Magnetomitotransfer: An efficient way for direct mitochondria transfer into cultured human cells

Mitochondrial transplantation: a promising strategy for the treatment of retinal degenerative diseases

The retina, a crucial neural tissue, is responsible for transforming light signals into visual information, a process that necessitates a significant amount of energy. Mitochondria, the primary powerhouses of the cell, play an integral role in retinal physiology by fulfilling the high-energy requirements of photoreceptors and secondary neurons through oxidative phosphorylation. In a healthy state, mitochondria ensure proper visual function by facilitating efficient conversion and transduction of visual signals. However, in retinal degenerative diseases, mitochondrial dysfunction significantly contributes to disease progression, involving a decline in membrane potential, the occurrence of DNA mutations, increased oxidative stress, and imbalances in quality-control mechanisms. These abnormalities lead to an inadequate energy supply, the exacerbation of oxidative damage, and the activation of cell death pathways, ultimately resulting in neuronal injury and dysfunction in the retina. Mitochondrial transplantation has emerged as a promising strategy for addressing these challenges. This procedure aims to restore metabolic activity and function in compromised cells through the introduction of healthy mitochondria, thereby enhancing the cellular energy production capacity and offering new strategies for the treatment of retinal degenerative diseases. Although mitochondrial transplantation presents operational and safety challenges that require further investigation, it has demonstrated potential for reviving the vitality of retinal neurons. This review offers a comprehensive examination of the principles and techniques underlying mitochondrial transplantation and its prospects for application in retinal degenerative diseases, while also delving into the associated technical and safety challenges, thereby providing references and insights for future research and treatment.

Connecting the dots: Mitochondrial transfer in immunity, inflammation, and cancer

Mitochondria are more than mere energy generators; they are multifaceted organelles that integrate metabolic, signalling, and immune functions, making them indispensable players in maintaining cellular and systemic health. Mitochondrial transfer has recently garnered attention due to its potential role in several physiological and pathological processes. This process involves multiple mechanisms by which mitochondria, along with mitochondrial DNA and other components, are exchanged between cells. In this review, we examine the critical roles of mitochondrial transfer in health and disease, focusing on its impact on immune cell function, the resolution of inflammation, tissue repair, and regeneration. Additionally, we explore its implications in viral infections and cancer progression. We also provide insights into emerging therapeutic applications, emphasizing its potential to address unmet clinical needs.

Therapeutic implications of mitochondrial transfer on stem cell fate in regenerative medicine

With the discovery of intercellular mitochondrial transfer, the intricate mitochondrial regulatory networks on stem cell fate have aroused intense academic interest. Apart from capturing freely released mitochondria from donor cells, stem cells are able to receive mitochondria through tunneling nanotubes (TNTs), gap junctional channels (GJCs) and extracellular vesicles (EVs), especially when undergoing stressful conditions such as inflammation, hypoxia, chemotherapy drug exposure, and irradiation. Stem cells that are potentiated by exogenous mitochondria show enhanced potential for proliferation, differentiation, and immunomodulation. The well-tolerated nature of either autogenous or allogenous mitochondria when locally injected in the human ischemic heart has validated the safety and therapeutic potential of mitochondrial transplantation. In children diagnosed with mitochondrial DNA deletion syndrome, functional improvements have been observed when empowering their hematopoietic stem cells with maternally derived mitochondria. Apart from the widely investigated applications of mitochondrial transfer in ischemia-reperfusion injury, neurodegenerative diseases and mitochondrial diseases etc., therapeutic potentials of mitochondrial transfer in tissue repair and regeneration are equally noteworthy, though there has been no systematic summary in this regard.This review analyzed the research and development trends of mitochondrial transfer in stem cells and regenerative medicine over the past decade from a bibliometric perspective, introduced the concept and associated mechanisms of mitochondrial transfer, summarized the regulations of intercellular mitochondrial transfer on stem cell fate. Finally, the therapeutic application of mitochondrial transplantation in diseases and tissue regeneration has been reviewed, including recent clinical studies related to mitochondrial transplantation.Mitochondrial transfer shows promise in modifying and reshaping the cellular properties of stem cells, making them more conducive to regeneration. Mesenchymal stem cells (MSCs)-derived mitochondria have shown multifaceted potential in promoting the revitalization and regeneration of cardiac, cutaneous, muscular, neuronal tissue. This review integrates novel research findings on mitochondrial transfer in stem cell biology and regenerative medicine, emphasizing the crucial translational value of mitochondrial transfer in regeneration. It serves to underscore the significant impact of mitochondrial transfer and provides a valuable reference for further exploration in this field.

Mitochondrial transplantation: Triumphs, challenges, and impacts on nuclear genome remodelling

Mitochondria are membrane-bound organelles of eukaryotic cells that play crucial roles in cell functioning and homeostasis, including ATP generation for cellular energy. Mitochondrial function is associated with several complex diseases and disorders, including cardiovascular, cardiometabolic, neurodegenerative diseases and some cancers. The risk for these diseases and disorders is often associated with mitochondrial dysfunction, particularly the quantitative and qualitative features of the mitochondrial genome. Emerging results implicate mito-nuclear crosstalk as the mechanism by which mtDNA variation affects complex disease outcomes. Experimental approaches are emerging for the targeting of mitochondria as a potential therapeutic for several of these diseases, particularly in the form of mitochondrial transplantation. Current approaches to mitochondrial transplantation generally involve isolating healthy mitochondria from donor cells and introducing them to diseased recipients towards amelioration of mitochondrial dysfunction. Using such a protocol, several reports have shown recovery of mitochondrial function and improved disease outcomes post-mitochondrial transplantation, highlighting its potential as a therapeutic method for several complex, severe and debilitating diseases. Additionally, the mitochondrial genome can be modified prior to transplantation to target disease-associated site-specific mutations and to reduce the ratio of mutant-to-WT alleles. These promising results may underlie the potential impact of mitochondrial transplantation on mito-nuclear genome interactions in the setting of the disease. Further, we recommend that mitochondrial transplantation experimentation include an assessment of potential impacts on remodelling of the nuclear genome, particularly the nuclear epigenome and transcriptome. Herein, we review these and other triumphs and challenges of mitochondrial transplantation as a potential novel therapeutic for mitochondria-associated diseases.

