Balloon Flower Root-Derived Extracellular Vesicles: In Vitro Assessment of Anti-Inflammatory, Proliferative, and Antioxidant Effects for Chronic Wound Healing.

Excessive reactive oxygen species (ROS) in wound lesions can lead to oxidative stress and failure of normal wound healing processes, eventually resulting in chronic skin wounds. A multitude of researchers have investigated various natural products with physiological activities, including antioxidant effects, for healing chronic skin wounds. Balloon flower root (BFR), which contains bioactive components such as platycodins, is known for its anti-inflammatory and antioxidant effects. In this study, we isolated BFR-derived extracellular vesicles (BFR-EVs) that possess anti-inflammatory, proliferative, and antioxidant activities via a combination of polyethylene glycol-based precipitation and ultracentrifugation. Our objective was to investigate the potential of BFR-EVs in treating chronic wounds caused by ROS. Despite efficient intracellular delivery, BFR-EVs showed no significant cytotoxicity. In addition, BFR-EVs inhibited the expression of pro-inflammatory cytokine genes in lipopolysaccharide-stimulated RAW 264.7 cells. Furthermore, water-soluble tetrazolium salt-8 assay showed that BFR-EVs had a proliferation-promoting effect on human dermal fibroblasts (HDFs). Scratch closure and transwell migration assays indicated that BFR-EVs could promote the migration of HDFs. When the antioxidant effect of BFR-EVs was evaluated through 2',7'-dichlorodihydrofluorescein diacetate staining and quantitative real-time polymerase chain reaction, the results revealed that BFR-EVs significantly suppressed ROS generation and oxidative stress induced by H 2 O 2 and ultraviolet irradiation. Our findings suggest that BFR-EVs hold the potential as a natural candidate for healing chronic skin wounds.