The Preparation And Properties Of Chitosan/Graphene Oxide Composite Scaffold Materials

Scaffold plays an important role in the field of tissue engineering and it provides structure support and space in the process of cell growth.At present,mechanical properties and biocompatibility of scaffold effect its application.In this work,three-dimensional directional porous foam scaffolds,two-dimensional fiber membrane scaffolds were prepared by directional freezing and electrospun technique with chitosan(CS)and graphene oxide(GO)as the host material.The main work is as follows:1.The graphene oxide(GO)was prepared by a modified Hummers method.The aligned porous scaffolds was prepared by directional freezing,which is similar to the ordered structures of lamellar bone in the mature bone tissue.The scaffolds was used to guide the directional alignmen of mouse embryos osteoblast precursor cell(MC3T3-E1).The effect of chitosan molecular weight,GO content and solid content on the morphology of scaffold.Width of pore passage was controlled to change from 7.5 to 40 p.m by adjusting the solid content.After chemical crosslinking,the strength of the scaffold was increased from 60 to 140 kPa in the direction of the channel when it was compressed 50%.Results show that the GO significantly promoted the adhesion and reproduction of cells on the surface of the scaffold,and directional pore structure facilitates arrangement of cells along the direction of pore channels.At the same time,the scaffold was good hydrophilicity and the structure was stable after repeat compression.In addition,the experimental results of mineralization and in vitro degradation indicated GO can promote the hydroxyapatite mineralization in surface and interior,and the degradation rate of scaffolds was reduced after addition of GO a certain extent.2.Two-dimensional CS/PVA/GO composite fiber membrane scaffolds were prepared by electrospun.The diameter of the fiber was significantly reduced after addition of GO,fiber mean diameter was decreased from 700 to 300 nm.Tensile strength of fiber membrane was increased from 2.3 to 6.8 MPa,the elongation at break was changed from 20%to 35%.The GO shown the ability to promote fiber membrane mineralization under the condition of a simulated body fluid(10×SBF)mineralization.Meanwhile,the MC3T3-E1 cells culture experiment results shown that the GO to promote the growth of cells on the surface of two-dimensional fiber membrane.