Electrochemical modulation of plasma fibronectin surface conformation enables filament formation and control of endothelial cell–surface interactions

Abstract

The control of cell behavior to increase biocompatibility of implantable medical devices can be improved by protein coatings. Plasma fibronectin (FN) is a circulating soluble protein capable of assembling into insoluble filaments, fibrils and networks which promote various cellular processes and tissue integrity. FN fibrillogenesis is initiated by a conformational change, which has been proposed to involve charge-mediated opening of its structure. In this study, we have used a bare gold surface polarized electrochemically in the double-layer region to modulate its charge from highly positive to highly negative. The negatively charged surface promoted molecular extension and assembly of FN into beaded filaments and creation of a stable protein coating as examined by atomic force microscopy and electrochemical differential capacitance measurements. Gold surfaces with open and filamentous FN showed significantly improved endothelial cell adhesion while allowing formation of cell–cell contacts. Such surfaces may be used to promote rapid endothelialisation of cardiovascular stents.