In this type of central vision loss, blood vessels grow at the back of the eye, which does not occur in the normal eye. The new drug-delivery system, using a biodegradable time-release coating, helped the drug stay in the eye longer.
Tests showed the drug halted the blood vessel growth in mice with similar eye conditions as people with age-related macular degeneration (AMD). If further results show it’s effective in humans, it could dramatically reduce the number of injections needed to treat the disease, lowering the risk of infection for patients.
About 200,000 Americans have wet AMD, says Peter Campochiaro, M.D., the George S. & Dolores Dore` Eccles Professor of Ophthalmology & Neuroscience. The macula, located in the back of the eye in the middle of the retina, is responsible for central vision, needed to do such things as drive or read. The blood vessels at the back of the eye break in wet AMD patients, and leak fluid, impairing sight.
Jordan Green, Ph.D., assistant professor of biomedical engineering and ophthalmology at The Johns Hopkins University worked with Campochiaro and Aleksander Popel, PH.D., professor of biomedical engineering. Popel’s lab identified the new drug, and Green’s laboratory designed the new drug-delivery system.
Current conventional drug treatments block a stimulator of abnormal blood vessel growth. The new drug was found to destroy, and stop the growth of, blood vessel cells. Success was also found on tests with mice, but the drug naturally washed out of the eye after about a month, the same length of time as current treatments.
Slowing the flow of the drug was achieved by wrapping it in a non-toxic, biodegradable coating, thereby creating a nanoparticle. This form of the drug stayed in the eyes of mice for 14 weeks, tripling the effective treatment time. In humans, the treatment may last even longer, says Green.
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Source: Biomaterials, Oct-2013; 1R1EY022986; R01EY012609