A Novel Magneto-fluorescent Nano-bioprobe for Cancer Cell Targeting, Imaging and Collection.pdf

A Novel Magneto-fluorescent Nano-bioprobe for Cancer Cell Targeting, Imaging and Collection Yicheng Wu Maoquan Chu Bizhi Shi Zonghai Li Received: 1 June 2010 /Accepted: 7 September 2010 / Published online: 16 October 2010 # Springer Science+Business Media, LLC 2010 Abstract Silica-coated magnetic polystyrene nanospheres (MPN) containing CdTe/CdS quantum dots (QDs) and Fe3O4 nanoparticles were prepared, and novel anti-EGFR antibodies were conjugated onto these magneto-fluorescent nanocomposites (MPN–QDs– SiO2) for cancer cell targeting, imaging and collection. Transmission electron microscopy (TEM), scanning electron microscopy (SEM) images and energy-dispersive x-ray spectrometry (EDS) data showed that the MPN had been successfully coated with QDs and a silica shell, and the nanocomposites obtained with negative charged surfaces were well dispersed. The bioconjugates could be used for specifically labeling and separating cancer cells (MDA-MB-435S, SMMC-7721), but did not recognize and separate the K562 cells because the human epidermal growth factor receptor (EGFR) was not expressed on the surface. Because the anti-EGFR antibody, which we have developed, could specifically recognize certain cancer cells that highly expressed EGFR on their surface, these nanoscale bioconjugates, synchronously exhibiting fluorescence and magnetism, may be used in novel bioprobes for labeling and collecting rare cancer cells, which may be beneficial for early cancer diagnosis. Appl Biochem Biotechnol (2011) 163:813–825 DOI 10.1007/s12010-010-9085-y Y. Wu :M. Chu School of Life Science and Technology, Tongji University, Shanghai 200092, People’s Republic of China M. Chu (*) Institute for Advanced Materials and Nano Biomedicine, Tongji University, Shanghai 200092, People’s Republic of China e-mail: mqchu98@tongji.edu.cn B. Shi : Z. Li State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Shanghai, People’s Republic of China Z. Li (*) School of Medicine, Shang