Polyhexamethylene biguanidine coated silver nanoparticles embedded into chitosan thiourea/PVA nanofibers as wound healing mats: In vitro and in vivo studies.

Burn injuries are prone to infection, leading to significant public health concerns and economic implications. There is a growing demand to develop innovative wound dressings with antibacterial activity. In this study, silver nanoparticles coated with polyhexamethylene biguanidine (Ag/PHMBG) were embedded into chitosan thiourea (CST) nanofibers as a novel multifunctional wound healing mat for treating second-degree burn wounds. Structural, mechanical, and biological properties of nanofibers were investigated using FE-SEM, XRD, ATR-FTIR, and In vitro degradation. The animal study was performed to investigate the suitability of the polymeric mats as a wound healing/dressing system. FE-SEM analysis revealed that the average diameter of the obtained uniform and bead-less Ag/PHMBG-loaded CST nanofibers was around 75 nm. CST-based nanofibers with 3 wt% Ag/PHMBG (PCT3) demonstrated notable antimicrobial efficacy against both S. aureus and P. aeruginosa, achieving 95 % growth inhibition within 3 days while exhibiting no cytotoxic effects on normal fibroblast cells. In addition, CST nanofibers have good breathability with a water vapor transmittance rate of 2.9 ± 0.41-4.4 ± 0.47 kg/m. d. The animal studies showed that the wound healing and tissue regeneration process by PCT3 nanofibers were faster than the other groups. In conclusion, CST-based nanofibers are a potentially promising substitute for conventional wound dressings in clinical applications.