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BioMed Research International
Volume 2014, Article ID 954307, 9 pages
http://dx.doi.org/10.1155/2014/954307
Research Article

Specific Intracellular Uptake of Herceptin-Conjugated CdSe/ZnS Quantum Dots into Breast Cancer Cells

1School of Applied Chemical Engineering, Kyungpook National University, Daegu 702-701, Republic of Korea
2School of Advanced Materials Engineering, Kyungpook National University, Daegu 702-701, Republic of Korea
3Department of Chemistry, Missouri University of Science and Technology, Missouri, MO 65409, USA

Received 14 November 2013; Accepted 14 December 2013; Published 9 January 2014

Academic Editor: Oh Hyeong Kwon

Copyright © 2014 Seung-Jin Han et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Herceptin, a typical monoclonal antibody, was immobilized on the surface of CdSe/ZnS core-shell quantum dots (QDs) to enhance their specific interactions with breast cancer cells (SK-BR3). The mean size of the core-shell quantum dots (28 nm), as determined by dynamic light scattering, increased to 86 nm after herceptin immobilization. The in vitro cell culture experiment showed that the keratin forming cancer cells (KB) proliferated well in the presence of herceptin-conjugated QDs (QD-Her, 5 nmol/mL), whereas most of the breast cancer cells (SK-BR3) had died. To clarify the mechanism of cell death, the interaction of SK-BR3 cells with QD-Her was examined by confocal laser scanning microscopy. As a result, the QD-Her bound specifically to the membrane of SK-BR3, which became almost saturated after 6 hours incubation. This suggests that the growth signal of breast cancer cells is inhibited completely by the specific binding of herceptin to the Her-2 receptor of SK-BR3 membrane, resulting in cell death.