预分化脂肪干细胞与纤维蛋白胶和磷酸钙骨水泥自体异位构建血管化移植物

背景：预构骨皮瓣研究启发人们构建预构血管化骨进行游离移植来替代带血管蒂游离自体骨移植修复大段骨缺损的想法。 目的：设计一种基于预分化脂肪干细胞、纤维蛋白胶和多孔磷酸钙骨水泥支架复合体的血管化移植物。 方法：将体外分离培养的大鼠脂肪干细胞在条件培养基中进行血管内皮细胞定向分化，经鉴定活性后，复合至纤维蛋白胶和多孔磷酸钙骨水泥构建血管化组织工程支架。将血管化组织工程支架、纤维蛋白胶/多孔磷酸钙骨水泥支架及多孔磷酸钙骨水泥支架分别植入SD大鼠股四头肌肌袋内，植入后2，4周进行组织学检测、血管定量分析和Western blot检测。 结果与结论：向血管内皮细胞分化的脂肪干细胞与纤维蛋白胶和多孔磷酸钙骨水泥共培养7 d，可见细胞密度适中，与支架组织结合较好。植入实验中，各组支架孔隙中充填有纤维血管组织和脂肪组织，血管化组织工程组支架孔隙中均长入大量血管，并有小动脉长入，不同时间点的血管直径和数量及血管内皮生长因子C的表达量均优于纤维蛋白胶/多孔磷酸钙骨水泥组和多孔磷酸钙骨水泥组(P < 0.01)。表明构建的血管化组织工程支架能够实现可靠迅速血管化。中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程全文链接：

Prefabrication of vascularized grafts based on pre-differentiated adipose derived stem cells,fibrin sealant and porous calcium phosphate cement scaffold

BACKGROUND:Construction of vascularized bone substitutes to mimic free vascularized fibular grafting in treating large bone defects still remains challenges to researchers during the past years. OBJECTIVE:To design and construct a new vascularized tissue-engineered bone graft using pre-differentiated adipose derived stem cells, fibrin sealant and porous calcium phosphate cement scaffold.  METHODS:Adipose derived stem cells isolated from rats were directly differentiated to endothelial cells and then incorporated in fibrin sealant and porous calcium phosphate cement scaffolds in vitro. Subsequently, the different composites of the three groups including vascularized tissue-engineered bone scaffold (group A), fibrin sealant and porous calcium phosphate cement scaffold (group B) and porous calcium phosphate cement scaffold (group C) were directly embedded into the quadriceps of the rats. Histological quantitative analysis and western blot assay were conducted 2 and 4 weeks after implantation. RESULTS AND CONCLUSION:The pre-differentiated adipose derived stem cells were demonstrated in good condition after 7 days co-culturing with the fibrin sealant and porous calcium phosphate cement scaffold. The  results of in vivo experiments showed that the scaffolds were in-grown together with fibrous connective tissues and blood vessels. Newly formed vessels and immature capillaries were observed in the group A. The vessel density, vessel diameter and vascular endothelial growth factor C expression in the group A were significantly higher than those in the groups B and C. Our findings demonstrated that compared with simply fibrin sealant and porous calcium phosphate cement scaffold, the combination of pre-differentiated adipose derived stem cells (endothelial differentiation) and fibrin sealant can achieve rapid angiogenesis of porous calcium phosphate cement scaffold.