NIR-II Responsive Platinum-Engineered Vanadium Carbide MXene Endows Poly-L-Lactic Acid Bone Scaffold with Photothermal Antibacterial Property

Vanadium carbide (V₂C) MXene shows great potential for addressing challenging implant-associated infections in bone regeneration due to its strong photothermal conversion efficiency. However, its photothermal efficacy is restricted to the near-infrared I (NIR-I) region due to a limited absorption range. To address this, we designed platinum nanoparticle-decorated V₂C heterostructures (Pt@V₂C) via an in situ growth method, leveraging Pt's plasmonic and catalytic properties to extend the photoresponse to the NIR-II window. Subsequently, Pt@V₂C was integrated into poly-L-lactic acid (PLLA) to fabricate PLLA-Pt@V₂C scaffolds with photothermal antibacterial function by selective laser sintering. The optimized PLLA-Pt@V₂C scaffold achieves a record photothermal conversion efficiency (56.03% at 1064 nm), triggering simultaneous hyperthermia (>52 °C) and catalytic ·OH radical generation. In vitro studies demonstrate exceptional antibacterial efficacy against Staphylococcus aureus and Escherichia coli, achieving over 99% killing rates upon 1064 nm near-infrared irradiation. Furthermore, the scaffold demonstrated significant inhibition of biofilm formation, achieving over 90% reduction in biofilm biomass. Moreover, the scaffold demonstrated high cell viability, confirming its dual functionality of potent bactericidal activity and biocompatibility that supports tissue regeneration. This work provides a feasible strategy for combating implant-associated infections.