of its weakest characteristics like the high brittleness, the production cost and the narrow processing window. This improvements can be achieved using different extraction, purification and modification technics that result in materials with different physicochemical characteristics and production costs. In this work different extraction, purification and modification processes were evaluated in order to obtain a polymer with the properties required to make it competitive in the industry. Fatty acids were used as carbon source and the fermentations were made in 5L, 20L and 100L bioreactors. Initially, the polymer must be extracted and separated from the surrounding PHA hyper-productive mutant bacteria Burkholderia cepacia B27 biomass, using techniques like chemical digestion with SDS and NaOH, centrifugation and solvent precipitation. Then the polymer was purified to remove protein and oil residues from the fermentation, for this the performance of different solvents such as acetic acid, acetone, ethanol and methanol was tested under different operation conditions. Finally, the polymer was modified blending it with other biodegradable polymers like polyethilenglycol and adding different organic fillers to evaluate improvements in the mechanical characteristics. The samples where characterized by TGA and DSC essays and different mechanical tests. The results indicate that the use of organic polar solvents such as methanol and ethanol allow to obtain a colorless, odorless and high purity polymer. Also, use this or other solvents as acetic acid and acetone avoid the use of chloroform in the process, which is an expensive and hazardous solvent that can’t be used at the industrial production level.

Biography

Andrés Felipe Ramos is a chemical engineer from Los Andes University in Bogotá, Colombia and is finishing his MSc in Chemical Engineering in the National University of Colombia. Is member of the Bioprocess and Bioprospecting research group of the national university since January of 2017, the research group has several publications about P3HB production process published in international scientific journals.

Speaker
Andrés Felipe Ramos Universidad Nacional de, Colombia

Abstract

Polyaniline is one of the most extensively studied conducting polymers because of its simple and low cost synthesis, unique redox properties, high conductivity, excellent environmental stability and ability to form various nanostructures. Our research group introduced for the first time an enhanced microwave eco-friendly synthesis method as a fast and convenient way of producing high quality polyaniline nanomaterials at ambient temperature for environmental monitoring, water reuse, energy storage, food and biomedical applications. By externally cooling the reaction vessel and simultaneously applying irradiating microwaves, a steady amount of energy can be transmitted to the reaction mixture, while preserving a constant temperature. The high yield obtained, short reaction time, and a low energy consumption suggest that enhanced microwave synthesis of advanced polyaniline nanomaterials could be a favourable alternative for their large-scale industrial production compared to conventional chemical synthesis method. The influence of reaction conditions on morphology and physical properties of enhanced microwave synthesised polyaniline nanomaterials are studied and discussed.

Biography

Marija Gizdavic-Nikolaidis got her Ph.D. in Polymer Chemistry at the University of Auckland, New Zealand in 2005. She is a Senior Research Fellow at the University of Auckland and Assistant Professor at the University of Belgrade, Serbia on government awarded research projects. She has 20+ years research experience in the field of polymer chemistry, working with both academic and industrial groups worldwide. Marija is also an inventor of succesfully commercialised bioactive polymer technology and a Member of Advisory board for Polymer Science, Cambridge Scholars Publishing, United Kingdom.

Speaker
Marija Gizdavic-Nikolaidis The University of Auckland, New Zealand

Abstract

Rapidly increase in the consumer goods consumption led to the rise of a new group of problems related with the production of environmentally friendly engineering materials and management of post-consumer wastes. In order to limit negative impact of polymer materials on the environment, natural fibers are often used in production of polymer-based composites. Jute, flax, hemp and mineral fibers dominate in combination with polymer matrices. Fibre type, fabric geometry, physical and mechanical properties of fabrics and volume fraction of fibres have significant effects on the properties of the composite materials. Therefore, the aim of this study was to verify the influence of basalt fiber and flax fiber addition on thermomechanical properties epoxy composites. Moreover, epoxy matrix was hybridized with inorganic powder filler. Basalt fiber is produced in an energy-saving process involving melting volcanic rock without additives and have better mechanical strength, thermal stability and chemical resistance than glass fibre. On the oter hand, flax fiber is characterizd with low-cost, ability to biodegradation and good mechanical properties. The epoxy composites were fabricated in a mold using hand lay-up, cured at ambient temperature for 24 h and post-cured at 80ºC for 3 h. The reinforcement layers from two types of fiber were arranged into polymer matrix in various configurations. Mechanical and thermomechanical properties were determined by means of static tensile test, Charpy impact strength method, dynamic mechanical thermal analysis and thermogravimetric analysis.

