Nanotech system, cellular heating may improve treatment of ovarian cancer


Oct 17, 2013 
    

       Nanotech system, cellular heating may improve treatment of ovarian cancerEnlarge        

 A new drug delivery system that incorporates heat, nanotechnology and chemotherapy shows promise in improving the treatment of ovarian cancer. Credit: Oregon State University

The combination of heat, chemotherapeutic drugs and an innovative delivery system based on nanotechnology may significantly improve the treatment of ovarian cancer while reducing side effects from toxic drugs, researchers at Oregon State University report in a n

The findings, so far done only in a laboratory setting, show that this one-two punch of mild hyperthermia and chemotherapy can kill 95 percent of ovarian cells, and scientists say they expect to improve on those results in continued research.

The work is important, they say, because – one of the leading causes of cancer-related deaths in women – often develops resistance to if it returns after an initial remission. It kills more than 150,000 women around the world every year.

“Ovarian cancer is rarely detected early, and because of that chemotherapy is often needed in addition to surgery,” said Oleh Taratula, an assistant professor in the OSU College of Pharmacy. “It’s essential for the chemotherapy to be as effective as possible the first time it’s used, and we believe this new approach should help with that.”

It’s known that elevated temperatures can help kill , but heating just the cancer cells is problematic. The new system incorporates the use of  nanoparticles that can be coated with a cancer-killing drug and then heated once they are imbedded in the cancer cell.

Other features have also been developed to optimize the new system, in an unusual collaboration between engineers, material science experts and pharmaceutical researchers.

A peptide is used that helps guide the nanoparticle specifically to cancer cells, and the nanoparticle is just the right size – neither too big nor too small – so the immune system will not reject it. A special polyethylene glycol coating further adds to the “stealth” effect of the nanoparticles and keeps them from clumping up. And the interaction between the cancer drug and a polymer on the nanoparticles gets weaker in the acidic environment of cancer cells, aiding release of the drug at the right place.

“The hyperthermia, or heating of cells, is done by subjecting the magnetic nanoparticles to an oscillating, or alternating magnetic field,” said Pallavi Dhagat, an associate professor in the OSU School of Electrical Engineering and Computer Science, and co-author on the study. “The absorb energy from the oscillating field and heat up.”

The result, in laboratory tests with , was that a modest dose of the chemotherapeutic drug, combined with heating the cells to about 104 degrees, killed almost all the cells and was far more effective than either the drug or heat treatment would have been by itself.

Doxorubicin, the cancer drug, by itself at the level used in these experiments would leave about 70 percent of the cancer cells alive. With the new approach, only 5 percent were still viable.

The work was published in the International Journal of Pharmaceutics, as a collaboration of researchers in the OSU College of Pharmacy, College of Engineering, and Ocean NanoTech of Springdale, Ark. It was supported by the Medical Research Foundation of Oregon, the PhRMA Foundation and the OSU College of Pharmacy.

“I’m very excited about this delivery system,” Taratula said. “Cancer is always difficult to treat, and this should allow us to use lower levels of the toxic chemotherapeutic drugs, minimize side effects and the development of drug resistance, and still improve the efficacy of the treatment. We’re not trying to kill the cell with heat, but using it to improve the function of the drug.”

Iron oxide particles had been used before in some medical treatments, researchers said, but not with the complete system developed at OSU. Animal tests, and ultimately human trials, will be necessary before the new system is available for use.

Drug delivery systems such as this may later be applied to other forms of cancer, such as prostate or pancreatic cancer, to help improve the efficacy of  in those conditions, Taratula said.

Explore further:     New ovarian cancer treatment succeeds in the lab

Read more at: http://phys.org/news/2013-10-nanotech-cellular-treatment-ovarian-cancer.html#jCp

Read more at: http://phys.org/news/2013-10-nanotech-cellular-treatment-ovarian-cancer.html#jCp

Nanoparticle Helps Eradicate an Ovarian Tumor in a Day


101813CancerTherapyIllustrationFIU-1382113148346Slip Inside: In the presence of a magnetic field (H), magneto-electric nanoparticles cause pores to form in tumor cells, allowing cancer drugs in.

Researchers at Florida International University (FIU) have developed a novel approach to treating ovarian cancer that employs nanoparticles in combination with a magnetic field to target cancer cells while leaving nearby healthy cells untouched.

In research published in the journal Scientific Reports (“Magneto-electric Nanoparticles to Enable Field-controlled High-Specificity Drug Delivery to Eradicate Ovarian Cancer Cells”), the FIU team demonstrated how the so-called magneto-electric nanoparticles (MENs) enable the chemotherapy drug, Taxol, to completely eradicate a tumor within 24 hours while leaving the healthy ovarian cells intact.

“Sparing healthy cells has been a major challenge in the treatment of cancer, especially with the use of Taxol; so in addition to treating the cancer, this could have a huge impact on side-effects and toxicity,” said Carolyn Runowicz, M.D., professor of gynecology and obstetrics at the Herbert Wertheim College of Medicine at FIU, in a press release.

While the use of various nanoparticles for delivering drugs to specific targets in the body has been with us for a decade now and has already created a billion-dollar industry for itself,  this marks the first time that these MENs nanoparticles have been used in this kind of therapy.

The basis of nano-enabled drug delivery has typically involved connecting the nanoparticle to some antibody that is attracted to a tumor and sending the nanoparticle through the bloodstream to find its target. There has been some question about the efficacy and specificity of this antibody approach.

This new technology developed at FIU appears to be more specific because it separates the cancer cells from the healthy cells by exploiting differences in the electrical properties of the two kinds of cells’ membranes.

This separation is achieved because of the unique properties of the MENs. Unlike typical magnetic nanoparticles (MN), which can be controlled by a remote magnetic field, the MENs can have their intrinsic electric fields controlled by the external magnetic field. This means that the MENs can operate as localized magnetic-to-electric-field nano-converters. In other words, the MENs can generate the electric signals that govern molecular interactions. By creating a particular electric field, the MENs change the membrane properties of the cancer cells and not the healthy cells making them more porous.

As the Scientific Reports articles describes it: “The interaction between the MENs and the electric system of the membrane effectively serves as a field-controlled gate to let the drug-loaded nanoparticles enter specifically the tumor cells only.”

“This is an important beginning for us. I’m very excited because I believe that it can be applied to other cancers including breast cancer and lung cancer,” said Sakhrat Khizroev, professor of electrical and computer engineering at FIU in the press release.

Illustration: Florida International University

101813CancerTherapyIllustrationFIU-1382113148346