复合血管内皮细胞的不同孔径磷酸钙陶瓷体内血管化的比较研究

A Comparative Study on Vascularization of Two Different Pore Structure β-TCP Combined with Vascular Endothelial Cell in Vivo

目的：比较不同孔径多孔β-TCP材料复合血管内皮细胞后的体内血管化，探索孔隙大小对人工骨材料体内血管形成的作用。方法：血管内皮细胞与连通径均为100μM，而孔径分别为200-300μM和300-400μM两种不同孔隙结构β-TCP材料复合后包埋入36只成年新西兰兔的腿部肌肉内，相同结构的空白β—TCP材料作对照，术后2、4、8周对材料进行组织学观察、免疫组织化学分析，计算新生血管密度。结果：复合血管内皮细胞的材料血管形成启动过程早于空白对照组，术后第4周血管管腔已基本成形，并基本稳定，至第8周开始血管充盈，微血管密度高于对照组（P〈0．05）。而不同孔径的材料比较发现，不论是复合血管内皮细胞的材料还是空白材料，孔径300-400μM的材料内新生血管密度显著显著高于孔径200-300μM材料（P〈0．05）。结论：材料孔隙较大的材料更有利于材料体内的血管化，而复合血管内皮细胞后，更加快了其血管化进程，这一研究结果提示材料孔隙间的连通是影响材料体内血管化的关键因素，该研究结论将为改善人工骨材料体内血管化的方法提供新的思路，同时也为骨移植材料的最优结构的选择提供一定的借鉴。

Objective： To compare the vascularization of two different three-dimensional structure β-TCP biomaterials combined with vascular endothelial cell in vivo. To explore the effect of pore in the vascularization of artifical bone. Methods： Thirty-six adult rabb- its were selected for operation. Two different three-dimensional structure β-TCP biomaterials （ the pore diameter is 200-300 μM and 300-400μM, but the same pore interconnection diameter is 100 μM） were planted separately into muscle of every rabbit. The specimens were harvested in 2,4,8 weeks after surgery for histology, immunohistochemistry and account the neovessels density in β-TCP. Results： The vascularization of β-TCP combined with vascular endothelial cell was earlier than that in blank control group. In four weeks of implantation, blood vessel lumens were formed in β-TCP combined with vascular endothelial cell, and angioplerosis could be found in 8 weeks. The microvessel density in β-TCP combined with VEC was higher than thatofblank control group（P〈0.05）. No matter with VEC or not, the microvessel density in the β-TCP with pore diameter 300-400 μM was higher than that in the β-TCP with pore diameter 200-300 μM（P〈0.05）. Conclusion： The larger pore can induct more complete vascularization of scaffolds, and the vascularizafion can be accelerated as scaffolds combined with vascular endothelial cell. These conclusions will provide new ideas for the improvement of the efficiency of bioceramic bone substitutes vascularisation in vivo. At the same time, these conclusions will help to choose the optimal structure of bone implants.