In situ growth of ZIF-8 nanoparticles on pure chitosan nanofibrous membranes for efficient antimicrobial wound dressings

Bacterial infections and excessive accumulation of wound exudates remain the main obstacles and clinical challenges to the healing of chronic cutaneous wounds. Conventional dressings are commonly used medical materials for acute wound care, but they do not possess the bacterial infection resistance required for chronic wound treatment. Herein, we prepared pure chitosan nanofibrous membranes (C) by electrospinning with poly(ethylene oxide) (PEO) as a sacrificial additive and then loaded with zinc-based metal-organic framework (MOF) as a novel antimicrobial wound dressing. Thermogravimetric and differential scanning calorimetry confirmed the complete removal of PEO. Morphological characterization of the nanofibrous membrane (C) revealed the formation of uniform, bead-free fibers with an average diameter of approximately 148 nm. SEM confirmed the uniform and continuous modification of zeolite imidazolium salt framework-8 (ZIF-8) nanoparticles on the surface of the composite fibrous membrane (C/ZIF). The experimental results showed that the removal of PEO and the incorporation of ZIF-8 significantly improved the rapid liquid absorption of the composite fiber membrane. Rapid uptake of up to 9.2 g/g of liquid in media of the characteristic pH of wound exudates. The results of the MTT assays demonstrated that the C/ZIF composite fiber membrane possesses excellent biocompatibility. The composite fiber membrane released Zn²⁺ in a stable and continuous manner and exhibited strong antimicrobial activity against Escherichia coli and Staphylococcus aureus. This study presents a novel approach for controlling wound exudation and preventing wound infections.