Biography

Danuta Matykiewicz graduated from University of Sciences and Technology in Bydgoszcz, Faculty of Chemical Technology and Engineering with specialization: Chemical Technology/Industrial Biotechnology in 2010, and obtained Ph.D. Eng. in 2015 in the field of Material Engineering in Poznan University of Technology, Faculty of Mechanical Engineering and Management. Since 2013 she works as a researcher in the Polymer Processing Division, Institute of Materials Technology at the Poznan University of Technology. She is the author and co-author of over 30 peer-reviewed articles. Her research interests are polymeric composites with fibrous and powder filler, hybrid composites and thermal analysis.

Speaker
Danuta Matykiewicz Poznan University of Technology, Poland

Abstract

Voltammetric degradation of phenol was carried out at microbial electrode. This electrode is based on graphite carbon and natural phosphate modified by bacteria inserted in the phosphate matrix, the whole is covered by a polymer developed in situ on the surface. This electrode, designated subsequently by bacteria-NP-CPE, Showed stable response and was characterized with voltametric methods, as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The experimental results revealed that the prepared electrode could be a feasible for degradation of hazardous phenol pollutants. The prepared electrode is based on natural phosphate and graphite carbon powders coated with a polymer that has made it possible to protect the surface of the electrode against dissolution. The presence of the polymer at the surface has resulted in the loss of electrode conductivity. Subsequently we modified this electrode by microorganisms deposited on the surface by self assembly; the pre-concentration time is 15 minutes. The presence of bacteria on the surface of the electrode to improve the activity of the electrode with respect to the oxidation of phenol. Figure: Cyclic voltammograms at different concentrations of phenol (from 2 mM to 12 mM) in 0.1 M NaCl (pH = 7) on CPE-NP-polymer-bacteria, V = 100 mV.S-1

Biography

Speaker
CHTAINI Sultan Moulay Slimane University, Morocco

Abstract

In this work high-molecular-weight AA-BB-type aliphatic polyesters (PEs) were synthesized via Cu(I)-catalyzed click step-growth polymerization (SGP) following a new synthetic strategy. The synthesis was performed between diyne and diazide monomers in an organic solvent as one pot process using three components and two stages. The di-propargyl esters of dicarboxylic acids (component 1) were used as diyne monomers, di-(bromoacetic acid)-alkylene diesters (component 2) were used as precursors of diazide monomers, and sodium azide (component 3) was used for generating diazide monomers. The SGP was carried out in two steps: at the Step-1 di-bromoacetates interacted with two moles of sodium azide resulting in diazide monomers which interacted in situ with diyne monomers at the Step-2 in the presence of Cu(I) catalyst (Scheme 1). A systematic study was done for optimizing the multiparameter click SGP in terms of the solvent, duration of the both Step-1 and Step-2, solution concentration, catalyst concentration, catalyst and ligand nature, catalyst/ligand mole ratio, temperature of the both steps of the click SGP. As a result, high-molecular-weight (MW up to 74 kDa) elastic film-forming click PEs were obtained. These polymers contain 1,4-disubtituted 1,2,3-triazoles in the backbones. The presence of the main-chain triazoles significantly improved the thermal properties of the PEs. Elastic films and nanoparticles made of the new PEs are suitable as biodegradable biomaterials for biomedical applications. Our work should encourage the synthesis of novel heterochain polymers of various types and classes with 1,4-disubtituted 1,2,3-triazoles by applying the new synthetic strategy to both Cu(I)-catalyzed and copper-free click step-growth polymerizations.

