Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > Researchers hone technique to KO pediatric brain tumors

Karen Wooley
Karen Wooley

Abstract:
An interdisciplinary team of researchers at Washington University in St. Louis, led by Karen L. Wooley, Ph.D., James S. McDonnell Distinguished University Professor in Arts & Sciences, is a step closer to delivering cancer-killing drugs to pediatric brain tumors, similar to the tumor that Senator Ted Kennedy is suffering from.

Researchers hone technique to KO pediatric brain tumors

ST. LOUIS, MO | Posted on July 14th, 2008

Such tumors are often difficult to completely remove surgically; frequently, cancerous cells remain following surgery and the tumor returns. Chemotherapy, while effective at treating tumors, often harms healthy cells as well, leading to severe side effects especially in young children that are still developing their brain functions.

Slow hand

In an effort to solve this problem, the Wooley lab has developed polymeric nanoparticles that can trap doxorubicin, a drug commonly used in chemotherapy, and slowly release the drug over an extended time period. By fine-tuning the polymer composition, they were able to tailor the release rate of the drug and improve its solubility.

The work was published in Chemical Communications and supported by The Children's Discovery Institute of St. Louis Children's Hospital and by the National Heart, Lung and Blood Institute of the National Institutes of Health as a Program of Excellence in Nanotechnology.

With their approach, the Wooley lab was able to load more doxorubicin into the cores of the nanoparticles, compared with similar constructs.

"Typically, a polymeric micelle has three to four percent (drug) loading per nanoparticle mass. In our case, we achieved 18 to 19 percent for our nanoparticles," said Andreas Nystrom, Ph.D., a post-doctoral associate, supported by the Knut and Alice Wallenberg Foundation, who worked on the project.

However, the nanoparticles carrying the doxorubicin were not as effective at killing cancer cells compared to the neat drug, because in these initial nanoparticles, no targeting groups were included and also the entire drug payload of the nanoparticle is not released. The identification and attachment of targeting ligands onto the nanoparticles and the rate and extent of drug release are now what the researchers will concentrate on and seek to improve. Ligands in this application are comprised of peptides and antibodies that bind to specific cell receptors over-expressed in cancer cells.

The cell studies were performed in vitro by Zhiqiang (Jack) Xu, Ph.D., a post-doctoral associate, together with Professor Jeff Leonard, M.D., in the Department of Neurological Surgery and Professor Sheila Stewart, Ph.D., in the Department of Cell Biology and Physiology, both in the School of Medicine at Washington University. Ultimately, in vivo, the nanoparticles are expected to target the tumors through the use of active targeting ligands and also through passive diffusion, as particles are well known to be taken up selectively into tumors by a process called the enhanced permeability and retention effect. The amount of drug released from the nanoparticles "might be enough for the intended therapy, if side effects are limited by selective tumor targeting," Nystrom said.

Seek and destroy

For these drug-filled nanoparticles to be effective for treating brain tumors, one challenge remains decorating the nanoparticles with signatures that direct them to the tumors and away from healthy cells, a process known as tissue specific targeting. Once attached to the tumor, the nanoparticles can release their deadly contents, killing the cancer cells and leaving the healthy cells unharmed.

"Everything depends on getting the nanoparticle to the tissue (tumor) of choice," said Nystrom.

Wooley agrees. "We have been studying these nanoparticles for some time now as a platform technology, achieving high radiolabeling efficiencies and demonstrating variable bio-distributions through a collaboration with the laboratory of Professor Mike Welch, in the Department of Radiology," she said. "Now, we are poised to take advantage of the progress made to develop the particles for diagnosis and treatment of several diseases.

"In this latest work, the nanoparticles were designed with thermally tunable core properties to serve as a host system that retains drug molecules at room temperature and then releases the cargo at physiological temperature, with a controlled drug release profile. The results are highly promising and are allowing us to move forward to a fully functional, tumor-targeted drug delivery device. The key to making this happen is the interdisciplinary team of investigators, each of whom brings a different chemical, biological or medical expertise."

####

For more information, please click here

Contacts:
Subject Matter Experts:
Karen Wooley

(314) 935-7136

Media Assistance:

Tony Fitzpatrick
Senior Science Editor

(314) 935-5272

Copyright © Washington University in St. Louis

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Ultra-flat circuits will have unique properties: Rice University lab studies 2-D hybrids to see how they differ from common electronics July 25th, 2016

Attosecond physics: Mapping electromagnetic waveforms July 25th, 2016

Borrowing from pastry chefs, engineers create nanolayered composites: Method to stack hundreds of nanoscale layers could open new vistas in materials science July 25th, 2016

Integration of novel materials with silicon chips makes new 'smart' devices possible July 25th, 2016

Nanomedicine

Accurate design of large icosahedral protein nanocages pushes bioengineering boundaries: Scientists used computational methods to build ten large, two-component, co-assembling icosahedral protein complexes the size of small virus coats July 25th, 2016

New remote-controlled microrobots for medical operations July 23rd, 2016

New superconducting coil improves MRI performance: UH-led research offers higher resolution, shorter scan time July 23rd, 2016

New probe developed for improved high resolution measurement of brain temperature: Improved accuracy could allow researchers to measure brain temperature in times of trauma when small deviations in temperature can lead to additional brain injury July 23rd, 2016

Discoveries

Attosecond physics: Mapping electromagnetic waveforms July 25th, 2016

Borrowing from pastry chefs, engineers create nanolayered composites: Method to stack hundreds of nanoscale layers could open new vistas in materials science July 25th, 2016

Integration of novel materials with silicon chips makes new 'smart' devices possible July 25th, 2016

Accurate design of large icosahedral protein nanocages pushes bioengineering boundaries: Scientists used computational methods to build ten large, two-component, co-assembling icosahedral protein complexes the size of small virus coats July 25th, 2016

Announcements

Borrowing from pastry chefs, engineers create nanolayered composites: Method to stack hundreds of nanoscale layers could open new vistas in materials science July 25th, 2016

Integration of novel materials with silicon chips makes new 'smart' devices possible July 25th, 2016

Accurate design of large icosahedral protein nanocages pushes bioengineering boundaries: Scientists used computational methods to build ten large, two-component, co-assembling icosahedral protein complexes the size of small virus coats July 25th, 2016

XEI Scientific Partners with Electron Microscopy Sciences to Promote and Sell its Products in North and South America July 25th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic