# Mitochondrial transplant in Boston: 80% of 17 infants came off ECMO in a non-randomized series

- Published: 2026-11-14 06:05 UTC
- Section: Life & Health › Medicine
- Tags: mitochondrial transplantation, autologous mitochondria, ECMO in newborns, ischemia-reperfusion injury, congenital heart defect, James McCully, Sitaram Emani, Leigh syndrome, mitochondria stroke, Boston
- URL: https://realtech.media/news/rt-9de0077e412d37012866dbac_mitochondrial_transplant_in/

**Newborns' own mitochondria are injected into the heart after surgery; a clinical trial has started, and kidney and brain tests are under way.**

![Mitochondrial transplant in Boston: 80% of 17 infants came off ECMO in a non-randomized series](https://realtech.media/media/2026/11/024b3c1da1c1a6d9.jpg)
*de.futuroprossimo.it*

Mitochondrial transplantation means taking mitochondria from a patient's healthy muscle and injecting them into a failing organ. According to de.futuroprossimo.it, surgeons in Boston have used it for about ten years on the hearts of newborns after cardiac surgery. As of April, 17 infants had been treated, and 80% of them came off ECMO, twice the usual rate [1]. Other groups are now testing the approach on kidneys and the brain.

## Newborn hearts after surgery

During the operation the heart is briefly without blood (ischemia). When flow returns, cells that lacked oxygen take a second hit: their mitochondria swell, lose fragments and trigger cell self-destruction. This is ischemia-reperfusion injury [1]. A stunned heart is connected to ECMO, a machine that pumps and oxygenates blood in place of the heart and lungs. Only 4 in 10 neonates connected to it come off and survive [1].

The idea came from molecular biologist James McCully, who found in a pig that mitochondria injected into a fibrillating heart restored its regular beat [1]. Today surgeon Sitaram Emani performs the procedure: a fragment of muscle is taken, mitochondria are extracted and loaded into a syringe, and they are injected into the areas that move least on ultrasound. It takes 30 minutes from sampling to injection, and the team wants to cut that to 20 [1]. The mitochondria are the patient's own, so rejection is ruled out, and this also eased FDA clearance [1].

A pilot study in The Journal of Thoracic and Cardiovascular Surgery (September 2021) compared 10 treated infants with 14 untreated ones. Eight treated and 4 untreated infants came off the machine (80% and 29%), and heart function recovered in 2 days versus 9 [1]. The study is retrospective and non-randomized. The 17 patients were all treated in one hospital, and the doctors say it is too early to know whether survival improves, so a clinical trial has been started [1].

## Kidneys, brain and Leigh syndrome

Very few mitochondria are enough for the heart to recover, too few to supply the missing energy. A Nature study by Boston colleagues suggests the injected organelles act as a signal that prompts cells to clear damaged mitochondria and make new ones [1].

In pigs, kidneys treated with mitochondria before transplantation accumulated less damage than untreated ones. The work involves Giuseppe Orlando of Wake Forest University and Benedetta Bussolati's laboratory at the University of Turin. A human kidney trial is authorized and awaiting funding [1].

For stroke, Melanie Walker of the University of Washington delivered mitochondria through an artery during clot removal, when the blood-brain barrier is more permeable. The first test included 4 treated patients and 12 controls, with no side effects attributed to mitochondria. The ethics committee allowed half the dose calculated as effective, so the study shows only safety [1].

In Leigh syndrome, a rare genetic disease, most children with the common form die by age 3. Jon Brestoff's group at Washington University in St. Louis extended the life of sick mice by about one fifth and is now studying patients' cells. Here the mitochondria would have to come from another person; Brestoff warns the immune system may see them as foreign, while McCully saw no such problems in animals [1].

## Sources

1. [de.futuroprossimo.it](https://www.futuroprossimo.it/2026/11/il-trapianto-di-mitocondri-riaccende-i-cuori-e-punta-al-cervello)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-9de0077e412d37012866dbac_mitochondrial_transplant_in/