Piezoelectric copper-doped bioactive glass composite dressing for antibacterial-immune synergistic regulation and wound healing

The core mechanism underlying infection-related wound healing difficulties is closely linked to the disruption of the local immune microenvironment. Macrophages, as central cells in immune regulation, play a pivotal role, and their functional imbalance is a critical factor contributing to healing impairment. Hence, we designed and fabricated a multifunctional electrospun dressing—PLLA@Cu—by incorporating copper-doped bioactive glass (Cu-MBG) nanoparticles into polarized PLLA fibers, resulting in a composite material with piezoelectric properties. Under the synergistic effect of ultrasound (US) and copper ions (Cu²⁺), PLLA@Cu exhibited remarkable antibacterial activity. Additionally, it effectively promoted M1 macrophage polarization, significantly enhancing their phagocytic and bactericidal capabilities. In vivo experiments demonstrated that PLLA@Cu could rapidly eliminate infecting bacteria, while modulating macrophage polarization to improve the immune microenvironment of the wound. This resulted in increased collagen deposition and enhanced angiogenesis, significantly accelerating wound healing. Furthermore, the material promoted cell adhesion and accelerated re-epithelialization by increasing surface energy and roughness. Therefore, the multifunctional electrospun dressing developed in this study holds great potential for treating infected wounds and shows promise as a novel candidate material for wound healing applications.