Story URL: http://news.medill.northwestern.edu/chicago/news.aspx?id=173415
Story Retrieval Date: 12/1/2010 5:31:57 PM CST
Nanoparticles show promise for cancer treatment
by SARAH PLUMRIDGE
Nov 19, 2010
A Caltech researcher told an audience Thursday at Northwestern University about how nanoparticles can be delivered as a drug treatment for cancer.
Mark Davis, a professor of chemical engineering at the California Institute of Technology in Pasadena, Calif. explained the challenges of developing nanoparticles that target tumor cells.
The nanoparticles used in this research carry siRNA, or small interfering RNA, a double-stranded molecule in which each strand is made up of 21 nucleotide bases that can interfere with the expression of specific genes.
The siRNA targets a protein that the tumor manufactures, he said.
Davis compares the process to an overflowing bathtub.
“If I have a tumor that is spitting out a lot of a protein, it is like the water filling up a bathtub,” said Davis.
In the analogy, the drug mops up the extra protein or the water spilling out of the tub and onto the floor. The siRNA drug being delivered attempts to keep up with the production of the protein, he said.
“It is a great example of how useful nanotechnology can be with systemic administration of drugs,” said Marina Damiano, a graduate student in Northwestern’s Department of Chemistry. “And [it's] a promising example of how nanotechnology and nanoscience in general have a strong future in drug development.”
The idea is that the nanoparticle moves through the tumor and delivers the RNA into the cell, Davis said.
Using animal models the researchers showed that the nanoparticles delivered siRNA without an immune response, he said. The targeted delivery system entered a Phase I clinical trial in 2008.
The nice thing about the nanoparticles is that they have low toxicity and do not stimulate the immune system and they can carry a large load of drugs, Davis said.
He walked the audience through different studies and the first results from the patients in the clinical trials.
“He was pushing the field of cancer treatment forward by using this interesting system with siRNA,” said Ali Alhasan, a graduate student in Interdepartmental Biological Sciences. “That was pretty brilliant since he was able to apply it to humans.”
Davis showed photos of the nanoparticles inside tumors and not in other tissues meaning that the nanoparticle effectively targeted the cancer cells.
“Not the cure to speak about yet,” he said. “We never saw any regression, but we were able to stabilize the spread of cancer.”