Recent advances in mitochondrial transplantation to treat disease

Mitochondrial transplantation (MT), an innovative regenerative technique widely used to treat diseases caused by mitochondrial dysfunction, shows great promise for clinical application. This procedure can increase the number of mitochondria and improve the function of damaged mitochondria, resulting in increased adenosine triphosphate levels, decreased reactive oxygen species production, improved Ca2+ buffering capacity, modulated inflammatory response, and reduced apoptosis to protect cells, thus promoting tissue repair. In this review, we describe research advances in MT over the last five years, focusing on its application in treating various diseases, including ischaemic injuries (of the kidney, heart, lung, and liver), neurodegenerative disorders, spinal cord injury, sepsis, diabetes mellitus, stroke, and ultraviolet radiation injuries, as well as in procedures such as organ transplantation, focusing on instances where MT demonstrated good efficacy. We also cover the application of engineered mitochondria and mitochondrial combination therapies and present the latest advances in improving MT efficiency, as well as the current clinical applications and shortcomings of MT, aiming to provide a theoretical foundation for enhanced MT utilisation in the future.

Engineered mitochondria in diseases: mechanisms, strategies, and applications

Mitochondrial diseases represent one of the most prevalent and debilitating categories of hereditary disorders, characterized by significant genetic, biological, and clinical heterogeneity, which has driven the development of the field of engineered mitochondria. With the growing recognition of the pathogenic role of damaged mitochondria in aging, oxidative disorders, inflammatory diseases, and cancer, the application of engineered mitochondria has expanded to those non-hereditary contexts (sometimes referred to as mitochondria-related diseases). Due to their unique non-eukaryotic origins and endosymbiotic relationship, mitochondria are considered highly suitable for gene editing and intercellular transplantation, and remarkable progress has been achieved in two promising therapeutic strategies-mitochondrial gene editing and artificial mitochondrial transfer (collectively referred to as engineered mitochondria in this review) over the past two decades. Here, we provide a comprehensive review of the mechanisms and recent advancements in the development of engineered mitochondria for therapeutic applications, alongside a concise summary of potential clinical implications and supporting evidence from preclinical and clinical studies. Additionally, an emerging and potentially feasible approach involves ex vivo mitochondrial editing, followed by selection and transplantation, which holds the potential to overcome limitations such as reduced in vivo operability and the introduction of allogeneic mitochondrial heterogeneity, thereby broadening the applicability of engineered mitochondria.

Mitochondrial transplantation in brain disorders: Achievements, methods, and challenges

Mitochondrial transplantation is a new treatment strategy aimed at repairing cellular damage by introducing healthy mitochondria into injured cells. The approach shows promise in protecting brain function in various neurological disorders such as traumatic brain injury/ischemia, neurodegenerative diseases, cognitive disorders, and cancer. These conditions are often characterized by mitochondrial dysfunction, leading to impaired energy production and neuronal death. The review highlights promising preclinical studies where mitochondrial transplantation has been shown to restore mitochondrial function, reduce inflammation, and improve cognitive and motor functions in several animal models. It also addresses significant challenges that must be overcome before this therapy can be clinically applied. Current efforts to overcome these challenges, including advancements in isolation techniques, cryopreservation methods, finding an appropriate mitochondria source, and potential delivery routes, are discussed. Considering the rising incidence of neurological disorders and the limited effectiveness of current treatments, this review offers a comprehensive overview of the current state of mitochondrial transplantation research and critically assesses the remaining obstacles. It provides valuable insights that could steer future studies and potentially lead to more effective treatments for various brain disorders.

Unveiling the power of mitochondrial transfer in cancer progression: a perspective in ovarian cancer

Mitochondria are dynamic organelles integral to metabolic processes, coordination of essential biological pathways, and oncogenesis and tumor progression. Recent studies have revealed that mitochondria can be transferred between cells via multiple mechanisms, implicating their involvement in the pathogenesis and progression of ovarian cancer. This review provides a comprehensive analysis of intercellular mitochondrial transfer within the context of ovarian cancer and its tumor microenvironment. We also propose targeted pathways and therapeutic strategies that could be utilized to modulate diseases associated with mitochondrial transfer therapy. Finally, we examine recent advancements in this field and identify several unresolved questions.

From dysfunction to healing: advances in mitochondrial therapy for Osteoarthritis

Osteoarthritis (OA) is a chronic degenerative joint condition characterised by cartilage deterioration and changes in bone morphology, resulting in pain and impaired joint mobility. Investigation into the pathophysiological mechanisms underlying OA has highlighted the significance of mitochondrial dysfunction in its progression. Mitochondria, which are cellular organelles, play a crucial role in regulating energy metabolism, generating reactive oxygen species, and facilitating essential biological processes including apoptosis. In recent years, the utilisation of exogenous drugs and MT to improve mitochondrial function in chondrocytes has shown great promise in OA treatment. Numerous studies have investigated the potential of stem cells and extracellular vesicles in mitochondrial transfer. This review aims to explore the underlying mechanisms of mitochondrial dysfunction in OA and assess the progress in utilising mitochondrial transfer as a therapeutic approach for this disease.

Mitochondrion-based organellar therapies for central nervous system diseases

As most traditional drugs used to treat central nervous system (CNS) diseases have a single therapeutic target, many of them cannot treat complex diseases or diseases whose mechanism is unknown and cannot effectively reverse the root changes underlying CNS diseases. This raises the question of whether multiple functional components are involved in the complex pathological processes of CNS diseases. Organelles are the core functional units of cells, and the replacement of damaged organelles with healthy organelles allows the multitargeted and integrated modulation of cellular functions. The development of therapies that target independent functional units in the cell, specifically, organelle-based therapies, is rapidly progressing. This article comprehensively discusses the pathogenesis of mitochondrial homeostasis disorders, which involve mitochondria, one of the most important organelles in CNS diseases, and the machanisms of mitochondrion-based therapies, as well as current preclinical and clinical studies on the efficacy of therapies targeting mitochondrial to treat CNS diseases, to provide evidence for use of organelle-based treatment strategies in the future.

