Nanofiber-mediated sequential photothermal antibacteria and macrophage polarization for healing MRSA-infected diabetic wounds

Background: Diabetic wound healing remains a challenge because of its susceptibility to drug-resistant bacterial infection and its persistent proinflammatory state. Switching from proinflammatory M1 macrophages (M phi s) to proregenerative M2 dominant M phi s in a timely manner accelerates wound healing by coordinating inflammatory, proliferative, and angiogenic processes. Methods: We propose a sequential photothermal antibacterial and subsequent M2 M phi polarization strategy based on nanofibers (NFs) consisting of polydopamine (PDA) coating on curcumin (Cur) nanocrystals to treat Methicillin-resistant Staphylococcus aureus (MRSA)-infected diabetic wounds. Results: The PDA/Cur NFs showed excellent photothermal conversion and antibacterial effects due to the PDA shell under laser irradiation, consequently resulting in the release of the inner Cur with the ability to promote cell proliferation and reinforce the M2 M phi phenotype in vitro. In vivo studies on MRSA-infected diabetic wounds showed that PDA/Cur NFs not only inhibited MRSA infection but also accelerated the wound regeneration process. Furthermore, the NFs displayed the ability to promote the M2 M phi phenotype with enhanced collagen deposition, angiogenesis, and cell proliferation. Conclusion: Overall, the NFs displayed great potential as promising therapeutics for healing infected diabetic wounds through a sequential photothermal antibacterial and M2 M phi polarization strategy.

Automated summary

This study proposed a sequential photothermal antibacterial and subsequent M2 M phi polarization strategy using PDA/Cur NFs to treat MRSA-infected diabetic wounds. The NFs showed great potential in inhibiting MRSA infection and accelerating wound healing through promoting the M2 M phi phenotype.