NUS LEAF Photosynthetic Dry-Eye Research 2026

Plant-derived eye-drop approach

NUS researchers developed LEAF (Light-reaction Enriched thylAkoid NADPH-Foundry), a light-activated approach that uses nanosized photosynthetic membranes extracted from spinach and delivered to corneal cells as eye drops. NUS reported the work on 16 May 2026; the study was published online in Cell on 15 May 2026. NUS says the team’s patented extraction method preserves the thylakoid machinery responsible for the light reactions of photosynthesis while removing the chloroplast component that consumes NADPH (NUS, 16 May 2026, accessed 10 September 2026).

The resulting particles are roughly 400 nanometres across and are intended to work under ambient light, without an external device or power source. In the proposed mechanism, light exposure enables LEAF inside corneal cells to produce NADPH, a molecule used in antioxidant defences. NUS describes this as a way to address the oxidative-stress cycle associated with inflamed corneal tissue; the description concerns a research mechanism, not a self-administered product or published dosing instruction (NUS, 16 May 2026, accessed 10 September 2026).

Proposed biological mechanism

The transplanted plant-derived machinery uses ambient visible light to produce NADPH in corneal cells, supporting antioxidant defences against reactive oxygen species (ROS). In laboratory tests on inflamed cells, LEAF restored NADPH levels within 30 minutes of light exposure, suppressed ROS and shifted corneal immune cells from a pro-inflammatory toward an anti-inflammatory state. In tear samples collected from patients with dry-eye disease, NUS reported roughly a 20-fold increase in NADPH and more than 95% reduction in hydrogen peroxide. These are experimental results, not evidence of an approved human treatment (NUS, 16 May 2026, accessed 10 September 2026).

The mechanism is designed around the biology of the eye: unlike most internal organs, the cornea receives visible light, allowing the plant-derived machinery to operate without an implanted light source. NUS characterises LEAF as a nanosized version of the thylakoid grana—the stacked membrane compartments in chloroplasts where light energy is converted into NADPH. The work therefore combines materials engineering, cell biology and ophthalmic research, but it does not show that human eyes can photosynthesise in the same way as plants or that the research changes the ordinary standard of dry-eye care (NUS, 16 May 2026, accessed 10 September 2026).

Preclinical evidence boundary

In a preclinical trial, LEAF eye drops under ambient indoor lighting reversed corneal damage toward near-healthy levels within five days and outperformed Restasis in that study. A second preclinical trial also confirmed the therapeutic effect, while two-month safety assessments covering skin sensitisation, eye irritation and organ toxicity reported no adverse effects in the described experiments (NUS, 16 May 2026, accessed 10 September 2026). These findings are evidence from preclinical and laboratory settings, not a clinical trial in patients.

NUS says the team plans to conduct clinical trials to further validate the technology. Until such evidence and the relevant regulatory steps exist, LEAF remains a research-stage approach. The release does not establish human clinical efficacy, regulatory approval, dosing guidance, a treatment recommendation or availability to patients in Singapore. “Outperformed Restasis” refers to the stated preclinical comparison and should not be converted into a claim that LEAF is superior for people with dry-eye disease (NUS, 16 May 2026, accessed 10 September 2026).