Royal Jelly Extracellular Vesicles Enhance Diabetic Wound Healing via Inflammation Modulation, Fibroblast Migration, and Angiogenesis

Yen-Yu Tsai,1 Long-Sen Chang,1 Chun-Wen Lan,1– 3 Ying-Jung Chen,4– 6 Jen-Hao Yang1 1Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan; 2SCT-Biomed Co., Ltd, Kaohsiung, Taiwan; 3Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; 4Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung, Taiwan; 5Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan; 6Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, TaiwanCorrespondence: Ying-Jung Chen, Kaohsiung Medical University, Kaohsiung, Taiwan, Tel +886 07 3121101 ext.2804, Email [email protected] Jen-Hao Yang, National Sun Yat-Sen University, Kaohsiung, Taiwan, Tel +886 07 5252000 ext.7104, Email [email protected]: Diabetic wounds present a significant clinical challenge because of impaired healing and persistent inflammation. This study explored the therapeutic potential of extracellular vesicles derived from Apis mellifera royal jelly (RJEVs) to enhance diabetic wound repair.Methods and Results: RJEVs were characterized using nanoparticle tracking analysis, transmission electron microscopy, and Western blotting. The results showed that RJEVs had a nanoscale size of approximately 118 nm and were characterized by a double-layered lipid membrane and extracellular vesicle markers CD63 and syntenin. In vitro, RJEVs significantly improved migration by 31.4 ± 4.4% and reduced senescence by 24.7 ± 5.8% in high-glucose-stimulated human dermal fibroblasts. Furthermore, RJEVs restored collagen type I protein expression by 41.9 ± 7.6% under hyperglycemic conditions. RJEVs also mitigated inflammation in lipopolysaccharide-stimulated macrophages and THP-1 cells by downregulating pro-inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α. Additionally, RJEVs restored endothelial cell migration by 35.7 ± 5.6% and tube formation by 36.1 ± 2.4% under hyperglycemic conditions, accompanied by increased expression of VEGF and CD31. In vivo, RJEVs treatment significantly accelerated wound closure in streptozotocin-induced diabetic porcine models by 32.5 ± 7.2% compared to the control group.Conclusion: These findings indicate that RJEVs facilitate diabetic wound healing through the coordinated regulation of fibroblast function, immune modulation, and angiogenesis. This study introduces a nature-derived, non-mammalian extracellular vesicle platform with translational potential for chronic wound management in diabetes, offering a biocompatible and multifaceted therapeutic alternative to conventional approaches.Plain Language Summary: Wound healing in patients with diabetes is often slow due to damaged blood vessels, excessive inflammation, and impaired fibroblast migration. Extracellular vesicles (EVs) are nanosized, membrane-bound bubbles that are released by cells. They carry materials such as proteins, DNA, and RNA to other cells to communicate and exchange information that impacts everything from tissue repair to disease development. In this study, EVs isolated from the superfood royal jelly (RJEVs), which is widely known for its antioxidant and anti-inflammatory effects, can accelerate diabetic wound healing in diabetic pigs. Further results from this study showed that RJEVs stimulated the formation of new blood cells and fibroblast migration and decreased inflammation in cellular conditions. Keywords: skin, diabetes, high glucose, lipopolysaccharide, streptozotocin, porcine model