iPSC-derived exosomes promote diabetic wound healing by attenuating inflammatory responses.

Abstract

Owing to impaired glucose metabolism, the high-glucose microenvironment in diabetic patients disrupts a series of biological reactions that hinder the wound healing process, resulting in a significant cost to the health care system and an urgent need for new and advanced therapies. In this study, induced pluripotent stem cell-derived exosomes (iPSC-Exos) were isolated from iPSC culture supernatant via centrifugation and ultrafiltration. We evaluated the therapeutic effects of iPSC-Exos on diabetic wound healing through two clinically relevant animal models (spontaneous genetic diabetic mouse model and streptozotocin (STZ)-induced diabetic mouse model). iPSC-Exos were topically administered to full-thickness cutaneous wounds in diabetic mice. The therapeutic effects were systematically assessed by measuring wound closure rates, conducting comprehensive histopathological evaluations, and performing quantitative analysis of inflammatory mediators via ELISA. We demonstrated that iPSC-Exos can significantly accelerate diabetic wound healing through two clinically relevant animal models (spontaneous genetic diabetic mouse model and STZ-induced diabetic mouse model) for the first time. The multifaceted therapeutic mechanisms include: (ⅰ) Direct activation of tissue regeneration (promotion of re-epithelialization, tissue remodeling and scar attenuation); (ⅱ) Modulation of the inflammatory microenvironment (promoting macrophage polarization toward anti-inflammatory M2 phenotype/suppressing inflammation). This dual-animal model approach, which closely recapitulates key pathophysiological features of human diabetic wounds, offers superior clinical translatability compared to single-animal model studies. Our findings not only establish a robust scientific foundation for clinical development of iPSC-Exos therapy, but also present a transformative, cell-free treatment paradigm for chronic diabetic wounds that addresses critical unmet medical needs.