PREPARATION OF PEPTIDE-CARRYING MICROSPHERES WITH BIOACTIVITY ON PLATELETS

A tetrapeptide RGDS (Arg-Gly-Asp-Ser), which is one of the active site s of cell adhesive proteins, was synthesized according to the solution method and covalently coupled onto monodisperse microspheres. The bio specific activity of the RGDS-carrying microspheres was investigated b y measuring the stimulatory effect of the microspheres on platelets. L arge and tightly packed platelet aggregation accompanied with drastic ATP release was induced by the RGDS-carrying microspheres. It was conf irmed that the specific platelet aggregation was attributed to the act ivity of the immobilized RGDS by comparison with those induced by othe r microspheres.