Progress in using magnetic fields to target tumors

October 19, 2012

(—Since the advent of cancer nanotechnology, researchers have sought to use magnetic fields to increase the concentration of drug-loaded iron oxide nanoparticles that reach a tumor. However, magnetic fields drop off quickly with distance, making it almost impossible to consider such an approach for tumors located more than a few centimeters from the skin. To solve what appears to be a fundamentally unsolvable problem, researchers at the Stanford University Center of Cancer Nanotechnology Excellence (Stanford CCNE) have taken a two-pronged approach, one that uses an external magnetic field and an implantable magnetizable mesh to create local magnetic fields strong enough to trap nanoparticles at a specific location.

Sanjiv Gambhir and Shan Wang led the research team that developed this new approach to magnetic targeting. The team reported its findings in the journal ACS Nano. Drs. Gambhir and Wang are the co- of the Stanford CCNE.

To boost the strength of the magnetic field near a tumor, the investigators used a commercially available micromesh made of nickel. When implanted close to tumors growing in mice, the mesh developed strong magnetic field gradients when a was placed next to the animal. These gradients were sufficient to capture large numbers of biocompatible magnetic iron oxide nanoparticles that the researchers injected into the animals.

The idea driving this work is that such a mesh could be implanted near a tumor in a procedure that would be far less invasive than tumor-removing surgery. The patient could then be treated with carrying large doses of antitumor drug. Such a procedure could also be useful in cases where surgical is not feasible.

In one set of experiments, the investigators dosed tumor-bearing animals with an iron oxide nanoparticle coated with a molecule known to block angiogenesis, the growth of new blood vessels that tumors require to grow and spread. While the nanoparticles alone caused tumors to shrink, when administered along with magnetic field trapping, the rate of tumor shrinkage increased dramatically. The investigators noted that effect of generating a localized magnetic field in the vicinity of the tumor was similar to that seen when they doubled the dose of anti-angiogenic nanoparticles without additional magnetization.

Explore further: New Nanoparticle Structure Boosts Magnetic Properties

More information: "Fluorescent magnetic nanoparticles for magnetically enhanced cancer imaging and targeting in living subjects." ACS Nano.

Related Stories

New Nanoparticle Structure Boosts Magnetic Properties

December 19, 2005

Magnetic nanoparticles have shown promise as contrast-enhancing agents for improving cancer detection using magnetic resonance imaging (MRI), as miniaturized heaters capable of killing malignant cells, and as targeted drug ...

Remote Magnetic Field Triggers Nanoparticle Drug Release

November 8, 2007

Magnetic nanoparticles heated by a remote magnetic field have the potential to release multiple anticancer drugs on demand at the site of a tumor, according to a study published in the journal Advanced Materials. Moreover, ...

Magnetic field directs nanoparticles to tumors

November 25, 2010

( -- To improve the tumor-specific delivery of drug to tumors, a team of investigators from the University of California, San Diego (UCSD) has created a system of nanoparticles-within-a-nanoparticle that can be ...

Tracking therapeutic nanoparticles that target breast tumors

December 17, 2010

Researchers at Rice University, collaborating with investigators at the Baylor College of Medicine, have used two different types of imaging technologies to track the delivery of a therapeutic nanoparticle to breast tumors. ...

Recommended for you

Physicists develop new technique to fathom 'smart' materials

November 26, 2015

Physicists from the FOM Foundation and Leiden University have found a way to better understand the properties of manmade 'smart' materials. Their method reveals how stacked layers in such a material work together to bring ...

Mathematicians identify limits to heat flow at the nanoscale

November 24, 2015

How much heat can two bodies exchange without touching? For over a century, scientists have been able to answer this question for virtually any pair of objects in the macroscopic world, from the rate at which a campfire can ...

New sensor sends electronic signal when estrogen is detected

November 24, 2015

Estrogen is a tiny molecule, but it can have big effects on humans and other animals. Estrogen is one of the main hormones that regulates the female reproductive system - it can be monitored to track human fertility and is ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.