Degree of immobilization of synthetic RGDS(PO₃H₂)PA peptides on titanium surfaces

Abstract

The purpose of this study was to characterize the chemical interaction between titanium surfaces and the peptide RGDS(PO₃H₂)PA (P-RGD) synthesized from RGD peptide (RGD) and o-phospho-L-serine (P-Ser), and to determine the degree of peptide immobilization on the titanium surface. X-ray photoelectron spectroscopy showed that the adsorption amount of RGD was significantly smaller than those of P-Ser and P-RGD (p<0.05). Furthermore, although it appeared that P-RGD bonded to the surface, ultrasonic rinsing with water caused it to dissociate, releasing RGD and leaving only S(PO₃H₂)PA bonded to the surface. These findings show that although it remains difficult to obtain a stable P-RGD layer, the phosphate functional group greatly improves immobilization of the molecule on titanium surfaces.