Construction of poly (vinyl alcohol)/poly (lactide-glycolide acid)/vancomycin nanoparticles on titanium for enhancing the surface self-antibacterial activity and cytocompatibility.

Comparing with traditional drug dosage form, controlled release systems offer more effective and favorable route to deliver drugs in optimum dose to specific sites with long term release duration. In this work, an effective drug delivery system composed of poly (vinyl alcohol) (PVA)/poly (lactide-glycolide acid) (PLGA) nanoparticles (NPs) with encapsulated vancomycin (Van), is constructed on the surface of biomedical titanium. The PVA/PLGA/Van NPs synthesized via double emulsion route are grafted onto the surface of titanium plates modified by alkaline-heat treatment and subsequent aminopropyltriethoxysilane (APTES) deposition. In vitro tests disclose that NPs can release a small amount of drugs continuously due to the slow swelling or hydrolysis of polymer chain segments as the immersion time increases. As the pH value reduces, the ester bonds rupture with releasing more drugs, which is why this drug delivery system exhibits the highest antibacterial efficiency at the lowest pH value of 4.5 in this work. Cell culture results reveal that this smart surface system on titanium facilitates the cell attachment and proliferation on implants. Hence, this pH controlled drug delivery system can be successfully applied as a bio-platform for improving both the osteoblasts adhesion and antibacterial activity of metallic implants.