Study On The Biocompatibility Of Chitosan/gelatin Blending Materials

The biocompatibility of some materials including films, microspheres and scaffold materials prepared with chitosan or gelatin alone are not ideal, so these materials are often modified to improve their biocompatibility for practical application, and the method of blending modification is just one of the easiest and the most widely used methods. In this study we prepared chitosan/gelatin composite films and three-dimensional porous microspheres carriers by the method of blending modification, and then further study and investigate the biocompatibility of these materials. The main research contents and the results are as follows: a) A series of chitosan-gelatin composite films with different proportions of gelatin combined. Many properties of these films including surface morphology, hydrophilicity, hydrophobicity, adsorption of fibronectin (FN) as well as the rate of degradation by lysozyme in vitro are systematically examined. The results showed that the surface hydrophilicity and the degradation rate in vitro of chitosan materials can significantly be enhanced by blending modification; besides, the adsorption of fibronectin on the surface of the film materials would increase when gelatin blended with a certain percentage. b) Cell experiments with MC3T3-E1 osteoblast-like cells and rat adipose-derived stem cells (ADSCs) which were isolated and cultured in vitro were subsequently carried out to evaluate the biocompatibility of the blending composite films described above. More specifically, cell morphology, spreading, adhesion, proliferation and differentiation on the surfaces of all the blending composite films were systematically examined and analyzed. The results showed that the interaction between these materials and cells were dramatically affected when the composite films were modified by blending chitosan and gelatin materials. In this study, MC3T3-E1 cells and ADSCs cells on the surface of the film 5C5G (prepared by blending 2.5% (w/w) chitosan solution and 10% (w/w) gelatin solution with volume ratio of 1:1) showed best cell morphology, spreading, and significantly higher level of adhesion, proliferation and differentiation when compared to chitosan film control and other blending composite films in some aspects. c) Chitosan-gelatin porous microspheres were prepared by emulsification cross-linking method with HDI (1, 6-hexamethylene diisocyanate ) as a cross-linking agent, and the biocompatibility of the microspheres was further evaluated. The results showed that the average diameter of the microspheres was about 180~200μm, and the balling rate was more than 80%. These chitosan-gelatin porous microspheres showed low cell toxicity and good biocompatibility when MC3T3-E1 cells were cultured on the surface of them. Therefore, these chitosan/gelatin porous microspheres materials were expected to be applied in the field of bone regeneration tissue engineering in the future after some improvement.