Featured Research

from universities, journals, and other organizations

Nanoparticles help researcher deliver steroids to retina

Date:
December 14, 2011
Source:
Mayo Clinic
Summary:
Hitching a ride into the retina on nanoparticles called dendrimers offers a new way to treat age-related macular degeneration and retinitis pigmentosa.

Hitching a ride into the retina on nanoparticles called dendrimers offers a new way to treat age-related macular degeneration and retinitis pigmentosa. A study by investigators at Mayo Clinic, Wayne State University and Johns Hopkins Medicine shows that steroids attached to the dendrimers target the damage-causing cells associated with neuroinflammation, leaving the rest of the eye unaffected and preserving vision.

The findings appear in the journal Biomaterials.

Dry age-related macular degeneration and retinitis pigmentosa are caused by neuroinflammation, which progressively damages the retina and can lead to blindness. Macular degeneration is the primary cause of vision loss in older Americans, affecting more than 7 million people, according to the National Institutes of Health. Retinitis pigmentosa encompasses many genetic conditions affecting the retina and impacts 1 in 4,000 Americans, the NIH estimates.

"There is no cure for these diseases," says Mayo Clinic ophthalmologist Raymond Iezzi, M.D., a lead author of the study. "An effective treatment could offer hope to hundreds of millions of patients worldwide."

Iezzi and fellow principal author Rangaramanujam Kannan, Ph.D., an ophthalmology professor at The Wilmer Eye Institute of Johns Hopkins, developed an intracellular, sustained-release drug delivery system. The research, conducted in part at Wayne State University's Kresge Eye Institute with collaboration from Wayne State's College of Engineering and Ligon Research Center of Vision, tested the dendrimer delivery system in rats that develop neuroinflammation.

The target was microglial cells, inflammatory cells in charge of cleaning up dead and dying material in the eye, Dr. Iezzi says. When activated as "trash collectors," the cells cause damage via neuroinflammation -- a hallmark of each disease. The microglial cells gobble up the dendrimers, and the drug then shuts down the cells' activity.

"Surprisingly, the activated microglia in the degenerating retina appeared to eat the dendrimer selectively, and retain them for at least a month. The drug is released from the dendrimer in a sustained fashion inside these cells, offering targeted neuroprotection to the retina," Kannan says.

The treatment reduced neuroinflammation in the rat model and protected vision by preventing injury to photoreceptors in the retina. Though the steroid offers only temporary protection, the treatment as a whole provides sustained relief from neuroinflammation.

The study was funded by grants from the Ligon Research Center of Vision at Wayne State University, the Ralph C. Wilson Foundation and Research to Prevent Blindness.

Co-authors include Bharath Raja Guru, Ph.D., Case Western Reserve University; Inna Glybina and Alexander Kennedy, both of Wayne State University; and Manoj Mishra, Ph.D., of Johns Hopkins University.


Story Source:

The above story is based on materials provided by Mayo Clinic. Note: Materials may be edited for content and length.


Journal Reference:

  1. Raymond Iezzi, Bharath R. Guru, Inna V. Glybina, Manoj K. Mishra, Alexander Kennedy, Rangaramanujam M. Kannan. Dendrimer-based targeted intravitreal therapy for sustained attenuation of neuroinflammation in retinal degeneration. Biomaterials, 2011; DOI: 10.1016/j.biomaterials.2011.10.010

Cite This Page:

Mayo Clinic. "Nanoparticles help researcher deliver steroids to retina." ScienceDaily. ScienceDaily, 14 December 2011. <www.sciencedaily.com/releases/2011/12/111213144719.htm>.
Mayo Clinic. (2011, December 14). Nanoparticles help researcher deliver steroids to retina. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2011/12/111213144719.htm
Mayo Clinic. "Nanoparticles help researcher deliver steroids to retina." ScienceDaily. www.sciencedaily.com/releases/2011/12/111213144719.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
China's Ageing Millions Look Forward to Bleak Future

China's Ageing Millions Look Forward to Bleak Future

AFP (July 24, 2014) China's elderly population is expanding so quickly that children struggle to look after them, pushing them to do something unexpected in Chinese society- move their parents into a nursing home. Duration: 02:07 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins