Department for biomaterials research

Welcome to the Department for biomaterials research. These webpages will guide you through the main information on our staff, projects, principal equipment, facilities and publications.

Our main activities in several research areas are:

  • Encapsulation of living cells towards the diabetes treatment

    Encapsulation of living cells towards the diabetes treatment


    For a number of years we have been dealing with utilization of polymeric materials in the diabetes treatment by transplanted pancreatic islets. Transplanted islets are protected from the attack of the immune system by encapsulation in the polymeric semipermeable membrane. We are proud of being the partners of The Chicago Diabetes Project (www.chicagodiabetesproject.org) led by Prof. Jose Oberholzer. In a close cooperation with laboratories in USA and Europe we work on development of microcapsules prepared by polyelectrolyte complexation and the process of encapsulation with the aim of pre-clinical testing. These microcapsules function, in various extend, in rodent animal models and, importantly, do not exhibit a significant immune response after implantation to peritoneal cavity of baboons used as a non-human primate model. Recently we proposed several principles for improving microcapsules to avoid stimulation of the human immune system tested in the human whole blood model in the cooperation with NTNU Trondheim. Apart from recipes and process for microcapsule formation, we focus on physico-chemical characterization of microcapsules and serve as the testing laboratory for a number of cooperating laboratories. We are also in a close contact with those affected by diabetes (patients, their relatives, diabetologists) and we communicate about our work via the non-profit foundation Cukrovka n.f. (www.cukrovkanf.sk).

    In addition to encapsulation of pancreatic islets for diabetes treatment, in cooperation with the Institute of Chemistry SAS our expertise in microencapsulation technology is also utilized in the biotechnological field. In the last years, whole cells (Nocardia tartaricans), enzymes (i.e., glucose oxidase) and other types of biocatalysts (Escherichia coli over-expressing Baeyer–Villiger monooxygenases) were successfully immobilized in polyelectrolyte microcapsules resulting in enhanced stability and activity of immobilized biocatalysts.

    Projects

    Materials and processes for functional encapsulation of pancreatic islets in diabetes treatment (MEREDIT), APVV-14-0858

    Multicomponent microcapsules for allogeneic islet transplantation in a comprehensive, preclinical non-human primate model. Juvenile Diabetes Research Foundation. Grant Key: 2-SRA-2014-288-Q-R

    The Chicago Diabetes Project: Global collaboration for a functional cure, UIC Foundation, Washington Health Square Foundation and Christopher Family

    Carbonic anhydrase IX as a functional component of cancer progression: the role in epithelial-mesenchymal transition and intercellular signaling. Slovak Research and Development Agency APVV-0658-11

    Kinetics and bioapplications of zwitterionic polymers, VEGA 2/0198/14

    Detailed information about projects find HERE

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  • Biomaterials based on 2-oxazoline chemistry

    Biomaterials based on 2-oxazoline chemistry


    Poly(2-alkyl-2-oxazoline)s belong to a unique class of polymers with exceptional properties for their use in various biomedical applications. Current research and implementation reach the first clinical trials. Therefore it is of high importance to recognize behavior of this class of polymers inside a living organism as well as to control the circulation and therapeutic effects. In this context, our effort is mainly focused on the synthesis of functional polymers based on 2-oxazolines and polymers with complex architecture and on the study of their interactions with various cell lines.

    Functional polymers are an irreplaceable part in the preparation of conjugates with biomolecules. In our department, one of the main research topics is the synthesis of various functional polymers based on 2-oxazolines. Due to their long-term effects such constructs may be applied, for example, in vaccines against different types of bacterial or fungal infections.

    Hydrogels based on poly(2-oxazolines) represent promissing materials for the use in pharmaceutical applications as well as in tissue engineering and 3D cell cultivation. We work on hydrogels from 2-alkyl-2-oxazolines using different crosslinking agents and varying network density. In addition, the temperature-dependent swelling behaviour in water, morphology of hydrogels, viability and growth of the cells on the surface and in the inner structure of the hydrogels are also investigated.

