骨髓间充质干细胞与同种异体骨复合修复犬下颌骨缺损:成骨能力检测

Bone mesenchymal stem cells with allogeneic bone to repair canine mandibular defects:detection of osteogenic ability

背景:同种异体骨与自体骨有相似解剖外形和生物学特性,是较佳的生物支架材料。自体骨髓来源的间充质干细胞具有多分化潜能,能向成骨、成软骨细胞分化,加速骨组织及软骨组织的形成。目的:探讨同种异体骨支架复合自体骨髓间充质干细胞促进犬下颌骨半侧缺损的新骨成骨能力。方法:拔出24只比格犬左侧下颌牙,伤口愈合后2个月,人为造成犬下颌骨缺损,对照组用单纯冻干同种异体骨修复,实验组用同种异体冻干骨加自体骨髓间充质干细胞修复。术后4,12,24周对下颌骨体部进行骨密度扫描以及Micro-CT检查。结果与结论:实验组移植后12周开始,下颌骨的骨密度显著高于对照组(P<0.05),随着时间推移,实验组和对照组骨密度均增高,但实验组增高明显高于对照组。随时间推移,实验组骨结构参数成阶梯式递增或递减,对照组虽也有递增或递减,但不明显。术后24周实验组感兴趣区骨小梁分离度大于对照组(P<0.05),骨体积分数、骨小梁数量、骨小梁厚度小于对照组(P<0.05)。结果表明骨髓间充质干细胞能加速同种异体骨的骨改建速度。

BACKGROUND：Al ogeneic bone has anatomical appearance and biological features similar to autogenous bone, which is an excel ent biological scaffold material. Mesenchymal stem cel s originating from autogenous bone marrow have mutli-lineage differentiation potential, can differentiate into osteoblasts and chondrocyte, and thus can accelerate the formation of bone tissue and cartilage tissue. OBJECTIVE：To establish the osteogenic ability of al ogeneic bone with autogenous bone marrow mesenchymal stem cel s for repairing major mandibular defects. METHODS：The left mandibular teeth of 24 beagles were extracted, and at 2 months after wound healing, mandibular defects were made artificial y. The beagles were divided into two groups：control group treated with lyophilized al ogeneic bone, and experimental group with autogenous bone marrow mesenchymal stem cel s and lyophilized al ogeneic bone. Densitometry with CT and Micro-CT was conducted 4, 12, and 24 weeks after surgery. RESULTS AND CONCLUSION：Compared with the control group, the bone density of the mandible was significantly higher in the experimental group at 12 weeks after transplantation （P〈0.05）. Over time, the bone densities in the two groups were both increased, but the bone density in the experimental group was always higher than that in the control group. Bone structure parameters were progressively increased or decreased in the two groups, especial y in the experimental group. At 24 weeks after surgery, the degree of trabecular separation in regions of interest was higher in the experimental group than the control group （P〈0.05）, but the bone volume fraction, number of trabecular bone, and bone trabecular thickness were significantly lower in the experimental group than the control group （P〈0.05）. These findings indicate that bone marrow mesenchymal stem cel s are capable of accelerating the reconstruction of al ogeneic bones.