Third End Year Meeting of

Transcription

1 Third End Year Meeting of Shaping and Transformation in the Engineering of Polysaccharides (STEP) Marie Curie Initial Training Network Funded from the European Community s 7 th Framework Programme under Grant Agreement No Poster Abstracts September 2011 University of Maribor, Slovenia

2 Laccase mediated functionalisation of chitosan by caffeic and gallic acids for modulate antioxidant and antimicrobial properties Mojca Božič, Selestina Gorgieva, Vanja Kokol University of Maribor, Institute for Engineering Materials and Design, Maribor, Slovenia A new environmentally friendly strategy for the modulated functionalisation of chitosan polymer with phenolics, using laccase as reaction catalysts will be presented. The laccase catalyzed oxidation and polymerization of two chemically similar phenolics, caffeic acid (CA) and gallic acid (GA), at different phs were studied using UV Vis spectroscopy, cyclic voltammetry, and HPLC Size exclusion chromatography. The reaction of laccase oxidized phenolics with chitosan polymer was investigated as a function of ph in order to obtain different chitosan phenolic conjugates, being characterized by FTIR and 1 H NMR. The results showed that, laccase oxidized phenolics resulted in covalent bonding or electrostatic attraction to the chitosan polymer, depending on the ph conditions. In stronger acidic conditions (under ph 4.5), the grafting of phenolics was disabled due to the chitosans fully protonated amino groups, thus only ester linkages through chitosan hydroxyl groups and/or electrostatic interactions were detected, whilst under weaker acidic conditions (ph 5.5 and ph 6.5), CA and GA reacted with non protonated primary amino groups on the chitosan forming the amine bonds. It was concluded that laccase activity, phenolic dissociation, and chitosan nucleophilicity can be controlled by ph variation, thus suggesting that the chitosan antimicrobial and antioxidant activities can be varied depending on the type and quantity of its functionalisation with phenolics and the degree of phenolic polymerization. This may provide a novel way of preparing and exploiting many other multifunctional chitosan based materials for wider applications. This work was supported by the Ministry of Higher Education, Science and Technology [Eureka, grant no. E!4952]. Enzymatic hydrolysis of different allomorphic forms of microcrystalline cellulose Diana Ciolacu 1,2, Selestina Gorgieva 1, Daniel Tampu 2, Vanja Kokol 1 1 University of Maribor, Institute for Engineering Materials and Design, Smetanova ul. 17, SI 2000, Maribor, Slovenia 2 Petru Poni Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, , Iasi, Romania The biological conversion of cellulose materials to nano and micro sized materials and glucose has been shown to be a useful method to obtain valuable products, such as nanocomposites, bioethanol and various chemicals. Thus, the complex enzymatic hydrolysis of cellulose has been studied intensively in the last 50 years. However, the effect of the variety of physical structures adopted by the cellulose macromolecules being in different crystalline forms, on their biodegradation were not yet detailed investigated. In the contribution, the enzymatic hydrolysis of three main allomorphic forms (I, II, III) of microcrystalline cellulose using different celluloses, from Trichoderma reesei and from Aspergillus niger, respectively will be presented. The efficiency of the enzymatic hydrolysis of Page 1 of 8

