(T1088) SMALL EXTRACELLULAR VESICLES (SEV) FROM GLYCOLYTICALLY ACTIVATED MESENCHYMAL STEM/STROMAL CELLS PROMOTE CHONDROPROTECTION IN VITRO AND CARTILAGE REGENERATION IN VIVO

Abstract: Osteoarthritis (OA) affects the articular cartilage causing an increase in oxidative stress leading to cartilage damage. It has been shown that mesenchymal stem/stromal cells (MSCs) therapeutic effects depend on their small extracellular vesicles (sEVs). However, for optimal clinical outcomes there is a need to enhance their therapeutic efficacy and to improve their storage for potential clinical application. We propose that sEVs derived from metabolically reprogrammed glycolytic-MSC (Glyco-sEVs) have a better therapeutic effect that those under basal conditions (Basal-sEVs) and that after a lyophilized process they maintain their phenotype and function against OA progression. Chondrocytes were isolated from the knee of OA patients. Chondroprotective effect of frozen or lyophilized Glyco-sEVs was measured by an apoptotic assay with menadione through annexin/PI kit and flow cytometry. To determinate the clinical effect of freeze or freeze dried Glyco-sEVs, both were injected intraarticularly in a collagenase murine model of OA (CIOA) and evaluated by MicroCT and histopathology. Our results showed that lyophilized Glyco-sEVs do not change their sEV characteristics, therefore they maintained their chondroprotective effect on chondrocytes when exposed to menadione as a source of oxidative stress. Moreover, CIOA mice treated with both frozen or lyophilized Glyco-sEVs showed a significant reduction in bone mineral density and the clinical damage score obtained from joint histology. Lyophilized Glyco-sEVs maintain their phenotype by expressing CD63, CD81 and CD9 and their size and shape with yield of 86,5%. Moreover, they do not change their chondroprotective effect in vitro since as frozen Glyco-sEVs, they display higher resistance to apoptosis induced by oxidative stress as compared to basal sEVs. Moreover, CIOA mice treated with both Glyco-sEVs showed a regenerative effect with significance evidenced in the histomorphometry parameters and the clinical joint score by histology. These results show that lyophilized Glyco-sEVs represents a potential new strategy for treating OA through their chondroprotective and regenerative properties.

Funding Source: This research was supported by ANID: FONDEF N°21110194; and IMPACT-FB-210024, FONDECYT-Regular N°1211353 and FONDECYT-Iniciación N°11220549.

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