Nakayama Yasuhide, Furumoto Akiko, Kidoaki Satoru, Matsuda Takehisa
Department of Bioengineering, National Cardiovascular Center Research Institute, Suita, Osaka, Japan.
Photochem Photobiol. 2003 May;77(5):480-6. doi: 10.1562/0031-8655(2003)077<0480:pocaap>2.0.co;2.
In this study photoinduced cation generation, based on the photochemical properties of malachite green (MG), was used for the surface design and in vitro photochemical control of cell adhesion and proliferation. The MG-derivatized surface was prepared by coating a photoreactive polymer as a substrate onto a poly(ethylene terephthalate) (PET) sheet. The photoreactive polymer was radical copolymer of styrene with the MG-derivatized monomer diphenyl(4-vinylphenyl)methane leucohydroxide (degree of substitution of MG unit: 12.4 mol%). Water contact angle measurements and X-ray photoelectron spectroscopy revealed high hydrophobicity and homogeneous distribution of the MG groups on the outermost surface of the coated film, respectively. When the coated film was exposed to ultraviolet light (UV) irradiation at wavelengths of 290-410 nm, a time-dependent color change of the film was observed from pale yellow, before irradiation, to green. These results indicated generation of cations on the film surface by photochemical cation generation of the MG groups, which was quantitatively characterized by force versus distance curves measurements in atomic force microscopic (AFM) observation using a carboxylated AFM tip. The seeding and culture of endothelial cells showed a marked reduction in adhesion on the nonirradiated coated film surface, whereas the UV-irradiated surface promoted cell adhesion and proliferation except for incubation in serum-free medium, which was similar to commercial tissue culture PET sheet. These observations may be due to adsorption of cell adhesive proteins, typified by fibronectin, in serum-containing medium onto the cationized photoreactive copolymer surface by electrostatic interactions.
在本研究中，基于孔雀石绿（MG）的光化学性质，光诱导阳离子生成被用于细胞粘附和增殖的表面设计及体外光化学控制。通过将作为底物的光反应性聚合物涂覆在聚对苯二甲酸乙二酯（PET）片材上来制备MG衍生化表面。该光反应性聚合物是苯乙烯与MG衍生化单体二苯基（4-乙烯基苯基）甲烷无色氢氧化物的自由基共聚物（MG单元的取代度：12.4摩尔%）。水接触角测量和X射线光电子能谱分别揭示了涂膜最外表面具有高疏水性以及MG基团的均匀分布。当涂膜暴露于波长为290 - 410 nm的紫外光（UV）照射时，观察到膜的颜色随时间从照射前的浅黄色变为绿色。这些结果表明通过MG基团的光化学阳离子生成在膜表面产生了阳离子，这在使用羧基化原子力显微镜（AFM）尖端进行的AFM观察中的力与距离曲线测量中得到了定量表征。内皮细胞的接种和培养显示，在未照射的涂膜表面上细胞粘附显著减少，而紫外照射的表面促进了细胞粘附和增殖，但在无血清培养基中培养除外，这与商业组织培养PET片材相似。这些观察结果可能是由于血清中以纤连蛋白为代表的细胞粘附蛋白通过静电相互作用吸附到阳离子化的光反应性共聚物表面上。
