[Research progress on the application of stem cells and their derivatives in chronic wound repair]

Chronic wounds are characterised by factors including persistent inflammation, impaired angiogenesis, cellular dysfunction, and infection, which hinder the normal healing process, thereby not only severely compromising patients' quality of life but also imposing a substantial socioeconomic burden. For this type of wounds, conventional treatments are often limited in efficacy and associated with issues such as prolonged treatment duration and high costs. Recently, research on stem cells and their derivatives in the field of wound repair has been developing rapidly. Stem cells accelerate wound healing primarily through potent paracrine effects and immunomodulatory functions, complemented by multilineage differentiation potential, which synergistically modulate inflammation, promote angiogenesis, and facilitate collagen remodeling. Furthermore, engineering strategies including genetic modification, three-dimensional culture, and biomaterial-based delivery have significantly improved stem cell bioactivity and adaptability to the wound microenvironment. Concurrently, stem cell derivatives, particularly exosomes, have attracted increasing attention as a next-generation "cell-free" therapeutic strategy owing to their low immunogenicity, high stability, abundance of bioactive factors, and capacity for bioengineering modification. It offers a new approach to the precise regeneration of complex wounds. This review aims to review the pathological mechanisms underlying chronic wounds, research progress on therapeutic application of stem cells and their derivatives, engineering strategies, and translational challenges in clinical application, providing a reference for future research in the field.