Artificial mitochondria generate energy and save damaged cells

Artificial mitochondria capable of releasing energy, which can be used to repair damaged cells, have been created, claim a team of researchers.

Within cells numerous chemical reactions are catalysed by enzymes simultaneously, all of which are essential for cellular and metabolic processes. To carry out these complex chemical reactions in parallel, cells have adopted a spatial approach whereby enzymes are organised into subcellular nanoreactors. Due to this phenomenon, the creation of artificial organelles, such as mitochondria, have been of interest to scientists due to the potential cellular benefits of elevated energy release.

When asked about their recent study, the team of scientists behind the research from the Institute for Basic Science, Ulsan, South Korea claimed it 'represents an advance in the mimicking of nature's own organelles... we assembled an artificial component that can communicate effectively within the living system'.

To create artificial mitochondria the team used biological vesicles known as exosomes. Exosomes typically function as mediators of intercellular signalling. An exosome is released by one cell and subsequently taken up by another adjacent cell, releasing its contents into that cell. It is this process that the team sought to manipulate using an approach known as synthetic biology.

Exosomes were used as natural compartments to encapsulate multiple reagents used to drive enzymatic reactions within the cell. By fusing several exosomes containing different reagents, the team was able to facilitate a multienzyme catalytic reaction within the exosome nanoreactors to generate adenosine triphosphate (ATP) inside living cells. ATP is the compound that provides energy to drive many processes within cells.

The ability to use exosomes as an artificial method of producing ATP has several therapeutic benefits, including cancer diagnosis, drug delivery, and the regulation of tissue ageing. Furthermore, when in oxygen-starved conditions cells release toxic compounds, such as reactive oxygen species (ROS). The production of such compounds destroys organelles and leads to the death of the cell. This study demonstrated the ability of the engineered exosome nanoreactors to boost cellular ATP synthesis, leading to a significant reduction in ROS production and prolonged cell life.

Highlighting the novel aspect of these findings the authors of the study said, 'to the best of our knowledge, there are no studies reporting this ability related to exosome fusion'.

There are now several pressing questions that need to be addressed to progress this research further. The authors will attempt to establish how the immune system reacts to the presence of these natural bioreactors as well as identifying how long they can remain active within the body.

Although research of this nature is in its infancy, the use of synthetic biology in this manner could have far-reaching therapeutic benefits.

This research was published in the journal Nature Catalysis.