Physically crosslinked PVA/graphene-based materials/aloe vera hydrogel with antibacterial activity

Burn is a major skin injury that occurs worldwide. For second-degree burns, special treatment should be given for creating a suitable wound healing environment. Hydrogel wound dressing as the primary care should possess extra properties that include antibacterial activity and cytocompatibility to enhance the treatment effectiveness. Additional therapy such as electrical stimulation can be applied as well promote wound healing. Herein, we used the tissue engineering concept to create a novel antibacterial and cytocompatible hydrogel made of polyvinyl alcohol (PVA), graphene-based material (GBM), and aloe vera extract (Av) through the freeze-thaw process. We prepared the PVA/GBM/Av hydrogel and examined its potential as a wound dressing. We found that it exhibited excellent hydrophilicity with a contact angle between 15 and 31 degrees and electrical conductivity within the range of 0.0102-0.0154 S m^-1, which is comparable to that of the human skin tissue and possesses tensile strength up to 1.5 MPa with elongation of 405%. It also demonstrated good stability in phosphate buffer saline with a weight ratio of 73-80% after 14 days of immersion. We presented that the addition of graphene and graphene oxide (GO) inhibited the growth of Gram-positive Staphylococcus aureus ATCC 6538 with the lowest bacterial population observed in PVA/GO, which is 1.74 × 10⁷ cfu mL^-1 after 1 day incubation and 99.94% bacterial reduction. Furthermore, our PVA/GBM/Av showed no toxicity to 3T3 fibroblast cells after 48 h with viability up to 295% for PVA/GO/Av. In summary, our fabricated hydrogels have shown their potential as wound dressing with antibacterial and non-cytotoxic properties.