Mitochondrial transplantation: A promising therapy for mitochondrial disorders

As a vital energy source for cellular metabolism and tissue survival, the mitochondrion can undergo morphological or positional change and even shuttle between cells in response to various stimuli and energy demands. Multiple human diseases are originated from mitochondrial dysfunction, but the curative succusses by traditional treatments are limited. Mitochondrial transplantation therapy (MTT) is an innovative therapeutic approach that is to deliver the healthy mitochondria either derived from normal cells or reassembled through synthetic biology into the cells and tissues suffering from mitochondrial damages and finally replace their defective mitochondria and restore their function. MTT has already been under investigation in clinical trials for cardiac ischemia-reperfusion injury and given an encouraging performance in animal models of numerous fatal critical diseases including central nervous system disorders, cardiovascular diseases, inflammatory conditions, cancer, renal injury, and pulmonary damage. This review article summarizes the mechanisms and strategies of mitochondrial transfer and the MTT application for types of mitochondrial diseases, and discusses the potential challenge in MTT clinical application, aiming to exhibit the good therapeutic prospects of MTTs in clinics.

Mitochondrial transplantation for the treatment of cardiac and noncardiac diseases: mechanisms, prospective, and challenges

Mitochondrial transplantation (MT) is a promising therapeutic strategy that involves introducing healthy mitochondria into damaged tissues to restore cellular function. This approach has shown promise in treating cardiac diseases, such as ischemia-reperfusion injury, myocardial infarction, and heart failure, where mitochondrial dysfunction plays a crucial role. Transplanting healthy mitochondria into affected cardiac tissue has resulted in improved cardiac function, reduced infract size, and enhanced cell survival in preclinical studies. Beyond cardiac applications, MT is also being explored for its potential to address various noncardiac diseases, including stroke, infertility, and genetic mitochondrial disorders. Ongoing research focused on refining techniques for mitochondrial isolation, preservation, and targeted delivery is bolstering the prospects of MT as a clinical therapy. As the scientific community gains a deeper understanding of mitochondrial dynamics and pathology, the development of MT as a clinical therapy holds significant promise. This review provides an overview of recent research on MT and discusses the methodologies involved, including sources, isolation, delivery, internalization, and distribution of mitochondria. Additionally, it explores the effects of MT and potential mechanisms in cardiac diseases, as well as non-cardiac diseases. Future prospects for MT are also discussed.

Considerations for developing mitochondrial transplantation techniques for individualized medicine

Tweetable abstract Mitochondrial transplantation has been used to treat various diseases associated with mitochondrial dysfunction. Here, we highlight the considerations in quality control mechanisms that should be considered in the context of mitochondrial transplantation.

Mitochondrial transfer - a novel promising approach for the treatment of metabolic diseases

Metabolic disorders remain a major global health concern in the 21st century, with increasing incidence and prevalence. Mitochondria play a critical role in cellular energy production, calcium homeostasis, signal transduction, and apoptosis. Under physiological conditions, mitochondrial transfer plays a crucial role in tissue homeostasis and development. Mitochondrial dysfunction has been implicated in the pathogenesis of metabolic disorders. Numerous studies have demonstrated that mitochondria can be transferred from stem cells to pathologically injured cells, leading to mitochondrial functional restoration. Compared to cell therapy, mitochondrial transplantation has lower immunogenicity, making exogenous transplantation of healthy mitochondria a promising therapeutic approach for treating diseases, particularly metabolic disorders. This review summarizes the association between metabolic disorders and mitochondria, the mechanisms of mitochondrial transfer, and the therapeutic potential of mitochondrial transfer for metabolic disorders. We hope this review provides novel insights into targeted mitochondrial therapy for metabolic disorders.

Powering prescription: Mitochondria as "Living Drugs" - Definition, clinical applications, and industry advancements

Mitochondria's role as engines and beacons of metabolism and determinants of cellular health is being redefined through their therapeutic application as "Living Drugs" (LDs). Artificial mitochondrial transfer/transplant (AMT/T), encompassing various techniques to modify, enrich, or restore mitochondria in cells and tissues, is revolutionizing acellular therapies and the future of medicine. This article proposes a necessary definition for LDs within the Advanced Therapeutic Medicinal Products (ATMPs) framework. While recognizing different types of LDs as ATMPs, such as mesenchymal stem cells (MSCs) and chimeric antigen receptor T (CAR T) cells, we focus on mitochondria due to their unique attributes that distinguish them from traditional cell therapies. These attributes include their inherent living nature, diverse sources, industry applicability, validation, customizability for therapeutic needs, and their capability to adapt and respond within recipient cells. We trace the journey from initial breakthroughs in AMT/T to the current state-of-the-art applications by emerging innovative companies, highlighting the need for manufacturing standards to navigate the transition of mitochondrial therapies from concept to clinical practice. By providing a comprehensive overview of the scientific, clinical, and commercial landscape of mitochondria as LDs, this article contributes to the essential dialogue among regulatory agencies, academia, and industry to shape their future in medicine.

Mitochondrial transplantation: the advance to therapeutic application and molecular modulation

Mitochondrial transplantation provides a novel methodology for rescue of cell viability and cell function following ischemia-reperfusion injury and applications for other pathologies are expanding. In this review we present our methods and acquired data and evidence accumulated to support the use of mitochondrial transplantation.

Association with cationized gelatin nanospheres enhances cell internalization of mitochondria efficiency

The objective of this study is to confirm the methodological feasibility of cationized gelatin nanospheres (cGNS) to enhance the internalization efficiency of mitochondria (Mt) isolated to cells for their increasing functions. The cGNS were simply associated on the surface of Mt by the electrostatic interaction. Different sizes of cGNS were used to allow Mt to associate on the Mt surface (Mt-cGNS). As a control, cationized gelatin (cG) was used to modify the Mt surface (Mt-cG). The Mt-cG and Mt-cGNS prepared were cultured with H9c2 cells to examine their internalization. The internalization efficiency significantly increased by utilizing cGNS. However, there was no significant difference in the internalization efficiency among cGNS with different sizes. After incubation of Mt, Mt-cG, and Mt-cGNS, the superoxide amount and ATP generation were evaluated. Significantly lower superoxide amount and higher ATP amount were observed for the Mt-cGNS group compared with those of non-modified Mt group. It is conceivable that cGNS enhance the cellular internalization of Mt, leading to an improve mitochondrial functions in the recipient cells. In conclusion, cGNS are promising to improve the efficacy in mitochondria internalization.

Mitochondrial transplantation and transfer: The promising method for diseases

Mitochondria are organelles that serve as the powerhouses for cellular bioenergetics in eukaryotic cells. It is responsible for mitochondrial adenosine triphosphate (ATP) generation, cell signaling and activity, calcium balance, cell survival, proliferation, apoptosis, and autophagy. Mitochondrial transplantation is a promising disease therapy that involves the recovery of mitochondrial dysfunction using isolated functioning mitochondria. The objective of the present article is to provide current knowledge on natural mitochondrial transfer processes, in vitro and in vivo applications of mitochondrial transplantation, clinical trials, and challenges associated with mitochondrial transplantation.

