Navigation Links
Improved nanoparticles deliver drugs into brain
Date:9/11/2012

The brain is a notoriously difficult organ to treat, but Johns Hopkins researchers report they are one step closer to having a drug-delivery system flexible enough to overcome some key challenges posed by brain cancer and perhaps other maladies affecting that organ.

In a report published online on August 29 in Science Translational Medicine, the Johns Hopkins team says its bioengineers have designed nanoparticles that can safely and predictably infiltrate deep into the brain when tested in rodent and human tissue.

"We are pleased to have found a way to prevent drug-embedded particles from sticking to their surroundings so that they can spread once they are in the brain," says Justin Hanes, Ph.D., Lewis J. Ort Professor of Ophthalmology, with secondary appointments in chemical and biomolecular engineering, biomedical engineering, oncology, neurological surgery and environmental health sciences, and director of the Johns Hopkins Center for Nanomedicine.

After surgery to remove a brain tumor, standard treatment protocols include the application of chemotherapy directly to the surgical site to kill any cells left behind that could not be surgically removed. To date, this method of preventing tumor recurrence is only moderately successful, in part, because it is hard to administer a dose of chemotherapy high enough to sufficiently penetrate the tissue to be effective and low enough to be safe for the patient and healthy tissue.

To overcome this dosage challenge, engineers designed nanoparticles about one-thousandth the diameter of a human hair that deliver the drug in small, steady quantities over a period of time. Conventional drug-delivery nanoparticles are made by entrapping drug molecules together with microscopic, string-like molecules in a tight ball, which slowly breaks down when it comes in contact with water. According to Charles Eberhart, M.D., a Johns Hopkins pathologist and contributor to this work, these nanoparticles historically have not worked very well because they stick to cells at the application site and tend to not migrate deeper into the tissue.

Elizabeth Nance, a graduate student in chemical and biomolecular engineering at Hopkins, and Hopkins neurosurgeon Graeme Woodworth, M.D., suspected that drug penetration might be improved if drug-delivery nanoparticles interacted minimally with their surroundings. Nance first coated nano-sized plastic beads of various sizes with a clinically tested molecule called PEG, or poly(ethylene glycol), that had been shown by others to protect nanoparticles from the body's defense mechanisms. The team reasoned that a dense layer of PEG might also make the beads more slippery.

The team then injected the coated beads into slices of rodent and human brain tissue. They first labeled the beads with glowing tags that enabled them to see the beads as they moved through the tissue. Compared to non-PEG-coated beads, or beads with a less dense PEG coating, they found that a dense coating of PEG allowed larger beads to penetrate the tissue, even those beads that were nearly twice the size previously thought to be the maximum possible for penetration within the brain. They then tested these beads in live rodent brains and found the same results.

The researchers then took biodegradable nanoparticles carrying the chemotherapy drug paclitaxel and coated them with PEG. As expected, in rat brain tissue, nanoparticles without the PEG coating moved very little, while PEG-covered nanoparticles distributed themselves quite well.

"It's really exciting that we now have particles that can carry five times more drug, release it for three times as long and penetrate farther into the brain than before," says Nance. "The next step is to see if we can slow tumor growth or recurrence in rodents." Woodworth added that the team "also wants to optimize the particles and pair them with drugs to treat other brain diseases, like multiple sclerosis, stroke, traumatic brain injury, Alzheimer's and Parkinson's." Another goal for the team is to be able to administer their nanoparticles intravenously, which is research they have already begun.


'/>"/>

Contact: Cathy Kolf
ckolf@jhmi.edu
443-287-2251
Johns Hopkins Medicine
Source:Eurekalert  

Related medicine news :

1. Improved cancer treatments the focus of $6 milion research project
2. 30-day mortality after AMI drops with improved treatment
3. PSA Testing Linked to Improved Prostate Cancer Survival
4. Prostate cancer survival rates improved since introduction of PSA testing
5. East meets West to bring improved sanitation and hygiene practices to Vietnam, Cambodia
6. By studying animal health, researchers find improved ways for developing, testing cancer therapies
7. Health care organizations quest for reduced costs and improved quality
8. HCOs find risks & opportunities in quest for reduced costs & improved quality
9. Is Improved Vaccine Causing Whooping Cough Outbreaks?
10. Expanding Medicaid to low-income adults leads to improved health, fewer deaths
11. Analysis of KRYSTEXXA phase III data demonstrates improved health-related quality of life and physical function in refractory chronic gout patients
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Improved nanoparticles deliver drugs into brain
(Date:10/13/2017)... ... ... Global Healthcare Management’s 4th Annual Kids Fun Run brought out many kids this ... by Global Healthcare Management’s CEO, Jon Letko, is aimed at getting kids excited about ... ages; it is a non-competitive, non-timed event, which is all about having fun and ...
(Date:10/13/2017)... ... , ... “America On The Brink”: the Christian history of the United States ... creation of published author, William Nowers. Captain Nowers and his wife, Millie, have ... thirty years in the Navy. Following his career as a naval aviator and ...
(Date:10/12/2017)... ... 12, 2017 , ... IsoComforter, Inc. ( https://isocomforter.com ), one of ... innovative new design of the shoulder pad. The shoulder pad provides optimal support ... your pain while using cold therapy. By utilizing ice and water that is circulated ...
(Date:10/12/2017)... ... ... HMP , a leader in healthcare events and education, today announced that ... ‘Best B-to-B Healthcare Website.’ Winners were announced during the Eddie & Ozzie Awards luncheon ... editorial and design excellence across a range of sectors. This year’s program included the ...
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... ... of $3,296 in property taxes a year. In some states—like New York, New ... , By contrast, many overseas retirement havens have extremely low property-tax rates, which ...
Breaking Medicine News(10 mins):
(Date:9/12/2017)... 12, 2017   EcoVadis , the leading platform for environmental, social ... annual edition of its Global CSR Risk and Performance Index. The report ... based on Scorecard Ratings that analyzed nearly 800,000 data points across the ... ... ...
(Date:9/12/2017)...  ValGenesis Inc., the global leader in Enterprise ... announce the appointment of Dr. Ajaz Hussain ... Directors and Chairman of Advisory Board beginning September ... to manage their entire validation lifecycle process electronically ... process. Furthermore, ValGenesis VLMS enables rigorous compliance, helps ...
(Date:9/9/2017)... -- Dealmed Medical Supplies, New York City,s ... drugs, vaccines, and specialty medical products and services, announced ... acquire Vantage Medical Supplies, a major distributor of medical ... York . ... practices, will operate under the Dealmed name as of ...
Breaking Medicine Technology: