Work

Light-activated viologen-based metal-covalent organic framework sprayable hydrogel for accelerated healing of infected skin wounds

Year: 2026

Type: article

Abstract: Bacterial resistance and recurrent infection remain major challenges for infected wound healing. Antibacterial photodynamic therapy (aPDT) features excellent spatiotemporal control and low risk of inducing bacterial resistance, making it a promising antibacterial modality. However, many photosensitizers used in wound therapy are photounstable, bind weakly to bacteria, and generate insufficient reactive oxygen species (ROS). We developed a viologen-functionalized metal-covalent organic framework (Vio-MCOF) by covalently embedding viologen units into the MCOF framework, and integrated this material into a sprayable, ionically crosslinked sodium alginate hydrogel. In this system, viologen units serve as electron mediators and work cooperatively with the copper-cluster active sites to suppress charge recombination and may increase ROS production under simulated solar light. The positive charge of the viologen units promotes electrostatic binding of Vio-MCOF to negatively charged bacterial membranes, improving its photodynamic antibacterial performance. In vitro experiments showed that Vio-MCOF at 200 μg mL -1 achieved a bactericidal rate of over 99% against S. aureus after 30 min of simulated solar light irradiation. In vivo experiments demonstrated that the Vio-MCOF hydrogel reduced bacterial colonization in infected wounds, suppressed TNF-α and IL-6 expression, alleviated inflammation, and promoted angiogenesis and collagen deposition, leading to accelerated wound healing. Collectively, the sprayable Vio-MCOF hydrogel holds promise as an antibiotic-free dressing for infected skin wounds.

Source: Frontiers in Cellular and Infection Microbiology

DOI: 10.3389/fcimb.2026.1975470