Preparation And Characterization Of Calcium Phosphate Cement/Chitosan-Gelatin Composite Scaffold

The development of new technologies of bone tissue engineering requires urgently scaffold materials with high mechanical strength and good biocompatibility. In this study, a new method to produce calcium phosphate cement/chitosan-gelatin (CPC/CS-Gel) composite scaffold with macropores was presented, and the resulted products were among the most promising materials for hard tissue replacement.The macroporous scaffolds ofα-tricalcium phosphate (α-TCP) CPC were made in low temperature with hydrogen peroxide as a foaming agent. XRD and SEM analysis revealed that the end-product of CPC was calcium deficient hydroxyapatite (CDHA) with low crystallinity. The average pores of the scaffolds were about 400μm with good interconnectivity, and the whole porosity was around 70%. The mechanical test revealed the low values of the compressive strength and Young's modulus of the scaffolds.The macroporous CPC scaffolds as obtained were immersed in different concentration of CS-Gel solution under vacuum and the CPC/CS-Gel composite macroporous scaffolds were formed by freeze-drying process with solid-liquid phase separation. SEM photos showed that micropores were formed in the macropores of the CPC scaffolds in average diameter 200μm. Porosity measurement revealed a reduction of the whole porosity, however, the mechanical strength was significantly improved where the compressive strength and flexural strength reached at 1.95MPa and 5.17Mpa, respectively.Evaluation of biocompatibility of materials by cell culture techniques is an easy,quick and repeatable way, which is playing particular role in tissue engineering. In the present study, two kinds of cells were used. Using L929 fibroblasts and MC3T3-E1 osteoblasts as model systems, it showed that the CPC/CS-Gel composite macroporous scaffolds were nontoxic. The MC3T3-EI cells could adhere on the composite scaffolds and proliferate to form cell/scaffold construction. The work described here provides potential applicability of the CPC/CS-Gel composite scaffolds in bone tissue engineering.