负载IGF-1的聚多巴胺改性PLGA多孔微载体的制备及对MC3T3-E1细胞增殖、分化的影响

Preparation of polydopamine-modified PLGA porous microcarrier loaded with IGF-1 and its effect on proliferation and differentiation of MC3T3-E1 cells

目的 探讨聚多巴胺改性聚乳酸-羟基乙酸共聚物（PLGA）及负载胰岛素样生长因子1（IGF-1）后对材料性能和MC3T3-E1细胞增殖、分化的影响.方法 乳化挥发法制备PLGA多孔微载体,使用聚多巴胺对微载体进行表面改性并负载IGF-1.采用扫描电子显微镜、傅里叶变换红外光谱仪和接触角测试仪检测聚多巴胺改性前后PLGA多孔微载体的表面形貌结构、表面基团和亲水性,以溶菌酶为模型蛋白采用BCA法检测改性前后材料的蛋白吸附能力.PLGA微载体（PLGA组）、聚多巴胺改性PLGA微载体（PD-PLGA组）和负载IGF-1的聚多巴胺改性PLGA微载体（PD-PLGA/IGF-1组）分别与MC3T3-E1细胞共培养,采用MTT法、DIPI染色和碱性磷酸酶（ALP）活性测定观察PLGA多孔微载体聚多巴胺改性和负载IGF-1后对MC3T3-E1细胞增殖、黏附和成骨分化的影响.结果 扫描电子显微镜观察显示PLGA微载体表面呈多孔结构,红外光谱分析证明聚多巴胺成功附着在PLGA微载体表面.聚多巴胺改性后PLGA微载体亲水性能得到很大改善,表面蛋白吸附能力显著提高（均P＜0.05）.与MC3T3-E1细胞共培养7d后,PD-PLGA组和PD-PLGA/IGF-1组的细胞增殖率和ALP活性均显著高于PLGA组（均P＜0.05）.与MC3T3-E1细胞共培养3d后,DIPI染色显示PD-PLGA组和PD-PLGA/IGF-1组的贴壁细胞数均高于PLGA组.结论 PLGA多孔L微载体经聚多巴胺表面改性后其生物性能有很大程度的提高,负载IGF-1后能显著促进细胞增殖和成骨分化.

Objective To investigate the effect of polydopamine-modified poly （lactic-co-glycolic acid） （PLGA） and loaded with insulin-like growth factor 1 （IGF-1） on the material performance,and proliferation and differentiation of MC3T3-E1 cells.Methods The PLGA porous microcarriers were prepared by emulsion-solvent evaporation.The microcarriers were surface-modified with polydopamine and loaded with IGF-1.The surface morphology,surface groups and hydrophilicity of PLGA porous microcarriers were determined by scanning electron microscopy,Fourier transform infrared spectroscopy （FTIR） and contact angle tester before and after polydopamine modification.Lysozyme was used as the model protein,and BCA method was used to examine the protein adsorption of the material before and after the modification.PLGA microcarriers （PLGA group）,polydopamine-modified PLGA microcarriers （PD-PLGA group） and IGF-l-loaded polydopamine-modified PLGA microcarriers （PD-PLGA/IGF-1 group） were co-cultured with MC3T3-E 1 cells,respectively.The effect of polydopamine-modified and IGF-l-loaded PLGA microcarriers on proliferation,adhesion and osteogenic differentiation of MC3T3-E1 cells were determined by MTT assay,DIPI staining and alkaline phosphatase （ALP） activity assay.Results Scanning electron microscopy showed that the surface of PLGA microcarriers was porous.Infrared spectroscopy analysis showed that polydopamine was successfully adhered to the surface of PLGA microcarriers.The hydrophilicity of PLGA microcarriers modified by polydopamine was greatly improved,and the adsorption capacity of surface protein was increased significantly （both P〈0.05）.At 7 d after co-culture with MC3T3-E 1 cells,the cell proliferation and ALP activity in the PD-PLGA group and PD-PLGA/IGF-1 group were significantly higher than those in the PLGA group （all P〈0.05）.At 3 d after co-culture with MC3T3-E1 cells,DIPI staining showed that the number of adherent ceils in the PD-PLGA group and PD-PLGA/IGF-1 group was higher than that in the PLGA group.Conclusion After the surface modification with polydopamine,the biological properties of PLGA porous microcarriers can be significantly improved;and loaded with IGF-1,it can significantly promote cell proliferation and osteogenic differentiation.