Abstract
Mitochondrial dysfunction is a major contributor to myocardial ischemia-reperfusion injury, and limits cardiac recovery after blood flow is restored. Although mitochondria transplantation may help restore cellular energy metabolism, its therapeutic benefit is reduced by extracellular calcium-induced mitochondrial damage. Here we show that a thermosensitive phase-separated hydrogel made of gelatin and PEG can condense, protect and deliver freshly isolated mitochondria. Compared with conventional single-phase hydrogels, this system remains injectable at physiological temperature and enables rapid mitochondria release after transplantation. Furthermore, the phase-separated structure improves mitochondrial packing and preserves activity through spatial confinement and calcium chelation by gelatin. In vitro, condensed mitochondria show improved membrane potential and ATP production. In vivo, transplanted mitochondria are efficiently internalized by cardiomyocytes, improving cardiac function and reducing tissue injury after myocardial ischemia-reperfusion. These findings identify phase-separated hydrogels as a promising platform for mitochondria transplantation.
Similar content being viewed by others
Data availability
All other data are provided in the manuscript or Supplementary Information. Source data for all Figures are provided in the Source Data file accompanying the manuscript. Source data is available for Fig. 2C, F–H; 3B, C, D, F, I–O; 4C, G, F; 5 A–D, F, H, J, L, M; 6B, C, E–G, I, J, L–N; Supporting Fig. 4A, B; 5; 8B; 11 A, B; 12B; 13–15 in the associated source data file. Source data are provided alongside this paper. Source data are provided with this paper.
References
Kivimäki, M. & Steptoe, A. Effects of stress on the development and progression of cardiovascular disease. Nat. Rev. Cardiol. 15, 215–229 (2018).
Takahashi, K. et al. Ten-year all-cause death according to completeness of revascularization in patients with three-vessel disease or left main coronary artery disease: insights from the SYNTAX extended survival study. Circulation 144, 96–109 (2021).
Yellon, D. M. & Hausenloy, D. J. Myocardial reperfusion injury. N. Engl. J. Med 357, 1121–1135 (2007).
Scarabelli, T. M. & Gottlieb, R. A. Functional and clinical repercussions of myocyte apoptosis in the multifaceted damage by ischemia/reperfusion injury: old and new concepts after 10 years of contributions. Cell Death Differ. 11, S144–S152 (2004).
Heusch, G. Myocardial ischaemia-reperfusion injury and cardioprotection in perspective. Nat. Rev. Cardiol. 17, 773–789 (2020).
Lesnefsky, E. J., Chen, Q., Tandler, B. & Hoppel, C. L. Mitochondrial dysfunction and myocardial ischemia-reperfusion: implications for novel therapies. Annu Rev. Pharm. Toxicol. 57, 535–565 (2017).
Ponnalagu, D. et al. CLIC4 localizes to mitochondrial-associated membranes and mediates cardioprotection. Sci. Adv. 8, eabo1244 (2022).
Bertero, E. & Maack, C. Calcium signaling and reactive oxygen species in mitochondria. Circ. Res 122, 1460–1478 (2018).
Harrington, J. S., Ryter, S. W., Plataki, M., Price, D. R. & Choi, A. M. K. Mitochondria in health, disease, and aging. Physiol. Rev. 103, 2349–2422 (2023).
Wyant, G. A. et al. Mitochondrial remodeling and ischemic protection by G protein-coupled receptor 35 agonists. Science 377, 621–629 (2022).
Hinton, A. Jr. et al. Mitochondrial structure and function in human heart failure. Circ. Res. 135, 372–396 (2024).
Zhu, D. et al. Intrapericardial exosome therapy dampens cardiac injury via activating Foxo3. Circ. Res. 131, e135–e150 (2022).
Godoy, L. C. et al. Association of beta-blocker therapy with cardiovascular outcomes in patients with stable ischemic heart disease. J. Am. Coll. Cardiol. 81, 2299–2311 (2023).
Cohn, P. F., Fox, K. M. & Daly, C. Silent myocardial ischemia. Circulation 108, 1263–1277 (2003).
Bagai, A., Dangas, G. D., Stone, G. W. & Granger, C. B. Reperfusion strategies in acute coronary syndromes. Circ. Res. 114, 1918–1928 (2014).
Jacoby, E. et al. Mitochondrial augmentation of hematopoietic stem cells in children with single large-scale mitochondrial DNA deletion syndromes. Sci. Transl. Med. 14, eabo3724 (2022).
Ikeda, G. et al. Mitochondria-rich extracellular vesicles from autologous stem cell-derived cardiomyocytes restore energetics of ischemic myocardium. J. Am. Coll. Cardiol. 77, 1073–1088 (2021).
