Biomimetic surface modification of tissue engineering scaffolds with glycosaminoglycans

The replacement of bone and cartilage by tissue engineering is still hampered by the lack of degradable biomaterials that stimulate the growth and differentiation of cells. Biomimetic surface modifications of polymers have been considered as a tool to achieve this goal. However, covalent binding of biological molecules may result in loss or reduction of their biological activity. The layer-by-layer (LbL) technique has been identified as a useful tool to immobilise biogenic (charged) macromolecules maintaining their biological activity. It is an environmental safe, simple and cost efficient method to create material surfaces that are organised at the nanometer scale.  LbL technique has been applied recently to coat the surface of biomedical materials using simple combinations of synthetic polyions and certain biological molecules, such as chitosan, collagen, DNA, etc. It is the aim of the project to apply the LbL technique for the biomimetic surface modification of polylactid acid (PLA) as a material approved for biomedical applications. The coating shall resemble main components the structure of the extracellular matrix (ECM) by using collagens and different glycosaminoglycans (GAG). The signalling capabilities of the ECM shall be mimicked by incorporation of adhesive proteins, such as fibronectin and growth factors. The binding of these molecules shall be achieved by their inclusion during the LbL process as well as their biospecific adsorption to the outermost layer of GAGs. The structure and properties of the LbL coating will be investigated by physicochemical methods. The biological activity will be studied with cultures of mesenchymal stem cells looking at cell growth and differentiation. Hence, the scientific focus of the project is on nanobiotechnologies and nanometre scale engineering techniques which is a subtheme of the NMP priority. The project is also aimed to help the fellow to become an independent and experienced researcher by a number of training activities. This involves beside the experimental work, the participation in courses and the cooperation with experienced scientists to become trained in planning and management of research, to learn how to disseminate scientific results within the scientific community and the general public up to the exploitation of project results.