Electrospun PVA-chitosan nanofibers with antibacterial properties for wound healing: unveiling the potential of low molecular weight chitosan.

Chitosan (CS) is a high molecular weight biopolymer derived from the deacetylation of chitin, which is naturally present in the exoskeletons of crustaceans. However, its inherently low water solubility limits many biomedical applications. In contrast, low-MW CS (LMWCS) is water-soluble and exhibits promising biological properties. Herein, we report the synthesis of two LMWCS (CS1 and CS7) and their incorporation into electrospun poly(vinyl alcohol) (PVA) nanofibers (NFs) at various loadings. Both LMWCS samples were successfully integrated into PVA NFs without crosslinkers, with tunable encapsulation and release confirmed by elemental analysis, UV-vis and NMR spectroscopy. Comparative evaluations revealed that CS7-containing fibers exhibited superior antimicrobial efficacy against S. aureus, E. coli, P. aeruginosa, and C. albicans, and significantly promoted HaCaT-ras A5 keratinocyte migration in scratch assays. Together, this work establishes molecular weight-dependent design principles for engineering multifunctional electrospun wound dressings that integrate both antimicrobial activity and pro-regenerative capability.