Biography

Tengiz Kantaria has his expertise in the preparation and characterization of nanoparticles on the basis of amino acid based biodegradable poly(ester amide)s (MS thesis, 2015). Currently as a PhD student he is engaged in the synthesis and characterization of new biodegradable polymers (polyesters, polyamides, and poly(ester amide)s) via Cu(I) catalyzed alkyne–azide 1,3-cycloaddition click reaction.

Speaker
Tengiz Kantaria Agricultural University of Georgia, Georgia

Abstract

The elaboration of nano- and microscale drug delivery systems is very actual nowadays since the selective (targeted) drug delivery is one of the important problems of modern pharmacotherapy. Polymeric nanoparticles (NPs) are of high interest for numerous applications in medicine. The important technological advantages of NPs usage as drug carriers are their high stability, high carrier capacity, feasibility of encapsulation of both hydrophilic or hydrophobic substances, as well as a high variety of possible administration routes. One of the most promising for the design of NPs are amino acid-based biodegradable polymers - poly(ester amide)s (PEAs) which will be cleared from the body after the fulfilment of their function. The used PEAs are composed of naturally occurring and non-toxic building blocks such as α-amino acids, fatty diols and dicarboxylic acids. In our previous research we have performed a sistematic study for the preparation of biodegradable NPs by nanoprecipitation method using PEAs. The present work deals with the fabrication of the surface modified biodegradable NPs that includes the PEGylation (coating with polyethylene glycol, PEG) and imparting positive charge to the particulates. The PEGylation of NPs is important for improving their biocompatibility whereas positive surface charge is necessary for enhancing permeability through the biological barriers. The PEA composed of L-leucine, 1,6-hexanediol and sebacic acid (8L6) was used as a basic polymer for fabricating the NPs. An originally designed comb-like PEA, containing lateral PEG-2000 chains along with 8L6 anchoring fragments, was used as a PEGylating surfactant.

Biography

Temur Kantaria has his expertise in the preparation and characterization of nanoparticles on the basis of amino acid based biodegradable poly(ester urea)s (MS thesis, 2015). Currently as a PhD student he is engaged in the preparation, modification and characterization of new biodegradable nano- and microparticles on the bases of amino-acid-based ester polymers (poly(ester amide)s and poly(ester urea)s).

Speaker
Temur Kantaria Agricultural University of Georgia, Georgia

Abstract

The present study describes the development of nano-TiO2 based composite of starch-co-poly(acrylamide) copolymer. The graft copolymer was characterized by Fourier transform infrared (FT-IR), thermal gravimetric analysis (TGA), scanning electron microscopy (FE-SEM), and X-Ray Diffraction (XRD) confirmed that acrylamide (AM) was grafted onto starch successfully. The effects of pH, initiator dosage, temperature, and time on grafting percentage (GP) and grafting efficiency (GE) were also investigated. The synthesized TiO2 nanoparticles were successful to enhance the thermal and biological properties of a native copolymer which was confirmed by TGA and biological assay. This synthesized nanocomposite starch-co-poly(acrylamide) was used as a superabsorbent polymer (SAP) with great thermal property and antibacterial activity which regulates the growth of the mung bean plant. Graphical Abstract: Keywords: Starch-co-poly(acrylamide) copolymer; TiO2 nanoparticles; Antibacterial activity; Superabsorbent polymer; Plant growth regulator. Acknowledgements: One of the authors, Mr. Nandkishor Shirsath acknowledges Shri. GH Raisoni Doctoral Fellowship for financial support

