Influencing factors and biological property of novel biomedical materials: Porous silicon carbide coated with bioactive tantalum / 中国组织工程研究

ABSTRACT

BACKGROUND: Porous silicon carbide has excellent physical and chemical properties and can be used to repair complex shapes and long weight-bearing bone defects, but it has no biological activity and cannot promote bone remodeling and integration. OBJECTIVE: A tantalum (Ta) coating was deposited on the surface of the porous silicon carbide scaffold to evaluate its biological activity. METHODS: The chemical vapor deposition method was used to deposit a Ta coating on the surface of the porous silicon carbide scaffold. The optimal experimental parameters were explored by setting different gas reaction flow rates and temperatures. The Ta coating was prepared with the best experimental parameters to test the mechanical properties of porous Ta. Human osteoblasts were co-cultured with the Ta coating specimens, and were observed by scanning electron microscopy after 3 and 7 days of cultivation. RESULTS AND CONCLUSION: (1) After the optimization of experimental parameters, the best experimental conditions were controlled as follows deposition temperature of 1 050 °C, hydrogen flow rate of 180 mL/min and chlorine flow rate of 100 mL/min. (2) The compressive strength of the Ta coated specimen was (61.4±3.2) MPa; the yield strength was (45.8±2.9) MPa; and the elastic modulus was 4.8 GPa. (3) Scanning electron microscopy demonstrated that after 3 days of co-cultivation, a large number of cells adhered to the surface of the porous silicon carbide scaffold that is coated with Ta and the porous structure. Some of the cells protruded from the pseudopod and were connected to each other. After 7 days of co-cultivation, the cell protrusions fused to form a sheet covering the surface of the porous Ta. In the porous structure, the cells protruded from the pseudopods, cross-linked to each other across the pores, secreted in the matrix, and coated the microparticle structure, gradually spreading in the pores. (4) The results show that the Ta coating on the surface of porous silicon carbide scaffold has good mechanical properties and biological activity.