Nanoscale magnetic discs actually physically wreck cancer cells. Nanotech is offering a lot of medical treatments, particularly in cancer research.
From the link:
Laboratory tests found the so-called “nanodiscs”, around 60 billionths of a metre thick, could be used to disrupt the membranes of cancer cells, causing them to self-destruct.
The discs are made from an iron-nickel alloy, which move when subjected to a magnetic field, damaging the cancer cells, the report published in Nature Materials said.
One of the study’s authors, Elena Rozhlova of Argonne National Laboratory in the United States, said subjecting the discs to a low magnetic field for around ten minutes was enough to destroy 90 percent of cancer cells in tests.