Damaged tissues or organs often cannot be replaced by transplantation due to the shortage of organ donors. The solution available in such sitautions is that offered by tissue engineering based on taking cells from a patient, ex vivo culturing them and implanting back into the patients body. This technique requires the application of cell culture supports which should allow fast cell division. In the case of culturing stem cells the supports may also actively influence the direction to which the cells differentiate.

Goals of the research

The goal of this research was to develop photocrosslinkable polymeric cell culture supports in the form of multilayer films obtained using the layer-by-layer method (LbL). The photoactive polymer used to obtain the films was diphenylamine-4-diazoresin. The polymer is cationic therefore easily form polyelectrolyte multilayers with a polyanion. Upon irradiation with about 380 nm light the diazonium groups of the diazoresin can react with carboxylic, sulfonate or phosphate groups of the polyanion resulting in the photocrosslinking of the multilayer. The diazonium groups may also react with the carboxylic groups of biomolecules such as proteins resulting in their immobilization on the surface of the multilayer. The influence of the photocrosslinking of the polymeric supports and immobilization of insulin on the physicochemical and biological properties of the supports were studied.

Results of the research

The ultrathin multilayer films composed of diphenylamine-4-diazoresin and different anionic polysaccharides such as pectin, heparin, chondroitin sulfate, hyaluronic acid, and carrageenan, were obtained. The thickness of the films was a few nanometers. The photocrosslinked multilayer films formed upon irradiation were very stable for at least one month. The adult human bone marrow stromal cells (hMSC) cultured on the supports proliferated efficiently and could be easily detached. The films enhanced osteogenic differentiation of the cells suggesting the suitability of the films for bone tissue regeneration. hMSC cells cultured on the films containing sulfated polymers (heparin, chondroitin sulfate and carrageenan) could be easily detached and the growth of new cell monolayer was initiated.

Collaboration

Prof. Anna M. Osyczka, Jagiellonian University, Institute of Zoology and Biomedical Research, Department of Cell Biology and Imaging