Oxidized Dextran as Crosslinker for Chitosan Cryogel Scaffolds and Formation of Polyelectrolyte Complexes between Chitosan and Gelatin

Macroporous scaffolds composed of chitosan and using oxidized dextran as a crosslinker are produced through cryogelation. Introducing gelatin as a third component into the structure results in the formation of mesopores in the pore walls, which are not seen if gelatin is excluded. The mesoporous structure is explained by the formation of polyelectrolyte complexes between chitosan and gelatin before crosslinking takes place. The scaffolds exhibit highly elastic properties withstanding compressions up to 60%. The in vitro biocompatibility of the cryogels is evaluated using fibroblasts from a mouse cell line (L929) and it is seen that the cells adhere and proliferate on the scaffolds. The mesoporous structure seems to have a positive effect on proliferation. The formation of PECs between chitosan and gelatin under subzero conditions in a one-step preparation using oxidized dextran as a crosslinker is presented. These scaffolds exhibit a heterogeneous structure with macropores and mesoporous pore walls. Fibroblast cultures show that the PEC-based materials have better cell growth compared to scaffolds with no PEC.