新型多孔钽金属支架材料的生物学评价

Biological evaluation of a novel porous tantalum scaffold

背景:利用涂层制备技术在传统材料基体上沉积金属钽涂层,既利用了金属钽优异生物学性能又可降低成本,为金属钽器件的应用提供了一条切实可行的方向。目的:制备金属钽涂层支架材料,观察其体内外生物相容性。方法:采用常压化学气相沉积技术在多孔碳化硅基体上制备多孔金属钽涂层支架材料,进行以下实验:(1)体外实验:将骨髓间充质干细胞与多孔金属钽涂层支架材料共培养2周,MTT法检测细胞增殖;培养第5,10,15天,扫描电镜观察细胞在材料表面附着情况;(2)体内实验:在犬股骨头骨缺损处植入多孔钽材料,分别于植入后6,12周处死实验动物,将标本硬组织切片染色后,显微镜下观察多孔钽材料与周围组织的生长情况。结果与结论:(1)体外实验结果:随着培养时间的延长,骨髓间充质干细胞呈现出极其旺盛的增殖,相互排列紧密,细胞之间连接并爬行生长进入多孔钽孔隙中,细胞完全覆盖在多孔钽表面,细胞与细胞之间形成团状重叠现象;(2)体内实验结果:植入6周,材料与骨组织周围界限清晰,多孔钽孔隙中有少量骨组织爬行,有少许骨小梁长入,未附着部分可见孔隙周围空虚及缝隙,材料周围未见组织破坏及排斥反应;植入12周,可明显观察到材料与骨组织生长良好,多孔钽表面和孔隙内大量骨组织长入,材料孔隙与组织紧密连接,有大量骨小梁长入,多孔钽与骨组织融于一体;(3)结果表明:采用常压化学气相沉积技术制备的金属钽涂层支架材料具有良好的生物相容性。

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 an in 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 an in vivo experiment, the porous tantalum-coated silicon carbide material was implanted into the region of femoral head defects in dogs. Experimental animals were killed 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.