Preferential adsorption of cell adhesive proteins from complex media on self-assembled monolayers and its effect on subsequent cell adhesion

摘要

We examined the effect of surface chemistry on adsorption of fibronectin (Fn) and vitronectin (Vn) and subsequent cell adhesion, employing self-assembled monolayers (SAMs) of alkanethiols carrying terminal methyl (CH3), hydroxyl groups (OH), carboxylic acid (COOH), and amine (NH2). More Fn and Vn adsorbed to COOH- and NH2-SAMs than to CH3- and OH-SAMs from a mixture with bovine serum albumin (BSA) and from 2% fetal bovine serum. Adhesion of human umbilical vein endothelial cells (HUVECs) on CH3- and OH-SAMs preadsorbed with Fn and BSA decreased with decreasing adsorbed Fn; however, HUVECs adhered to COOH- and NH2-SAMs even in the presence of BSA at 1000-fold more than Fn in a mixture because of the preferential adsorption of Fn and/or displacement of preadsorbed BSA with Fn and Vn in a serum-containing medium. SAMs coated with a mixture of Vn and BSA exhibited adhesion of HUVECs regardless of surface functional groups. A well-organized focal adhesion complex and actin stress fibers were observed only for COOH- and NH2-SAMs when SAMs were preadsorbed with Vn and BSA. These results suggest that COOH- and NH2-SAMs allow for both cell adhesion and cell spreading because of the high density of cell-binding domains derived from adsorbed Vn.