MU scientists pursue nanoparticle radiation treatment for cancer
After further testing, the scientists could seek FDA approval.
Feb. 08, 2013
MU researchers developed a new nanoparticle that serves as a harness for radiation therapy and could potentially be used to more effectively treat cancer.
MU professor J. David Robertson and graduate student Mark McLaughlin used a gold coating to contain the radiation the nanoparticle emits and to pinpoint small cancer tumors while causing minimal damage to surrounding body tissue.
Radiopharmaceuticals generally use low-energy beta particles, which emit lower levels of radiation than high-energy alpha particles, Robertson said. The harness allows high-energy treatment to speed up the process of cancer therapy without causing an uncontrollable spread of radiation. The study was published in scientific and medical journal PLOS One.
“The alpha particle is like a cannonball,” Robertson said. “It’s powerful with high energy. Except, when it is released, the cannon goes in the other direction. We wanted to make sure that when we let the alpha particles out, we don’t use much energy.”
The study originated when Robertson, after conversing with his colleagues and reading papers about problems with using alpha particles in therapy, pitched a “crazy and off the wall” idea to McLaughlin — killing cancer cells through radiation treatment without taking a toll on the entire body by harnessing nanoparticles.
The study became McLaughlin’s main graduate project.
“I was hooked from the get-go,” he said.
McLaughlin partnered with chemist Saed Mirzadeh at Oak Ridge National Laboratory in Knoxville, Tenn., for 10 months. They used actinium, which is a soft, silvery radioactive metal that produces alpha particles, as the core of the nanoparticle.
“(McLaughlin) worked like a dog,” Mirzadeh said. “It was very intense. He had to make the particles and know the reactivity. He could not use too much radioactive material, he had to limit.”
Together, the researchers created a multi-layered nanoparticle with actinium as its center, four layers of material surrounding it, and a gold coating.
McLaughin said he faced a challenge designing the particle.
“I had to find the right size and synthetic condition,” he said. “Layering the particle with gold was challenging. We had to find a happy medium with how much gold to use.”
Stephen J. Kennel, a scientist and radio-biochemist of the University of Tennessee-Knoxville, assisted McLaughlin with animal testing. Kennel was able to take actinium and put it into the blood stream of small animals. The animal testing allowed the researchers to see how many radioactive atoms were retained in the particle.
“We did a celebratory dance after we viewed the results,” Robertson said.
More than 80 percent of the actinium remained in the nanoparticle 24 hours after it was created, Robertson said in a MU News Bureau news release.
“I feel very excited about the results,” McLaughlin said. “I’m excited to see as many applications as possible. We’re extraordinarily excited. When I realized how many atoms were retained, I was on cloud nine.”
The team will conduct more studies, including further animal testing to determine how the radioactivity will affect the body. Local toxicity must be retained to kill targeted cancer cells while global toxicity must be reduced to avoid harming the body, Mirzadeh said.
If further studies are successful, the officials can request Federal Drug Administration approval to develop human trials. McLaughlin said he hoped all along that, with hard work, he could contribute to cancer therapy.
“I’ve always been cautiously optimistic, but always thought that with a lot of hard work I could be a part of something very important to cancer therapy,” he said.