Cuttlefish Ink-Derived Melanin/MXene Composites: Boosting Stability and Unleashing Synergistic Photothermal-Mechanical Antimicrobial Effects Against Biofilms.

The advancement of MXene-based antibacterial platforms has been impeded by two critical limitations. Specifically, these include rapid oxidative degradation in physiological environments and potential cytotoxicity derived from their metallic nature. To address these challenges, we develop a core-shell structured nanikohybrid (CI@MXene) through the integration of natural cuttlefish ink melanin (CI) with MXene nanosheets. This biomimetic design establishes a protective barrier that effectively prevents MXene oxidation, thereby preserving its structural integrity and granting it durable antibacterial activity with sustained efficacy even after prolonged storage. Furthermore, the composite enables a mild photothermal therapy (PTT) under near-infrared irradiation, maintaining skin temperature below 45°C. This gentle thermal effect synergizes with the preserved nano-knife capability of the encapsulated MXene, resulting in remarkable eradication rates exceeding 95% against both E. coil and S. aureus, along with approximately 80% disruption of established biofilms. More importantly, in vivo evaluation using a murine wound infection model demonstrated accelerated wound closure, significantly reduced bacterial burden, and attenuated inflammatory responses, accompanied by enhanced tissue regeneration. This work not only provides fundamental insights into the rational design of stable and biosafe MXene-based nanomaterials but also establishes a novel strategy for synergistic physical antibacterial therapy, offering a promising approach for combating biofilm-associated infections.