    Unimolecular nanoparticles based on star-shaped copolymers belong to the polymeric structures suitable for controlled drug delivery. The hydrophobic hyperbranched core of these polymers prepared in our laboratory has been used for attachment of hydrophilic 2-alkyl-2-oxazoline arms. Main advantage of such amphiphilic polymeric system is in their higher stability compared to micelles.

    2-Oxazoline polymers are also used for preparation of biocompatible surfaces. Several principles have been employed for modification of supports (glass, metal, silica, plastics) involving plasma, electrochemical and chemical activation.

    Projects

    M2Neural: Functional Materials for Advanced Neural Interfaces, M-ERA.NET Transnational Call 2013

    Polymers based on 2-oxazolines for targeted drug delivery and controlled cell adhesion, VEGA project No. 2/0163/15

    Detailed information about projects find HERE

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  • Polymers for anti-cancer therapy

    Polymers for anti-cancer therapy


    Understanding the molecular basis and biological processes responsible for the development and progression of various cancer types is a necessary prerequisite for the design of novel, more specific and selective systems for anti-cancer therapy. Interdisciplinary effort combining medicine (requirements) and polymer chemistry (realization) thus provides a promising platform not only towards the design of innovative treatment strategies but also towards their final realization into an applicable form.

    Drug delivery systems based on chitosan sub-micron particles
    Chitosan particles ranging from nano- to micrometer scale are utilized in various medical disciplines, whereas their size determines their final biomedical application. However, there is a lack of published data on factors affecting the size of particles and their stability. Understanding the impact of various physico-chemical factors on the size of produced particles should lead to a well-defined and controlled preparation of chitosan particles with desired dimensions and colloidal stability. Our work is therefore focused on the analysis of various parameters that may influence size and stability of chitosan sub-micron particles. Beside this, tailored chemical modifications of chitosan particles are carried out in order to (i) selectively and specifically target various tumour cells, (ii) enable their detection in parallel, and (iii) control the release of embedded/bound therapeutic agents. Drug delivery systems towards hypoxic tumors and for chronic myeloid leukemia are being developed and tested.

    Magnetite nanoparticles for anti-cancer therapy: the role of surface modifications
    Magnetite nanoparticles Fe3O4 (MNPs) are the most frequently used forms of iron oxide nanoparticles with a great potential as nanocarriers or heating mediators in cancer therapy. Additionally, it has been demonstrated that particle size between 50 and 200 nm is optimal for targeted drug delivery. Therefore MNPs represent a promising tool for in vivo intracellular utilization. Coating of MNPs with either synthetic or natural chemical moieties enhances their desirable properties including their size, which has a direct impact on overall colloidal stability and cell internalization efficiency. With respect to the intended intracellular application, our work is focused on the investigation of impact of various surface modifications on (i) size distribution and colloidal stability of MNPs in different media mimicking in vivo conditions, (ii) cellular uptake and cytotoxicity of MNPs towards various human tumor cells, and (iii) capacity of MNPs to generate reactive oxygen species in diverse cell types and tissues.

    Morpholino: synthesis and implementation into innovative treatment strategies
    Morpholino, as a nucleic acid derivative, is primarily used in the field of molecular biology to modulate the expression of target genes. However, due to its chemical structure and unique properties there is an enormous effort to implement Morpholino besides research purposes into various fields of human medicine, particularly into the field of anti-cancer therapies focused on gene silencing and the field of invasive medicine and implantations. In this project, the emphasis is put on the chemical synthesis of Morpholino and its oligomers and their subsequent implementation into innovative treatment strategies intended for chronic myelogenous leukemia and diabetes mellitus type 1.

    Projects

    Carbonic anhydrase IX as a functional component of cancer progression: the role in epithelial-mesenchymal transition and intercellular signaling. Slovak Research and Development Agency. APVV-0658-11

    Kinetics and bioapplications of zwitterionic polymers, VEGA 2/0198/14

    Modeling and synthesis of hybrid conjugated systems for anticancer therapy, VEGA project No. 2/0094/15

    Mechanisms of gold and magnetite nanoparticles effects on renal cells, VEGA project No. 2/0113/15

    Detailed information about projects find HERE

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  • Zwitterionic non-biofouling / biocompatible polymers and hydrogels

    Zwitterionic non-biofouling / biocompatible polymers and hydrogels


    Poly(zwitterions) represent biocompatible and non-biofouling polymers. Their importance in different biomedical fields has been rapidly increasing, since they are compatible with blood, exhibit ultra-low biofouling, enhance the protein stability and bioactivity, and can be used for encapsulation of cells.

