Scientists at Georgia Tech have developed a method that relies on injected nanoparticles to filter circulating tumor cells (CTC) out of blood. In some cancers, like ovarian, the primary tumor is not the typical cause of death. Rather metastasis, thanks to CTC’s, creates secondary tumors that are the truly dangerous ones.
The new filtration system was tested on mice, each of which was injected with half a million murine ovarian cancer cells. The final results showed that mice treated with the new system lived on average a third longer than mice without treatment. A spinoff company called Sub-Micro has been formed to commercialize the technology.
In the experimental group, the researchers removed fluid from the abdomens of the mice immediately after injection of the cancer cells. They then added the magnetic nanoparticles to the fluid, allowed them to mix, then magnetically removed the nanoparticles along with the attached cancer cells before returning the fluid. The steps were repeated six times for each mouse.
One control group received no treatment at all, while a second control group underwent the same treatment as the experimental group — but without the magnetic nanoparticles. Mice in the two control groups survived a median of 37 days, while the treated mice lived 12 days longer — a 32 percent increase in longevity.
The researchers hope to have a prototype circulation and filtration device ready for testing within three years. After that will come studies into the best treatment regimen, examining such issues as the number of magnetic nanoparticles to use, the number of treatments and treatment spacing. If those are successful, the company will work with the FDA to design human clinical trials.
The researchers also studying how their magnetic nanoparticles could be engineered to capture ovarian cancer stem cells, which are not affected by existing chemotherapy. Removing those cells could help eliminate a potent source of new cancer cells.
Press release: Study Suggests New Treatment Option for Ovarian Cancer…
Abstract in Nanomedicine: Targeted removal of migratory tumor cells by functionalized magnetic nanoparticles impedes metastasis and tumor progression