Multifunctional Metal Polyphenol Nanoparticles Based on Photothermal Therapy for Bacterial Eradication and Wound Healing.

Balancing short-term antibacterial needs with long-term anti-inflammatory effects remains a major challenge in wound healing. Multifunctional bioactive materials capable of both efficient antibacterial action and inflammation modulation represent a promising solution. However, the majority of traditional antibacterial biomaterials possess only a single antibacterial effect, and their synthesis and preparation are intricate, which might restrict their clinical transformation. Chlorogenic acid is a natural compound endowed with anti-inflammatory properties. However, it is beset by certain inherent drawbacks, including poor water solubility and limited bioavailability. To overcome these difficulties, we have fabricated multifunctional nanoparticles (chlorogenic acid-iron nanoparticles, CA-Fe NPs) through the co-assembly of chlorogenic acid and iron ions in a straightforward manner. We found that CA-Fe NPs exhibit excellent photothermal conversion performance in vitro. Upon near-infrared (NIR) irradiation, they exhibit potent broad-spectrum antimicrobial activity against Staphylococcus aureus, Escherichia coli, Candida albicans, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The CA-Fe NPs markedly reduced H2O2-induced reactive oxygen species levels and apoptosis in epithelial cells and suppressed lipopolysaccharide-induced M1 macrophage polarization in RAW 264.7 cells. Transmission electron microscopy results revealed enhanced bacterial membrane disruption by CA-Fe NPs under NIR irradiation, causing pronounced protein leakage. Transcriptomic analysis indicates that CA-Fe NPs combined with NIR disrupt the tricarboxylic acid cycle, cell-wall organization, and other metabolic processes. In vivo, within a methicillin-resistant Staphylococcus aureus-infected skin wound model, CA-Fe NPs maintained photothermal efficacy, effectively reduced serum levels of interleukin-1 beta, interleukin-6, and tumor necrosis factor alpha, and accelerated wound healing. These findings suggest that CA-Fe NPs are multifunctional materials with broad-spectrum bactericidal ability, antioxidant, anti-inflammatory, and wound-healing-promotion properties. These nanoparticles possess promising prospects for biomedical applications.