Mitochondrial transfer: A comprehensive analysis of mechanistic insights, preclinical applications, and technological...

Mitochondrial transfer, the intercellular exchange of functional mitochondria, is crucial for maintaining cellular homeostasis and promoting tissue repair, particularly in neurological disorders associated with mitochondrial dysfunction. This review addresses the mechanisms through which mitochondrial transfer occurs, including tunneling nanotubes, extracellular vesicles, gap junction channels, and cell fusion. Mitochondrial transfer and transplantation have demonstrated positive therapeutic effects in various disease models, such as cerebral hemorrhage, ischemic stroke, Alzheimer's disease, and multiple sclerosis. Exogenous mitochondria can integrate into recipient cells, enhancing adenosine triphosphate production, restoring redox balance, and improving cellular survival under stress conditions. However, clinical translation faces significant hurdles, including immune rejection, limited recipient cell uptake capacity, a lack of standardized manufacturing protocols, and unresolved ethical concerns regarding mitochondrial sourcing. To address these challenges, cutting-edge biotechnological strategies, such as mitochondrial surface modification, nanocarrier-based delivery, biomaterial-assisted transplantation, and the use of engineered vesicles, are being developed to enhance the precision, stability, and biocompatibility of mitochondrial delivery. Furthermore, innovative approaches, including CRISPR-based genome editing, 3D-bioprinted tissue models, and artificial intelligence-assisted predictive platforms, are being explored to enhance mitochondrial function and delivery efficiency. Current strategies to harness mitochondrial transfer include pharmacological agents that enhance mitochondrial dynamics, stem cell-based delivery of healthy mitochondria, and the aforementioned bioengineered platforms. In conclusion, the integration of mitochondrial transfer as a groundbreaking treatment option for neurological disorders relies on addressing two to three fundamental challenges. These include the establishment of standardized and scalable protocols for production and quality control, formulating approaches to minimize immune reactions and improve the efficiency of mitochondrial integration, and creating a well-defined ethical and regulatory framework for sourcing and utilizing mitochondria. The primary contribution of this work lies in its integrated analysis of mechanistic insights, preclinical applications, and technological innovations, providing a consolidated roadmap for advancing mitochondrial transplantation from bench to bedside.