Muscle mitochondrial transplantation can rescue and maintain cellular homeostasis

Mitochondria control cellular functions through their metabolic role. Recent research that has gained considerable attention is their ability to transfer between cells. This has the potential of improving cellular functions in pathological or energy-deficit conditions, but little is known about the role of mitochondrial transfer in sustaining cellular homeostasis. Few studies have investigated the potential of skeletal muscle as a source of healthy mitochondria that can be transferred to other cell types. Thus, we isolated intermyofibrillar mitochondria from murine skeletal muscle and incubated them with host cells. We observed dose- and time-dependent increases in mitochondrial incorporation into myoblasts. This resulted in elongated mitochondrial networks and an enhancement of bioenergetic profile of the host cells. Mitochondrial donation also rejuvenated the functional capacities of the myoblasts when respiration efficiency and lysosomal function were inhibited by complex I inhibitor rotenone and bafilomycin A, respectively. Mitochondrial transfer was accomplished via tunneling nanotubes, extracellular vesicles, gap junctions, and by macropinocytosis internalization. Murine muscle mitochondria were also effectively transferred to human fibroblast cells having mitochondrial DNA mutations, resulting in augmented mitochondrial dynamics and metabolic functions. This improved cell function by diminishing reactive oxygen species (ROS) emission in the diseased cells. Our findings suggest that mitochondria from donor skeletal muscle can be integrated in both healthy and functionally compromised host cells leading to mitochondrial structural refinement and respiratory boost. This mitochondrial trafficking and bioenergetic reprogramming to maintain and revitalize tissue homeostasis could be a useful therapeutic strategy in treating diseases.NEW & NOTEWORTHY In our study, we have shown the potential of mouse skeletal muscle intermyofibrillar mitochondria to be transplanted in myoblasts and human fibroblast cells having mitochondrial DNA mutations. This resulted in an augmentation of mitochondrial dynamics and enhancement of bioenergetic profile in the host cells. Our findings suggest that mitochondria from donor skeletal muscle can be integrated into both healthy and functionally compromised host cells leading to mitochondrial structural refinement and respiratory boost.

Multifaceted roles of mitochondria in wound healing and chronic wound pathogenesis

Mitochondria are intracellular organelles that play a critical role in numerous cellular processes including the regulation of metabolism, cellular stress response, and cell fate. Mitochondria themselves are subject to well-orchestrated regulation in order to maintain organelle and cellular homeostasis. Wound healing is a multifactorial process that involves the stringent regulation of several cell types and cellular processes. In the event of dysregulated wound healing, hard-to-heal chronic wounds form and can place a significant burden on healthcare systems. Importantly, treatment options remain limited owing to the multifactorial nature of chronic wound pathogenesis. One area that has received more attention in recent years is the role of mitochondria in wound healing. With regards to this, current literature has demonstrated an important role for mitochondria in several areas of wound healing and chronic wound pathogenesis including metabolism, apoptosis, and redox signalling. Additionally, the influence of mitochondrial dynamics and mitophagy has also been investigated. However, few studies have utilised patient tissue when studying mitochondria in wound healing, instead using various animal models. In this review we dissect the current knowledge of the role of mitochondria in wound healing and discuss how future research can potentially aid in the progression of wound healing research.

Mitochondrial transplantation: an overview of a promising therapeutic approach

Mitochondrial transplantation is a promising therapeutic approach for the treatment of mitochondrial diseases caused by mutations in mitochondrial DNA, as well as several metabolic and neurological disorders. Animal studies have shown that mitochondrial transplantation can improve cellular energy metabolism, restore mitochondrial function, and prevent cell death. However, challenges need to be addressed, such as the delivery of functional mitochondria to the correct cells in the body, and the long-term stability and function of the transplanted mitochondria. Researchers are exploring new methods for mitochondrial transplantation, including the use of nanoparticles or CRISPR gene editing. Mechanisms underlying the integration and function of transplanted mitochondria are complex and not fully understood, but research has revealed some key factors that play a role. While the safety and efficacy of mitochondrial transplantation have been investigated in animal models and human trials, more research is needed to optimize delivery methods and evaluate long-term safety and efficacy. Clinical trials using mitochondrial transplantation have shown mixed results, highlighting the need for further research in this area. In conclusion, although mitochondrial transplantation holds significant potential for the treatment of various diseases, more work is needed to overcome challenges and evaluate its safety and efficacy in human trials. [BMB Reports 2023; 56(9): 488-495].

Mitochondrial transplantation: an overview of a promising therapeutic approach

Mitochondrial transplantation is a promising therapeutic approach for the treatment of mitochondrial diseases caused by mutations in mitochondrial DNA, as well as several metabolic and neurological disorders. Animal studies have shown that mitochondrial transplantation can improve cellular energy metabolism, restore mitochondrial function, and prevent cell death. However, challenges need to be addressed, such as the delivery of functional mitochondria to the correct cells in the body, and the long-term stability and function of the transplanted mitochondria. Researchers are exploring new methods for mitochondrial transplantation, including the use of nanoparticles or CRISPR gene editing. Mechanisms underlying the integration and function of transplanted mitochondria are complex and not fully understood, but research has revealed some key factors that play a role. While the safety and efficacy of mitochondrial transplantation have been investigated in animal models and human trials, more research is needed to optimize delivery methods and evaluate long-term safety and efficacy. Clinical trials using mitochondrial transplantation have shown mixed results, highlighting the need for further research in this area. In conclusion, although mitochondrial transplantation holds significant potential for the treatment of various diseases, more work is needed to overcome challenges and evaluate its safety and efficacy in human trials. [BMB Reports 2023; 56(9): 488-495].

What can we do to optimize mitochondrial transplantation therapy for myocardial ischemia-reperfusion injury?

Mitochondrial transplantation is a promising solution for the heart following ischemia-reperfusion injury due to its capacity to replace damaged mitochondria and restore cardiac function. However, many barriers (such as inadequate mitochondrial internalization, poor survival of transplanted mitochondria, few mitochondria colocalized with cardiac cells) compromise the replacement of injured mitochondria with transplanted mitochondria. Therefore, it is necessary to optimize mitochondrial transplantation therapy to improve clinical effectiveness. By analogy, myocardial ischemia-reperfusion injury is like a withered flower, it needs to absorb enough nutrients to recover and bloom. In this review, we present a comprehensive overview of "nutrients" (source of exogenous mitochondria and different techniques for mitochondrial isolation), "absorption" (mitochondrial transplantation approaches, mitochondrial transplantation dose and internalization mechanism), and "flowering" (the mechanism of mitochondrial transplantation in cardioprotection) for myocardial ischemia-reperfusion injury.

