【摘要】 采用紫外活化二氧化氯自由基（ClO₂·）氧化甲基的方法,在聚乳酸（PLA）表面接枝了羧基等含氧官能团,以增加PLA表面的亲水性和生物相容性。通过X射线光电子能谱分析和接触角分析,探究了改性后PLA表面元素组成的变化、最佳的氧化条件及氧化反应对PLA表面亲水性的影响。通过拉伸实验分析了氧化过程对PLA力学性能的影响。通过体外细胞增殖和细胞活性测试研究了改性后PLA表面的生物相容性变化。结果表明,羧基等含氧官能团在PLA表面成功生成;最佳氧化时间为10 min,最佳氧化温度为90℃,该条件下氧化后材料的表面接触角由82°降低至62.5°,表面亲水性得到改善;改性后PLA的拉伸强度不变,断裂伸长率略有下降;氧化后PLA表面显示出更好的细胞黏附能力和细胞增殖能力,更有利于细胞的生长。更多还原

【Abstract】 The oxygen-containing functional groups such as carboxyl groups were generated on the surface of poly(lactic acid)(PLA)by means of methyl oxidation through ultraviolet-activated sodium chlorite free radicals(ClO·). This can enhanced the hydrophilicity and cytocompatibility of the PLA surface. The surface element composition,optimum oxida-tion condition,and influence of oxidation reaction on the surface hydrophilicity of PLA were investigated by X-ray photo-electron spectroscopy and contact angle analysis. The effect of oxidation process on the mechanical properties of PLA was analyzed through a tensile test. The biocompatibility of the surface-modified PLA was studied by cell proliferation and cell activity tests in vitro. The experimental results indicated that the oxygen-containing functional groups such as car-boxyl group were successfully generated on the surface of PLA. The optimal oxidation time and temperature were deter-mined to be 10 min and 90 °C,respectively. Under such a condition,the surface contact angle of the oxidized material de-creased from 82 ° to 62. 5 °,but its surface hydrophilicity was improved. The surface-modified PLA exhibited the un-changed tensile strength and a slight decrease in elongation at break. After oxidation,the surface of PLA showed better cell adhesion and cell proliferation,which was more beneficial to the growth of cells.更多还原