Tumor-specific nano-entities for optical detection and hyperthermic treatment of breast cancer.

The ultimate goal of this study is to develop a tumor-specific multi-functional, nano-entity that can be used for both cancer detection and treatment. Low heat (42 approximately 45 degrees C) hyperthermia is an effective cancer treatment method with little side effect. Magnetic nanoparticles, such as Fe3O4, can be heated by alternating electromagnetic (AEM) fields at well selected frequencies, without heating normal tissue. Nanogold particles (NGPs) are effective optical absorbers and also excellent fluorescent enhancers. Therefore, coating gold on Fe3O4 particles can enhance the optical contrast as well as keeping the particle property for hyperthermia. Indocyanine green (ICG), a FDA approved fluorophore, has a very low quantum yield, and its fluorescence can be enhanced by linking ICG to gold-coated Fe3O4 nanoparticles. Luteinizing hormone releasing hormone (LHRH), which has high affinity to breast cancer, can be used for tumor-specific targeting. Our study results showed: Fe3O4 particles at a size range of 10 approximately 30 nm can be heated well by an AEM field at a rate of 18 degrees C/wt%-minute; the fluorescence of ICG was extensively enhanced by NGPs; LHRH-coated gold nanoparticles provided as much cancer specificity as LHRH alone. Combining these properties in one entity, i.e., LHRH/ICG linked, gold-coated Fe3O4 nanoparticles, can be a tumor-specific nano-agent for optical detection and electro-magnetically induced hyperthermia for breast cancer.