Piezoelectric-powered osseointegration and photothermal-driven infection defense: a dual-functional BCG nanocomposite coating for dental implants

Titanium (Ti) implants, though clinically prevalent for dentition restoration, suffer from insufficient osteogenic activity and lack of antibacterial properties. The role of bioelectricity in bone homeostasis suggests that piezoelectric materials which generate micro-electric fields via mechanical stimuli (e.g., mastication) may be able to promote osseointegration. Herein, thiolated barium titanate-chitosan-graphene oxide nanoparticles (BCG-NPs) were fabricated, as well as grafted onto Ti through polydopamine (PDA). BCG-Ti exhibited good piezoelectric properties which allow it to convert mechanical force into electrical signals, inducing osteogenic differentiation of Human Umbilical Cord Wharton’s Jelly-Derived Mesenchymal Stem Cells (hWJ-MSCs) and M2 macrophage polarization, and thus improving bone regeneration. Moreover, BCG-Ti possessed excellent photothermal effect, and it demonstrated near-infrared (NIR) irradiation triggered localized hyperthermia for broad-spectrum bacterial eradication. By integrating bioelectric and photothermal modalities, this strategy establishes a pro-healing microenvironment, addressing key limitations of traditional implants to extend their functional lifespan.