A research team led by the National University of Singapore has developed an innovative method for treating dry eye syndrome: introducing the photosensitive structure in spinach into the eyes to keep them continuously moist. This method is simple, effective, and completely non-invasive, providing a new approach for the treatment of dry eye syndrome. The relevant paper was published in the latest issue of the journal Cell. Dry eye syndrome affects over 1.5 billion people. At present, commonly used drugs mainly exert their effects by inhibiting inflammation, but there are problems such as slow onset and high cost. At the cellular level, dry eye syndrome is driven by a continuously amplifying "vicious cycle": corneal inflammation produces a large amount of reactive oxygen species (ROS), which continue to damage cellular structures. Under normal circumstances, the eyes rely on their own antioxidant system to clear ROS, and this process relies on reduced nicotinamide adenine dinucleotide phosphate (NADPH) to provide "reducing power support". But in a diseased state, ROS is generated too quickly, and the defense system is constantly depleted, further exacerbating inflammation. This time, researchers have proposed a new approach: transplanting the key structure of plant photosynthesis into corneal cells, allowing them to autonomously generate NADPH under ambient light. Inspired by the phenomenon of sea slugs borrowing chloroplasts for photosynthesis in nature, researchers extracted the core structure of photosynthesis - thylakoids - from spinach leaves, packaged them into particles with a diameter of about 400 nanometers, and named them "LEAF" (Light Reaction Enhanced thylakoid NADPH Factory). The key to this structure lies in the "subtractive design", which removes the energy consuming part of chloroplasts and only retains the core module that can capture light energy and generate NADPH, making it a micro "energy factory" that can be activated by light inside the cell. Under natural or indoor lighting conditions, it can sustainably produce NADPH, enhancing the ability of cells to remove reactive oxygen species. Experiments have shown that LEAF can restore NADPH levels and significantly reduce reactive oxygen species levels within about 30 minutes after entering cells, leading to a shift in inflammation related immune status towards anti-inflammatory effects. In the tear samples of patients with dry eye syndrome, this system increased NADPH by about 20 times and reduced hydrogen peroxide by over 95%. In a collaborative experiment with the Second Affiliated Hospital of Zhejiang University School of Medicine in China, an animal model using LEAF eye drops recovered corneal injury to near healthy levels within 5 days, with better efficacy than existing standard treatment drugs, and no significant eye irritation or toxic reactions were observed. (Looking into the New Era)