Chinese Researchers Unveil Nanozyme Eye Drops Targeting Retinal Diseases

Researchers from Zhengzhou University have achieved a significant milestone in ophthalmology with the development of innovative nanozyme eye drops designed to treat retinal neovascularization diseases, including age-related macular degeneration (AMD). Published in Science Advances in September 2025, this breakthrough offers a noninvasive alternative to traditional treatments. The study demonstrates how these eye drops penetrate deep into retinal tissues, scavenging reactive oxygen species (ROS) and repairing vascular damage, potentially transforming care for millions affected by blinding conditions in China.

Age-related macular degeneration, a leading cause of vision loss among the elderly, affects an estimated 27 million people in China, with prevalence rates climbing due to the nation's rapidly aging population. Early AMD impacts around 5% of those over 50, while late-stage cases contribute significantly to blindness rankings globally, where China holds a high position. This research from Zhengzhou University's Nanozyme Laboratory highlights China's growing prowess in nanotechnology-driven biomedical solutions.

Understanding Nanozymes: Artificial Enzymes for Medical Innovation

Nanozymes are nanomaterials that mimic the catalytic activity of natural enzymes, such as superoxide dismutase (SOD) and catalase (CAT), but offer superior stability, cost-effectiveness, and tunability. Unlike biological enzymes, nanozymes resist harsh physiological conditions, making them ideal for therapeutic applications like ROS scavenging in oxidative stress-related diseases.

At Zhengzhou University, the Nanozyme Laboratory in Zhongyuan, led by pioneers like Academician Yan Xiyun, has been at the forefront of this field. Yan Xiyun, director of the lab and honorary dean of the School of Basic Medical Sciences, introduced key concepts in nanozyme research, bridging nanotechnology and biology. The university ranks among China's top institutions for nanoscience and nanotechnology, placing third nationally according to U.S. News rankings.

The Burden of AMD and Retinal Neovascularization in China

In China, AMD prevalence varies regionally, with South Central China reporting the highest cases at over 10 million for any AMD in recent modeling. The crude prevalence of early AMD stands at about 4.9%, rising sharply with age—reaching 18.98% in those 85-89 years old. Retinal neovascularization, a hallmark of wet AMD, leads to abnormal blood vessel growth, leakage, and vision loss.

Current standard treatments rely on intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections, such as conbercept or ranibizumab. While effective, these require frequent administrations—up to monthly—posing challenges like patient discomfort, infection risks, poor compliance, and high costs. A global survey highlights these issues in Chinese patients, underscoring the need for noninvasive options. For more on research careers in ophthalmology, explore research jobs at leading Chinese institutions.

Engineering the Nanozyme Eye Drops: Design and Penetration Strategy

The FR-PolyRu nanozyme eye drops feature liposomes composed of fluorinated phospholipids (DSPE-PEG-F₇) and RGD-modified phospholipids (DSPE-PEG-RGD), encapsulating PolyRu—a ruthenium-based nanozyme. Fluorination enhances lipophilicity, reducing transmembrane energy barriers, while RGD targets vascular endothelium for transcytosis. The generated oxygen from CAT activity further aids diffusion through tissues.

Step-by-step process:

• Synthesis: PolyRu formed from RuCl₃ and PVP; encapsulated in liposomes (~50 nm size, stable for 30 days).
• Barrier Crossing: Cornea, vitreous humor, blood-retinal barrier penetrated via passive diffusion, active transport, and O₂-driven propulsion.
• ROS Cascade: SOD converts O₂^•− to H₂O₂; CAT decomposes to H₂O + O₂.

Density functional theory (DFT) confirms efficient ROS adsorption and decomposition on Ru surfaces. This design ensures high bioavailability without toxicity.

Experimental Validation: From Cells to Mouse Models

In vitro tests on human retinal endothelial cells (HRECs) and human umbilical vein endothelial cells (HUVECs) exposed to oxidative stress showed FR-PolyRu restoring cell viability, mitochondrial membrane potential, and ATP levels while reducing ROS and lipid peroxidation.

In vivo, using the oxygen-induced retinopathy (OIR) mouse model—mimicking pathological neovascularization—eye drops (1 mg/ml, twice daily) significantly reduced neovascular areas, repaired avascular zones, and lowered apoptosis and ROS. Transcriptomic analysis revealed suppression of IGFBP6 signaling via PI3K-AKT and ERK pathways, key to vessel normalization.

Safety assessments confirmed no ocular or systemic toxicity over 30 days. For faculty positions in nanomedicine, check higher ed faculty jobs.

Photo by ling ze on Unsplash

Zhengzhou University's Leadership in Nanozyme Research

Zhengzhou University (ZZU), a top-tier institution in Henan Province, excels in nanoscience, ranking #3 in China for nanotechnology per U.S. News. The Nanozyme Laboratory, under Academician Yan Xiyun, has pioneered applications from cancer diagnostics to ocular therapies. Bai Xue, first author, exemplifies emerging talent from this hub.

ZZU's interdisciplinary approach integrates basic medical sciences with engineering, fostering innovations like these eye drops. This positions China as a global leader in nanomedicine, with implications for higher education collaborations. Interested in university rankings? Visit the university rankings.

Overcoming Current Treatment Limitations

Anti-VEGF therapies dominate wet AMD management in China but face hurdles: high dropout rates due to injection burden, geographic access issues in rural areas, and costs exceeding RMB 10,000 annually per patient. Nanozyme drops address these by enabling self-administration, reducing visits, and targeting root oxidative stress.

• Noninvasive: No needles, lower infection risk.
• Targeted: Deep penetration to fundus.
• Sustained: Cascade activity for prolonged effect.
• Cost-Effective: Scalable nanomaterial production.

Comparative studies show superior ROS scavenging over natural enzymes.

Broader Implications for Ocular and Beyond

Beyond wet AMD, these drops hold promise for diabetic retinopathy and retinopathy of prematurity. In China, where diabetes affects 140 million, retinal complications are surging. Nanozyme tech could extend to neuroprotection or oncology.

ZZU's work aligns with national priorities like 'Healthy China 2030,' boosting research funding and talent. For career advice in biotech, see how to write a winning academic CV.

Challenges, Future Directions, and Clinical Translation

While promising in preclinical models, human trials are needed to confirm efficacy in AMD patients. Regulatory hurdles in China via NMPA and scalability remain. ZZU plans collaborations for Phase I studies.

Future outlook: Integration with AI for personalized dosing or combo therapies. This innovation underscores Chinese universities' role in global health solutions.

Impact on Higher Education and Research Ecosystem in China

ZZU's success attracts top talent and funding, enhancing Henan Province's biotech hub status. Nanozyme research exemplifies interdisciplinary training, vital for China's 'Double First-Class' initiative. Students and postdocs gain hands-on experience, preparing for postdoc positions.

Stakeholder perspectives: Clinicians praise reduced burden; policymakers see economic benefits from IP commercialization.

Photo by Zheng XUE on Unsplash

Conclusion: A Visionary Step Forward

Zhengzhou University's nanozyme eye drops herald a new era in noninvasive retinal therapy, addressing AMD's massive burden in China. As research progresses, this could restore sight to millions. Explore opportunities at Rate My Professor, higher ed jobs, higher ed career advice, university jobs, or recruitment pages. For China-specific roles, visit China higher ed.