A research team at the National Institute of Standards and Technology (NIST) studying sugar-coated nanoparticles for use as a possible cancer therapy has uncovered a delicate balancing act that makes the particles more effective than conventional thinking says they should be. Just like individuals in a crowd respecting other people's personal space, the particles work because they get close together, but not too close.
In cooperation with colleagues at The Johns Hopkins University, Dartmouth College, the University of Manitoba and two biopharmaceutical companies, the NIST team has demonstrated that the particles-essentially sugar-coated bits of iron oxide, about 100 nanometers wide-are potent cancer killers because they interact with one another in ways that smaller nanoparticles do not. The interactions, thought by many bioengineers to be undesirable, actually help the larger particles heat up better when subjected to an alternating magnetic field. Because this heat destroys cancer cells, the team's findings may help engineers design better particles and treatment methods.
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.