Protocatechuic acid-mediated injectable antioxidant hydrogels facilitate wound healing

Overproduction of free radicals in vivo leads to oxidative stress, which substantially slows the healing of wound. Here, a series of injectable antioxidant hydrogels were designed by protocatechuic acid (PA)-mediated carbox-ylated chitosan (CCS) composed by conjugating oxidized hyaluronic acid (OHA). These biocompatible OHA/CCS-PA composite hydrogels presented stable chemical structure, physical properties, and effective antibacterial properties against common pathogens exceeding 99%. In addition, OHA/CCS-PA hydrogels demonstrated satisfactory antioxidant capacity to scavenge over 85% of overproduced free radicals, which could reduce the damage of oxidative stress to cellular activity and diminish the expression of reactive oxygen species in vitro by the long-lasting release of phenolic hydroxyl element. More importantly, the results of in vivo animal tests confirmed that OHA/CCS-PA hydrogels could significantly promote wound healing with higher collagen disposition (86.29%) in comparison with commercial TegadermTM film and the control hydrogel with physical mixing of PA. These findings indicated that OHA/CCS-PA hydrogel had great potential for wound healing.

Automated summary

Injectable antioxidant hydrogels composed of protocatechuic acid (PA)-mediated carboxylated chitosan (CCS) and oxidized hyaluronic acid (OHA) conjugate were designed to reduce oxidative stress and promote wound healing. These hydrogels exhibited stable chemical structure, satisfactory physical properties, and effective antibacterial properties. In addition, the hydrogels demonstrated significant antioxidant capacity and promoted collagen deposition in wound healing in animal tests.