Researchers Use Fat to Fight Cancer
Despite medical advances, humans are not winning the war on cancer. Cancer will overtake heart disease as the world’s top killer by 2010, according to the World Health Organization. Cancer diagnoses will reach 12 million and deaths related to cancer are expected to reach 7 million this year.
Treatments for cancer include chemotherapy, radiation therapy and surgery. Unfortunately, current cancer treatments can devastate the body as well as cancer cells.
“The problem with current cancer treatment is that the chemicals attack more good cells than the bad,” Gregory Salamo, the Joe N. Basore Professor in Nanotechnology and Innovation, said. “We try to push the body to the limit to possibly kill the cancer.”
These therapies sometimes succeed, but in the process, they may kill the patient, he said.
Conclusion? Cancer is bad. Cancer treatment that potentially kills is bad as well. What else is bad… fat? Not according to Rachel Lee, a physics and chemical engineering senior in the honors college who is researching how liposomes made from fat act as carriers for controlled drug delivery.
Lee has been on a research team that is looking at ways to use new technologies – with the help of artificial cells made from fat – to deliver cancer-fighting drugs directly to cancer cells.
The research team is funded by a $1.6 million Howard Hughes Medical Institute grant through 2010. The grant brings together undergraduates in different disciplines in a studio environment to solve interdisciplinary problems.
Lee is one of six undergraduates who work on this project. All are seeking a better drug delivery system, but they are using different approaches.
Their research is an essential part of a bigger cancer research plan. The team of faculty include Salamo and Daniel Fologea in physics, Xiaogang Peng and David Paul in chemistry, and Ralph Henry, David McNabb and Ines Pinto in biological sciences. They work in conjunction with the University of Arkansas for Medical Sciences located in Little Rock.
Scientists at the medical school are researching how to target cancerous tumors with drugs released from liposomes.
Two chemistry students are creating quantum dots, or nanoparticles of a crystal that easily emits light, to test for different properties of the healthy and cancerous cells.
Two biology students are growing different cell lines and seeing how the quantum dots and other parts of the group’s drug delivery system impact the cells.
Lee is working with liposomes with another physics student. A liposome is an artificial microscopic sac consisting of an aqueous core enclosed in one or more lipid layers. Liposomes have cores that are able to hold and protect concentrated drugs from degradation inside the body with its bilayers.
Liposomes are currently FDA approved for use with the popular cancer treatment drug, doxorubicin. One such doxorubicin formulation is Doxil. Lee works to see how the liposomes, loaded with doxorubicin, would react with external stimuli and whether they would completely release the medication it carries. Lee thinks the research can further the use of doxorubicin, but the liposomes could also be modified to incorporate other drugs.
For this project, Lee had to manufacture liposomes from fats, a time-consuming process that must be finished before any research can be started. The lipids needed from the fats are dissolved in chloroform, which allows them to be mixed in the desired proportions. After mixing, the solution is dried under vacuum to produce a lipid cake.
The next few steps in Lee’s research process sound like a sci-fi movie from the not too distant past. She works with extruders, spectrofluorometers, fluorescent microscopes and electrodialysis machines. She also uses nanotechnology to make and study the liposomes.
An extruder is used to push the liposomes through a membrane that produces the different sizes of liposomes needed for Lee’s experiment.
Using liposomes as a controlled delivery method for medications can provide a much higher dose of medication to the needed areas without inducing the severe side effects that normally limit dosage, especially in the treatment of cancer. Lee’s goal is to find the best possible liposome for cancer treatment.
“It’s nice to think that my work could eventually lead to better cancer drugs,” Lee said.
The simple lipid bilayers make it easy for scientists to concentrate the drug, evade early removal from the body and release the drug when required. After the liposome releases the drug, the lipids are removed from the body by its normal cleaning systems.
The results of Lee’s study support the further use of liposomes as drug carriers because of their uniformity, stability, and ability to evade the immune system’s self-defense while still concentrating a drug inside the cell.
The university is pursuing patent protection and is seeking a commercialization partner for some aspects of this research.