Biography

Speaker
Nandkishor B. Shirsath North Maharashtra University, India

Abstract

Carbon dioxide is an inexhaustible inexpensive chemical raw material, and it has been recently noted to fix carbon dioxide into a chemical material on a large scale. Since Inoue et al.[ 1] synthesized aliphatic polycarbonates with high molecular weight by using the copolymerization of carbon dioxide and an epoxy compound in 1969, the study on the copolymerization of carbon dioxide and epoxy compounds has been continuously deepened and develop[2-3]. More recently, Poly(propylene carbonate) (PPC), the copolymerization product of carbon dioxide and propylene oxide, was chlorinated in our laboratory.[4-5] Nuclear magnetic resonance (NMR) spectroscopy and ion chromatography test showed that chlorine atoms were successfully introduced onto the PPC polymer chains. We named this newborn polymer material as chlorinated poly(propylene carbonate) (CPPC). What’s more important was that CPPC possessed many more distinguished properties in solubility, wettability, adhesive, and gas barrier comparing with PPC. For examples, the bonding strength of CPPC as thermal adhesive is nearly four times higher than that of PPC for wood, stainless steel and glass. The oxygen permeability coefficient of CPPC exhibits a decrease of 33% comparing with PPC. Moreover, CPPC is quite stable in air, whereas it could be well biodegraded in soil comparing with PPC. Finally, CPPC was successfully compounded with maize straw. The composite is fully biodegradable, without formaldehyde and with high performance. References [1] Inoue, S., Koinuma, H. and Tsuruta, T., J. Polym. Sci., Part B: Polym. Lett., 1969, 7: 287. [2] Coates, G. W. and Moore, D. R., Angew. Chem. Int. Ed., 2004, 43: 6618. [3] Lu, X. B. and Wang, Y., Angew. Chem. Int. Ed., 2004, 43: 3574. [4] Jiang, W., Zhao, G. Y., Dong, L. S., Jin, J. and Cui, J., Patents: US9546245, EU2933283, JP5909009, CN201410155108.8. [5] Cui, X.H., Jin, J., Cui, J., Zhao, G.Y., Jiang, W., Chinese Journal of Polymer Science 2017, 35: 1086.

Biography

Speaker
Wei Jiang Chinese Academy of Sciences, China

Abstract

Electron beam (EB) irradiation, which is one of the most effective sustainable technologies to chemically modify polymer materials, has been used to modify the morphological, thermal and degradation properties of polylactide (PLA) [1-3]. According to many reports, the predominant effect induced by irradiation at room temperature in PLA is supposed to be chain scission and the radiation processing in absence of crosslinking agents does not crosslink PLA [4-7]. In this work, electron induced chemical reactions of neat PLA have been studied at temperatures above its glass transition temperature. The results confirmed the degradation of neat PLA at room temperature by chain scission reaction. In contrast, cross-linking of neat PLA was observed at elevated temperature above its glass transition temperature due to enhanced polymer chain segment mobility. The maximum gel content of 33 wt% was observed at 80 °C after an EB treatment with 200 kGy. In addition, the rheological tests demonstrated that crosslinked PLA showed a higher elastic behavior. The radiation induced degradation of PLA at room temperature can be diminished by using irradiation temperature above its glass transition temperature due to enhanced polymer chain segment mobility.

Biography

Ms. Ying Huang received her Bachelor's Degree in 2014 and Master's Degree in 2017 from Beijing University of Chemical Technology, China. Since 2017, she joined Dr. Uwe Gohs’ group as a Ph.D candidate at Leibniz Institute for Polymer Research Dresden, Germany. Her research interest focuses on the preparing of toughened melt spinnable PLA by electron induced reactive processing and its medical applications.

Speaker
Ying Huang Leibniz-Institute for Polymerforschung, Germany

Abstract

Collagen, the dominant component in the extracellular matrix (ECM), thus of highest importance for connective tissue and all organs integrity and functionality, has found a wide range of applications as a preferred material in biomedical areas due to known advantages, such as: availability, biocompatibility, biodegradability, low immunogenicity and a high chemistry, allowing development of materials with tuneable functional performance. Considering the last aspect, the disadvantages related to the low mechanical strength and denaturation possibilities (limiting the range of preparation and sterilization approaches) are issues to be solved by experts in chemistry/chemistry engineering. As result of the last years efforts collagen-based materials are nowadays widely used in medical (i.e. opthalmology, general surgery, dermatology, dentistry, orthopedics, urology), pharmaceutical (drug/gene delivery) and cosmetics (skin and hair care products) domains in form of films, sheets, discs, sponge, particles, injectable or even 3D printable hydrogels. Here are presented data on preparation, characterization and applicability evaluation (preliminary data) of some collagen-based materials in form of dense membranes, sponges, nanoparticles. The combination with other polymers (hyaluronan and poly(ε-caprolactone) derivatives) or inorganic materials (nano-hydroxyapatite) and application of different preparative protocols permitted the development of new biomaterials with controlled properties. Taking into account the relations between structure - preparative parameters - properties and making use of computer aided material selection the most suitable aternative can be obtained for envisaged purposes. The developed biomaterials were evaluated for possible use as a scaffold or gene-activated matrix, as drug/gene delivery systems or dressings.

