Study On The Application Of Chitosan Modified With Blending Different Polymers In Tissue Engineering

Tissue engineering can repair tissue defects in vitro or in vivo,replace or reconstruct the structure of organs to maintain or improve tissues and organs,through the construction of the three-element system of seed cells,biological scaffolds and cell growth regulators.At present,tissue engineering method has been widely used in the bone repair and the nerve repair.Bone repair is a process that multiple bone cells participate in the activation,absorption and formation of bone.Osteoblasts are the main functional cells in bone formation,which are responsible for the synthesis,secretion and mineralization of bone matrix.Therefore,what we are concerned with is how to promote osteoblast mineralization to accelerate bone formation.Neural stem cell has become the most promising cell type for the repair of central nervous system injury because of its self-renewal and multi-directional differentiation potential.How to maximize the differentiation of neural stem cells into neurons and guide the axonal regeneration through the glial scar is the key problem in the treatment of central nervous system injury.Chitosan has unique advantages as a natural biological material widely used in tissue engineering.A large number of studies have shown that modification can improve the biological properties of chitosan,so as to broaden its application in tissue engineering.In this paper,chitosan was modified with polyethylene glycol,gelatin and polylysine to study the effect of modified chitosan on the proliferation,differentiation and mineralization of MC3T3-E1 cells,and the effect on the proliferation and differentiation of C17.2 neural stem cell.The results showed that the chitosan membranes modified by blending different polymers could promote the proliferation of the two kinds of cells,compared to the chitosan membranes alone.The alkaline phosphatase activity and mineralization level of MC3T3-E1 cells cultured on the different polymer-modified chitosan membranes and the neuronal differentiation level of C17.2 neural stem cells cultured on the different polymer-modified chitosan membranes,were higher than that on the chitosan membranes alone.The effect of blending gelatin-modified chitosan membranes on the behavior of both cells is most favorable.The results of this study provided a richer theoretical basis and experimental basis for the further study of the bone defect repair and the central nervous system injury repair by using tissue engineering methods.