Electrophoretic deposition of Ag-Cu-CTS coatings on porous titanium with photothermal-responsive antibacterial effect.

Porous architecture of titanium implants offers significant advantages in promoting osseointegration and mitigating the "stress shielding" effect. However, challenges remain in enhancing vascularization and preventing infection, especially given the complexities of modifying the intricate surface structure of porous titanium (PT). This study introduces a novel surface modification technique of PT using anti-gravity perfusion electrophoretic deposition (EPD) technique to fabricate antibacterial coatings containing silver (Ag) and copper (Cu) co-doped mesoporous silica nanoparticles (Ag-Cu@MSN) and chitosan binder on the surface of PT. The developed coating exhibits rapid and stable photothermal response to 808 nm near-infrared (NIR) light, leading to a localized temperature rise and triggered release of Ag and Cu ions for synergistic bactericidal efficacy against both E. coli and S. aureus. In vitro studies further demonstrated that the coated PT significantly promoted the proliferation of mouse calvaria pre-osteoblast (MC3T3-E1) and human umbilical vein endothelial cells (HUVECs), with a notable increase in HUVECs migration and angiogenesis, attributable to the presence of Cu ions. This innovative EPD-based coating strategy offers a promising avenue for developing uniform, photothermally-activated antibacterial surfaces on PT implants, with substantial implications for advancing clinical bone repair applications.