Biological evaluation of a novel porous tantalum scaffold

Xie Hui1,2; Ma Zhi-jie2; Wang Jian-chuan2; Wang Ben-jie2; Wang Wei2; Wei Xiao-wei2; Qin Kai-rong1; Zhao De-wei1,2

Abstract：BACKGROUND:Based on the excellent biological performance of tantalum, tantalum coating can be prepared on the conventional substrate by the coating preparation technique, which lowers the cost and importantly provides a feasible direction for the application of tantalum metal devices.OBJECTIVE:To study the biocompatibility of porous silicon carbide scaffold with tantalum coating.METHODS: By atmospheric pressure chemical vapor deposition, the porous tantalum-coated silicon carbide scaffold was prepared. In anin vitro experiment, bone marrow mesenchymal stem cells were co-cultured with the porous tantalum-coated silicon carbide scaffold for 2 weeks. Then cell proliferation was detected using MTT method. Cell adhesion on the scaffold was observed using scanning electron microscope at 5, 10, 15 days after culture. In anin vivo experiment, the porous tantalum-coated silicon carbide material was implanted into the region of femoral head defects in dogs. Experimental animals were kiled at 6, 12 weeks after implantation, and then the specimens of hard tissue sections were stained to observe the implant material and growth of its surrounding tissues under the microscope.RESULTS AND CONCLUSION: (1)In vitro experiment results: with increasing time in the co-culture, bone marrow mesenchymal stem cells exhibited very strong proliferation, mutual connection and close arrangement. Interconnected cells crept into the pores of the porous tantalum-coated silicon carbide scaffold, and completely covered the tantalum surface, then forming overlapped cell clusters. (2)In vivo experimental results: 6 weeks after implantation, there was a clear boundary between the implant and surrounding bone tissues, and only a small amount of bone tissues crept into the porous tantalum-coated silicon carbide material in the presence of a little trabecular bone. Some voids and cracks around the pores of the implant were detectable. Neither damage nor rejection of tissues around materials occurred. At 12 weeks after implantation, the implant was fused well with the surrounding tissues in the presence of a large amount of bone tissues growing into the surface and pores and a large number of trabecular bones. To conclude, the tantalum-coated silicon carbide scaffold prepared by the atmospheric pressure chemical vapor deposition has good biocompatibility.