以基因修饰的脂肪来源干细胞结合自体脂肪组织骨架治疗萎缩型骨不连疗效的研究

The treatment of atrophic non-union remains as a clinical challenge in orthopedic. The commonly used external fixation treatment is ineffective. Various difficulties lie in the use of autologous transplantation, allograft and biological materials, such as bio-stimulation treatment. Stem cells and BMP-2 can promote the reparation of bone injury. In our previous study, we found that Nell-1 can significantly improve the rat spinal fusion, and it can greatly improve the segmental femoral bone critical defects in a dose-dependent manner. VEGF and bFGF have demonstrated benefit in bone regeneration. Our recent study also demonstrated that Oct-4 transduced ASCs can accelerate bone repair in rats by using an adipose scaffold forming into a desired shape. Moreover, in preliminary experiments we demonstrated that BMP-2 combined with Nell-1 dramatically increased bone regeneration. Adipose-derived stem cells have the advantages of easy preparation and in vitro cell expansion. The genetic engineered stem cells combined with autologous adipose tissue scaffold represent a promising approach for bone regeneration in atrophic non-union. In order to develop an effective strategy for stem cell-based therapy of atrophic non-union, this proposal wants to: 1) establish a rat atrophic nonunion model; 2) evaluate the efficacy of genetic engineered ASCs combined with adipose tissue scaffold on the bone regeneration, and 3) use collagen scaffold controls, to compare the efficacy of different scaffold for bone regeneration in atrophic non-union. The aim of this study is to explore and provide a scientific basis for effective treatment of atrophic nonunion.

萎缩型骨不连的治疗需同時促进骨再生及血供，单纯通过外固定治疗效果欠佳。我们先前的大段骨缺损相关研究表明聯合干细胞和BMP-2等骨生长因子可促进骨修复；并证明Nell-1可显着改善大鼠脊柱融合及股骨节段性临界缺损的骨再生；预实验更显示BMP-2 联合Nell-1在大段骨缺损大鼠模型可大幅促进骨再生。脂肪组织来源干细胞(ASCs)具有制备容易，细胞增殖快的优点；我们先前研究已成功利用自体脂肪组织作为骨架，植入Oct-4修饰的ASCs后可大幅加速骨损伤的修复。而文献表明VEGF和bFGF可促进血管生成，调节骨组织血液供应并参与骨发育。本课题擬应用先前研究成果，通过萎缩型骨不连大鼠模型，探讨联合Nell-1, BMP-2, VEGF和bFGF基因修饰的ASCs对萎缩型骨不连的治疗效果，并比较使用脂肪组织骨架和胶原骨架的差异，为开发基因转染干细胞临床治疗萎缩型骨不连提供有效治疗方案及理论依据。

萎缩型骨不连的治疗需同時促进骨再生及血供，单纯通过外固定治疗效果欠佳。我们先前 的大段骨缺损相关研究表明联合干细胞和BMP-2等骨生长因子可促进骨修复；并证明Nell-1可 显着改善大鼠脊柱融合及股骨节段性临界缺损的骨再生；预实验更显示BMP-2 联合Nell-1在大 段骨缺损大鼠模型可大幅促进骨再生。脂肪组织来源干细胞(ASCs)具有制备容易，细胞增殖快 的优点；我们先前研究已成功利用自体脂肪组织作为骨架，植入Oct-4修饰的ASCs后可大幅加 速骨损伤的修复。而文献表明VEGF和bFGF可促进血管生成，调节骨组织血液供应并参与骨发育 。本课题擬应用先前研究成果，通过萎缩型骨不连大鼠模型，探讨联合Nell-1, BMP-2, VEGF 和bFGF基因修饰的ASCs对萎缩型骨不连的治疗效果，并比较使用脂肪组织骨架和胶原骨架的差 异，为开发基因转染干细胞临床治疗萎缩型骨不连提供有效治疗方案及理论依据。