The favorable role of oxidized pullulan as a multipurpose crosslinker in polyvinyl alcohol (PVA)/chitosan/collagen films for promoting human skin fibroblast viability, antibacterial activity and healing of methicillin-resistant Staphylococcus aureus (MRSA) infected wounds in mice

In this study, pullulan was oxidized by NaIO 4 into low, medium and high oxidation degrees (OPL1,OPL2,OPL3) and used as a crosslinker to enhance physicochemical and biological properties of the wound dressings based on polyvinyl alcohol(PVA)/chitosan/collagen (FPL,FOPL1,FOPL2,FOPL3). Physicochemical, mechanical and biological properties of OPL samples as well as crosslinked films were characterized. The results showed that OPL not only increased the cell viability of human skin fibroblasts but also promoted antibacterial activity. Fourier transform infrared spectroscopy, rheological and gel content results proved the crosslinking effect of OPL. Mechanical properties of FOPL2 and FOPL3 films was >2 times higher than FPL film. The viability of human skin fibroblast cells was higher than the control for all films, and antibacterial activity of the film FOPL3 was significantly higher compared to other films. Wound healing effect of FOPL3 film was evaluated in a methicillin-resistant staphylococcus aureus (MRSA) infected full-thickness skin defect model in mice. The results showed a significantly lower wound area after 7,10,14 days of treatment compared to the control group treated by normal saline. The findings of this research enlighten wound healing potentials of oxidized pullulan to be used as a multifunctional ingredient for the development of future skin care biomaterials.