Porous Chitosan Microspheres For Culturing Hamscs And Coding I-Collagen Peptide

The chitosan microspheres, gelatin-chitosan and collagen-chitosan composite microspheres were prepared with different methods. The microspheres were used for the culture of hAMSCs. At the same time, the carboxymethyl chitosan microsphere (CMCs microsphere) loaded with the I-collagen peptide was prepared, and the effects of the CMCs microsphere on the hairless mice irradiated with UV were investigated.Human amnioticmesenchymal cells (hAMSCs) with mesenchymal stem cell and multi-directional differentiation potency are derived from amnia of human placentae. Comparing with ones of the bone marrow, the proliferation capacity of hAMSCs possesses stronger proliferation capacity,lower immunogenicity and non-dispute on ethics.In the thesis, the extraction method of hAMSCs was improved and simplified. The primary hAMSCs with abundance, high-purity and high-quality were obtained. The method could shorten the phase of the cell cycle then degrade contamination. So, the method is simple and good for the extraction of hAMSCs.Type I collagen peptide can repair radial damage and resist cell oxidation. The collagen was obtained through the pepsin hydrolysis. By the gel electrophoresis analysis, the collagen showed the typical Type I collagen ladder where the al and a2 sub-chain structure was clear. The result indicated that the collagen with high-purity was Type I collagen.The microspheres including chitosan, gelatin-chitosan and collage-chitosan microspheres were prepared in the thesis, and had good spherical shape and dispersibility. Especially, the gelatin-chitosan microsphere possessed porous surface, and its particle size distribution was wide. hAMSCs could grow on the three microspheres and cluster. It was difficult to degrade the chitosan microsphere. The cohesiveness to the microsphere and hAMSCs and bioactivity of the microsphere were not good so that the microsphere was unfavorable to proliferation of cells. The cohesiveness and bioactivity of the gelatin-chitosan and collagen-chitosan microspheres was better, and could promote hAMSCs proliferation. The gelatin-chitosan microsphere was more susceptible to degradation and strongly cohesive to hAMSCs as compared with the collagen-chitosan one.The effects of CMCs peptide microsphere on the mice irradiated with UV and mice thymus lymphocytes with X ray were investigated. The CMCs peptide microsphere prepared could enhance the anti-X ray activity of the mice thymus lymphocytes. The CMCs microsphere could effectively ameliorate the injured degree of mice skin, and prevent mice skin from free radicals injury in UV irradiation and moderate skin photoaging. In summary, the CMCs microsphere can prevent mice skin from UV irradiation and moderate skin photoaging.