(P-BT-15) Harnessing Human Umbilical Cord Blood-Derived Exosomes for Inflammation Modulation and Tissue Regeneration: A Promising Therapeutic Approach

Tissue injury often triggers an inflammatory response characterized by releasing pro-inflammatory cytokines like TNF. This inflammatory environment can impair tissue regeneration and prolong healing. However, the recent discovery of exosomes, which possess anti-inflammatory properties due to their cargo of various molecules, has opened up new and exciting avenues in the field. This study delves into the novel and intriguing area of investigating the potential therapeutic role of human umbilical cord blood-derived exosomes (UCB-Exo) in mitigating inflammation and promoting tissue regeneration.

Study

Design/Methods: UCB-Exos were meticulously isolated from the whole umbilical cord blood using a highly precise ultracentrifugation method. In brief, exosomes diluted in PBS were analyzed with utmost precision by nanoparticle tracking using the NanoSight NS300 equipment. These exosomes were then treated to a human skin fibroblast cell line for a functional assay. The efficacy of UCB-Exos on wound healing was evaluated by measuring wound closure rates with high accuracy. The scratch wound assay and MTT assay were conducted to assess the effects of UCB-Exos on the migration and proliferation of human skin fibroblasts. Meanwhile, using the ELISA kit, the roles of the candidate cytokine in UCB-Exos-induced regulation of the immunomodulation of macrophage cell line were assessed with meticulous attention to detail.

Results/Findings: NTA analysis was performed to identify the purified nanoparticles derived from UCB. Isolated exosomes were characterized by their cup-shaped spheroidal morphology (size: ~115.4 nm) and exosome-specific markers, i.e., CD9, CD63, and CD81 proteins. UCB-Exos contained high levels of small RNAs, and we speculated that UCB-Exos would have anti-inflammatory functions. UCB-Exo from different donors were incubated with activating RAW 264.7, and the expressions of pro-inflammatory cytokines were evaluated by ELISA kit. All UCB-Exo significantly decrease TNF expression to a certain degree in LPS-challenged macrophages, suggesting the presumptive anti-inflammatory potentials for UCB-Exo. Next, we incubated CCD966SK cells with exosomes isolated from UCB. MTT assays and the scratch wound assay showed that UCB-Exo significantly promoted cell proliferation and migration ability, indicating their potential in tissue regeneration.

Conclusions: In conclusion, our study uncovers the exciting potential for the clinical application of UCB-Exos. It highlights their significant anti-inflammatory effects in vitro, particularly in reducing TNF expression levels in LPS-induced macrophage inflammation. Furthermore, their ability to enhance cell proliferation in skin fibroblasts suggests a promising avenue for therapeutic intervention. The implications for treating inflammatory conditions and promoting tissue regeneration are substantial, paving the way for further exploration of UCB-Exos in clinical settings.