. . "A method for promoting cell attachment to a substrate comprising the steps of:immobilizing on the substrate a composition of matter comprising a non-naturally occurring peptide X-Arg-Gly-Asp-R-Y wherein X is H or at least one amino acid and Y is OH or at least one amino acid, and R is an amino acid selected from Ser Thr, Cys or other amino acid, such that said peptide has cell-attachmentpromoting" . .