Copper-coordinated fungal chitosan sutures with antibacterial and pro-healing performance

Fungal-derived chitosan (FCS) has emerged as a sustainable alternative to animal-derived chitosan (ACS) for biomedical applications. In this study, FCS fibers were fabricated via wet spinning and systematically compared with ACS fibers. FCS fibers exhibited a smaller fiber diameter, slightly lower crystallinity, and higher elongation, while maintaining a comparable chemical structure and thermal stability to ACS fibers. FCS fibers were subsequently twisted into yarns and functionalized with copper ions (Cu^2 +) to prepare antibacterial sutures (Cu@FCS). Cu²⁺ loading onto FCS yarns increased with copper solution concentration, reaching 9.32 ± 4.01‰ (Cu-L@FCS), 30.83 ± 3.43‰ (Cu-M@FCS), and 126.25 ± 21.11‰ (Cu-H@FCS). Importantly, both Cu-L@FCS and Cu-M@FCS exhibited excellent cytocompatibility and hemocompatibility, whereas Cu-H@FCS showed cytotoxicity. Both Cu-L@FCS and Cu-M@FCS demonstrated potent antibacterial activity against S. aureus and E. coli. These groups also significantly enhanced L929 cell migration, achieving wound closure rates of 95.17 ± 2.78% and 96.97 ± 1.93% at 24 h. In vivo, Cu-M@FCS sutures effectively reduced inflammatory cell infiltration and promoted the healing of infected wounds. Collectively, Cu@FCS sutures combine sustainability, robust antibacterial activity, and enhanced wound-healing performance, underscoring their considerable promise for clinical translation in biomedical applications.