Multi-form antibacterial dressings based on a deep eutectic supramolecular polymer promote healing of burn wounds through a weakly acidic microenvironment

Burn damage causes loss of the barrier function of the skin against bacteria, but providing a weakly acidic environment is beneficial for preventing bacterial invasion and promoting wound healing. The utilization of the natural antibacterial properties of chitosan is ideal for treating wounds. In this work, a deep eutectic supramolecular polymer (DESP) prepared with a cyclodextrin and an organic acid effectively improved the antibacterial properties of chitosan through its cavity structure and provided a weakly acidic environment for wound healing. Through genipin crosslinking, the mechanical strength and swelling rate of the prepared dressing reached 9.79 MPa and 1100 %, respectively. As a wound dressing, this new material shows good flexibility, breathability and stability. The cell survival rate when using this new wound dressing was greater than 90.0 %, and the hemolysis rate was less than 5.0 %. It had high biocompatibility and cell compatibility and facilitated cell proliferation. The dressing showed excellent antibacterial effects on E. coli and S. aureus, and the size of the inhibition rings was up to 11 mm and 14 mm. In in vivo wound healing experiments, new capillaries and collagen fibers appeared earlier, and the dressing in multiple forms could reduce inflammation, promote angiogenesis, and accelerate wound healing. Therefore, the use of a DESP with a cavity structure provides an effective strategy for the preparation of future medical materials.