Therapeutic nanoparticles give new meaning to sugar-coating medicine
In cooperation with colleagues from 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 potent cancer-are murderers because they interact with each other so that small nanoparticles are not. The interaction of many bioengineers thinking is not desirable, actually help the larger particles are warmer than when subjected to an alternating magnetic field. Because heat destroys cancer cells, the team’s findings may help engineers design better particles and methods of treatment.
Nanoparticles have the promise to fight cancer without harmful side effects of chemotherapy or radiotherapy. Tiny balls of iron oxide can be coated with sugar molecules that makes them particularly attractive for resource hungry cancer cells. Once the particles are injected, the cancer cells then ingest, and doctors may then apply an alternating magnetic field which causes the iron oxide centers to heat and kill cancer, while leaving surrounding tissue unharmed.
Two biotechnology companies, and Adur Partikeltechnologie MicroMod BioTech created particles that showed great potential in the treatment of cancer in mice, and asked NIST to help understand why it worked so well. “But we sent the particles were much larger than what conventional wisdom says they should be,” says NIST materials scientist Cindi Dennis. “Larger particles are more strongly magnetic and tend to cluster, making them large enough to attract the body’s defense systems before they can reach a tumor. Nanoparticles companies, however, have this problem. ”
Neutron scattering probes the NIST Center for Neutron Research revealed that the cores of larger particles of iron oxide attract each other, but the sugar coating has fibers running out, so that resemble a dandelion, and these fibers are pushing each other when two particles get close together, making them spring apart and maintain an antibody that defy the distance instead of clumping. Moreover, when particles do not approach the iron oxide to turn all schools together under the influence of a magnetic field, both in generating more heat and this heat deposit locally. All these factors helped to nanoparticles destroy breast tumors in three out of four mice after treatment no regrowth.
“The tug of war is part of a tug of war that sets the distance between the nanoparticles,” says Dennis. “This suggests that it can stabilize the particles interact in ways that could pay at the clinic.”
More information: C.L. Dennis, A.J. Jackson, J.A. Borchers, P.J. Hoopes, R. Strawbridge, A.R. Foreman, J. van Lierop, C. Gruttner and R. Ivkov. Nearly complete regression of tumors via collective behavior of magnetic nanoparticles in hyperthermia. Nanotechnology, 20 (2009) 395103. doi:10.1088/0957-4484/20/39/395103
Source: National Institute of Standards and Technology (web)