Mitochondria-derived cell-to-cell communication

In addition to their intracellular mobility, mitochondria and their components can exist outside the cells from which they originate. As a result, they are capable of acting on non-parental distant cells and mediate intercellular communication in physiological conditions and in a variety of pathologies. It has recently been demonstrated that this horizontal transfer governs a wide range of biological processes, such as tissue homeostasis, the rescue of injured recipient cells, and tumorigenesis. In addition, due to mitochondria's bacterial ancestry, they and their components can be recognized as damage-associated molecular patterns (DAMPs) by the immune cells, leading to inflammation. Here, we provide an overview of the most current and significant findings concerning the different structures of extracellular mitochondria and their by-products and their functions in the physiological and pathological context. This account illustrates the ongoing expansion of our understanding of mitochondria's biological role and functions in mammalian organisms.

Emerging Landscape of Cell-Penetrating Peptide-Mediated Organelle Restoration and Replacement

Organelles are specialized subunits within a cell membrane that perform specific roles or functions, and their dysfunction can lead to a variety of pathophysiologies including developmental defects, aging, and diseases (cancer, cardiovascular and neurodegenerative diseases). Recent studies have shown that cell-penetrating peptide (CPP)-based pharmacological therapies delivered to organelles or even directly resulting in organelle replacement can restore cell function and improve or prevent disease. In this review, we summarized the current developments in the precise delivery of exogenous cargoes via CPPs at the organelle level, CPP-mediated organelle delivery, and discuss their feasibility as next-generation targeting strategies for the diagnosis and treatment of diseases at the organelle level.

Mitochondria as biological targets for stem cell and organismal senescence

Organismal aging is impacted by the deterioration of tissue turnover mechanisms due, in part, to the decline in stem cell function. This decline can be related to mitochondrial dysfunction and underlying energetic defects that, in concert, help drive biological aging. Thus, mitochondria have been described as a potential interventional target to hinder the loss of stem cell robustness, and subsequently, decrease tissue turnover decline and age-associated pathologies. In this review, we focused our analysis on the most recent literature on mitochondria and stem cell aging and discuss the potential benefits of targeting mitochondria in preventing stem cell dysfunction and thus influencing aging.

Mitochondrial transfer/transplantation: an emerging therapeutic approach for multiple diseases

Mitochondria play a pivotal role in energy generation and cellular physiological processes. These organelles are highly dynamic, constantly changing their morphology, cellular location, and distribution in response to cellular stress. In recent years, the phenomenon of mitochondrial transfer has attracted significant attention and interest from biologists and medical investigators. Intercellular mitochondrial transfer occurs in different ways, including tunnelling nanotubes (TNTs), extracellular vesicles (EVs), and gap junction channels (GJCs). According to research on intercellular mitochondrial transfer in physiological and pathological environments, mitochondrial transfer hold great potential for maintaining body homeostasis and regulating pathological processes. Multiple research groups have developed artificial mitochondrial transfer/transplantation (AMT/T) methods that transfer healthy mitochondria into damaged cells and recover cellular function. This paper reviews intercellular spontaneous mitochondrial transfer modes, mechanisms, and the latest methods of AMT/T. Furthermore, potential application value and mechanism of AMT/T in disease treatment are also discussed.

Mitochondrial transplantation as a promising therapy for mitochondrial diseases

Mitochondrial diseases are a group of inherited or acquired metabolic disorders caused by mitochondrial dysfunction which may affect almost all the organs in the body and present at any age. However, no satisfactory therapeutic strategies have been available for mitochondrial diseases so far. Mitochondrial transplantation is a burgeoning approach for treatment of mitochondrial diseases by recovery of dysfunctional mitochondria in defective cells using isolated functional mitochondria. Many models of mitochondrial transplantation in cells, animals, and patients have proved effective via various routes of mitochondrial delivery. This review presents different techniques used in mitochondrial isolation and delivery, mechanisms of mitochondrial internalization and consequences of mitochondrial transplantation, along with challenges for clinical application. Despite some unknowns and challenges, mitochondrial transplantation would provide an innovative approach for mitochondrial medicine.

Mitochondria transfer restores fibroblasts-like synoviocytes (FLS) plasticity in LPS-induced, in vitro synovitis model

Background

Synovitis (SI) is one of the most common and serious orthopedic diseases in horses of different age, breed and sex, which contributes to the development of osteoarthritis. The burden of SI includes economic loss and represents a real challenge for current veterinary health care. At the molecular level, fibroblasts-like synoviocytes (FLS) are recognized as major cell populations involved in SI pathogenesis. In the course of SI, FLSs are losing their protective and pro-regenerative cytological features, become highly proliferative and initiate various stress signaling pathways.

Methods

Fibroblast-like synoviocytes were treated with LPS in order to generate SI in vitro model. Mitochondria were isolated from peripheral blood derived mononuclear cells and co-cultured with FLS. After 24 h of culture, cells were subjected to RT-qPCR, western blot, cytometric and confocal microscopy analysis.

Results

Mitochondrial transfer (MT) was observed in vitro studies using confocal microscopy. Further studies revealed, that MT to LPS-treated FLS reduced cell proliferation, modulated apoptosis and decreased inflammatory response. Overall, MT Resulted in the considerable recovery of recipient cells cytophysiological properties.

Conclusions

Presented data provides evidence that mitochondria transfersignificantly modulate FLS proliferative and metabolic activity through improved mitochondrial biogenesis and dynamics in activated FLS. Obtained results for the first time demonstrate that horizontal MT might be considered as a therapeutic tool for synovitis treatment; however, further clinical studies are strongly required.

