Lys调节PLGA纳米纤维的体外降解产物酸度的研究  

Effect of Lysine on Regulating Acidity of PLGA Nanofiber Degradation in vitro

作　　者：包敏[1] 周雅慧[1] 袁卉华[1] 娄向新[1] 张彦中[1] 

机构地区：[1]东华大学化学化工与生物工程学院,上海201620

出　　处：《高分子学报》2014年第5期604-612,共9页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号51073032);上海市科学技术委员会"浦江人才计划"(项目号10PJ1400200);中央高校基本科研业务费专项资金项目(项目号11D10540);教育部留学回国人员科研启动基金项目(基金号11W10523)

摘　　要：采用向PLGA纳米纤维中添加碱性氨基酸——赖氨酸（Lys）的方法来降低降解产物的集酸程度．用电纺丝技术制备载Lys的PLGA／Lys复合纳米纤维，并用SEM、DSC、及力学测试等表征手段对该复合纳米纤维的形貌、热学性质以及力学性质等方面进行表征；研究PLGA／Lys复合纳米纤维中Lys的释放特性；对PLGA与PLGA／Lys纳米纤维进行体外降解实验，评价纤维降解过程中的形貌和降解液pH值；用已降解8周的纳米纤维降解液对血管平滑肌细胞进行培养，MTT检测细胞毒性．结果表明，在电压为12kV，注射速率1．0mL／h，温度23℃，湿度20％，接收距离14cm时可以纺出形貌较好的PLGA／Lys复合纳米纤维，Lys含量越多，复合纳米纤维的直径越细．纳米纤维中Lys的含量影响Lys的释放特性．Lys促进PLGA的降解并对改善其降解产物的酸度有一定的缓解作用，含2％Lys的纳米纤维降解8周后可以使降解液pH维持在7．4～6．7之间．降篇的酸性产物不利于平滑肌细胞生长，但含Lys降解液的培养基中细胞生长状态良好，这可能是由于Lys能减轻酸性降解产物对细胞功能的影响，同时也能为细胞增殖提供营养物质．The objective of this study was to alleviate the acidity of PLGA nanofiber degradation in vitro by introducing the basic amino acid Lysine （Lys） into the PLGA nanofibers. PLGA and PLGA/Lys composite nanofibers were prepared via electrospinning, and the morphology,thermodynamic and mechanical properties of these nanofibers were characterized by SEM,DSC and mechanical testing,respectively. Release profiles of the Lys from the PLGA-based composite nanofibers were thereafter determined. Morphology of the degraded nanofibers and pH of the PBS solution,in which PLGA and PLGA/Lys nanofibrous mats were soaked at 37 ~C for up to eight weeks,were assessed to detect the degradation behavior. Finally, cytotoxicity was performed by culturing vascular smooth muscle cells （SMCs） with fluid containing degraded product after eight weeks of degradation. It was found that the release kinetics of Lys from the electrospun PLGA/Lys nanofibers was Lys content dependent. Incorporation of Lys enhanced the degradation process of PLGA and mitigated the decrease of PBS solution pH （acidity）. PLGA nanofibers containing 2% Lys are capable of maintaining the pH value between 7.4 and 6.7. Proliferation of SMCs was hindered in the presence of acidic products. But the SMCs grew well in the solution containing degraded products and Lys.

关 键 词：电纺丝 乳酸-乙醇酸共聚物 赖氨酸 降解 细胞相容性 

分 类 号：R318.08[医药卫生—生物医学工程]