3 cellulosic substrates will be estimated by the amounts of reducing sugar and by the yield of the reaction, being established by chemical and HPLC SEC analysis. The relative susceptibility of different cellulosic substrates to enzymes will be determinate as the modifications in the average particle size of the residues resulted after the hydrolysis process. The changes of the supramolecular structure of cellulosic residues will be observed as alterations of crystalline index and crystallites dimension of the corresponding allomorphic forms by X ray diffraction method. The microstructures of cellulose allomorph residues will be presented using optical and scanning electron microscopies. This research was supported by the Marie Curie Transfer of Knowledge Fellowship of the EC FP6 under the contract nr. MTKD CT POLYSURF. Antithrombotic properties of sulphated wood derived galactoglucomannans Aleš Doliška 1, Stefan Willför 3, Simona Strnad 1, Volker Ribitsch 2, Karin Stana Kleinschek 1, Patrik Eklund 4, Chunlin Xu 3,5 1 University of Maribor, Faculty of Mechanical Engineering, Institute for Engineering Materials and Design, Slovenia; 2 University of Graz, Institute for Chemistry, Austria; 3 Åbo Akademi University, Process Chemistry Centre, Laboratory of Wood and Paper Chemistry, Finland; 4 Åbo Akademi University, Process Chemistry Centre, Laboratory of Organic Chemistry, Finland; 5 Royal Institute of Technology (KTH), AlbaNova University Centre, School of Biotechnology, Sweden Galactoglucomannans (GGM) are the main hemicellulose type in softwoods and are normally present in amounts of 15 20% of the wood material. These water soluble polysaccharides are released and accumulated in process waters in the production of thermo mechanical pulp and are partially removed with the process waters. At the moment there is no industrial use of wood derived mannans. Chemical derivatization such as sulphation can increase the antithrombotic or anticoagulant properties of polysaccharides. In this study, GGM extracted from thermo mechanical pulp, as well as further carboxymethylated GGM (CM GGM), were sulphated to increase their antithrombotic properties. Results showed a significant increase of the antithrombotic effect of the sulphated galactoglucomannans from spruce wood and thus a potential new use of woodderived mannans. Surface Modification of Biopolymer Films using Functional Polyelectrolyte/Clay Multilayers Gerald Findenig 1, Rupert Kargl 1, Aleš Doliška 2, Karin Stana Kleinschek 2, Volker Ribitsch 1 1 Karl Franzens University Graz, Institute of Chemistry, AT 8010 Graz, Heinrichstraße 28, Austria; 2 University Maribor, Faculty of Mechanical Engineering, SI 2000 Maribor, Smetanova Ulica 17, Slovenia The meanwhile well known Layer by Layer (LbL) technique consists of the alternating deposition of positively and negatively charged components on a substrate and offers the Page 2 of 8

4 possibility of integrating a lot of different functionalities and properties into a surface coating. This makes the LbL technique a powerful tool for preparing customized surface coatings. In the scope of our work we analyzed the influence of different salt concentrations on the film forming characteristics of various polyelectrolyte/clay combinations. One type of clay (Laponite) and three different kinds of polyelectrolytes, namely polyethyleneimine (PEI), polydiallyl dimethylammonium chloride (pdadmac) and cationic starch were chosen in order to compare their film forming properties. Sarfus measurements showed almost no influence of the salt concentration on the film thickness in the dry state for the experiments with PEI, whereas the film thickness of the coatings containing cationic starch and pdadmac increased with higher salt concentrations. Monitoring the LbL build up with a crystal microbalance exhibited differences in the electrolyte dependent mass increases of the PEI/clay coating compared to the pdadmac/clay and cationic starch/clay coatings. Atomic force microscopy revealed in each case a granular surface morphology, which was just slightly different for the different used polyelectrolytes and salt concentrations. Thomas Heinze from the Friedrich Schiller University in Jena is highly acknowledged for providing the cationic starch. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/ ) under grant agreement n Formulation of new dual responsive cellulose based hydrogels for cotton knitwear functionalization Selestina Gorgieva and Vanja Kokol University of Maribor, Institute of Engineering Materials and Design, Maribor, Slovenia A unique cellulose polymer based hydrogel with specific dual responsive (ph and temeprature) absorption properties was prepared from carboxymethyl (CMC) and hydroxyethyl (HEC) cellulose in an aqueous solution employing citric acid (CA) as a crosslinking agent, being an alternative to commonly used poly(nipam) derivatives, problematic in term of toxicity, water solubility and biodegradation. The effect of preparation conditions, such as the polymer content and the CA amount, on the crosslinking process was investigated by estimating the formation of ester bonds (FTIR), as well as the hydrogel temperature transition (DSC and optical transparency), weight swelling ration measurements and morphology (SEM) as a function of time, temperature, and ph medium. The results show that the increment of the HEC content in the polymer solution diminishes the crosslinking degree and, consequently, reduces the ph dependency of the hydrogel. The results also show that the temperature responsive swelling ability of hydrogel can be formulated based on the hydrogel s composition, and the degree of crosslinking. The swelling profile of knitted cotton fabric treated with a thin surface layer of modifying hydrogels was studied as a function of its fabrication and the conditions of its incubation, showing an opposite effect. Page 3 of 8

