中文摘要：

目的探讨基底硬度与形貌协同对大鼠骨髓间充质干细胞（rat bone mesenchymal stem cells,r BMSCs）形态、增殖以及成骨分化的影响。方法分别在硬度为3.5 MPa、槽、脊宽为0.3μm的聚二甲基硅氧烷（polydimethylsiloxane,PDMS）基底;硬度为3.5 MPa、槽、脊宽为1.8μm的PDMS基底;硬度为3.5 MPa的平面PDMS基底;硬度为0.27 MPa、槽、脊宽为0.3μm的PDMS基底;硬度为0.27 MPa、槽、脊宽为1.8μm的PDMS基底;硬度为0.27 MPa的平面PDMS基底上培养r BMSCs,利用倒置荧光显微镜观察r BMSCs的形态,CCK-8试剂盒检测r BMSCs的增殖情况,碱性磷酸酶（alkalinephosphatase,ALP）试剂盒检测r BMSCs的ALP活性,免疫荧光技术检测骨钙蛋白（osteocalcin,OCN）及I型胶原（collagen type I,COL I）的表达,qRT-PCR检测Runx2 mRNA的表达。结果在硬度为3.5 MPa以及槽、脊宽为0.3μm的PDMS上r BMSCs铺展更好、增殖更快,ALP活性更高,OCN、COL I及Runx2mRNA表达量明显多于其他各组。结论基底硬度对r BMSCs的增殖有明显影响,而硬度与形貌能协同促进r BMSCs的增殖及成骨分化。研究结果有助于了解生物物理因素在某些疾病（如骨质疏松）发病机制过程中的作用,并可为骨组织工程新材料的研发提供理论基础。

英文摘要：

Objective To investigate the synergic effects of substrate stiffness and topography on the morphology,proliferation and osteogenic differentiation of rat bone mesenchymal stem cells（ r BMSCs）. Methods r BMSCs were cultured on polydimethylsiloxane（ PDMS） substrates with different stiffness（ 3. 5,0. 27 MPa） and ordered ridges and grooves（ width 0. 3 or 1. 8 μm,depth 0. 5 μm） or planar substrate. Inverted fluorescence microscope was used to observe the morphology of r BMSCs. CCK-8 reagent was used to detect the proliferation of r BMSCs.Alkaline phosphatase（ ALP） kit was used to detect the ALP activity of r BMSCs. Immunofluorescence technique was used to detect the expression of osteocalcin（ OCN） and collagen I（ COL Ⅰ）. QRT-PCR technique was used to detect the expression of Runx2 mRNA. Results r BMSCs cultured on substrate with 3. 5 MPa stiffness,0. 3 μm ridge width,0. 3 μm groove width showed greater proliferation,spreading,cytoskeleton arrangement,and OCN and COL Ⅰ secretion,ALP activity,Runx2 mRNA expression were significantly increased as compared to cells cultured on other groups. Conclusions Substrate stiffness has an obvious influence on r BMSCs proliferation,while substrate stiffness and topography can synergistically promote the proliferation and osteogenic differentiation of r BMSCs. The research findings not only help to understand the biophysical factors in the pathogenesis of certain diseases（ such as osteoporosis）,but also provide a theoretical basis for developing new materials for bone tissue engineering.