posted on 2005-09-07, 00:00authored byYong-Min Huh, Young-wook Jun, Ho-Taek Song, Sungjun Kim, Jin-sil Choi, Jae-Hyun Lee, Sarah Yoon, Kyung-Sup Kim, Jeon-Soo Shin, Jin-Suck Suh, Jinwoo Cheon
The unique properties of magnetic nanocrystals provide them with high potential as key probes
and vectors in the next generation of biomedical applications. Although superparamagnetic iron oxide
nanocrystals have been extensively studied as excellent magnetic resonance imaging (MRI) probes for
various cell trafficking, gene expression, and cancer diagnosis, further development of in vivo MRI
applications has been very limited. Here, we describe in vivo diagnosis of cancer, utilizing a well-defined
magnetic nanocrystal probe system with multiple capabilities, such as small size, strong magnetism, high
biocompatibility, and the possession of active functionality for desired receptors. Our magnetic nanocrystals
are conjugated to a cancer-targeting antibody, Herceptin, and subsequent utilization of these conjugates
as MRI probes has been successfully demonstrated for the monitoring of in vivo selective targeting events
of human cancer cells implanted in live mice. Further conjugation of these nanocrystal probes with fluorescent
dye-labeled antibodies enables both in vitro and ex vivo optical detection of cancer as well as in vivo MRI,
which are potentially applicable for an advanced multimodal detection system. Our study finds that high
performance in vivo MR diagnosis of cancer is achievable by utilizing improved and multifunctional material
properties of iron oxide nanocrystal probes.