聚磷腈微球搭载生长因子时间缓释对骨髓间充质干细胞粘附和增殖的影响

Effects of Polyphosphazene Microspheres Controlled Release of Growth Factors on the Adhesion and Proliferation of Bone Marrow Mesenchymal Stem Cells

目的:考察聚磷腈微球搭载生长因子时间缓释对骨髓间充质干细胞粘附和增殖的影响。方法:根据聚磷腈聚合物侧链氨基取代比例不同,应用双乳液法制备两种聚磷腈缓释微球,分别装载转化生长因子TGF-β1和胰岛素样生长因子IGF-1,使用ELISA探索其体外缓释性能并设计生长因子时空缓释策略,并利用SD大鼠骨髓间充质干细胞测试聚磷腈微球材料的生物活性、细胞粘附性,以及吖啶橙染色方法比较生长因子缓释对细胞增殖的影响。结果:两种聚磷腈微球具有不同的形貌特征,分为表面光滑和粗糙两种微球,粒径分布集中,两种微球的平均粒径分别为54.22±19.19μm和34.11±18.82μm。体外释放试验提示两种微球具有不同的缓释特性,设计时间缓释策略为早期突发释放TGF-β1和IGF-1发挥生长因子协同作用,后期持续释放TGF-β1诱导干细胞分化。吖啶橙染色结果显示聚磷腈微球支持细胞粘附和生长,无明显细胞毒性,并且生长因子时空缓释策略能够明显提高BMSCs的增殖效果。结论:聚磷腈缓释微球具有良好的缓释效能,两种微球构建的时间缓释体系能够在组织工程领域具有良好的应用前景。

Objective To investigate the effect of polyphosphazene（PAGP） microspheres controled release of growth factors on the adhesion and proliferation of bone marrow mesenchymal stem cells（BM-SCs）. Methods Two kinds of functional poly（alanine ethyl ester-co-glycine ethyl ester） phosphazene microspheres with different ratios of side-substituent groups were synthesized using the emulsion technique. The rate of degradation/hydrolysis of the polymers was carefully tuned to suit the desired application for controlled release. The enzyme-linked immune sorbent assay was utilized to investigate the characterization of the temporal controlled release strategy of microspheres loaded with transforming growth factor-beta 1（TGF-β1） and insulin-like growth factor-1（IGF-1） respectively. The cell adhesion and proliferation stimulated by different growth factors were evaluated by acridine orange staining. Results The morphological difference between two PAGP microspheres was identified according to SEM images. The average diameter of two microspheres was 54.22 ± 19.19 μm and 34.11 ± 18.82 μm respectively. The release assay showed that two kinds of microspheres had different release characteristics,with earlier outburst of TGF-β1 and IGF-1 for them to cooperate and later sustained release of TGF-β1 to stimulate the differentiation of stem cells. The result of the acridine orange staining demon-strated that PAGP microspheres supported cell adhesion and growth without obvious cytotoxicity. Mean-while,the growth factors release strategy significantly improved the proliferation of BMSCs. Conclusion The two polyphosphazene microspheres have a great release-control effect and their controlled release system will have a promising prospect in the future tissue engineering field.