溶胶-凝胶生物活性玻璃与胶原复合多孔支架的生物相容性研究

摘要

实验前期用冷冻干燥法合成一种溶胶-凝胶生物活性玻璃(BG/COL)与粗胶原纤维复合的组织工程支架.本实验将支架与鼠骨髓间充质干细胞(rMSCs)共同培养,评价支架材料的细胞相容性.并将复合了成骨细胞的支架材料植入裸鼠皮下,探讨其异位成骨的性能.研究结果显示rMSCs可以在BG/COL多孔支架材料表面成功粘附、铺展、并向多孔支架内部迁移,随着培养时间的延长,双链DNA(ds DNA)数量增多,细胞增殖情况与对照组差异明显.将种在复合材料上的骨髓间充质干细胞诱导培养14d后切片染色,其碱性磷酸酶(ALP)和钙素表达均呈强阳性.体内植入实验的裸鼠健康状况良好,伤口完全愈合,6w后BG/COL周边及内部有骨组织和血管生成.由此证明,这种新型的复合多孔支架材料具有良好的生物相容性,其复合了成骨细胞的组织工程骨具有良好的诱导成骨的性能,因此这种材料是理想的应用于骨组织修复和再生的组织工程支架材料.%Biomimetic scaffold for bone tissue engineering was prepared by mixing Sol-Gel bioactive glass with type I collagen through freeze-drying technique. In vitro, the biocompatibility of the scaffold was investigated by observing the adhesive, proliferative and differential behaviors of the rat mesenchymal stem cells (rMSCs). In vivo, the composite scaffold seeded with osteoblasts was implanted subcutaneously into the immunodeficient mice for 6w. It was proved that the composite scaffold was non-cytotoxic and suitable for cells' proliferation, which was confirmed by the increase of double stranded DNA (ds DNA). The differentiation of rMSCs on the composite scaffold was also observed by positive expressions of alkaline phosphatase (ALP) and osteocalcin after osteoinduction for 14d. The results of general and histological observation showed that cells successfully spread on the surface and migrated into the interior of the scaffold. Moreover, bone formation analysis of cell-scaffold constructs in vivo showed that bone tissue and blood vessels were regenerated both inside and on the border of the scaffold-stack. All results demonstrate the Sol-Gel bioactive glass-type I collagen scaffold with good biocompatibility and osteogenesis is a new ideal scaffold for bone tissue repair and regeneration.