March 20, 2006
Magnetic Nanoparticles Separate Tumor Cells from Healthy Blood Cells
One consistent finding in clinical oncology is that metastatic lesions, and not primary tumors, are the primary cause of cancer’s lethality. Since metastatic lesions invariably form when primary tumor cells migrate through the bloodstream, researchers have been developing methods for removing tumor cells from the bloodstream. Now, a chance discovery by a team of investigators in Germany has found that dextran-coated magnetic nanoparticles, under the right conditions, will accumulate in metastatic tumor cells but not in healthy leukocytes, or white blood cells.
Reporting its work in the Journal of Cancer Research and Clinical Oncology, a research team headed by Joachim Clement, M.D., of the Friedrich Schiller University in Jena, Germany, found that altering the incubation buffer used to mix blood samples with untargeted magnetic nanoparticles had a startling effect on the ability of tumor cells and healthy blood cells to take up the nanoparticles. Increasing the ionic strength of the buffer solution had no effect on the nanoparticles’ uptake by tumor cells while virtually eliminating uptake by healthy leukocytes and greatly reducing uptake by other types of healthy blood cells. Once labeled in this manner, tumor cells could be separated easily from healthy cells using a commercial magnetic cell sorter.
The researchers note that further studies of the effect of changing the incubation buffer surface coating could improve discrimination of tumor cells from healthy cells. So, too, could studies aimed at understanding how the nanoparticles’ surface coating affects the nanoparticles’ interactions with the cell membrane.
This work is detailed in a paper titled, “Differential interaction of magnetic nanoparticles with tumor cells and peripheral blood cells.” Investigators from the Ernst-Moritz-Arndt University in Greifswald, Germany, and from two companies, MagneticFluids in Berlin, Germany, and INNOVENT, in Jena, Germany, also participated in this study. An abstract of this paper is available through PubMed.