Blow-Spun Si₃N₄-Incorporated Nanofibrous Dressing with Antibacterial, Anti-Inflammatory, and Angiogenic Activities for Chronic Wound Treatment

The effective and safe healing of chronic wounds, such as diabetic ulcers, presents a significant clinical challenge due to the adverse microenvironment in the wound that hinders essential processes of wound healing, including angiogenesis, inflammation resolution, and bacterial control. Therefore, there is an urgent demand for the development of safe and cost-effective multifunctional therapeutic dressings. Silicon nitride, with its distinctive antibacterial properties and bioactivities, shows great potential as a promising candidate for the treatment of chronic wounds. In this study, a silicon nitride-incorporated collagen/chitosan nanofibrous dressing (CCS) were successfully fabricated using the solution blow spinning technique (SBS). SBS offers compelling advantages in fabricating uniform nanofibers, resulting in a three-dimensional fluffy nanofibrous scaffold that creates an optimal wound healing environment. This blow-spun nanofibrous dressing exhibits excellent hygroscopicity and breathability, enabling effective absorption of wound exudate. Importantly, the incorporated silicon nitride within the fibers triggers surface chemical reactions in the aqueous environment, leading to the release of bioactive ions that modulate the wound microenvironment. Here, the CCS demonstrated exceptional capabilities in absorbing wound exudate, facilitating water vapor transmission, and displaying remarkable antibacterial properties in vitro and in a rat infected wound model (up to 99.7%, 4.5 × 10⁷ CFU/cm² for Staphylococcus aureus). Furthermore, the CCS exhibited an enhanced wound closure rate, angiogenesis, and anti-inflammatory effects in a rat diabetic wound model, compared to the control group without silicon nitride incorporation. Graphical abstract: (Figure presented.)