Protein adsorption and human osteoblast‐like cell attachment and growth on alkylthiol on gold self‐assembled monolayers

Abstract

Protein adsorption and growth of primary human osteoblasts on self-assembled monolayers of alkylthiols on gold (SAMs) with carboxylic acid and hydroxyl and methyl termini were investigated. Single-component SAMs and SAMs patterned by photolithographic techniques were used. Cell growth on patterned SAMs demonstrated preferences for one pattern region in all combinations of alkylthiols, with the hierarchical preference COOH > OH > CH(3). Patterned SAMs and immunochemistry were used to investigate adsorption of fibronectin and albumin with respect to different alkylthiol termini. Fibronectin adsorption from both pure solution and serum containing cell culture medium (SDMEM) followed the sequence COOH > OH > CH(3). Albumin adsorption from pure solution followed the sequence OH > COOH > CH(3); from SDMEM the sequence was CH(3) > OH > COOH. Cell attachment to SAMs with the above termini, after preadsorption with fibronectin, albumin, or mixtures of fibronectin and albumin, was measured. Attachment was maximal on COOH-terminated SAMs precoated with fibronectin. Attachment to COOH was significantly reduced only when fibronectin was omitted from the protein preadsorption solution. On OH and CH(3) SAMs increasing the proportion of albumin in the solution was sufficient to significantly reduce cell attachment. The distribution vinculin and the integrins alpha(5)beta(1) and alpha(v)beta(3) indicated that focal contact formation by cells varied with alkylthiol termini in the following sequence: COOH > OH > CH(3).