Automated Optical Tweezers Manipulation to Transfer Mitochondria from Fetal to Adult MSCs to Improve Antiaging Gene Expressions

Mitochondrial dysfunction is considered to be an important factor that leads to aging and premature aging diseases. Transferring mitochondria to cells is an emerging and promising technique for the therapy of mitochondrial deoxyribonucleic acid (mtDNA)-related diseases. This paper presents a unique method of controlling the quality and quantity of mitochondria transferred to single cells using an automated optical tweezer-based micromanipulation system. The proposed method can automatically, accurately, and efficiently collect and transport healthy mitochondria to cells, and the recipient cells then take up the mitochondria through endocytosis. The results of the study reveal the possibility of using mitochondria from fetal mesenchymal stem cells (fMSCs) as a potential source to reverse the aging-related phenotype and improve metabolic activities in adult mesenchymal stem cells (aMSCs). The results of the quantitative polymerase chain reaction analysis show that the transfer of isolated mitochondria from fMSCs to a single aMSC can significantly increase the antiaging and metabolic gene expression in the aMSC. The proposed mitochondrial transfer method can greatly promote precision medicine for cell therapy of mtDNA-related diseases.

Leber's hereditary optic neuropathy: Current approaches and future perspectives on Mesenchymal stem cell-mediated rescue

Leber's Hereditary Optic Neuropathy (LHON) is an inherited optic nerve disorder. It is a mitochondrially inherited disease due to point mutation in the MT-ND1, MT-ND4, and MT-ND6 genes of mitochondrial DNA (mtDNA) coding for complex I subunit proteins. These mutations affect the assembly of the mitochondrial complex I and hence the electron transport chain leading to mitochondrial dysfunction and oxidative damage. Optic nerve cells like retinal ganglion cells (RGCs) are more sensitive to mitochondrial loss and oxidative damage which results in the progressive degeneration of RGCs at the axonal region of the optic nerve leading to bilateral vision loss. Currently, gene therapy using Adeno-associated viral vector (AAV) is widely studied for the therapeutics application in LHON. Our review highlights the application of cell-based therapy for LHON. Mesenchymal stem cells (MSCs) are known to rescue cells from the pre-apoptotic stage by transferring healthy mitochondria through tunneling nanotubes (TNT) for cellular oxidative function. Empowering the transfer of healthy mitochondria using MSCs may replace the mitochondria with pathogenic mutation and possibly benefit the cells from progressive damage. This review discusses the ongoing research in LHON and mitochondrial transfer mechanisms to explore its scope in inherited optic neuropathy.

Mitotherapy: Unraveling a Promising Treatment for Disorders of the Central Nervous System and Other Systemic Conditions

Mitochondria are key players of aerobic respiration and the production of adenosine triphosphate and constitute the energetic core of eukaryotic cells. Furthermore, cells rely upon mitochondria homeostasis, the disruption of which is reported in pathological processes such as liver hepatotoxicity, cancer, muscular dystrophy, chronic inflammation, as well as in neurological conditions including Alzheimer’s disease, schizophrenia, depression, ischemia and glaucoma. In addition to the well-known spontaneous cell-to-cell transfer of mitochondria, a therapeutic potential of the transplant of isolated, metabolically active mitochondria has been demonstrated in several in vitro and in vivo experimental models of disease. This review explores the striking outcomes achieved by mitotherapy thus far, and the most relevant underlying data regarding isolated mitochondria transplantation, including mechanisms of mitochondria intake, the balance between administration and therapy effectiveness, the relevance of mitochondrial source and purity and the mechanisms by which mitotherapy is gaining ground as a promising therapeutic approach.

Mitochondrial transplantation in cardiomyocytes: foundation, methods, and outcomes

Mitochondrial transplantation is emerging as a novel cellular biotherapy to alleviate mitochondrial damage and dysfunction. Mitochondria play a crucial role in establishing cellular homeostasis and providing cell with the energy necessary to accomplish its function. Owing to its endosymbiotic origin, mitochondria share many features with their bacterial ancestors. Unlike the nuclear DNA, which is packaged into nucleosomes and protected from adverse environmental effects, mitochondrial DNA are more prone to harsh environmental effects, in particular that of the reactive oxygen species. Mitochondrial damage and dysfunction are implicated in many diseases ranging from metabolic diseases to cardiovascular and neurodegenerative diseases, among others. While it was once thought that transplantation of mitochondria would not be possible due to their semiautonomous nature and reliance on the nucleus, recent advances have shown that it is possible to transplant viable functional intact mitochondria from autologous, allogenic, and xenogeneic sources into different cell types. Moreover, current research suggests that the transplantation could positively modulate bioenergetics and improve disease outcome. Mitochondrial transplantation techniques and consequences of transplantation in cardiomyocytes are the theme of this review. We outline the different mitochondrial isolation and transfer techniques. Finally, we detail the consequences of mitochondrial transplantation in the cardiovascular system, more specifically in the context of cardiomyopathies and ischemia.

Mitochondria Donation by Mesenchymal Stem Cells: Current Understanding and Mitochondria Transplantation Strategies

The phenomenon of mitochondria donation is found in various tissues of humans and animals and is attracting increasing attention. To date, numerous studies have described the transfer of mitochondria from stem cells to injured cells, leading to increased ATP production, restoration of mitochondria function, and rescue of recipient cells from apoptosis. Mitochondria transplantation is considered as a novel therapeutic approach for the treatment of mitochondrial diseases and mitochondrial function deficiency. Mitochondrial dysfunction affects cells with high energy needs such as neural, skeletal muscle, heart, and liver cells and plays a crucial role in type 2 diabetes, as well as Parkinson's, Alzheimer's diseases, ischemia, stroke, cancer, and age-related disorders. In this review, we summarize recent findings in the field of mitochondria donation and mechanism of mitochondria transfer between cells. We review the existing clinical trials and discuss advantages and disadvantages of mitochondrial transplantation strategies based on the injection of stem cells, isolated functional mitochondria, or EVs containing mitochondria.

Mitochondrial DNA Dynamics in Reprogramming to Pluripotency

Mammalian cells, with the exception of erythrocytes, harbor mitochondria, which are organelles that provide energy, intermediate metabolites, and additional activities to sustain cell viability, replication, and function. Mitochondria contain multiple copies of a circular genome called mitochondrial DNA (mtDNA), whose individual sequences are rarely identical (homoplasmy) because of inherited or sporadic mutations that result in multiple mtDNA genotypes (heteroplasmy). Here, we examine potential mechanisms for maintenance or shifts in heteroplasmy that occur in induced pluripotent stem cells (iPSCs) generated by cellular reprogramming, and further discuss manipulations that can alter heteroplasmy to impact stem and differentiated cell performance. This additional insight will assist in developing more robust iPSC-based models of disease and differentiated cell therapies.