Borcherding, N. & Brestoff, J. R. The power and potential of mitochondria transfer. Nature 623, 283–291 (2023).
Sun, M. et al. Mitochondrial transplantation as a novel therapeutic strategy for cardiovascular diseases. J. Transl. Med. 21, 347 (2023).
Chang, J. C. et al. Mitochondrial transplantation regulates antitumour activity, chemoresistance and mitochondrial dynamics in breast cancer. J. Exp. Clin. Cancer Res. 38, 30 (2019).
Lin, R. Z. et al. Mitochondrial transfer mediates endothelial cell engraftment through mitophagy. Nature 629, 660–668 (2024).
Cowan, D. B. et al. Transit and integration of extracellular mitochondria in human heart cells. Sci. Rep. 7, 17450 (2017).
Islam, M. N. et al. Mitochondrial transfer from bone-marrow-derived stromal cells to pulmonary alveoli protects against acute lung injury. Nat. Med. 18, 759–765 (2012).
Xu, J. et al. Targeted transplantation of engineered mitochondrial compound promotes functional recovery after spinal cord injury by enhancing macrophage phagocytosis. Bioact. Mater. 32, 427–444 (2024).
McCully, J. D., Cowan, D. B., Emani, S. M. & Del Nido, P. J. Mitochondrial transplantation: From animal models to clinical use in humans. Mitochondrion 34, 127–134 (2017).
Zhou, M. et al. Mitochondrial transplantation via magnetically responsive artificial cells promotes intracerebral hemorrhage recovery by supporting microglia immunological homeostasis. Adv. Mater. 37, e2500303 (2025).
Wu, Z. et al. Oral mitochondrial transplantation using nanomotors to treat ischaemic heart disease. Nat. Nanotechnol. 19, 1375–1385 (2024).
Kubat, G. B. et al. Biotechnological approaches and therapeutic potential of mitochondria transfer and transplantation. Nat. Commun. 16, 5709 (2025).
Ya, H. et al. Transplantation of mitochondria encapsulated in hydrogel ameliorates myocardial ischemia-reperfusion injury. Chem. Eng. J. 460, 141799 (2023).
Hassanpour, P. et al. Mitochondria-loaded alginate-based hydrogel accelerated angiogenesis in a rat model of acute myocardial infarction. Int J. Biol. Macromol. 260, 129633 (2024).
Patel, S. P. et al. Erodible thermogelling hydrogels for localized mitochondrial transplantation to the spinal cord. Mitochondrion 64, 145–155 (2022).
Isshiki, M., Mutoh, A. & Fujita, T. Subcortical Ca2+ waves sneaking under the plasma membrane in endothelial cells. Circ. Res. 95, e11–e21 (2004).
Berridge, M. J., Bootman, M. D. & Roderick, H. L. Calcium signalling: dynamics, homeostasis and remodelling. Nat. Rev. Mol. Cell Biol. 4, 517–529 (2003).
Inoue, D. & Pappano, A. J. L-palmitylcarnitine and calcium ions act similarly on excitatory ionic currents in avian ventricular muscle. Circ. Res 52, 625–634 (1983).
Bertero, E., O’Rourke, B. & Maack, C. Mitochondria do not survive calcium overload during transplantation. Circ. Res. 126, 784–786 (2020).
Bertero, E., Maack, C. & O’Rourke, B. Mitochondrial transplantation in humans: “magical” cure or cause for concern?. J. Clin. Invest 128, 5191–5194 (2018).
Abbas, M., Lipiński, W. P., Nakashima, K. K., Huck, W. T. S. & Spruijt, E. A short peptide synthon for liquid-liquid phase separation. Nat. Chem. 13, 1046–1054 (2021).
Zhou, L. et al. Water dynamics in the formation of single-component-based multiphasic droplets. J. Am. Chem. Soc. 147, 31290–31299 (2025).
Nishiguchi, A., Ito, S., Nagasaka, K. & Taguchi, T. Liquid-liquid phase-separated hydrogel with tunable sol-gel transition behavior as a hotmelt-adhesive postoperative barrier. ACS Appl Bio Mater. 5, 4932–4941 (2022).
Banani, S. F., Lee, H. O., Hyman, A. A. & Rosen, M. K. Biomolecular condensates: organizers of cellular biochemistry. Nat. Rev. Mol. Cell Biol. 18, 285–298 (2017).
Lee, S., de Rutte, J., Dimatteo, R., Koo, D. & Di Carlo, D. Scalable fabrication and use of 3D structured microparticles spatially functionalized with biomolecules. ACS Nano 16, 38–49 (2022).
Zhou, L. et al. Multiphasic condensates formed with mono-component of tetrapeptides via phase separation. Nat. Commun. 16, 2706 (2025).
