Research on a novel poly (vinyl alcohol)/lysine/vanillin wound dressing: Biocompatibility, bioactivity and antimicrobial activity

Burn wound dressings have played significant roles in daily clinical practice. An "ideal" burn wound dressing is non-adhesion, absorbency and antimicrobial activity. However, such a dressing is currently not available. A novel composite hydrogel was based on poly (vinyl alcohol) (PVA) containing lysine (Lys) and vanillin (V) using freezing-thawing method. The properties of this hydrogel were characterized by environmental scanning electron microscope (ESEM), attenuated total reflectance fourier transform infrared spectroscopy (ATRFTIR), tensile testing, differential scanning calorimetry (DSC) and water vapour transmission rate (WVTR). Then the antibacterial activity of PVA/Lys/V composite hydrogel was examined by bacteriolytic plate. In vivo experiment, a burn rat model was used to evaluate the histological analysis of this hydrogel. In results, the Schiff base formed in the three-phase system. It improved the tensile strength and crystallization of the PVA/Lys/V composite hydrogel. Meanwhile, this hydrogel showed excellent bactericidal activities to both gram-negative bacteria (E. coli) and gram-positive bacteria ( S. aureus) due to the Schiff base. And the antibacterial activity toward gram-negative bacteria was better than another. On Day 7, 95-100% of the surface areas of PVA/Lys/V composite treated burns were covered with regenerating epidermis. And the new tissue and capillary vessel formed around the wounds after treatment. Therefore, it is suggested that treatment with PVA/Lys/V composite hydrogel will be effective also in patients with burns and other skin wounds.