A special eye drop containing photosynthetic components extracted from spinach leaves helped combat dry eyes, a new experiment in mice reveals.
In a new study, a team of scientists has developed a new eye drop that allows the eyes of mice to perform certain steps of photosynthesis.
The drops, which contain photosynthetic structures extracted from spinach leaves, use light-triggered reactions to improve symptoms of the so-called.
Although researchers have tested the eye drops on mice, the expectation is that, with further testing, the therapy could one day become used on people.
The study, whose results were presented in a recently published in the journal Cellis an “interesting application” of engineering inspired by symbiotic relationships existing in nature, he said Corey Allarda cellular biologist at Harvard Medical School, who was not involved in the work.
The plants depend on photosynthesis to produce energyin the form of glucose, from sunlight. Organelles called chloroplasts they carry out photosynthesis and give plants their green color.
Although no animal performs photosynthesis naturally by itself, some have developed that allow them to harness solar energy.
It is well known that some species of sea slug, including the “leaf sheep” (Costasiella kuroshimae) and the mangrove leaf slug (Elysia bangtawaensis), arrive at steal chloroplasts from the algae they feed on.
In the new study, David Tai Leonga chemical engineer at the National University of Singapore, and colleagues tested whether mammalian eyes would be able to tolerate similar behavior, in the hope of pointing out a possible way to treat dry eye disease, which affects the tear film that lines the eye and produces oxidants and inflammation that can harm vision.
To create the eye drops, the team started by removings spinach chloroplasts stacked compartments called grana — thylakoid stacks where structures rich in chlorophyll are found and where the first light-dependent steps of photosynthesis occur.
Next, the team encapsulated these sets of thylakoids in small shells, creating a system they called the “NADPH-foundry thylakoid-enriched light reaction,” or LEAF.
When incorporated into eye drops, LEAF was able to reduce eye inflammation in mice in which dry eye disease had been induced.
Throughout the process that leads to the production of glucose, chloroplasts produce a chemical substance called NADPH in the granum. NADPH acts as an antioxidant and helped eliminate compounds that were aggravating eye inflammation in mice.
After five days, mice treated with LEAF eye drops showed comparable results to those of mice treated with an existing commercially available drug for dry eye disease. They produced more tears and had fewer corneal injuries than mice that received only saline eye drops.
“The eye is particularly suitable for this type of strategy, since light is already an intrinsic component of its normal physiological function”, he stated Xianfeng Linorthopedic surgeon at Zhejiang University School of Medicine, China, at .
Although Lin was not involved in the new work, he and his colleagues published one in 2022 in the journal Nature using a similar photosynthetic system to combat inflammation caused by arthritis in the knees of mice.
“The work expands the role of light in the eyewhich is no longer purely sensorial and can now contribute to local metabolic support and tissue repair,” said Lin.
Although the eye drops contain chlorophyllthe concentration is very low, and the drops appear transparent.
“We were able to use a highly optimized photosynthetic structureso we don’t need large amounts of the LEAF system,” said Leong. “Because it’s at such a low concentration, the green color is not visible. So let’s not keep green eyes like the Incredible Hulk”.
If approved for human use, the drug will take advantage of the way our eyes work naturally, as it only needs ambient light to activate. A patient would be “receiving therapy aligned with how we normally spend our day”, disse Leong.
