Researchers from Stanford University have found a new way to use plants and plant processes to benefit human organs in their latest study.

This time, the researchers injected blue-green algae in the hearts of anesthetized mice and exposed them to light, mimicking photosynthesis that produced enough oxygen to keep the mice hearts beating.

The research team led by Dr. Joseph Woo, chair of cardiothoracic surgery at Stanford, was looking for a way to deliver oxygen to the oxygen-deprived areas of the heart during cardiac arrest when they stumbled upon the unusual solution.

"In nature, humans exhale carbon dioxide and plants convert it back to oxygen ... We wondered if there were any way to use plant cells and put them next to heart cells to produce oxygen from the carbon dioxide," Dr. Woo explained.

There have already been successful tests of improving heart function through 3D printing and using stem cells, so it was only natural to look toward nature for a solution.

Searching For An Oxygen Delivery System

It took a while before Dr. Woo's team found a viable solution in cyanobacteria because their first attempts were focused on using chloroplasts on heart cells, which proved unstable.

According to Dr. Woo, they first ground up kale and spinach leaves to combine with heart tissues on petri dishes, but the photosynthetic organs of the plants became unstable and were quick to expire.

The researchers, however, did not stop looking until they considered using cyanobacteria — a photosynthetic blue-green algae known for its ability to survive in water. This ability proved useful since up to 60 percent of the human body is composed of water.

The researchers noted that the cyanobacteria was able to survive on the petri dish with heart tissues, so it went on to the next stage, which is to test it on living tissue.

Photosynthesis In The Heart

In order to test their newfound oxygen production system, the researchers injected cyanobacteria in the hearts of live but anesthetized mice that suffered from cardiac ischemia — the condition which refers to the lack of blood and oxygen flow to the heart muscles.

The researchers observed two versions of the experiment for less than 20 minutes: mice with injected hearts exposed to light and mice that were kept in the dark.

Photosynthesis worked wonders for the mice exposed to light because their conditions improved.

"The group that received the bacteria plus light had more oxygen and the heart worked better," Dr. Woo said.

As for the cyanobacteria, Dr. Woo explained that it dissipated within 24 hours, but the hearts continued to improve for up to four weeks due to its photosynthesis. They noted, however, that results are still preliminary so there probably won't be any human trials happening anytime soon.

The team is considering investigating human applications of their research, as well as finding ways to deliver light to the heart without too much exposure.