Polyenephosphatidyl Choline

The development of multifunctional hydrogels, especially hydrogels with antibacterial and antioxidant properties, plays a crucial role in the effective healing of diabetic wounds. This work proposed a novel composite hydrogel with the oxidized gellan gum (O-GG) and hyaluronic acid (HA) as the hydrogel matrix, and the crosslinking was realized via the Ca²⁺. ε-polylysine/MnO₂ nanozymes (EM) offered antioxidant and antibacterial properties to the corresponding composite hydrogels. The results verified that the O-GG/HA@EM hydrogel exhibited excellent cytocompatibility and injectability. The CCK-8 data indicated that the proliferation rate of mouse fibroblasts reached 314.58 % after three days of coculture with the hydrogel. The hydrogel effectively alleviated oxidative stress and hypoxic microenvironments in wounds, inhibited bacterial infection, and promoted angiogenesis, thereby significantly accelerating the healing process of diabetic wounds. Data from a mouse diabetic wound model revealed that the wound closure rate in the sample group reached 92.4 % after 14 days. This composite hydrogel provides a novel and effective solution for the treatment of chronic diabetic wounds.

Antimicrobial peptides show promise in enhancing photothermal therapy, but their application is often limited by the challenge of constructing a delivery system that balances efficacy and safety. Our research demonstrated that the bactericidal efficacy of V₂C MXene-mediated photothermal therapy is enhanced in a concentration-dependent relationship with the introduction and coating of the antimicrobial peptide ε-polylysine (EPL). EPL exhibited a dual role in enhancing bacterial binding and disrupting bacterial membranes, thereby increasing heat transfer efficiency and reducing bacterial resistance to photothermal ablation. The core strategy of this study was to exploit the combined membranolytic-photothermal effect of EPL and V₂C by extensively applying EPL while regulating V₂C nanosheets usage to prevent overheating. This approach aims to achieve potent bactericidal efficacy through photothermal therapy below 60 °C. Consequently, we developed dissolving microneedles incorporated with V₂C nanosheets, where EPL served as the antimicrobial agent and primary matrix, increasing its loading capacity and minimizing the need for inactive excipients. Notably, this microneedle achieved a 99.9 % reduction in the abundance of methicillin-resistant Staphylococcus aureus on infected skin after a single application and resulted in a 92-fold reduction in the bacterial load compared to the group treated with commercial Bactroban ointment, with no apparent toxicity to the mice.