A team of researchers from Nihon University, University, and Meiji Pharmaceutical University found through studies in diabetic mice that nanoparticles* fenofibrate (a drug used to treat hyperlipidemia) when taken internally is considered effective for diabetic complications and can be used as eye drops to improve retinal blood flow disorders that occur early in diabetic retinopathy. A team of researchers from Nihon University, University and Meiji Pharmaceutical University announced that they have discovered this. The discovery could lead to the development of the world's first eye drops to treat diabetic retinopathy.
* Nanoparticles: Nanoparticles are particles with a size of 1-100 nanometers. When the same substance is reduced to the nanometer level, its specific surface area and surface energy increase, resulting in a significant change in physical properties.
Diabetic retinopathy is the leading cause of acquired blindness.
Diabetic retinopathy is one of the complications of diabetes and is a microangiopathy (a disease caused by damage to small blood vessels) that occurs in the retina. Diabetic retinopathy, the leading cause of acquired blindness, has always been a challenge to overcome.
Until now, the only treatment for diabetic retinopathy is surgical treatment, such as retinal photocoagulation (laser) surgery. These treatments are used to treat retinopathy that has progressed to threaten vision, but once vision deteriorates, it is not easy to restore visual function. Therefore, it is considered important to treat retinopathy in the early stages of good vision, even before retinopathy occurs.
◇ In nanoparticles, permeability increases, the drug reaches the retina.
Fenofibrate has been widely used to treat hyperlipidemia. There have been many reports that it is beneficial for diabetic complications when taken orally. However, when taking it internally, the risk of serious side effects such as rhabdomyolysis and liver damage should be taken into account. The study investigated whether fenofibrate can be used as an "eye drops" to treat diabetic retinopathy in order to exert its effect only locally in the eye while minimizing its systemic effects.
With traditional eye drops, it is already difficult to penetrate into the retina in an effective concentration and into the back of the eye. The method developed by a research team at the Department of Pharmacy at University in Japan makes it possible to improve the permeability of the drug in the cornea, through the sclera and uveum in the eye, and through the eye drops that fine the drug to the level of nanoparticles to reach the retina in high concentrations.
In this study, fenofibrate nanoparticle eye drops were prepared, and animal experiments with mice and rabbits confirmed that they did reach the retina in effective concentrations.
In the study, 6-week-old mice with type 2 diabetes were divided into an untreated control group and a nonofibrate nanoparticle eye drops group, with eye drops twice a day in the morning and evening, and retinal blood flow measured every other week from 8 to 14 years old. The results showed that the treatment group improved retinal blood flow disorders (vascular disorders caused by persistent hyperglycemia, such as bleeding and poor blood flow, leading to severe visual impairment) from the age of 8 years), and this response continued until the age of 14.
Immunomics studies have also shown an increase in the number of cells involved in the pathogenesis of diabetic retinopathy in the untreated control group, and increased glycoprotein expression involved in diabetic retinopathy and diabetic macular edema. Protein expression is also enhanced. On the other hand, both were suppressed in the treatment group, and in the untreated control group, the expression of a protein that is important for water regulation in the retinal tissue was reduced, but the decrease in the expression of this protein was improved by the fenofibrate nano pill.
Based on these results, the researchers believe that fenofibrate nano-eye drops can effectively penetrate into the retina, and long-term administration may have improved retinal dysfunction in mice and improved retinal blood flow response disorders.
Fenofibrate nano ophthalmic eye drops are also expected to be used in the treatment of "diabetic macular edema".
Fenofibrate nano eye drops are expected not only to be applied to diabetic retinopathy, but also to treat "diabetic macular edema". Currently, the first choice for the treatment of diabetic macular edema is "anti-vascular endothelial growth factor therapy", that is, the injection of the drug into the vitreous, but this is a burden for the patient.
If fenofibrate nano eye drops can be used to provide treatments that place less burden on the body, then it can not only be used to prevent diabetic retinopathy and diabetic macular edema, but it can also be combined with existing therapies for more effective treatment.
The team plans to use pigs with eye structure and morphology similar to the human eye to investigate the reproducibility and safety of this treatment. The research team noted: "In the future, we hope to investigate the therapeutic effect of the drug as a treatment for diabetic retinopathy and diabetic macular edema in clinical studies, and protect the visual function of diabetic patients, it is estimated that there are more than 10 million diabetic patients nationwide."
【Reference】 ・Nihon University, University, Meiji University of Pharmaceutical Sciences Press Release 2022/03/04
Follow us in our private message for more information on regeneration