Ultra-microskin as cytokine reservoirs promote diabetic wound healing: experimental research.

BACKGROUND

Chronic wounds, such as diabetic foot ulcers, are challenging to heal due to persistent inflammatory responses and imbalanced growth factors. Conventional microskin grafting techniques face limitations, including insufficient viability, orientation-dependent survival, and restricted paracrine functions. This study investigates the feasibility of using ultra-microskin grafts (approximately 0.3 mm thick, 0.4 × 0.4 mm in surface dimensions) at expansion ratios of 1:10 to enhance diabetic wound repair.

MATERIALS AND

METHODS

Ultra-microskins were prepared using an automated skin-cutting device. Viability assessment of ultra-microskin and conventional microskins was performed using CCK-8 assay, LIVE/DEAD staining, transmission electron microscopy, and explant culture. Ultra-microskin was transplanted onto full-thickness defects at 1:10 and 1:20 expansion ratios; the optimal size was determined based on viability results and the "Inter-Graft Spacing Theory." Cytokine release from ultra-microskin was quantified by ELISA. The effects of cytokines in ultra-microskin extracts on the migration, proliferation, and tube formation capabilities of human foreskin fibroblasts (HFB), human umbilical vein endothelial cells (HUVECs), and HaCaT cells were assessed. Ultra-microskin (0.4 mm) was transplanted onto diabetic rat wounds at a 1:10 ratio. Wound healing was evaluated via gross photography, H&E staining, Masson's trichrome staining, and CD31/Ki-67 immunohistochemistry. Proteomic analysis of wound tissues was conducted on posttransplant days 7 and 14.

RESULTS

Ultra-microskin sized ≥0.4 mm exhibited viability comparable to or exceeding that of conventional microskins. The optimal size for ultra-microskin was determined to be 0.4 mm. Ultra-microskin significantly enhanced the release of cytokines (TGF-α, EGF, MCP-1, TNF-α, IL-6, IL-10, VEGF-A, TGF-β1, IGF-1) and promoted the functions of wound healing-associated cells (HFB, HUVEC, HaCaT). Transplantation of ultra-microskin significantly attenuated inflammation, promoted vascularization and epithelialization, and accelerated the healing rate of diabetic wounds.

CONCLUSION

Ultra-microskin (0.4 mm) dynamically accelerates diabetic wound healing via cytokine release, offering a novel therapeutic strategy for chronic wounds, including diabetic ulcers.