A collaboration of researchers from Wayne State University, the Mayo Clinic and Johns Hopkins Medicine has discovered a potential new treatment for macular degeneration and retinitis pigmentosa. The investigators managed to attach steroids to dendrimers nanoparticles and showed that the drugs only targeted the activated microglia, the damage-causing cells associated with neuroinflammation. The researchers published their article online in the journal Biomaterials.
Age-related macular degeneration and retinitis pigmentosa are leading causes of blindness worldwide. Neuroinflammation plays a big role in both diseases. Activated microglia release substances that damage certain cells in the retina, which eventually can lead to vision loss.
Because steroids have neuroprotective and anti-inflammatory properties, the researchers tried to deliver them precisely to the right target. Therefore they used polyamidoamine dendrimers as drug delivery vehicles, which are about 3-10 nm in size. The activated microglia in the degenerating retina turned out to eat the dendrimers selectively and retain them for at least a month. The drug is slowly released from the dendrimer, offering neuroprotection to the retina.
Here’s a video of lead author Raymond Iezzi about the new delivery system:
Mayo Clinic’s news blog: Nanoparticles Help Mayo Clinic Researcher Deliver Steroids to Retina
Image credit : Robert D Bruce