New treatment developed to dramatically slow down the progression of blindness-causing retinal diseases

Key Takeaways

  • A research team has successfully incorporated anti-inflammatory drugs into a slowly degrading hydrogel to suppress inflammation in the retina and effectively deliver the drugs to the inflamed area.
  • The new sustained-release treatment, which was tested in mice, could reduce injection burden for patients suffering from retinal disease.

Age-related macular degeneration (AMD) and retinitis pigmentosa (RP) are incurable eye diseases that cause blindness due to the gradual damage of photoreceptor cells, which convert light into biological signals in the retina. Currently, one of the treatments is to inject anti-inflammatory drugs into the eye to slow down the degree of retinal damage. However, these injections only work for as long as the drug remains in the eye, requiring patients to visit a clinic for intraocular injections every four to 12 weeks, depending on how long the effect of the drug lasts.

Therefore, a Korean research team developed a hydrogel that slowly degrades upon encountering the enzyme cathepsin, which is typically overproduced in inflammatory environments, to deliver anti-inflammatory drugs. When the team’s drug-loaded inflammation-responsive hydrogel was injected into the eyes of mice suffering from retinal degeneration, inflammatory factors in the retina were reduced to approximately 6.1%. The team also found that the protective effect on photoreceptor cells, which are known to be destroyed by retinal degeneration, was about four times higher than in the control group, effectively delaying vision loss. The paper is published in the journal npj Regenerative Medicine.

Notably, the hyaluronic acid-based hydrogel, which has similar mechanical and optical properties to the vitreous humor of the eye, allows for different rates of hydrogel degradation in each patient. “For future commercialization, we plan to digitize the amount of drug and hydrogel used, as well as the treatment period, according to the progression of the disease. We also intend to assess the long-term stability of the drug delivery system,” said Dr. Maesoon Im of the Korea Institute of Science and Technology.

Source: National Research Council of Science and Technology, Medical Xpress, February 14, 2024; see source article