Bioenergetic benefits and therapeutic potential of storable mitochondria

Mitochondrial transplantation is an emerging therapeutic strategy for various diseases associated with mitochondria dysfunction; however, conventional isolation methods require fresh tissue due to the fragility of isolated mitochondria, limiting clinical application. We previously developed a novel isolation method to recover high-quality mitochondria (Mitochondria oRganelle Complex; MRC-Q) from cryopreserved cell stocks. In this study, we characterized the biological profiles of MRC-Q and investigated its intracellular behavior and metabolic impact on recipient cells. MRC-Q maintained exceptionally high structural integrity of both outer and inner membranes, respiratory capacity, and high catalase activity even after cryopreservation and thawing. When delivered to human fibroblasts and vascular endothelial cells, RFP-labeled MRC-Q was rapidly internalized as independent puncta without fusing with the endogenous mitochondrial network. MRC-Q treatment significantly enhanced cellular respiration and ATP levels, and upregulated the expression of electron transport chain components and mitochondrial transcription factor A (TFAM). Furthermore, MRC-Q conferred dose-dependent resistance to H₂O₂-induced oxidative stress. These results suggest that MRC-Q acts not only as a transient energy source but also as a biological catalyst that triggers endogenous mitochondrial biogenesis. Our findings demonstrated that MRC-Q is a scalable and potent candidate for next-generation mitochondrial replacement therapy.