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:2/11/2016)... ... February 11, 2016 , ... Student-doctors from Western University ... Match Program Tuesday, February 9, taking one of the final steps in their ... education positions across the country. Of the 103 student-doctors who comprise the College ...
(Date:2/11/2016)... ... February 11, 2016 , ... Image One USA ... new market, and it’s the buildings of Nashville that will benefit. , “I’ve enjoyed ... to relocate to Nashville, there was no question that I would bring my business ...
(Date:2/11/2016)... ... 11, 2016 , ... Thermi™, a world leader in thermistor-regulated ... the promotions of Allison Kelly to executive vice president of the company’s new ... of North American capital sales, and Wendy Oseas to vice president of global ...
(Date:2/11/2016)... Australia (PRWEB) , ... February 11, 2016 , ... ... potential ?" motivational speaker, trainer and author Ray Clarke poses a question as ... personal fulfillment . In his book, "Being in the Being" (published by Partridge ...
(Date:2/11/2016)... ... February 11, 2016 , ... AccuVein Inc. announces the ... Standards of Practice, to include vascular visualization as a standard practice. AccuVein ( ... of the market, facilitates adherence to this standard with its easy to use, ...
Breaking Medicine News(10 mins):
(Date:2/11/2016)... Feb. 11, 2016  Kindred Biosciences, Inc. (NASDAQ: ... improving the lives of pets, today announced the submission ... New Animal Drug Application (NADA) for Zimeta™ (dipyrone injection, ... (KB0120) of Zimeta for the control of pyrexia (fever) ... --> --> The Chemistry, ...
(Date:2/11/2016)... Potrero Medical, Inc., the developer of the Accuryn™ ... of George M. Rapier, III , MD, to its ... , WellMed is one of the nation,s largest physician owned ... in Texas and Florida ... own internal medicine practice, he has been instrumental to the ...
(Date:2/11/2016)... Feb. 11, 2016  AfterPill.com is reporting that this ... abstinence for all women who are at risk of ... each year and raises the risks of unprotected sex ... --> According to the Guttmacher Institute, there are ... of child-bearing age, who have sex without the intention ...
Breaking Medicine Technology: