本人前期实验表明载rhBMP-2中空HA微球/壳聚糖具有良好修复骨缺损作用，然而对于大段或腔隙大的骨缺损因局部种子细胞少或缺无，其骨修复效果仍待提高，修复大段骨缺损仍是一难题。增加载体内种子细胞数量可显著提高其修复能力。趋化因子能够诱导细胞向其趋化迁移，研究表明趋化因子CXCLl3可以募集间充质干细胞参与成骨。因此我们提出假设：能否在载rhBMP-2中空HA微球/壳聚糖复合物中加入CXCLl3，以期突破大段骨缺损修复难题？理论上该新型复合物具备以下优势：①中空HA让rhBMP-2和CXCLl3缓释，②CXCLl3可招募种子细胞，③rhBMP-2促进种子细胞成骨分化，④中空HA微球/壳聚糖是一良好骨生长支架。因此，该新型复合物很好地具备了骨组织工程支架、种子细胞、生长因子三要素。本申请拟从分子和细胞水平上探索其在体内的骨缺损修复作用机制,为其临床应用提供理论基础。

my pre-experiment contained recombinant human bone morphogenetic protein -2 (rhBMP-2) hollow hydroxyapatite (HA) microspheres / chitosan has a good effect repair of bone defects, however, for large bone defects or cavities large bone defects due to lack of local seed cells with little or no, its effect remains to improve bone repair. In previous studies combined with others on the basis of the relevant research, this study recruited to join the chemokine CXCLl3 seed cells in the complex, made carrier rhBMP-2 / rhCXCLl3 hollow hydroxyapatite (HA) microspheres / chitosan complex, theoretically achieve the following purposes, ①CXCLl3 recruit a sufficient number of complementary and vitality of seed cells, ②rhBMP-2 to promote recruitment from seed cells into osteoblasts, ③ hollow HA allows rhBMP-2 and CXCLl3 sustained, controlled release slow-release, you can better promote bone regeneration, bone repair. This application will study the composite system in rhBMP-2, rhCXCLl3 vivo release kinetics, keep active, osteoinductive properties of composite materials in vitro biocompatibility in vivo bone repair capacity and mechanisms for clinical applications theoretical basis.