Posted: March 8, 2008

Research has touch of gold

(Nanowerk News) Radioactive gold nanoparticles developed at the University of Missouri could be the next great leap in cancer-fighting technology.
MU Professor Kattesh Katti, who was honored Tuesday by the Missouri General Assembly, in collaboration with Assistant Professor Raghuraman Kannan, discovered how to use the tiny particles for imaging and cancer therapy.
In animal tests, the nanoparticles have killed cancer cells with high precision and no side effects.
"If we can treat the tumors at the cellular level, then we can free the patient of a tumor for all of his or her life," said Katti, a professor of radiology and physics who also directs MU’s Cancer Nanotechnology Platform.
With nanoscience, Katti said, "we can hit the disease at the pre-cancerous stage, which is the cellular stage."
The particles - 100,000 times smaller than the width of a human hair - bond to a special chemical attracted to the protein abundant on cancer cells. The particles then are injected into the body, where they migrate directly to the cancerous area.
Their tiny size allows nanoparticles to enter and latch onto cancer cells. The nanoparticles are first exposed to radiation at the MU Research Reactor. They have a radioactive life of about three days, meaning they release radioactive energy from inside the cancerous cell without harming other organs in the body. After the therapy, the nanoparticles are nontoxic.
Jerry Lee, project manager at the National Cancer Institute’s Alliance for Nanotechnology in Cancer in Bethesda, Md., said Katti’s work is helping to speed the use of nanotechnology in cancer treatment.
"If we want to eventually use this setting," Katti "has definitely been on the forefront of understanding where these nanoparticles are going and what kind of toxic effects they have," Lee said.
In general, Katti said, harsh toxic chemicals are needed to make nanoparticles. However, in a related discovery, his team has used the antioxidant property of soybeans combined with gold salts and water to create the chemical reaction that results in gold nanoparticles.
Lee also said Katti’s openness to sharing his research with experts in different disciplines was a chief objective of MU being awarded a $3.1 million grant from the NCI in 2005.
NCI has invested $143 million over five years with teams across the country, and it provides continuous updates of research and findings related to cancer and nanotechnology on its Web site, nano.cancer.gov.
"It’s a very exciting area of research," said Bill Caldwell, director of the Ellis Fischel Cancer Center at MU and a longtime friend and colleague of Katti. "If everything goes well, they can be put into early-phase clinical trials within the next one to two years."
Because of the collaborative relationship between researchers, Caldwell said, patients at Ellis Fischel could participate in early clinical trials, which are a major step toward FDA approval.
"One of the things that makes our ability to collaborate somewhat unique is we simultaneously have a research reactor, the college of veterinary medicine, the school of medicine, school of nursing, the college of engineering and a cancer program, all on one campus," Caldwell said. "Having multiple people with different types of expertise and different points of view creates a synergy that wouldn’t be there if only one person was trying to address the problem."
Katti said the technique would be better than current radiation and chemotherapy cancer treatments that cannot as effectively target the cancerous area and might cause harm to other parts of the body.
"If you inject normal isotopes into the tumor, isotope leaks out from the tumor almost instantly. There’s no affinity of that isotope to the tumor. Whereas if you have a nanoparticle, the nanoparticle has extreme high affinity to the proteins within the tumor. … Once it binds, it is irreversible. That’s why we don’t see any leakage."
With only a few milligrams of gold necessary to make the nanoparticles, Katti said the cost of gold is not an issue. Also, although his research is now focusing on breast and prostate cancer treatments, similarities in cancer morphology mean the nanoparticles could be adapted in the future to treat other forms of cancer.
Source: Columbia Tribune (Abraham Mahshie)