Westensee, I. N. et al. Mitochondria encapsulation in hydrogel-based artificial cells as ATP producing subunits. Small 17, e2007959 (2021).
Zhao, E. et al. Engineering a photosynthetic bacteria-incorporated hydrogel for infected wound healing. Acta Biomater. 140, 302–313 (2022).
Yang, L. Y. et al. Toxicity of polyhydroxylated fullerene to mitochondria. J. Hazard Mater. 301, 119–126 (2016).
Luo, L. et al. Pericardial delivery of SDF-1α puerarin hydrogel promotes heart repair and electrical coupling. Adv. Mater. 36, e2302686 (2024).
Cheng, K. et al. Transplantation of platelet gel spiked with cardiosphere-derived cells boosts structural and functional benefits relative to gel transplantation alone in rats with myocardial infarction. Biomaterials 33, 2872–2879 (2012).
Bagheri, H. S. et al. Mitochondrial donation in translational medicine; from imagination to reality. J. Transl. Med. 18, 367 (2020).
Zhang, T. G. & Miao, C. Y. Mitochondrial transplantation as a promising therapy for mitochondrial diseases. Acta Pharm. Sin. B 13, 1028–1035 (2023).
Zorov, D. B., Juhaszova, M. & Sollott, S. J. Mitochondrial reactive oxygen species (ROS) and ROS-induced ROS release. Physiol. Rev. 94, 909–950 (2014).
Li, J. et al. Inhalable stem cell exosomes promote heart repair after myocardial infarction. Circulation 150, 710–723 (2024).
Zhu, L. et al. Controllable mitochondrial aggregation and fusion by a programmable DNA binder. Chem. Sci. 14, 8084–8094 (2023).
Sun, C. et al. Supramolecular induction of mitochondrial aggregation and fusion. J. Am. Chem. Soc. 142, 16523–16527 (2020).
Zhou, H. X., Rivas, G. & Minton, A. P. Macromolecular crowding and confinement: biochemical, biophysical, and potential physiological consequences. Annu Rev. Biophys. 37, 375–397 (2008).
Mo, S. et al. Mimicking the process from secretory vesicles to organelles in eukaryotic cell evolution by clustering enzyme-liposomes in artificial cells. J. Colloid Interface Sci. 696, 137863 (2025).
Küchler, A., Yoshimoto, M., Luginbühl, S., Mavelli, F. & Walde, P. Enzymatic reactions in confined environments. Nat. Nanotechnol. 11, 409–420 (2016).
Cogliati, S. et al. Mitochondrial cristae shape determines respiratory chain supercomplexes assembly and respiratory efficiency. Cell 155, 160–171 (2013).
G. B. Im, J. M. Melero-Martin, Mitochondrial transfer in endothelial cells and vascular health. Trends Cell Biol. 25,00105-9 (2025).
Chan, D. C. Mitochondrial dynamics and its involvement in disease. Annu Rev. Pathol. 15, 235–259 (2020).
Tábara, L. C., Segawa, M. & Prudent, J. Molecular mechanisms of mitochondrial dynamics. Nat. Rev. Mol. Cell Biol. 26, 123–146 (2025).
Wang, S. et al. DNA-PKcs interacts with and phosphorylates Fis1 to induce mitochondrial fragmentation in tubular cells during acute kidney injury. Sci. Signal 15, eabh1121 (2022).
Brestoff, J. R. et al. Recommendations for mitochondria transfer and transplantation nomenclature and characterization. Nat. Metab. 7, 53–67 (2025).
Acknowledgements
This work was supported by Guangdong Basic and Applied Basic Research Foundation (2026A1515011632 to X.W.), National Natural Science Foundation of China (82202339 to X.W., 32322045 to Z.L. and 52203133 to X.F.).
Author information
Authors and Affiliations
Contributions
Conceptualization: Z.L., X.W. and J.A. Methodology: J.A., Y.X., Q.L., Y.X., W.L., J.D., W.D., R.Z., S.M., X.F. and Y.Z. Investigation: X.W., J.A. and Y.X. Visualization: J.A. and Y.X. Supervision: Z.L. and X.W. Writing—original draft: X.W. and J.A. Writing—review & editing: Z.L., X.W., J.A., Y.X., Q.L., W.L. and J.D.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Peer review
Peer review information
Nature Communications thanks Huaimin Wang and the other anonymous reviewer for their contribution to the peer review of this work. [A peer review file is available.]
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Source data
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
About this article
Cite this article
Ai, J., Xiao, Y., Li, Q. et al. Transplantation of active mitochondria condensed in liquid–liquid phase-separated hydrogels ameliorates myocardial ischemia-reperfusion injury. Nat Commun (2026). https://doi.org/10.1038/s41467-026-71765-6
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41467-026-71765-6
