Development of a Novel Chitosan/Sodium Hyaluronate/Iridium Hydrogel Nanocomposite to Enhance Keratinocyte Cell Migration for Wound Healing Applications

Chitosan is a chemical substance extracted from the shells of crustaceans, known for its impressive biocompatibility and antibacterial properties. Due to its low cost and easy availability, chitosan and its derivatives have been explored for biomedical applications, such as wound dressings, bio-scaffolds, drug delivery, and disease diagnosis. Our laboratory has developed a novel chitosan/sodium hyaluronate/iridium (CHI/SH/Ir) hydrogel nanocomposite through electrophoresis, featuring a unique microstructure with vertically aligned pores. The formation of ordered vertical pores in the CHI/SH/Ir hydrogel nanocomposite is due to the restriction of hydrogen bubbles generated by water electrolysis during the electrophoresis process, which limits their lateral movement and coalescence. The diameter of the vertical pores is 600-700 μm and the thickness is 500 μm in the wet state. The porosity of the CHI/SH/Ir hydrogel nanocomposite is 76.7%, and the water absorption rate is 350%. Compared to similar products without added iridium, its tensile strength is nearly doubled, reaching 8.7 MPa. In the CHI/SH/Ir hydrogel nanocomposite, iridium nanoparticles are uniformly distributed, with an average size of 3 nm. The CHI/SH/Ir electrophoretic suspension exhibits negligible cytotoxicity. In cell migration tests using human keratinocyte HaCaT cells, the relative migration rate of the CHI/SH/Ir hydrogel nanocomposite was 122.15 ± 9.02 % (p < 0.001) compared to the blank sample. Furthermore, reactive oxygen species (ROS) inhibition and next-generation sequencing experiments are applied to study the enhancement of migration properties. The vertically aligned pores observed with SH and iridium nanoparticles suggest broad prospects for applications in wound healing.