Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Improved nanoparticles deliver drugs into brain

12.09.2012
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.

Authors on the paper include Elizabeth Nance, Graeme Woodworth, Kurt Sailor, Ting-Yu Shih, Qingguo Xu, Ganesh Swaminathan, Dennis Xiang, Charles Eberhart and Justin Hanes, all from The Johns Hopkins University.

This work was supported by grants from the National Cancer Institute (R01CA164789 and U54CA151838).

On the Web:

Link to article in Science Translational Medicine: http://stm.sciencemag.org/content/4/149/149ra119

Hanes lab publications: http://www.hopkinsmedicine.org/kimmel_cancer_center/experts/Laboratory_Scientists/detail/A602624173773B994F71AE88C5BCF392/Justin_Hanes

Hanes' professorship announced at Wilmer Eye Institute: http://www.hopkinsmedicine.org/wilmer/news/hanes_professorship.html

Chemical and Biomolecular Engineering Department: http://www.jhu.edu/chembe/

Cathy Kolf | EurekAlert!
Further information:
http://www.jhmi.edu

More articles from Health and Medicine:

nachricht 3D images of cancer cells in the body: Medical physicists from Halle present new method
16.05.2018 | Martin-Luther-Universität Halle-Wittenberg

nachricht Better equipped in the fight against lung cancer
16.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>