氧化石墨烯-海藻酸钠-壳聚糖复合支架的制备及表征

Preparation and Characterization of Graphene Oxide-sodium Alginate-chitosan Composite Scaffold

通过冷冻干燥技术,将不同量的氧化石墨烯与海藻酸钠和壳聚糖复合,构建复合支架材料.研究了不同的氧化石墨烯含量(质量分数0,0.3%,0.5%,0.7%,1%)对支架材料微观结构、孔隙率、溶胀比、体外降解性能、机械性能及生物相容性的影响,以确定复合支架中最佳氧化石墨烯含量.研究结果表明,复合材料呈固态海绵状结构,具有一定的形态可塑性;扫描电子显微镜观察发现,各组支架均为三维网状结构,随着氧化石墨烯含量的增加,孔隙尺寸逐渐降低,孔壁厚度增加,孔隙尺寸在140~240μm之间;随氧化石墨烯含量的增加,复合支架溶胀比和体外降解速率逐渐降低,而机械强度明显增强;体外细胞毒性显示,当氧化石墨烯质量分数为0.3%时,细胞存活率最高,而当氧化石墨烯含量增高时,细胞活性会被明显抑制,造成细胞死亡.因此,氧化石墨烯在复合支架中最佳含量为0.3%.

The composite scaffold material was constructed by freeze-drying technology from graphene oxide,sodium alginate and chitosan.The effects of graphene oxide content on the microstructure,porosity,swelling ratio,in vitro degradation performance,mechanical properties and biocompatibility of the scaffold materials were studied to determine the optimal graphene oxide content in the composite scaffold.The results show that the composite material has a solid sponge-like structure with a certain morphological plasticity.Scanning elec⁃tron microscopy(SEM)observations show that each group of supports has a three-dimensional network struc⁃ture.As the content of graphene oxide increased,the pore size gradually decreased and the pore wall thickness increased,the swelling ratio and degradation rate of the composite scaffold gradually decreased while the mechanical strength was significantly enhanced.Results of in vitro cytotoxicity showed that when the graphene oxide content was 0.3%(mass fraction),the cell survival rate was the highest,and when the graphene oxide content increased,the cell activity was significantly inhibited,causing cell death.Finally,the optimal content of graphene oxide in the composite scaffold is 0.3%.Our research lays a good foundation for the application of graphene oxide in bone tissue engineering materials.