C201 抗HER2抗体標識量子ドットを用いたマウス腫瘍内での単粒子イメージング

Abstract

Quantum dot (Qdot) is nanometer-sized crystals which improved brightness, resistance against photobleaching compared with organic dyes and fluorescent proteins. Therefore, Qdot is thought to become new adjuncts of fluorescent bioprobes for medical applications, especially for cancer imaging 1, 2. We have used Qdot conjugated with, monoclonal anti-HER2 (human epithelial growth factor type 2 ) antibody (Trastuzumab) for molecular imaging of breast cancer cells. We utilized poly ethylene glycol (PEG) coated Qdot-Trastuzumab complex to label a cell membrane of the HER2 overexpressing breast cancer cells. Using this complex, we established the in vivo fluorescent cancer imaging method. After injection of the Qdot-Trastuzumab complex to the human breast cancer xenograft mouse model, the accumulation of Qdot to the tumor tissue was clearly observed at subcellular resolution with the original 3D intravital microscopic system. Furthermore, We report the tracking of single particles of quantum dots conjugated with trastuzumab in living mice. This suggests that we can eventually develop a novel cancer imaging and drug tracking system.