5 This work was supported by the Ministry of Higher Education, Science and Technology [Manunet Era Net NANOWELL grant no ] and the Slovenian Research Agency [PhD grant no ]. Interaction Of Carboxymethyl Cellulose With Polymeric Thin Films Studied With A Quartz Crystal Microbalance Rupert Kargl a, Tamilselvan Mohan b, Martin Kulterer a, Karin Tradt a, Aleš Doliška b, Stefan Köstler c, Karin Stana Kleinschek b, and Volker Ribitsch a a Karl Franzens University Graz, Institute of Chemistry, AT 8010 Graz, Heinrichstraße 28/III, Austria; b University Maribor, Faculty of Mechanical Engineering, SI 2000 Maribor, Smetanova Ulica 17, Slovenia; c Joanneum Research, MATERIALS Institute for Surface Technologies and Photonics, AT 8010 Graz, Steyrergasse 17 19, Austria The adsorption behavior of carboxymethyl cellulose (CMC) on several polymeric thin films was investigated. Regenerated cellulose, cellulose acetate, polyethylene terephthalate, cyclo olefin polymer and a hydrophilic surface were coated on sensors of a quartz crystal microbalance with dissipation detection. Surface bound CMC was detected via changes in frequency and dissipation values. The influence of CMC incubation on the surface wettability was followed with static contact angle measurements. Atomic force microscopy was further applied to characterize the homogeneity of the coatings. The amount of irreversibly bound CMC strongly depends on the character of the solid polymer surface. Cellulosic materials showed higher adsorption rates of CMC than the other polymeric surfaces. It is assumed that there is an interaction involved that can be attributed to the structural similarity of cellulose and CMC. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/ ) under grant agreement n Characterization of Polycation/Nanoclay Multilayers prepared by Layer by Layer assembly Simon Leimgruber 1, Gerald Findenig 1, Rupert Kargl 1, Karin Stana Kleinschek 2, Volker Ribitsch 1 1 Karl Franzens University Graz, Institute of Chemistry, AT 8010 Graz, Heinrichstraße 28, Austria; 2 University Maribor, Faculty of Mechanical Engineering, SI 2000 Maribor, Smetanova Ulica 17, Slovenia Abstract unavailable. Page 4 of 8

6 Study of in vitro release of ibuprofen as a function of wound dressing material Z. Peršin 1,2,3, T. Maver 1,2,, K. Stana Kleinschek 1,2,3 1 Institute for Engineering materials and Design, Faculty of Mechanical Engineering, University of Maribor, Smetanova 17, 2000 Maribor, Slovenia; 2 Centre of Excellence for Polymer Materials and Technologies (CO PoliMaT), Tehnoloski park 24, 1000 Ljubljana, Slovenia; 3 Member of the European Polysaccharide Network of Excellence The epidemiological studies indicate that one percent of the population has a chronic wound, and of that group some twenty percent have had the wound for more than two years. Chronic wound patients often report pain as dominant in their lives. It is recommended that healthcare providers handle the pain related to chronic wounds as one of the main priorities in chronic wound management, together with addressing the cause. At present there are few local options for the treatment of persistent pain, whilst managing the exudate levels present in many chronic wounds. Important properties of such local options are that they provide an optimal wound healing environment, while providing a constant local low dose release of non steroidal anti inflammatory drugs (NSAIDs) during wear time of the dressings. Baring this in mind, the aim of our study was to evaluate different combinations of wound dressing materials (viscose, alginate) with ibuprofen, to find the most effective delivery system for topical use. In vitro release testing was performed using the Franz diffusion cell, where samples have be collected at different times and the concentrations of the released drug have been measured using UV/VIS spectroscopy. NSAID release testing showed that the most suitable material for the incorporation was viscose, which exhibits slow release of the incorporated drug over 24h. Similar release behaviour could be observed for alginate; however a smaller amount of the drug could be incorporated into the latter. Acknowledgements: This work was supported by the MVZT of the Republic Slovenia (No ). New method of nanoparticle stabilization employing natural polysaccharides Ivana Tatarova 1, Silvo Hribernik 2, Karin Stana Kleinschek 2, Thomas Heinze 3, Jens Schaller 4, and Volker Ribitsch 1 1 Karl Franzens University Graz, Institute of Chemistry, AT 8010 Graz, Heinrichstraße 28/III, Austria; 2 University Maribor, Faculty of Mechanical Engineering, SI 2000 Maribor, Smetanova Ulica 17, Slovenia; 3 Friedrich Schiller University Jena, Institute of Organic Chemistry and Macromolecular Chemistry, Humboldtstraße 10, D Jena, Germany; 4 Thuringian Institute of Textile and Plastics Research e.v., Breitscheidstrasse 97, D Rudolstadt, Germany Nanoparticle research is an area of significant scientific interest that offers a wide range of potential applications in various fields such as electrochemistry, sensorics, catalysis, Page 5 of 8

