Scientists have achieved a remarkable feat by enabling rat eyes to take part of the photosynthesis process using specially designed eye drops derived from spinach leaves. The experimental treatment, developed by researchers at the National University of Singapore, was created to tackle dry eye disease, a condition that affects millions of people around the world. Instead of turning eyes into miniature plants, the therapy uses photosynthetic machinery to generate antioxidant molecules that help reduce inflammation and tissue damage. The findings, published in the journal Cell, suggest that plant-inspired biotechnology could one day offer a new way to treat eye disorders using nothing more than ordinary ambient light.
How did scientists make rats’ eyes? photosynthesis
The research team extracted structures called thylakoid grana from chloroplasts found in spinach leaves. These structures contain chlorophyll and are responsible for the light-dependent reactions of photosynthesis in plants.The scientists then encapsulated thylakoid grana into microparticles, creating a system called Light-Reaction Enriched Thylakoid NADPH-Foundry, or LEAF. When administered as eye drops, the system was able to absorb light and trigger reactions similar to the early stages of photosynthesis.Importantly, the treatment did not allow the mice to produce sugars like plants. Instead, it produced beneficial molecules that may help protect the eyes from damage.
How experiment targeted dry eye disease
Dry eye disease affects the tear film covering the surface of the eye. This condition can cause discomfort, burning sensation, blurred vision, and swelling. In severe cases, it can damage the cornea and affect overall eye health.The researchers focused on the disease because it is closely linked to oxidative stress, a process in which harmful molecules known as reactive oxygen species accumulate and damage tissues.The LEAF system was designed to generate NADPH, a molecule naturally produced during photosynthesis. NADPH acts as a powerful antioxidant, helping cells to neutralize harmful compounds and reduce inflammation.
What the study found
To test the treatment, researchers induced dry eye disease in mice before administering experimental eye drops. After five days, rats treated with LEAF showed significantly improved tear production and less corneal damage compared to animals that only received saline solution.The treatment also reduced the signs of inflammation in the eyes. According to the researchers, these improvements were comparable to those achieved with an existing commercially available drug used to treat dry eye disease.These results suggest that the plant-derived photosynthetic system helped successfully combat the biological processes driving this condition.
borrowing a trick from nature
Although photosynthesis is commonly associated with plants, some animal species have developed unusual relationships with photosynthetic organisms. For example, some sea slugs can retain chloroplasts from the algae they eat and use them for limited photosynthetic activity.Inspired by these natural examples, the researchers explored whether the components of photosynthesis could be adapted for use in mammalian tissues. His goal was not to make animals photosynthetic but to use useful aspects of the process for therapeutic purposes.The success of the experiment shows how biological systems found in nature can inspire novel medical technologies.
Will the treatment turn the eyes green?
Despite containing photosynthetic machinery originally derived from spinach, the eye drops are not expected to change eye color.The researchers said the concentration of chlorophyll-containing material in the solution was extremely low, making the droplets appear transparent. As a result, treated eyes do not turn green or display any plant-like visual characteristics.The therapy works at the microscopic biochemical level rather than changing the appearance of the eye.
what happens next?
This technology is still in its early stages and has been tested only on rats. Before it can be used in humans, researchers must conduct extensive safety evaluation and clinical trials to determine whether the treatment is both safe and effective.The team is currently working toward future human studies. If those trials prove successful, the therapy could provide a new, non-invasive treatment option for dry eye disease that relies on light-driven biological responses.While much work remains, the study offers a glimpse of a future where plant-inspired medicine could help address common eye conditions in entirely new ways.