Objective: To investigate the long-term integrity and the biological function of interface between the bioadhesive peptide modified implant surface and peri-implant tissue.
Methods: A short bioadhesive peptide containing Glycine-Tyrosine-Arginine-Glycine-Asparticacid-Serine (GYRGDS) sequence was immobilized onto the titanium implant surface by means of sol-gel coating technique and self-assembled monolayers (SAM). The chemical composition and organic functional groups on the titanium surfaces were characterized using XPS (X-ray photoelectron spectroscopy) and FTIR (Fourier transform infrared spectrometer). The adhesive strength and stability of osteoblasts on various implant surfaces were compared under flow condition.
Results: The results showed that alkali/hot water aging treatment could apparently improve the content of -OH functional groups of titanium surface. The chemical reactive Ti-O-Ti bonding at the surface of titanium played a vital role in inducing the formation of organosilane SAM. GYRGDS peptide can be covalently grafted onto the surface of titanium by SAM technique. The resistance of freshly adherent osteoblasts to detachment by flow was shear time dependent. When the four groups were compared under the same flow stress condition (2.05 Pa) at three specific time spans (30 min, 1 h, 2 h), the cells retention rates in GYRGDS-grafted groups were 93.0%, 54.4%, 34.4% respectively and were much higher than those in non-coated groups.
Conclusions: It was suggested that GYRGDS might have positive effects on maintaining stability and adherence of cells onto the substrates under flow condition.