Synergistic Effect of Hydrophilic Surface and Nano‐Ag 2 O in TiO 2 ‐Based Composites Coating on Antibacterial and Osteogenic Properties of Low Modulus Ti‐Mo‐Ag Alloy

Abstract

Ti‐15Mo‐2.5Ag alloy exhibited a low modulus and strong antibacterial ability but poor bioactivity. To resolve this problem, sandblasting and anodization were used to create a hydrophilic and nano‐Ag 2 O‐containing TiO 2 coating. Subsequently, the microstructure and physicochemical properties were investigated by scanning electron microscopy, X‐ray diffraction, inductively coupled plasma mass spectrometry, X‐ray photoelectron spectrometer and electrochemical testing. The coating exhibited superior hydrophilicity, enhanced corrosion resistance, and accelerated controllable Ag +  release. In vitro antimicrobial and cellular experiments were performed to evaluate the antimicrobial and osteogenic properties. The synergistic effect of the hydrophilic surface and Ag +  release improved the antibacterial activity; significantly promoted adhesion, spreading, and proliferation of L929 and MC3T3‐E1; and enhanced mineralization and the expression of osteogenic differentiation‐related genes (RUNX‐2, COL‐I, OCN and ALP) in MC3T3‐E1. RNA‐seq analysis in hFOB 1.19 suggested that the activation of mitochondrial oxidative phosphorylation and ribosomal pathways might contribute to these effects, although cross‐species extrapolation warrants caution. In vivo rat implant model test demonstrated that the nano‐Ag 2 O‐containing TiO 2 coating reduced local tissue inflammation and promoted the repair and regeneration of bone tissue. All results suggest that the hydrophilic and nano‐Ag 2 O‐containing TiO 2 coating could be a promising strategy to synergistically improve the antibacterial property and promote osseointegration of titanium alloy implants.