Exosome Therapy for Chronic Wound Healing.

Background: Chronic lower-extremity ulcers linked to diabetes, venous insufficiency, or smoking are difficult to heal because of impaired vascularity, persistent inflammation, and extracellular matrix dysfunction. Exosome therapy-a cell-free regenerative approach-may address these deficits by delivering proangiogenic and immunomodulatory cargo. We evaluated its clinical usage in a case series.

Methods: Four adults (age 42-62 y) with ulcers present for 6 months or more and refractory to compression, debridement, and topical care received monthly topical applications of adipose-derived stem-cell exosomes (Exo-HL, Primoris International Co., Ltd., Seoul, Korea), 1 × 10¹² particles/mL; 0.1 mL/cm² wound area). Wounds were photographed and measured every 2-4 weeks; Doppler ultrasonography quantified arterial resistive index and venous reflux at baseline and 3-month intervals. Follow-up continued for up to 7 months.

Results: Median baseline ulcer area was 12.4 cm² (range, 4.8-26.1 cm²). All wounds showed visible granulation within 2 weeks; 3 achieved complete closure after a median of 94 days (range, 60-180 d). Mean arterial resistive index decreased from 0.93 ± 0.04 to 0.77 ± 0.03, and venous reflux time fell from 2.8 ± 0.3 to 1.4 ± 0.2 seconds. No adverse events or wound infections occurred.

Conclusions: Exosome therapy was well tolerated and associated with rapid granulation, improved perfusion, and durable closure of refractory chronic ulcers. Although limited by small sample size and lack of controls, these findings support further controlled trials to define efficacy and optimize dosing.