Targeted Magnetic Nanoparticles Heat Tumors to Death
October 10, 2005
One idea for treating cancer that is gaining a foothold among researchers is that it may be possible to kill cancer, not with drugs, but with targeted nanoscale heaters that would essentially cook malignant cells to death from the inside out. Indeed, recent papers have reported preliminary success using carbon nanotubes and gold nanocages as the nanoscale thermal therapy devices. Now, thanks to work from the University of Paris in France, iron oxide nanoparticles have been added to the list of promising nanoscale thermal scalpels.
Reporting its work in the journal Bioconjugate Chemistry, a research team headed by Patrick Couvreur, Ph.D., describes its studies in which the investigators use folic acid to target magnetic nanoparticles to tumor cells. Once the tumor cells engulfed the nanoparticles, the researchers then heated the nanoparticles with a rapidly oscillating magnetic field. Preliminary data from these experiments suggest that the nanoparticles should be able to heat up cells beyond 43 °C – a known lethal temperature – after being in the oscillating magnetic field for 20 minutes.
Using electron microscopy and cells growing in culture, the researchers were able to document that only cancer cells bearing folic acid receptors on their surfaces were able to take up the magnetic nanoparticles. Each cancer cell took up approximately 300 nanoparticles, which the researchers calculated is sufficient to provide the necessary heat transfer to kill tumor cells. The investigators plan to conduct further experiments to test this hypothesis once they have completed constructing a device capable of focusing an oscillating magnetic field onto a test sample.
This work is detailed in a paper titled, “Folate-Conjugated Iron Oxide Nanoparticles for Solid Tumor Targeting as Potential Specific Magnetic Hyperthermia Mediators: Synthesis, Physicochemical Characterization, and in Vitro Experiments.” An abstract is available through PubMed. |
