Chitosan-reinforced nanocrystalline cellulose hydrogels containing activated carbon as antitoxin wound dressing

Wound infection causes wound chronicity as the presence of pathogens prolong wound healing time. Endotoxins lipopolysaccharides (LPS) are released from Gram-negative bacteria when they are lysed by host phagocytic cells during an immune response. These endotoxins in wounds are shown to be one of the causes of delayed wound healing. The porous activated carbon (AC) can act as an important absorptive material for the elimination of bacterial toxins, which makes it an attractive biomaterial for infected wounds. NCC is also reported to facilitate cell adhesion, proliferation, and migrations. Previously, our laboratory has shown that chitosan (CS) reinforced with Kenaf nanocrystalline celluloses (NCC) possesses vastly improved mechanical properties. This study explores the potential of incorporating AC into NCC-CS hydrogel (AC/NCC), with the aim of eliminating bacteria toxins in wounds as well as the acceleration of wound healing. The AC/NCC hydrogel was characterized in terms of rheological properties, swelling behaviour, fourier transform infrared spectroscopy as well as zeta potential. Then the AC/NCC hydrogel dressings were evaluated in vitro using a cytotoxicity study and toxin removal assay. The results showed that hydrogels exhibit desirable rheological properties with homogenous activated carbon particles. The hydrogels exhibit low cytotoxicity towards the human fibroblast and keratinocytes cells. The hydrogel can remove up to 85% of endotoxins when treated with 0.1 EU/mL of LPS. In summary, this study has shown that AC/NCC hydrogel has a vast potential as an antitoxin dressing for infected chronic wounds. Graphical Abstract AC/NCC hydrogel dressing eliminates endotoxin from infected wounds and accelerates wound healing