    Our expertise concerns preparation and characterization of non-biofouling poly(zwitterionic) surface coatings on different supporting materials with the aim to improve biocompatibility and performance of biomedical devices such as biosensors or other type of implants. Detailed study on preparation, characterization and non-biofouling properties of polysulfobetaine hydrogels has been performed. In parallel activities, the non-biofouling character of polysulfobetaine layer coated by electrografting deposition at the conductive surface was demonstrated.

    The motifs enabling an attachment of zwitterion-based hydrogels to polymeric surfaces and the photo-switchable zwitterionic system for controlled interaction of polymer layers with cells and DNA were also developed.

    Projects

    M2Neural: Functional Materials for Advanced Neural Interfaces, M-ERA.NET Transnational Call 2013

    Kinetics and bioaplication of zwitterionic polymers. Project VEGA 2/0198/14

    Detailed information about projects find HERE

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  • Kinetics and mechanism of free-radical polymerizations of water-soluble monomers

    Kinetics and mechanism of free-radical polymerizations of water-soluble monomers


    Polymerization of water-soluble monomers in aqueous phase is highly specific due to strong interactions provided by water used as the solvent, which influence both kinetics and mechanism of polymerization. The pulsed-laser initiated polymerization in conjunction with size-exclusion chromatography is used to obtain the propagation rate coefficients for various water-soluble monomers in homo and copolymerization studies. The solvent effect manifested by a strong dependence of propagation rate on monomer concentration is considered to be a genuine kinetic effect resulting from the impact of intermolecular interactions between solvent and transition state structure on rotational barriers of the transition state structure. In cooperation with the Institute of Physical Chemistry of the Georg-August University in Goettingen, Queens University in Kingston and BASF SE in Ludwigshafen these individual rate coefficients are utilized up to modelling of rate of polymerization and molar mass distributions. Among others, our studies are focused on following monomers: acrylic and methacrylic acid, acrylamide, N-vinylformamide, N-vinylpyrrolidone, sulfobetaines and others.

    Projects

    Determination of rate coefficients for water-soluble monomers with special emphasis on charged/ionizable monomers. Contract cooperation with BASF SE, Ludwigshafen

    Kinetics and bioapplications of zwitterionic polymers. VEGA project No 2/0198/14

    Detailed information about projects find HERE

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  • Evaluation of biocompatibility of polymers and polymeric materials

    Evaluation of biocompatibility of polymers and polymeric materials


    n the recent years, the polymeric materials represent the most growing group among the biomaterials. They are part of implants, health and diagnostic instruments, materials for a controlled drug release; they are used for reconstruction of bones and tissues and for formation of hydrogels. Toxicity of the most materials is evaluated from the point of acute cytotoxicity by measuring the cell proliferation (e.g. MTT assay), or by evaluation of immunocytotoxicity. In order to evaluate the immunocytotoxicity of polymers and polymeric biomaterials, we are focused on monitoring the induction of proinflammatory cytokines and growth factors in macrophages by enzyme-linked immunosorbent assay (ELISA). Recent publications show that the evaluation of the molecular changes on the cell metabolism, gene and protein expression after the exposure to polymers and biomaterials are of a great importance. Therefore, the apoptosis and necrosis of cells after interactions with polymers and materials is assessed and, by using the techniques of molecular biology, the activation of signal transduction pathways can be monitored.

    Projects

    Biocompatibility study of polymers and polymeric materials suitable for biomedical applications. In vitro analysis of cytotoxicity and cell response at the signal trasduction level. VEGA project No. 2/0156/15

    Multicomponent microcapsules for allogeneic islet transplantation in a comprehensive, preclinical non-human primate model. Juvenile Diabetes Research Foundation. Grant Key: 2-SRA-2014-288-Q-R

    Detailed information about projects find HERE

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