The Antibacterial Snd Osteogenic Activity Of Silver Ion Implanted Titanium

The bacterial adhesion, reproduction, and then a biofilm formation on implant is the key to implant-associated infection(IAI), which often leads to implant failure. Insufficient osseointegration of implant is another cause of implant failure. Titanium(Ti), the most commonly used implant materials at present, is lack of antibacterial activity and osseointegration. In this work, silver nanoparticles(Ag NPs) are fabricated and immobilized on Ti by silver plasma immersion ion implantation(Ag-PIII). The anti-biofilm activity and osseointegration rendered by the immobilized Ag NPs on Ti are assessed.The surface morphology of titanium after Ag ion implantation was observed by field emission scanning electron microscope; The elemental surface profiles and Ag chemical states were determined by x-ray photoelectron spectroscopy; The amounts of released silver after modified titanium incubation in electrolyte liquid were determined by analyzing the resulting solutions by inductively-coupled plasma optical emission spectrometry. Bacterial biofilm formation on the modified Ti surface was assessed by crystal violet staining, microbiological counting of the number of viable bacteria, scanning electron microscopy, laser scanning confocal microscope and other methods. A model involving implant-related tibia osteomyelitis in rats was used to evaluate the anti-biofilm effect in vivo. Human bone mesenchymal stem cells(h BMSCs) were used to test in vitro the influences of implanted Ti on cell adhesion, proliferation and osteogenic differentiation which was detected by alkaline phosphatase(ALP) vitality, extracellular matrix mineralization, osteogenesis related gene expression, and the levels of cellular protein RhoA. Rat femur model was adopted to examine in vivo osseointegration of ion implanted Ti.The results show that after Ag-PIII, Ag NPs are fabricated and immobilized on Ti; and the amounts of Ag NPs are proportional to the implanted time; and only a very small amount of silver was released from the immobilized Ag NPs. The immobilized Ag NPs can inhibit bacterial biofilm formation on the titanium surface and reduce the incidence of IAI. Furthermore, they have no significant cytotoxic effects, improve early adhesion of hBMSCs, increase cellular ALP vitality, extracellular matrix mineralization levels, increase expression levels of osteogenesis related gene and GTP-RhoA protein and enhance osseointegration of titanium.Thus, we conclude that, by Ag-PIII, Ag NPs can be controllable fabricated and immobilized on Ti, and endow Ti with anti-biofilm activity and osseointegration.