Inter and Intracellular mitochondrial trafficking in health and disease

Neurons and glia maintain central nervous system (CNS) homeostasis through diverse mechanisms of intra- and intercellular signaling. Some of these interactions include the exchange of soluble factors between cells via direct cell-to-cell contact for both short and long-distance transfer of biological materials. Transcellular transfer of mitochondria has emerged as a key example of this communication. This transcellular transfer of mitochondria are dynamically involved in the cellular and tissue response to CNS injury and play beneficial roles in recovery. This review highlights recent research addressing the cause and effect of intra- and intercellular mitochondrial transfer with a specific focus on the future of mitochondrial transplantation therapy. We believe that mitochondrial transfer plays a crucial role during bioenergetic crisis/deficit, but the quality, quantity and mode of mitochondrial transfer determines the protective capacity for the receiving cells. Mitochondrial transplantation is a new treatment paradigm and will overcome the major bottleneck of traditional approach of correcting mitochondria-related disorders.

Stable retention of chloramphenicol-resistant mtDNA to rescue metabolically impaired cells

The permanent transfer of specific mtDNA sequences into mammalian cells could generate improved models of mtDNA disease and support future cell-based therapies. Previous studies documented multiple biochemical changes in recipient cells shortly after mtDNA transfer, but the long-term retention and function of transferred mtDNA remains unknown. Here, we evaluate mtDNA retention in new host cells using ‘MitoPunch’, a device that transfers isolated mitochondria into mouse and human cells. We show that newly introduced mtDNA is stably retained in mtDNA-deficient (ρ0) recipient cells following uridine-free selection, although exogenous mtDNA is lost from metabolically impaired, mtDNA-intact (ρ+) cells. We then introduced a second selective pressure by transferring chloramphenicol-resistant mitochondria into chloramphenicol-sensitive, metabolically impaired ρ+ mouse cybrid cells. Following double selection, recipient cells with mismatched nuclear (nDNA) and mitochondrial (mtDNA) genomes retained transferred mtDNA, which replaced the endogenous mutant mtDNA and improved cell respiration. However, recipient cells with matched mtDNA-nDNA failed to retain transferred mtDNA and sustained impaired respiration. Our results suggest that exogenous mtDNA retention in metabolically impaired ρ+ recipients depends on the degree of recipient mtDNA-nDNA co-evolution. Uncovering factors that stabilize exogenous mtDNA integration will improve our understanding of in vivo mitochondrial transfer and the interplay between mitochondrial and nuclear genomes.

From Cell Entry to Engraftment of Exogenous Mitochondria

Mitochondrial transfer has been recognized to play a role in a variety of processes, ranging from fertilization to cancer and neurodegenerative diseases as well as mammalian horizontal gene transfer. It is achieved through either exogeneous or intercellular mitochondrial transfer. From the viewpoint of evolution, exogeneous mitochondrial transfer is quite akin to the initial process of symbiosis between α-protobacterium and archaea, although the progeny have developed more sophisticated machinery to engulf environmental materials, including nutrients, bacteria, and viruses. A molecular-based knowledge of endocytosis, including macropinocytosis and endosomal escape involving bacteria and viruses, could provide mechanistic insights into exogeneous mitochondrial transfer. We focus on exogeneous mitochondrial transfer in this review to facilitate the clinical development of the use of isolated mitochondria to treat various pathological conditions. Several kinds of novel procedures to enhance exogeneous mitochondrial transfer have been developed and are summarized in this review.

TAT-dextran-mediated mitochondrial transfer enhances recovery from models of reperfusion injury in cultured cardiomyocytes

Acute myocardial infarction is a leading cause of death among single organ diseases. Despite successful reperfusion therapy, ischaemia reperfusion injury (IRI) can induce oxidative stress (OS), cardiomyocyte apoptosis, autophagy and release of inflammatory cytokines, resulting in increased infarct size. In IRI, mitochondrial dysfunction is a key factor, which involves the production of reactive oxygen species, activation of inflammatory signalling cascades or innate immune responses, and apoptosis. Therefore, intercellular mitochondrial transfer could be considered as a promising treatment strategy for ischaemic heart disease. However, low transfer efficiency is a challenge in clinical settings. We previously reported uptake of isolated exogenous mitochondria into cultured cells through co‐incubation, mediated by macropinocytosis. Here, we report the use of transactivator of transcription dextran complexes (TAT‐dextran) to enhance cellular uptake of exogenous mitochondria and improve the protective effect of mitochondrial replenishment in neonatal rat cardiomyocytes (NRCMs) against OS. TAT‐dextran–modified mitochondria (TAT‐Mito) showed a significantly higher level of cellular uptake. Mitochondrial transfer into NRCMs resulted in anti‐apoptotic capability and prevented the suppression of oxidative phosphorylation in mitochondria after OS. Furthermore, TAT‐Mito significantly reduced the apoptotic rates of cardiomyocytes after OS, compared to simple mitochondrial transfer. These results indicate the potential of mitochondrial replenishment therapy in OS‐induced myocardial IRI.

Screening Yeast Display Libraries against Magnetized Yeast Cell Targets Enables Efficient Isolation of Membrane Protein Binders

When isolating binders from yeast displayed combinatorial libraries, a soluble, recombinantly expressed form of the target protein is typically utilized. As an alternative, we describe the use of target proteins displayed as surface fusions on magnetized yeast cells. In our strategy, the target protein is coexpressed on the yeast surface with an iron oxide binding protein; incubation of these yeast cells with iron oxide nanoparticles results in their magnetization. Subsequently, binder cells that interact with the magnetized target cells can be isolated using a magnet. Using a known binder-target pair with modest binding affinity (K_D ≈ 400 nM), we showed that a binder present at low frequency (1 in 10⁵) could be enriched more than 100-fold, in a single round of screening, suggesting feasibility of screening combinatorial libraries. Subsequently, we screened yeast display libraries of Sso7d and nanobody variants against yeast displayed targets to isolate binders specific to the cytosolic domain of the mitochondrial membrane protein TOM22 (K_D ≈ 272-1934 nM) and the extracellular domain of the c-Kit receptor (K_D ≈ 93 to K_D > 2000 nM). Additional studies showed that the TOM22 binders identified using this approach could be used for the enrichment of mitochondria from cell lysates, thereby confirming binding to the native mitochondrial protein. The ease of expressing a membrane protein or a domain thereof as a yeast cell surface fusion-in contrast to recombinant soluble expression-makes the use of yeast-displayed targets particularly attractive. Therefore, we expect the use of magnetized yeast cell targets will enable efficient isolation of binders to membrane proteins.

