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

## TL;DR

A new bone scaffold with antibacterial properties was developed using a material that converts near-infrared light into heat and reactive radicals to kill bacteria.

## Contribution

Pt@V2C heterostructures enable NIR-II photothermal antibacterial activity in a biocompatible scaffold.

## Key findings

- PLLA-Pt@V2C scaffold achieves 56.03% photothermal conversion efficiency at 1064 nm.
- The scaffold kills over 99% of S. aureus and E. coli under NIR-II irradiation.
- The scaffold reduces biofilm biomass by over 90% and maintains high cell viability.

## Abstract

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.