7 purification, diagnostics and drug delivery. New materials having unique properties can be designed using particles of nanoscale dimensions. Several kinds of nanoparticles are available on the market. However, their applicability is limited by their low stability and tendency to create agglomerates. Stabilization of nanoparticles can be achieved by change of their surface properties. Electrostatic stabilization is the most common method used to stabilize the nanoparticle colloid dispersions. Surfactants are known as the most effective electrostatic stabilizing agents. However, they suffer from the negative environmental impact. Polyelectrolytes can be used as alternative stabilizers, while the stabilization is achieved by electrosteric mechanism. New method of nanoparticle stabilization was developed employing natural polysaccharides, which can be used to design a wide range of nanostructured biopolymer composites. The (core shell) nanoparticles were prepared using top down approach. The polysaccharides used involved carboxymethylcellulose, hydroxymethylcellulose and starch. The stabilizing effect was evaluated using dynamic light scattering, microscopy and zeta potential measurements. The effects of duration of ultrasound dispersing treatment, presence of electrolyte in the dispersion and the stabilizer concentration were examined. Based on the presented procedure, stable nanoparticle dispersions were formed. The obtained dispersions have a great potential be used in the surface modification of polymer materials. Acknowledgement The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/ ) under grant agreement n Controlled layer by layer assembly of Chitosan and Carboxymethyl cellulose onto Cellulose Acetate supports: Influence of the ph in the absence of salt Karin Tradt 1, Martin R. Kulterer 1, Victoria E. Reichel 1, Tamilselvan Mohan 2, Rupert Kargl 1, Karin Stana Kleinschek 2, Volker Ribitsch 1 1 University Graz, Institute of Chemistry, CePoL Central Polymer Lab, NAWI Graz, AT 8010 Graz, Austria; 2 University of Maribor, Laboratory for Characterization and Processing of Polymers, Smetanova Ulica 17, SI 2000 Maribor, Slovenia Cellulose acetate, chitosan(chi) and carboxymethyl cellulose(cmc) are widely used and cheap macromolecules with unique properties like biocompatibility and biodegradability. The preparation of polyelectrolyte (PE) multilayer created by layer by layer self assembly has become an intensive research area. Promising applications are for example the development of sensor systems, friction reducing coatings, integrated optics, encapsulation of active components, and novel membrane materials. By tuning the solutions ph and salt content, one can trigger the PE electrostatics and solubility. Here we present a detailed study on the generation of CHI/CMC multilayer on cellulose acetate substrates. The CMC layer were applied at different ph values in absence of salt. The multilayer growth was analyzed by quartz crystal micro balance with dissipation mode (QCM D), water contact angle, and layer thickness measurements (by using the SARFUS technique).we could show that the adsorbed amount of CMC increases significantly with decreasing ph. Moreover, the Page 6 of 8

8 ph of the CMC solutions influenced the multilayer structure and stability significantly. This was shown by evaluating the resistivity of the multilayer films against acidic or alkali salt solutions and urea. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/ ) under grant agreement n Page 7 of 8