Nano-Functionalized Biopolymer Films with Green-Synthesized CuO/Attapulgite for Light-Promoted Antibacterial Therapy...

The rapid emergence of drug-resistant bacterial infections poses a significant global challenge to wound management, necessitating the development of alternative antibacterial strategies beyond conventional antibiotics. Herein, a plant-mediated green synthesis approach is employed for fabricating visible-light-responsive copper oxide/attapulgite (CuO/APT) nanocomposites using Olea europaea leaf extract. The one-dimensional APT serves as an effective biological template to promote heterogeneous nucleation and stabilization of ultrafine CuO nanoparticles (5-20 nm) with enhanced visible-light catalytic activity. The nanocomposites are subsequently incorporated intoκ-carrageenan/carboxymethyl chitosan (KC/CC) matrices to develop advanced photocatalytic wound dressings. The strong interfacial interactions between CuO/APT nanocomposites and biopolymer chains ensure homogeneous dispersion and improved mechanical performance. The optimal composite films exhibit good hydrophilicity with a water contact angle of 56.7°, superior moisture retention capacity of 64.9 ± 13.4% after 1 h drying, well-balanced mechanical properties, and enhanced antibacterial effect with 99.8% inhibition rate against methicillin-resistant Staphylococcus aureus. In a rat model of methicillin-resistant Staphylococcus aureus -infected full-thickness wounds, the composite films significantly accelerated healing through effective bacterial clearance, inflammation modulation, enhanced collagen deposition, and tissue regeneration. This study provides a sustainable and scalable strategy for designing light-activated wound dressings with synergistic antibacterial/pro-healing functions, offering a promising solution for combating drug-resistant wound infections.