多孔复合材料PHBV—SGBG的体外细胞相容性和体内成骨性

Preliminarily study of a novel porous composite： cytocompatibility in vitro and osteogenesis in vivo

目的 研究新型复合材料3-羟基丁酸-co-3-羟基戊酸共聚物-溶胶-凝胶生物活性玻璃（PHBV-SGBG）对骨髓基质细胞的细胞相容性,并建立动物骨缺损模型,探讨PHBV-SGBG的体内成骨效能.方法 采用MTT法和直接接触法检测复合材料PHBV-SGBG的细胞相容性.制备犬胫骨骨缺损模型,实验组在骨缺损区植入PHBV-SGBG材料,对照组不作处理,分别于术后2、4、8、12周取材,扫描电镜和X线能谱分析观察该材料的体内成骨效能.结果 复合材料PHBV-SGBG的细胞毒性分级在0～1之间,骨髓基质细胞可紧密附着于材料表面,黏附、生长、增殖,并有突起向材料的连通微孔内伸展.实验组术后2周已有明显新骨生成,术后4周时Ca/P元素比值（1.086±0.034）,对照组为（0.793±0.053）,术后12周时骨缺损区充填新生的成熟骨组织,扫描电镜和能谱分析显示实验组Ca峰值逐渐升高：12周时Ca/P元素比值（1.603±0.067）,优于对照组（11456±0.036）（P〈0.05）.结论 复合材料PHBV-SGBG无细胞毒性,具有很好的骨传导性和骨再生能力,有望成为新型的骨组织工程材料.

Objective To study the cytocompatibility of poly （3-hydroxybutyrate-co-3 -hydroxyvalerate）/sol-gel bioactive glass （PHBV/SGBG）composite with bone marrow stromal cells in vitro, and the in vivo osteogenesis efficiency of PHBV/SGBG composite under periosteal flap in bone defect animal models. Methods The cytocompatibility of PHBV/SGBG composite was tested by MTT assay and direct contact assay. Of established tibial defect canine models, PHBV/SGBG composite was embedded into the defects of the experimental group, while no treatment was given to the control group. Samples were harvested at weeks 2,4, 8, and 12 post-surgery. The effect of osteogenesis was inspected by scanning electron microscope observation and energy-dispersive X-ray analysis. Results The cytotoxicity score of PHBV/SGBG composite in the serial dilution extract and different culture time ranked from grades 0 to 1. Marrow stem cells （MSCs） attached to and then adhered firmly on the surface of PHBV/SGBG composite, and proliferated rapidly, with obvious cell prominences stretching into the micro-pores structure. In the experimental group, formation of new bone islands was observed at week 2 post-surgery, and mature bone regeneration at week 12. Scanning electron microscopy and energy-dispersive X-ray analysis showed increasing calcium peak in the experiment group. At week 4 Ca/P ratio was 1.086±0.034 in experiment group and 0.793±0.053 in control group. At week 12 Ca/P ratio was 1.603±0.067 in experiment group and 1.456±0.036 in control group （P〈0.05）. Conclusions PHBV/SGBG shows no cytotoxicity to MSCs, and possesses good osteo-conductibility and regeneration capability. It may be a promising composite for bone tissue engineering.