Synergistic antibacterial mechanisms from kapok cellulose fiber structure and chemistry promote infected wound healing

Natural antibacterial mechanism of kapok fiber • Nanobumps induced mechanical deformation and membrane rupture • Lignin, flavonoids and triterpenoids exhibited chemical antibacterial properties. • Kapok gauze promoted the healing process of wounds infected by bacteria. Kapok fibers demonstrate potential advantages in the field of medical dressings, though the intrinsic mechanisms of their antibacterial activity have not been systematically elucidated. This study utilizes an integrated approach involving physical characterization, chemical analysis, and antibacterial evaluation to elucidate the natural antibacterial mechanisms of kapok fibers. The results indicate that kapok fibers possess axially aligned nanoscale protrusions distributed across their surfaces. Chemical analysis reveals a complex composite wax layer on the fiber surface, which contains silanes, fatty acids, flavonoids, and triterpenoids. Comparative antibacterial experiments utilizing kapok fibers with varying compositions, along with physicochemical characterization, reveal three synergistic antibacterial mechanisms: (1) The superhydrophobic surface demonstrates minimal bacterial adhesion, thereby reducing microbial colonization. (2) Surface nanotopography induces mechanical deformation and subsequent membrane rupture of bacterial cells through tensile stress mechanisms. (3) Chemical constituents including lignin, flavonoids and triterpenoids exhibit membrane-disruptive activity. The hydroentangled kapok gauze promotes the healing of bacterially infected wounds by effectively reducing the bacterial load and modulating the wound microenvironment. This systematic investigation not only reveals the multi-level antibacterial mechanisms of kapok fibers but also establishes a theoretical foundation for developing novel kapok fiber medical gauzes.