实验观察脱胶蚕丝的纳米图案化修饰对干细胞黏附和增殖的影响

Observation of impacts of nanopattern modification on degummed silk and corresponding on stem cell adhesion and proliferation

目的探索脱胶蚕丝表面的纳米图案化修饰对干细胞黏附和增殖的影响。方法采用便捷的等离子体刻蚀技术对脱胶蚕丝表面进行较为规整的纳米图案化修饰,根据刻蚀时间分成对照组(未刻蚀)、刻蚀10 min组、刻蚀30 min组、刻蚀50 min组。采用高精度动态疲劳试验机测试各脱胶蚕丝的单丝力学性能。采用扫描电子显微镜分别观察干细胞接种培养1、4 d后的黏附状态和形貌特征,采用CCK-8试剂盒检测干细胞的增殖情况。结果脱胶蚕丝的力学性能随着刻蚀时间的增加逐渐下降;刻蚀10、30、50 min组的断裂强度保留率分别为90%、72%、64%;断裂伸长率保留率分别为92%、65%、42%。与对照组相比,纳米图案化修饰后的脱胶蚕丝上细胞黏附数量更多且铺展更好。纳米图案化修饰后的脱胶蚕丝可显著促进细胞的增殖,其吸光度变化率(OD_(4 d)/OD_(1 d))(5.5~6.1)远大于对照组(2.2)(P<0.05)。结论等离子体刻蚀技术可作为一种便捷、可大规模制备的纳米图案化修饰策略,用以提升脱胶蚕丝的生物活性。预计10 min刻蚀处理的脱胶蚕丝具有更优的应用前景。此类纳米图案化修饰既显著提升了干细胞的黏附和增殖能力,又保有原材料90%以上的断裂强度和断裂伸长率。

Objective To explore the effects of nanopattern modification of degummed silk on stem cell adhesion and proliferation.Methods Relative regular nanopatterns on the surface of degummed silk were prepared by a convenient plasma etching technology.According to the etching time,the corresponding silk materials were named as control group(non-etched silk,NE silk),10 min-etched silk(10E silk),30 minetched silk(30E silk),and 50 min-etched silk(50E silk).The mechanical properties of each single degummed silk were measured by a high-precision dynamic fatigue testing machine.The adhesion and proliferation of stem cells after 1 and 4 days of culture were tested by scanning electron microscopy and CCK-8 kit respectively.Results The mechanical properties of degummed silk decreased as the increase of etching time;the tensile strength retention rates of the 10,30 and 50 min-etched groups were 90%,72% and 64%;the elongation retention rates were 92%,65% and 42%,respectively.Compared with the control group,the stem cells exhibited a statistically significant higher cell density and larger cell spreading area on the degummed silk after nanopattern modification.The proliferation of cells on the degummed silk after nanopattern modification was also improved.The change rate of optical density(OD)value(OD_(4 d)/OD_(1 d))(5.5~6.1)was much higher than that of the control group(2.2)(P<0.001).Conclusion Plasma etching modification can be used as a convenient and easy method for large-scale preparation technology to enhance the bioactivity of degummed silk.It is expected that the 10 min-etched degummed silk has a better application potential.This nanopattern modification not only significantly improved the adhesion and proliferation of stem cells,but also retained more than 90% of the tensile strength and elongation of the raw silk.