Val-Ala-Pro-Gly, an elastin derived non-integrin ligand: Cell adhesion and specificity
The non-integrin derived peptide VAPG maybe useful as a biospecific cell adhesion ligand for smooth muscle cells. By grafting the peptide sequence into a hydrogel material, we were able to assess its effects on cell adhesion and spreading. These materials are photopolymerizable hydrogels based on acrylate-terminated derivatives of polyethylene glycol (PEG). PEG diacrylate derivatives can be mixed with adhesive peptide-modified PEG monoacrylate derivatives. Following photopolymerization, the PEG monoacrylate derivatives are grafted into the hydrogel network formed by the PEG diacrylate. This results in covalent immobilization of the adhesive peptides to the hydrogel via a flexible linker chain. The resistance of PEG to protein adsorption makes it an ideal material for this model system, since cell-material interactions are essentially limited to the biomolecules that are covalently incorporated into the material. In this case we were able to demonstrate that VAPG is specific for adhesion of smooth muscle cells, and this can aid in the design of tissue engineered vascular grafts.