Modification of titanium surfaces via surface-initiated atom transfer radical polymerization to graft PEG-RGD polymer brushes to inhibit bacterial adhesion and promote osteoblast cell attachment

Abstract

Implant-related infection is one of the key concerns in clinical medicine, so the modification of titanium to inhibit bacterial adhesion and support osteoblast cell attachment is important. In this article, two strategies were used to examine the above effects. First, modification of titanium via surface-initiated atom transfer radical polymerization (ATRP) was performed. The surface of the titanium was activated initially by a silane coupling agent. Well-defined polymer brushes of poly (ethylene glycol) methacrylate were successfully tethered on the silane-coupled titanium surface to form hydration shell to examine the anti- fouling effect. Second, functionalization of the Ti-PEG surface with RGD was performed to examine the anti-bacterial adhesion and osteoblast cell attachment ability. The chemical composition of modified titanium surfaces was characterized by X-ray photoelectron spectroscopy (XPS). Changes in surface hydrophilicity and hydrophobicity were characterized by static water contact angle measurements. Results indicated that PEG-RGD brushes were successfully tethered on the titanium surface. And anti-bacterial adhesion ability and osteoblast cell attachment ability were confirmed by fluorescence microscopy and scanning electron microscopy. Results indicated that PEG can inhibit both bacterial adhesion and osteoblast cell attachment, while PEG-RGD brushes can not only inhibit bacterial adhesion but also promote osteoblast cell attachment.