Arima Yusuke, Iwata Hiroo
Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Biomaterials. 2007 Jul;28(20):3074-82. doi: 10.1016/j.biomaterials.2007.03.013. Epub 2007 Mar 18.
Self-assembled monolayers (SAMs) of alkanethiols, which can provide flat and chemically well-defined surfaces, were employed as model surfaces to understand cellular interaction with artificial materials. SAMs presenting a wide range of wettabilities were prepared by mixing two kinds of alkanethiols carrying terminal methyl (CH(3)), hydroxyl (OH), carboxylic acid (COOH), or amino (NH(2)) groups. Adhesion behavior of human umbilical vein endothelial cells (HUVECs) and HeLa cells on these mixed SAMs were examined. The number of adhered HUVECs reached a maximum on CH(3)/OH mixed SAMs with a water contact angle of 40 degrees , while cell adhesion increased with decreasing water contact angle up to 60-70 degrees and then leveled off on CH(3)/COOH and CH(3)/NH(2) mixed SAMs. Numbers of adhered HeLa cells showed a maximum on CH(3)/OH and CH(3)/COOH mixed SAMs with a water contact angle of 50 degrees . These facts suggest that cell adhesion is mainly determined by surface wettability, but is also affected by the surface functional group, its surface density, and the kinds of cells. The effect of exchange of adsorbed proteins on cell adhesion was also examined. HUVECs were cultured on the mixed SAMs preadsorbed with albumin. Cell adhesion was effectively prohibited on hydrophobic SAMs pretreated with albumin. Albumin strongly adsorbed and resisted replacement by cell adhesive proteins on hydrophobic SAMs. On the other hand, cells adhered to albumin-adsorbed hydrophilic SAMs. Displacement of preadsorbed albumin with cell adhesive proteins effectively occurs on these hydrophilic SAMs. This effect contributes to induce SAMs with moderate wettability to give suitable surfaces for cell adhesion.
烷硫醇自组装单分子层（SAMs）能够提供平整且化学性质明确的表面，被用作模型表面以了解细胞与人工材料的相互作用。通过混合两种带有末端甲基（CH(3)）、羟基（OH）、羧酸（COOH）或氨基（NH(2)）的烷硫醇，制备了具有广泛润湿性的SAMs。研究了人脐静脉内皮细胞（HUVECs）和HeLa细胞在这些混合SAMs上的黏附行为。在水接触角为40度的CH(3)/OH混合SAMs上，黏附的HUVECs数量达到最大值，而在CH(3)/COOH和CH(3)/NH(2)混合SAMs上，细胞黏附随着水接触角减小至60 - 70度而增加，然后趋于稳定。在水接触角为50度的CH(3)/OH和CH(3)/COOH混合SAMs上，黏附的HeLa细胞数量最多。这些事实表明，细胞黏附主要由表面润湿性决定，但也受表面官能团、其表面密度和细胞种类的影响。还研究了吸附蛋白交换对细胞黏附的影响。将HUVECs培养在预先吸附有白蛋白的混合SAMs上。在用白蛋白预处理的疏水SAMs上，细胞黏附被有效抑制。白蛋白在疏水SAMs上强烈吸附并抵抗细胞黏附蛋白的置换。另一方面，细胞黏附于吸附有白蛋白的亲水SAMs。在这些亲水SAMs上，细胞黏附蛋白能有效置换预先吸附的白蛋白。这种效应有助于诱导具有适度润湿性的SAMs以提供适合细胞黏附的表面。
