蚕丝/聚乳酸-羟基乙酸共聚物支架降解液与骨髓间充质干细胞的增殖

背景：前期研究表明,蚕丝/聚乳酸-羟基乙酸共聚物支架浸提液具有良好的细胞相容性,基本无细胞毒性。目的：观察蚕丝/聚乳酸-羟基乙酸共聚物纤维细丝混合编织支架体外长期降解过程中降解液对兔骨髓间充质干细胞增殖活性的影响。方法：将蚕丝/聚乳酸-羟基乙酸共聚物细丝混合编织支架材料置于完全培养基中体外降解14周,每周换液1次,测定各周支架降解液的pH值。将兔骨髓间充质干细胞分组培养,实验组加入各周支架降解液和新鲜完全培养基各100 µL,阴性对照组加入完全培养基200 µL,培养4 d。MTT法检测细胞增殖、生长情况。结果与结论：①支架降解液pH值的变化：前3周下降缓慢,从7.00降到6.89;第4周起下降较快,6-11周较低,在5.16-5.67之间;12-14周呈上升趋势,回升到6.95。②骨髓间充质干细胞形态：实验组及阴性对照组细胞增殖生长及形态状况基本相似。降解7-10周支架降解液对细胞的生长有抑制作用,细胞数量相对较少、较疏,而其余各周支架降解液对细胞生长无明显抑制作用。③骨髓间充质干细胞的增殖：1-6周及11-14周的支架降解液对细胞增殖无显著影响,细胞相对增殖率均在92.1%以上,毒性分级为0或1级;7-10周的支架降解液虽对细胞增殖有抑制作用,但细胞相对增殖率为82.5%-87.9%,毒性分级为1级,为合格。表明蚕丝丝素/聚乳酸-羟基乙酸共聚物混合编织支架降解液具有良好的细胞相容性。

Silk/poly(lactic-co-glycolic acid) scaffold degradation fluid and proliferation of bone marrow mesenchymal stem cells

BACKGROUND:Previous studies showed that silk/poly(lactic/co-glycolic acid) copolymer scaffold has good cytocompatibility and no cytotoxicity.OBJECTIVE:To observe the effects of degradation fluid of silk/poly(lactic-co-glycolic acid) braided scaffold on the proliferation and growth of rabbit bone marrow-derived mesenchymal stem cells in vitro.METHODS:The silk/poly(lactic-co-glycolic acid) braided scaffold was degraded in complete culture medium for 14 weeks in vitro, and medium was replenished every week. The pH value of degradation fluid of the scaffold was determined every week. Rabbit bone marrow mesenchymal stem cells were cultured with degradation fluid and complete medium each 100 µL (experimental group), while negative control group was added with complete medium 200 µL, culturing for 4 days. The proliferation and growth of mesenchymal stem cells was detected with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.RESULTS AND CONCLUSION:(1) pH value changes of degradation fluid of silk/poly(lactic-co-glycolic acid) scaffold: pH value declined slowly with the first 3 weeks, from 7.00 to 6.89. However, the value went down quickly at 4 weeks, maintained a low level at 6-11 weeks, between 5.16 and 5.67. Then pH values increased at 12-14 weeks, rising to 6.95. (2) Morphology of mesenchymal stem cells: The proliferation and growth of mesenchymal stem cells in experimental group and negative control group were basically similar. Degradation fluid inhibited the cell growth at degradation 7-10 weeks, exhibiting relatively less counts and sparse arrangement of the cells, while degradation fluid in other weeks had no obviously inhibition on the cell growth. (3) Proliferation of mesenchymal stem cells: Degradation fluid of the scaffolds at 1-6 weeks and 11-14 weeks had no significant impact on cell proliferation, and the relative growth rates of the cells were all over 92.1%, with toxicity grade 0 or 1 level; degradation fluid at 7-10 weeks had an inhibition effect on cell proliferation, but relative growth rates were 82.5%-87.9%, with toxicity grade 1 level, as qualified. Experimental findings indicate that, the degradation fluid of silk/poly(lactic-co-glycolic acid) braided scaffold has a good cytocompatibility.