A novel technique is described to functionalize gold nanorods (GNRs) allowing for in vivo targeting of breast cancer tumors grown in athymic nude mice. GNRs were functionalized by covalent attachment of Herceptin (HER), a monoclonal antibody that enables molecular recognition of breast cancer cells expressing highly specific tumor associated antigens, and poly(ethylene glycol) (PEG) which obscures particles against the reticuloendothelial system in the body. The stability and functionality of fabricated particles (Her-PEG GNRs) were demonstrated in vitro in the presence of blood and then in vivo in nude mice model for breast cancer. The results demonstrate successful tumor accumulation of functionalized gold nanorods within HER2/neu overexpressing breast tumors in tumor-bearing nude mice and support the notions that GNRs can be used for molecular imaging of tumor.
