【摘要】 目的:研究和比较多孔β-磷酸三钙(β-TCP)陶瓷表面处理前后的成骨能力。方法:有机泡沫浸渍法制得多孔β-TCP陶瓷,用明胶对其表面进行处理,检测处理前后β-TCP陶瓷的孔径、孔隙率和最大抗压强度。将表面处理前(对照组)、处理后(实验组)的β-TCP陶瓷同时接种第2代人骨髓基质细胞(BMSCs),体外成骨诱导培养。测定碱性磷酸酶(ALP)活性和骨钙蛋白(OCN)含量,用以比较细胞在2组材料上的成骨分化能力。将体外培养7d的2组细胞材料复合物回植裸鼠皮下,分别于术后4、8、12周时取材,进行组织学观察与图像分析,评价2组的异位成骨情况。采用配对t检验,分别对实验组和对照组的MTT、ALP、OCN和新生骨小梁面积进行统计学分析。结果:采用明胶进行表面处理后,多孔β-TCP陶瓷的孔径和孔隙率无明显改变,最大抗压强度则显著提高。2组材料的MTT、ALP活性和OCN含量均无显著性差异。2组细胞材料复合物在裸鼠皮下4周时均已成骨,并随时间延长,新生骨量增多。2组在各时间点的新生骨小梁面积无显著性差异(P>0.05)。结论:明胶表面处理后的多孔β-TCP陶瓷的生物力学强度显著增高,并对人BMSCs的增殖与成骨分化能力无影响,为负重骨替代材料的研究提供了新的选择。更多还原

【Abstract】 PURPOSES:To study and compare the osteogenic capability of porous β-tricalcium phosphate(β-TCP)ceramics with and without surface cross-linking treatment.METHODS:The surface of porous β-TCP ceramics prepared by polymeric sponge method was modified by cross-linking treatment with gelatin.The pore size,porosity as well as maximum compressive strength of β-TCP ceramics with(experiment group)and without(control group)the surface treatment were measured respectively.Both β-TCP scaffolds were seeded with human bone marrow stromal cells(BMSCs)of the same cell density at passage 2 and cultured in osteogenic media in vitro.Cell proliferation and osteogenic differentiation on the scaffolds were evaluated with MTT assay,the alkaline phosphatase(ALP)activity,and osteocalcin(OCN)content was also measured.After 7 days of culture,simultaneously cultured scaffolds with and without surface cross-linking treatment and seeded with human BMSCs were implanted subcutaneously into nude mice.Samples were harvested at 4,8 and 12 weeks after implantation and the bone formation in each group was observed.The results of MTT,ALP,OCN and areas of newly formed trabeculae of the experimental group and the control group were evaluated with paired t test respectively.RESULTS:Maximum compressive strength of β-TCP scaffolds was improved dramatically with surface cross-linking treatment,while the pore size and porosity almost remained the same.After human BMSCs were seeded onto the scaffolds of both groups,MTT assay showed the same trend of cell proliferation on the scaffolds.Measurements of ALP activity and OCN content showed the osteogenic differentiation of human BMSCs on both scaffolds,and there was no significant difference between the groups.New bone formed after 4 weeks of implantation in both groups,and osteogenesis progressed with time.The proportion of bone to pores at each time showed no significant difference between the two groups.CONCLUSIONS:Surface cross-linking treatment could increase the biomechanical strength of β-TCP scaffolds,without impairing their capability of promoting cell proliferation and osteogenic differentiation of human BMSCs,so the modified β-TCP ceramics may be used as scaffolds to repair weight-bearing bone defects.Supported by National "973" Project-the Basic Scientific Problems in Tissue Engineering(Grant No.G1999054308),National "863" Project-Construction of Tissue Engineered Bone:Technical Research and Products Development(Grant No.2002AA205011)and Key in Key Subject Construction Project of Shanghai Municipal Education Commission.更多还原