In vitro and in vivo evaluation of a bioactive polysaccharide based self-healing hydrogel film for enhanced wound healing

The objective of this research was to develop a carboxymethyl chitosan (CMCS) loaded borax cross-linked guar gum (GG) self-healing hydrogel film dressing for enhanced wound healing. Cross-links between borax and GG were confirmed through FTIR, SEM, and zeta potential measurement. The optimized formulation demonstrated favourable characteristics, including a thickness of 0.25 ± 0.008 mm, a water vapour transmission rate of 592.9 ± 55.1 g m -2 day -1 , tensile strength of 37 ± 1 MPa in the wet state and 61.33 ± 4.16 MPa in the dry state, a swelling ratio of 557.84%, and 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of 53.132 ± 1.02%. Furthermore, the optimized formulation exhibited a healing efficiency of 43.949 ± 0.56%, as determined by tensile strength measurements of the self-healed hydrogel film dressings after 6 h. Antimicrobial testing revealed broad-spectrum activity against wound-associated pathogens, including Staphylococcus aureus and Escherichia coli . The therapeutic efficacy was evaluated through in vivo experiments using a rat full-thickness wound model, which demonstrated that the optimized formulation achieved greater wound closure than commercial Tegaderm and ofloxacin loaded dressings. The CMCS-loaded hydrogel film dressing showed significantly higher hydroxyproline levels than the commercial Tegaderm and ofloxacin dressings. Hydroxyproline levels increased from day 7 and day 14, indicating progressive collagen synthesis. Histopathology analysis revealed that the CMCS-loaded hydrogel film dressing promoted faster re-epithelialization, reduced inflammatory cell infiltration, and enhanced granulation tissue formation compared to Tegaderm and ofloxacin dressings.