Vitamin C encapsulated biomimetic nanogels with macrophage membrane decoration for chronic wound healing

Diabetic wound healing is usually accompanied by uncontrolled inflammation. Drug delivery systems containing antioxidants are expected to resolve inflammation in local wounds and beneficially accelerate the repairing efficiency of wound healing. In this paper, we designed a biomimetic nanogel to deliver magnesium ascorbate phosphate (MAP, a vitamin C derivative) for relieving local inflammation in the wound. We applied the microfluidic technology to prepare nanogels composed of gelatin methacrylate (GelMA) and alginate, loaded with MAP. The macrophage membrane is further wrapped on the surface of the nanogel, endowing it with the inflammation targeting ability. During wound treatment, MAP was continuously released from the nanogel, which then cleared reactive oxygen species and promoted the polarization of M2 macrophages, thereby regulating the inflammatory wound microenvironment. This biomimetic nanogel efficiently solved the multifaceted challenges of chronic wound healing and showed beneficial repair effects in diabetic rat wounds. The in vitro and in vivo results all demonstrate the superb potentiality of biomimetic nanogels in bioactive drug delivery, chronic wound treatment, and related applications.