负载BMP的新型组织工程骨的构建及骨缺损修复实验

目的 探讨以聚乳乙醇酸(poly-(D,L-lactide-co-glycolide),PLGA)、骨形态发生蛋白(BMP)、骨髓基质干细胞(BM-SCs)构建成新型组织工程骨并观察其在动物体内的成骨能力。方法 制作新西兰大白兔右桡骨中段15mm骨缺损实验模型,随机分为实验组、对照组和空白组,实验组植入同时负载5mgBMP及1×10⁶个已向成骨细胞诱导的BMSCs的PLGA、对照组植入负载1×10⁶个已向成骨细胞诱导的BMSCs的PLGA、空白组仅植入PLGA。术后对动物进行大体观察、摄X线片观察各组不同时相骨缺损修复情况、比较不同时相的骨缺损区X线阻射密度、并于术后第4、8、12周取出骨缺损区标本进行大体观察和组织学切片观察,图像分析骨小梁的生成数量。结果 实验组在12周内骨缺损完全修复,且同时期内新生骨的数量和质量显著优于对照组,空白材料组骨缺损主要由纤维结缔组织填充。结论 利用含BMP的PLGA支架与BMSCs复合构建的新型组织工程骨具有良好的骨缺损修复能力。

Bone defect repair with a new tissue-engineered bone carrying bone morphogenetic protein in rabbits

Objective To construct a new tissue-engineered bone with poly (D, L-lactide-co-glycolide) (PLGA), bone morphogenetic protein (BMP) and bone marrow-derived stem cells (BMSCs) and observe its effect in repairing segmental bone defects. Methods A 15-mm bone defect in the right radius was induced in New Zealand white rabbits, and the models were randomized into three groups to receive implantation of the tissue-engineered bone grafts constructed with PLGA carrying 5 mg BMP and about 1×10⁶ BMSCs (experimental group), grafts of PLGA with about 1×10⁶ BMSCs (control group), or grafts of exclusive PLGA (blank control group), respectively. The osteogenesis in the bone defect after the implantation on was evaluated X-ray films, and the histological changes of the tissues sampled from the bone defect 4, 8, and 12 weeks after operation were observed and new bone formation was measured by image analysis. Results The bone defect was completely repaired in the experimental group 12 weeks after the implantation, showing the best results among the 3 groups. The bone defects in the blank control group was filled with only fibrous and connective tissues at 12 weeks. Conclusion This tissue-engineered bone constructed with PLGA, BMP and BMSCs possesses good ability in repairing segmental bone defect.