Near-infrared light-triggered smart response platform integrating CeO2@Black phosphorus for enhanced antimicrobial, anti-inflammatory, and osseointegration properties of titanium implants

Abstract

Titanium implants are extensively utilized in biomedical applications due to their exceptional physicochemical properties. However, bacterial infections and subsequent inflammatory reactions post-implantation can hinder the osseointegration. To address this challenge, we have developed a near-infrared (NIR) light-triggered smart response platform that integrates polydopamine-heterojunction nanomaterial CeO₂@black phosphorus (CeO₂@BP) onto the surface of alkali heat-treated titanium wafers. Under NIR laser intervention, the platform demonstrated efficient antimicrobial activity via a tripartite mechanism involving CeO₂@BP, photothermal therapy, and photodynamic therapy, achieving 99 % inhibition against Pseudomonas aeruginosa and Staphylococcus aureus in vitro antimicrobial assays. Results from live/dead staining, CCK8 assays, and scratch tests confirmed the platform's excellent biocompatibility and wound healing capabilities. After seven days of osteogenic induction of MC3T3-E1 cells in vitro, the platform significantly enhanced the expression of intracellular alkaline phosphatase, RUNX2, OCN, and HSP70, thereby facilitating calcium ion deposition. In vivo, the platform exhibited superior osseointegration and anti-inflammatory properties. Specifically, it suppressed the expression of the pro-inflammatory factor IL-6, enhanced the expression of the anti-inflammatory factor Arg-1, and promoted the phenotypic switch of macrophages from M1 to M2. These results suggest that this platform design contributes to the generation of a favorable bone immunomodulatory microenvironment, which enhances the antimicrobial, anti-inflammatory, and osseointegration capabilities of titanium implants, promising expanded clinical applications.