Biography

Geta David is Professor at “Gh. Asachi” Technical University of Iasi (Romania) in the Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection “Cr. I. Simionescu”. After a position of research engineer in “P. Poni” Institute of Macromolecular Chemistry (for 9 years) she returned to the Technical University of Iasi, were she completed her PhD. She has published more than 70 papers and contributed to more than 16 projects/grants, dedicated mainly to functional polymer synthesis, characterization and applications. Recent research activities are related to smart polymers, nanocomposites and biopolymers-based materials for biomedical uses.

Speaker
Geta David Gh. Asachi Technical University of Iasi, Romania

Abstract

Materials used in biomedicine, such as polymers for drug encapsulation and tissue engineering scaffolds are preferably produced from natural compounds, such as collagen- based hybrids for bone repair and alginates for controlled drug delivery. So far, numerous of biopolymers have been studied, most of them belong to the three main classes of natural macromolecules: polysaccharides, lipids and proteins. Due to the development of novel biorefinery concepts, starting about fifteen years ago, lignin, the second most abundant polymer became available and gained increasing interest in academic research. In between, first biorefinery pilot plants are established and lignins from different processes (i.e. Kraft pulping, Organosolv and various steam explosion techniques) are available to a limited extent. Thus, remarkable progress was made in lignin research within the last five years, in particular regarding isolation conditions, structure analysis, functionalization and modification. Most recent developments include lignin-based nanomaterials for drug encapsulation. [1] However, research so far is mainly directed toward industrial utilization including lignin- derived fuel components and resins. Thus, experimental data on lignins used for medical applications are still very rare. The contribution reviews current stat-of-the-art of lignin-derived biomaterials used for drug release and tissue engineering, such as scaffolds for bone regeneration. In detail, the specific lignin structure characteristics will be focused including the antioxidant and antimicrobial capacity to be exploited for biomedical use.

Biography

Speaker
Margit Schulze Bonn-Rhein-Sieg University of Applied Science, Germany

Abstract

Self-assembly via non-covalent crosslinking provides a route to form injectable hydrogels with shear-thinning and self-healing properties arising from dynamic and reversible crosslinks. Due to the dynamic nature of these weak physical associations, formed networks can be dissociated under applied shear, the hydrogels flow and deform into liquids and recover back into hydrogels when stress is removed. Shear-thinning behaviour enables a pre-formed hydrogel with desired physical properties, as characterized ex vivo, to be delivered in vivo via application of shear stress during injection. As the hydrogel is pre-formed ex vivo, the effect of the local environment on cross-linking is almost negligible. Additionally, the recovery of elastic modulus after shear (self-healing) may be much faster in shear-thinning hydrogels than the gelation process of sol-gel types of hydrogels, reducing the risk of leaking precursor solutions and unreacted reagents. In recent years nanosized particles hydrogel termed nanogels have gained considerable attention as one of the most promising nano drug delivery systems owing to their unique potentials via combining the characteristics of a hydrogel system with a nanoparticle. This study proposed a new shear thinning and self-healing hydrogel based on polymer-nanogels interactions. The new hydrogel system combines pectin polymer chains physically cross-linked by chitosan nanogels. Shear thinning and self-healing behaviour were demonstrated using rheology tests. The influences of the nanogels size and quantity on the recovery rate and gel properties were evaluated using DLS, swelling and strength tests.

Biography

Yulia Shitrit started her research in the field of injectable hydrogels two years ago during her Ph.D. studying in the faculty of Chemical Engineering in the Technion. Her previous project focused on polymers for mucoadhesive drug delivery. She developed a new system based on acrylated chitosan and characterized it using novel methods. The research was published in International Journal of Pharmaceutics.

Speaker
Yulia Poshumensky-Shitrit Israel Institute of Technology, Israel

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