Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Phyathai Road, Pathumwan, Bangkok 10330, Thailand.
Department of Physics, Faculty of Science, Chulalongkorn University, Phyathai Road, Pathumwan, Bangkok 10330, Thailand; Plasma Technology and Nuclear Fusion Research Unit, Chulalongkorn University, 10330 Bangkok, Thailand.
Colloids Surf B Biointerfaces. 2013 Nov 1;111:579-86. doi: 10.1016/j.colsurfb.2013.07.009. Epub 2013 Jul 12.
Low energy plasma has been introduced to treat the surface of Thai silk fibroin which should be enhanced for cell adhesion due to its native hydrophobic surface. Plasma surface treatment could introduce desirable hydrophilic functionalities on the surface without using any chemicals. In this work, nitrogen glow discharge plasma was generated by a low energy AC50Hz power supply system. The plasma operating conditions were optimized to reach the highest nitrogen active species by using optical emission spectroscopy. X-ray photoelectron spectroscopy (XPS) revealed that amine, hydroxyl, ether, and carboxyl groups were induced on Thai silk fibroin surface after plasma treatment. The results on Fourier transform infrared attenuated total reflection (FTIR-ATR) spectroscopy confirmed that the plasma treated effects were only on the outermost layer since there was no change in the bulk chemistry. The surface topography was insignificantly changed from the detection with atomic force microscopy (AFM). The plasma-treated effects were the improved surface wettability and cell adhesion. After a 90-s treatment, the water contact angle was at 20°, while the untreated surface was at 70°. The early cell adhesion of L929 mouse fibroblast was accelerated. L929 cells only took 3h to reach 100% cell adhesion on 90 s N2 plasma-treated surface, while there was less than 50% cell adhesion on the untreated Thai silk fibroin surface after 6h of culture. The cell adhesion results were in agreement with the cytoskeleton development. L929 F-actin was more evident on 90 s N2 plasma-treated surface than others. It could be concluded that a lower energy AC50Hz plasma system enhanced early L929 mouse fibroblast adhesion on Thai silk fibroin surface without any significant change in surface topography and bulk chemistry.
低能量等离子体已被引入处理泰国丝素纤维的表面，由于其天然的疏水性表面，应该增强其细胞附着力。等离子体表面处理可以在不使用任何化学物质的情况下，在表面上引入理想的亲水官能团。在这项工作中，氮气辉光放电等离子体是由低能量的 50Hz 交流电源系统产生的。通过使用发射光谱学优化等离子体工作条件，以达到最高的氮活性物质。X 射线光电子能谱（XPS）显示，经过等离子体处理后，泰国丝素纤维表面诱导了胺、羟基、醚和羧基基团。傅里叶变换衰减全反射（FTIR-ATR）光谱的结果证实，由于没有改变体化学，等离子体处理的效果仅在最外层。原子力显微镜（AFM）的检测表明表面形貌没有明显变化。等离子体处理的效果是提高表面润湿性和细胞附着力。经过 90 秒的处理，水接触角为 20°，而未经处理的表面为 70°。早期的 L929 小鼠成纤维细胞的粘附得到了加速。在 90 秒 N2 等离子体处理的表面上，L929 细胞仅需 3 小时即可达到 100%的细胞粘附，而在未经处理的泰国丝素纤维表面上培养 6 小时后，细胞粘附率低于 50%。细胞粘附结果与细胞骨架的发育一致。在 90 秒 N2 等离子体处理的表面上，L929 F-肌动蛋白比其他表面更明显。可以得出结论，低能量的 50Hz 交流等离子体系统增强了 L929 小鼠成纤维细胞在泰国丝素纤维表面的早期粘附，而表面形貌和体化学没有任何显著变化。
