Modulating the biocompatibility of polymer surfaces with poly(ethylene glycol): Effect of fibronectin

Abstract

A novel approach described earlier for improving polymer substratum biocompatibility(1) is further elucidated. Polysulfone (PSf) spin-coating films were modified by covalent end-on grafting of hydrophilic and sterically demanding photo-reactive poly(ethylene glycol) (PEG) conjugates (ABMPEG; 10 kDa). The degree of grafting density was varied systematically, yielding a wide spectrum of attained surface characteristics monitored by air-water contact angles (captive bubble method). Fibronectin (FN) adsorption was studied by in situ ellipsometry and found to decrease monotonically as ABMPEG grafting density increased. The adhesive interaction of human skin fibroblasts with these substrata and, in particular, the effect of FN precoating were investigated in detail. A clear optimum of cell-substratum interactions was found for mildly modified substrata, employing well established microscopic and immunofluorescence techniques, namely the monitoring of cell adhesion and spreading, overall cell morphology, organization of FN receptors, and focal adhesions as well as FN matrix formation. The results suggest that cell interactions with hydrophobic polymer substrata are enhanced considerably when modified with hydrophilic and sterically demanding PEG moieties at a low surface coverage due to enhanced biologic activity of adsorbed and intercalated adhesive proteins such as FN.

Different assembly of type IV collagen on hydrophilic and hydrophobic substrata alters endothelial cells interaction

“…It is well documented that protein adsorption depends on the surface properties which produces great impact on the cellular interaction (Altankov et al, 2000;Keselowsky et al, 2003;Lan et al, 2005). Here we found that significantly increased Col IV adsorption on hydrophobic ODS does not support cellular interaction, a fact observed also for other matrix proteins (Grinnell and Feld, 1982;Tzoneva et al, 2002) and cell systems (Grinnell and Feld, 1982).…”

Modulation of Chondrocyte Phenotype for Tissue Engineering by Designing the Biologic−Polymer Carrier Interface

“…This is also applicable to the PEGT:PBT substrates synthesized and studied herein, and was examined using PEG length and weight ratio. Changes in substrate composition and wettability have been shown to influence Fn conformation 36 , with conformational interplay between competitively adsorbed Fn and albumin at the material-protein interface enhancing FN activity 37 . The amount of surface PEG in other polymers has been shown to inversely correlate with Fn coating and affects its conformation 38 .…”

Incorporation of Primary Amines via Plasma Technology on Biomaterials

“…Among other physical and chemical techniques to improve the surface biocompatibility [19][20][21][22], plasma surface modification is used to adapt the surface properties by functionalization of the material surface to control the biological response. Different functionalities have been investigated, such as carboxyl [23], hydroxyl [24] and primary amine [25] (see figure 2).…”