Photoreactive analog of peptide FN-C/H-V from the carboxy-terminal heparin-binding domains of fibronectin supports endothelial cell adhesion and spreading on biomaterial surfaces.

Abstract

The extracellular matrix protein fibronectin (FN) plays an important role in cell adhesion, spreading, and motility. Several cell-adhesion promoting domains exist within fibronectin, and peptide sequences from these domains have been shown to play an important role in cell interactions with fibronectin. Recently, a peptide sequence (FN-C/H-V) from the 33/66 kD carboxy-terminal heparin-binding domains of fibronectin was shown to promote the adhesion and spreading of vascular endothelial cells in vitro. Endothelial cell spreading on this peptide was followed by cytoskeletal reorganization, focal contact formation, and, ultimately, cell migration. In the current study, a photoreactive analog of FN-C/H-V (ASD-V) was generated using a heterobifunctional photoreactive crosslinking agent, sulfosuccinimidyl 2-(pazidosalicylamido) ethyl-1,3'-dithio-propionate. ASD-V was then covalently coupled to polystyrene (PS) and polyethylene terephthalate film (PET) in order to assess the utility of ASD-V for preparing biomaterial surfaces with endothelial cell-adhesion promoting properties. The effects of pre-adsorption time and initial coating concentration on the efficiency of ASD-V coupling to PS and to PET were examined. Contact angle measurements and atomic force microscopy were used to characterize ASD-V-modified surfaces. Finally, the adhesion and spreading of vascular endothelial cells on ASD-V-modified surfaces was assessed. Our results suggest that photoreactive peptides are an effective and convenient means of modifying biomaterial surfaces to impart adhesion-promoting properties and that ASD-V, when coupled to PS and PET, promotes endothelial cell adhesion and spreading and may therefore be useful as a biomaterial surface modification in applications where re-endothelialization is desired (e.g., autologous endothelial seeding of vascular grafts, or transplantation of genetically engineered endothelial cells via polymer-coated stents.