Eneficial effects in numerous illness models. Nevertheless, most mammalian cells secret little quantity of EV, which is a limitation for improvement of therapeutics. Consequently, the subsequent generation of EV-mimetic vesicles created by serial extrusion of cells produces greater number of vesicles, and could possibly be less difficult to scale up for therapeutic developments. In this study we aimed to test the efficacy of EV-mimetic vesicles derived from human adipose-derived stem cells (hASCs) on rat osteoarthritis (OA) model. Strategies: hASC-derived EV-mimetic vesicles (CDV) have been created by serial extrusions of cells via filters. The CDVs were characterized by transmission electron microscopy (TEM), nanoparticle evaluation method (NTA), and western blot and flow cytometry. CDVs have been injected into the joints in a MIA-induced osteoarthritis (OA) rat model. Improvement of discomfort following CDV injections was assessed by paw withdrawal threshold and weight bearing, whereas the joint destruction was evaluated by histology. We also estimated the effects of CDV on proliferation and migration of human chondrocytes in vitro by cell-counting and scratch assays. Results: The CDV were 5050 nm in diameter and carried a number of EV-associated tetraspanins (CD63, CD9, CD81). CDV-treated OA mice had decreased paw withdrawal and was much more weight bearing 17 days following therapy than PBS-treated. Further, histology showed lowered joint defects at 24 days. CDV-treated OA models displayed substantial improvement in pawJOURNAL OF EXTRACELLULAR VESICLESwithdrawal behaviour and weight bearing evaluation. Similarly, chondrocyte migration and proliferation have been enhanced by CDV within a dose-dependent manner. Summary/Conclusion: This study demonstrates for the first time the efficacy of hASC EV-mimetic vesicles in OA model. Most interestingly we have confirmed that hASC EV-mimetic vesicles can boost discomfort and regenerate defected cartilage. These benefits support the concept that a potential application of hASC EVmimetic is osteoarthritis, by providing CDV locally into affected joints.Funding: This project is sponsored by NIH grant R01DE027404 and also the Osteology Foundation Sophisticated Researcher award.PF08.Exosomes secreted during chondrogenic differentiation of human adipose-derived stem cells for osteoarthritis treatment Ye eun Yuna, Woo Sung Kima, Hyun-A Parkb, Su Yeon Kimb and Yong Woo Choc Division of Chemical Engineering, Hanyang University, Ansan, Republic of Korea; bExostemtech,Inc., Ansan, Republic of Korea; cHanyang University, Ansan, Republic of KoreaaPF08.All-natural and synthetic biomaterial mediated delivery of Mesenchymal Stem Cell derived exosomes Chun-Chieh Huanga, Miya Kanazawab, Praveen Gajendrareddyc and Sriram Ravindranaa University of Illinois at Chicago, Chicago, IL, USA; bUIC ULK2 drug College of Dentistry, Oral Biology, Chicago, IL, USA; Plasmodium custom synthesis cUniversity of Illinois, Chicago, Chicago, IL, USAIntroduction: Mesenchymal stem cell (MSC) derived exosomes are versatile agents that possess immunomodulatory and regenerative properties. Even so, systemic delivery of all-natural or engineered MSC exosomes lacks site-specificity and may trigger ectopic effects. Thus, biomaterial-mediated site-specific delivery of exosomes is essential. As exosomal membranes are subsets from the plasma membrane. We hypothesized that MSC exosomes can bound to extracellular matrix proteins and also the house may be utilized as a delivery approach. Approaches: To test this hypothesis, we evaluated the binding and delivery kinetics of MSC exosomes to a.