Nanoparticles help disrupt tumor blood supply, destroy tumors

July 15, 2013

( —In recent years, cancer researchers have been developing agents that destroy the blood vessels surrounding tumors with the goal of starving tumors to death. Some of these agents, such as tumor necrosis factor-alpha (TNF-α) have shown promising results, but often their toxicity has proven too great to be clinically useful. Using gold nanoparticles as a delivery vehicle for TNF-α has reduced this toxicity and the resulting construct has already completed a phase I clinical trial in humans.

Now, a team at the University of Minnesota headed by John Bischof, has shown that they can use this gold nanoparticle-TNF-? system to enhance the effects of either thermal therapy or cryosurgery. Moreover, the researchers demonstrated that they can use standard technology to visualize tumor destruction. Dr. Bischof and his colleagues reported their findings in the journal Molecular Pharmaceutics.

Experiments in a mouse model of human prostate cancer showed that the gold nanoparticle-TNF-? system disrupted blood flow into tumors within 90 minutes of injection, an effect that lasted up to six hours. Using a technique known as dynamic contrast-enhanced MRI, Dr. Bischof's team was able to clearly image the changes in blood flow into and around the tumor following nanoparticle treatment. The researchers note that in human patients, a simple five-minute MRI scan would be sufficient to detect a meaningful change in tumor blood vessel function.

Once the had been "preconditioned," Dr. Bischof and his collaborators treated the animals with either thermal therapy or cryosurgery, both of which produced marked reductions in tumors. They noted that none of the animals treated with thermal therapy died, an important finding given that an equivalent dose of TNF-? with no gold nanoparticle attached followed by thermal therapy was found to be lethal in a large percentage of animals. The researchers also showed that nanoparticle-delivered TNF-? did not trigger inflammatory reactions associated with activated neutrophils, something that does occur when tumors are treated with native TNF-?.

This work, which was supported in part by the National Cancer Institute, is detailed in a paper titled, "Nanoparticle delivered vascular disrupting agents (VDAs): use of TNF-alpha conjugated for multimodal cancer therapy." Investigators for the University of Arkansas for Medical Sciences also participated in this study. An abstract of this paper is available at the journal's website.

Explore further: Using radio waves to bake tumors

More information:

Related Stories

Using radio waves to bake tumors

April 6, 2012

( -- Nanothermal therapy – the use of nanoparticles to cook a tumor to death – is one of the many promising uses of nanotechnology to both improve the effectiveness of cancer therapy and reduce its side ...

Photo-immunotherapy boosts nanoparticle delivery to tumors

February 22, 2013

(—One of the main reasons that nanoparticles can boost the effectiveness of an anticancer drug while decreasing its toxicity is that they are able to accumulate at cancerous sites in the body through the abnormally ...

Gold nanoparticles: A new delivery for cancer drugs

May 8, 2013

( —The protein tumor necrosis factor-alpha (TNF-alpha) is a powerful weapon in the arsenal to control cancer. Unfortunately, as is the case with many potent cancer therapies, the use of TNF-alpha as an anti-cancer ...

How gold nanoparticles can help fight ovarian cancer

May 21, 2013

Positively charged gold nanoparticles are usually toxic to cells, but cancer cells somehow manage to avoid nanoparticle toxicity. Mayo Clinic researchers found out why, and determined how to make the nanoparticles effective ...

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 ...


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.