A research team at the National Institute of Standards and Technology, in cooperation with researchers at The Johns Hopkins University, Dartmouth College, the University of Manitoba and two biopharmaceutical companies have discovered that sugar-coated bits of iron oxide under certain circumstances can be deadly to tumors. The 100 nanometer wide sugar-coated iron oxide nanoparticles are attracted to tumor cells, where they can be heated magnetically, thus causing damage to the cells.
Nanoparticles hold the promise of battling cancer without the damaging side effects of chemotherapy or radiation treatment. Minuscule balls of iron oxide can be coated with sugar molecules making them particularly attractive to resource-hungry cancer cells. Once the particles are injected, cancer cells would then ingest them, and doctors would then be able to apply an alternating magnetic field that causes the iron oxide centers to heat, killing the cancer but leaving surrounding tissue unharmed.
Neutron scattering probes at the NIST Center for Neutron Research revealed that the particlesâ€™ larger iron oxide cores attract one another, but that the sugar coating has fibers extending out, making it resemble a dandelionâ€”and these fibers push against one another when two particles get too close together, making them spring apart and maintain an antibody-defying distance rather than clumping. Moreover, when the particles do get close, the iron oxide centers all rotate together under the influence of a magnetic field, both generating more heat and depositing this heat locally. All these factors helped the nanoparticles destroy breast tumors in three out of four mice after one treatment with no regrowth.
â€œThe push-pull is part of a tug of war that fixes the distance between nanoparticles,â€ Dennis says. â€œThis suggests we can stabilize interacting particles in ways that potentially pay off in the clinic.â€
Now thatâ€™s wicked cool.