Fractionated mitochondrial magnetic separation for isolation of synaptic mitochondria from brain tissue

While mitochondria maintain essential cellular functions, such as energy production, calcium homeostasis, and regulating programmed cellular death, they also play a major role in pathophysiology of many neurological disorders. Furthermore, several neurodegenerative diseases are closely linked with synaptic damage and synaptic mitochondrial dysfunction. Unfortunately, the ability to assess mitochondrial dysfunction and the efficacy of mitochondrial-targeted therapies in experimental models of neurodegenerative disease and CNS injury is limited by current mitochondrial isolation techniques. Density gradient ultracentrifugation (UC) is currently the only technique that can separate synaptic and non-synaptic mitochondrial sub-populations, though small brain regions cannot be assayed due to low mitochondrial yield. To address this limitation, we used fractionated mitochondrial magnetic separation (FMMS), employing magnetic anti-Tom22 antibodies, to develop a novel strategy for isolation of functional synaptic and non-synaptic mitochondria from mouse cortex and hippocampus without the usage of UC. We compared the yield and functionality of mitochondria derived using FMMS to those derived by UC. FMMS produced 3x more synaptic mitochondrial protein yield compared to UC from the same amount of tissue, a mouse hippocampus. FMMS also has increased sensitivity, compared to UC separation, to measure decreased mitochondrial respiration, demonstrated in a paradigm of mild closed head injury. Taken together, FMMS enables improved brain-derived mitochondrial yield for mitochondrial assessments and better detection of mitochondrial impairment in CNS injury and neurodegenerative disease.

Forms of extracellular mitochondria and their impact in health

Mitochondria play an important role as an intracellular energy plant and signaling organelle. However, mitochondria also exist outside cells where they could mediate cell-to-cell communication, repair and serve as an activator of the immune response. Their effects depend on the mitochondrial state or the form in which it is present, either as a whole functional structure as fragments or only as mitochondrial DNA. Herein, we provide evidence of why extracellular mitochondria and their varying forms are considered regenerative factors or pro-inflammatory activators. Understanding these aspects will provide the base of their use in therapy or as a biomarker of disease severity and prognosis.

Mitochondria in Ischemic Stroke: New Insight and Implications

Stroke is the leading cause of death and adult disability worldwide. Mitochondrial dysfunction has been regarded as one of the hallmarks of ischemia/reperfusion (I/R) induced neuronal death. Maintaining the function of mitochondria is crucial in promoting neuron survival and neurological improvement. In this article, we review current progress regarding the roles of mitochondria in the pathological process of cerebral I/R injury. In particular, we emphasize on the most critical mechanisms responsible for mitochondrial quality control, as well as the recent findings on mitochondrial transfer in acute stroke. We highlight the potential of mitochondria as therapeutic targets for stroke treatment and provide valuable insights for clinical strategies.

Delivery of exogenous mitochondria via centrifugation enhances cellular metabolic function

Mitochondria are essential organelles involved in the maintenance of cell growth and function, and have been investigated as therapeutic targets in various diseases. Recent studies have demonstrated that direct mitochondrial transfer can restore cellular functions of cells with inherited or acquired mitochondrial dysfunction. However, previous mitochondrial transfer methods are inefficient and time-consuming. Here, we developed a simple and easy mitochondrial transfer protocol using centrifugation, which can be applied to any cell type. By our simple centrifugation method, we found that the isolated mitochondria could be successfully transferred into target cells, including mitochondrial DNA-deleted Rho⁰ cells and dexamethasone-treated atrophic muscle cells. We found that mitochondrial transfer normalised ATP production, mitochondrial membrane potential, mitochondrial reactive oxygen species level, and the oxygen consumption rate of the target cells. Furthermore, delivery of intact mitochondria blocked the AMPK/FoxO3/Atrogene pathway underlying muscle atrophy in atrophic muscle cells. Taken together, this simple and rapid mitochondrial transfer method can be used to treat mitochondrial dysfunction-related diseases.

Macropinocytic entry of isolated mitochondria in epidermal growth factor-activated human osteosarcoma cells

Mammalian mitochondria can be transferred between cells both in culture and in vivo. There is evidence that isolated mitochondria enter cells by endocytosis, but the mechanism has not been fully characterised. We investigated the entry mechanism of isolated mitochondria into human osteosarcoma (HOS) cells. Initially we confirmed that respiratory-competent cells can be produced following incubation of HOS cells lacking mitochondrial DNA (mtDNA) with functional exogenous mitochondria and selection in a restrictive medium. Treatment of HOS cells with inhibitors of different endocytic pathways suggest that uptake of EGFP-labelled mitochondria occurs via an actin-dependent endocytic pathway which is consistent with macropinocytosis. We later utilised time-lapse microscopy to show that internalised mitochondria were found in large, motile cellular vesicles. Finally, we used confocal imaging to show that EGFP-labelled mitochondria colocalise with a macropinocytic cargo molecule during internalisation, HOS cells produce membrane ruffles interacting with external mitochondria during uptake and EGFP-labelled mitochondria are found within early macropinosomes inside cells. In conclusion our results are consistent with isolated mitochondria being internalised by macropinocytosis in HOS cells.

Artificial Mitochondria Transfer: Current Challenges, Advances, and Future Applications

The objective of this review is to outline existing artificial mitochondria transfer techniques and to describe the future steps necessary to develop new therapeutic applications in medicine. Inspired by the symbiotic origin of mitochondria and by the cell's capacity to transfer these organelles to damaged neighbors, many researchers have developed procedures to artificially transfer mitochondria from one cell to another. The techniques currently in use today range from simple coincubations of isolated mitochondria and recipient cells to the use of physical approaches to induce integration. These methods mimic natural mitochondria transfer. In order to use mitochondrial transfer in medicine, we must answer key questions about how to replicate aspects of natural transport processes to improve current artificial transfer methods. Another priority is to determine the optimum quantity and cell/tissue source of the mitochondria in order to induce cell reprogramming or tissue repair, in both in vitro and in vivo applications. Additionally, it is important that the field explores how artificial mitochondria transfer techniques can be used to treat different diseases and how to navigate the ethical issues in such procedures. Without a doubt, mitochondria are more than mere cell power plants, as we continue to discover their potential to be used in medicine.