Using Heated Nanoscale Bioprobes to Kill Breast Cancer Cells

Many researchers have evaluated using heat in treating cancer, but "the inability to deposit effective doses of heat in a tumor without applying similar heat to nearby normal tissue has prevented widespread clinical use,” said Dr. Sally J. DeNardo, professor of internal medicine and radiology with the School of Medicine at the University of California-Davis (UC Davis; Sacramento, USA). "Our animal study, which combined the future-oriented sciences of nanotechnology and molecular imaging, shows that a method for delivering thermal ablation--removing or destroying cancer cells by using heat--is feasible,” added the co-director of the university's radiodiagnosis and therapy section. "This exciting study, combining radiolabeled antibodies with nanoparticles or bioprocess, provides a new approach to direct thermal ablation specifically to tumor cells,” she noted.

Dr. DeNardo stressed that this heat treatment is still in the preclinical, developmental stage, having been used only in laboratory mice; further studies will need to be performed with cancer patients. The study was published in the March 2007 Journal of Nuclear Medicine.

Scientists from UC Davis and Triton Biosystems, Inc. (Chelmsford, MA, USA) injected trillions of magnetic iron-containing bioprobes into the bloodstream of a laboratory mouse bearing a human cancer tumor. The magnetic iron nanoprobes--more than 10,000 of which can fit on the end of a straight pin--are hidden in polymers and sugars, making them virtually invisible to the body's immune system. Antibodies (joined with a radioactive substance) on these probes latched onto receptors that are on the surface of tumor cells. The heating of the probes can be activated and controlled by the use of a magnetic field from outside the body. By applying an alternating magnetic field to the tumor area, the magnetic spheres altered polarity thousands of times per second and created heat. This heat weakened and destroyed the cancer cells. Upon deactivation of the magnetic field, the bioprobes cooled and passed out of the body.

Dr. DeNardo, commented, "By using heat--along with nanoparticles and a radiolabeled antibody--our quantitative imaging directed, and made safer, the application and development of therapy for cancer. This technique could join other cancer therapies, especially for cancers that are hard to treat now, such as breast cancer and metastatic melanoma.”


Related Links:
University of California-Davis
Triton Biosystems