Synthesis And Properties Of Multi-component Chitosan-based Bone Repair Materials

The biological scaffolds not only require good biocompatibility,three-dimensional network structure,but also need suitable biological activity,which can promote the cells proliferation and differentiation.The research progress and key problems of chitosan-based composite bone tissue engineering materials are presented in this paper.Chitosan and gelatin were coaxial electrospinned to simulate human bone cytoplasmic matrix.The research focused on how to effectively introduce active ions and prepare chitosan-based multi-component bone repair scaffolds.In this paper,zinc oxide/chitosan-polyoxyethylene@gelatin nanofiber scaffolds were prepared by magnetron sputtering on the basis of three-dimensional porous chitosan-polyoxyethylene@gelatin nanofibers.Zinc oxide/hydroxyapatite/chitosanpolyoxyethylene@gelatin nanofiber scaffolds and strontium apatite/chitosanpolyoxyethylene@gelatin nanofiber scaffolds were also prepared by chemical deposition and magnetron sputtering.The structure and properties of the scaffolds were studied by surface morphological characterization(SEM,TEM),structure and composition analysis(FTIR,TGA,XRD)and cell viability test(CCK-8,fluorescent staining).The results are summarized as follows:1.The core-shell chitosan-polyoxyethylene@gelatin nanofibers were prepared by coaxial electrospinning with a shell of about 150 nm and a core of about 100 nm.Zinc oxide/chitosan-polyoxyethylene@gelatin nanofibers were then prepared by growing zinc oxide particles on the surface of the above materials using RF magnetron sputtering.It was characterized by SEM,TEM and XRD and showed that the small particles on the surface of the fiber were nano zinc oxide.As the sputtering temperature was increased from 100 °C to 300 °C,the fiber was bent,the morphology of the nanofibers changed,and the three-dimensional structure changed.So 100 °C was selected as the best sputtering temperature.With the increase of sputtering time,the zinc oxide particles increased.The results of cell experiments showed that when MG-63 cells were cultured on the scaffolds,the cell survival rate was above 70%,showing that the material had good cytocompatibility.Compared to that of chitosan-polyoxyethylene@gelatin nanofibers,cell viability of zinc oxide/chitosan-polyoxyethylene@gelatin nanofibers was increased,showing that zinc oxide did promote cell growth and activity.It was found that as time increased,the toxicity of the material to the cells increased and the biological activity of the material decreased.2.Hydroxyapatite(HAP)was deposited on the surface of chitosan-polyoxyethylene@gelatin nanofibers by wet chemical method,and then zinc oxide particles were grown on the surface of the composite material by magnetron sputtering.The results of SEM,TEM and XRD showed that the surface layer of the fiber surface was HAP,and the small particles above the layer structure were zinc oxide particles.Through cytotoxicity experiments and proliferation experiments,it was found that the combination of HAP and Zn O could further enhance the shell aggregation.3.The strontium apatite/chitosan-polyoxyethylene@gelatin nanofibers were prepared by chemical deposition.When MG-63 cells were cultured on scaffold materials,the results showed that strontium apatite could further promoted cell growth and activity than apatite,and strontium apatite had good bioactivity and osteoinductivity.Strontium/apatite@chitosan-polyoxyethylene@gelatin nanofibers could be used as bone tissue engineering scaffolds to promote bone repair.