Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

U-M researchers use nanoparticles to target brain cancer

16.11.2006
Nanoparticles can carry drugs designed to image, treat tumors, study finds

Tiny particles one-billionth of a meter in size can be loaded with high concentrations of drugs designed to kill brain cancer. What's more, these nanoparticles can be used to image and track tumors as well as destroy them, according to researchers at the University of Michigan Comprehensive Cancer Center.

Researchers incorporated a drug called Photofrin along with iron oxide into nanoparticles that would target cancerous brain tumors. Photofrin is a type of photodynamic therapy, in which the drug is drawn through the blood stream to tumor cells; a special type of laser light activates the drug to attack the tumor. Iron oxide is a contrast agent used to enhance magnetic resonance imaging, or MRI.

"Photofrin goes into tumor blood vessels and collapses the vasculature, which then starves the tumor of the blood flow needed to survive. The problem with free photofrin therapy is that it can cause damage to healthy tissue. In our study, the nanoparticle becomes a vehicle to deliver the drug directly to the tumor," says study author Brian Ross, Ph.D., professor of radiology at the U-M Medical School and co-director of Molecular Imaging at the U-M Comprehensive Cancer Center.

Photofrin has been used to treat several types of cancer, including esophageal, bladder and skin cancers. It works by traveling through blood vessels until it reaches the vessels supplying blood to the tumor. When activated by light, the Photofrin collapses these blood vessels, starving the tumor of the blood it needs to survive.

Results of the study appear in the Nov. 15 issue of Clinical Cancer Research.

"Thinking outside the box is a must for developing brain cancer treatments. Drugs don't get into the brain when delivered in the normal way, which explains in part why some current treatments for brain tumors are generally not effective. Targeting the tumor vasculature with nanoparticles containing a payload will overcome these issues," says study author Alnawaz Rehemtulla, Ph.D., professor of radiology and radiation oncology at the U-M Medical School and professor of environmental health sciences at the School of Public Health.

Treating brain tumors is traditionally difficult because of the blood-brain barrier, which prevents harmful substances from traveling through the bloodstream into the brain. In order for chemotherapy to treat a tumor, it must penetrate this barrier.

Researchers tested the nanoparticles in cell cultures and animal models. The studies showed the nanoparticles traveled to the tumor, resulting in less Photofrin exposure throughout the body and enhanced exposure within the tumor. This allowed a larger window for activating the drug with light. It also would eliminate a common side effect of photodynamic therapy, in which healthy skin becomes sensitive to light.

In rat studies, researchers found those treated traditionally with Photofrin survived 13 days, while rats treated with Photofrin incorporated into a nanoparticle survived an average of 33 days. Forty percent of the rats remained disease-free six months after treatment.

The researchers also found twice the amount of the contrast agent at the tumor site when using targeted nanoparticles, suggesting the nanoparticles were attracted to the tumor site.

The advantage of this delivery system is the ability to attack the tumor with higher doses of a drug while sparing normal tissue from a drug's toxic side effects.

"Our research suggests that you can take a drug that may be toxic to normal tissue – it could be any type of drug, not just photodynamic – and you could deliver higher doses of that drug for a more powerful punch," says Rehemtulla, co-director of Molecular Imaging at the U-M Comprehensive Cancer Center.

If nanoparticle delivery proves to be safe in humans, it will allow researchers to re-examine previously developed drugs that were discarded because they caused too many dangerous side effects in patients.

By combining the drug with a contrast agent, researchers were able using imaging techniques to determine whether the drug actually got to the tumor. This technique could have potential to diagnosis brain tumors early, as well as to help researchers determine when to deliver a drug or when to administer the next dose.

Further lab research is needed before the nanoparticle technology can be tested in clinical trials. More than 18,800 people will be diagnosed with brain cancer this year, and 12,820 will die from it. For information about treatments that are currently available, call U-M's Cancer AnswerLine at 800-865-1125.

Nicole Fawcett | EurekAlert!
Further information:
http://www.umich.edu

More articles from Studies and Analyses:

nachricht Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Oxygen loss in the coastal Baltic Sea is “unprecedentedly severe”
05.07.2018 | European Geosciences Union

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>