Quantum Dots As Fluorescent Bio-labels In Cancer Diagnostic

In this work we present and discuss some results concerning the application of colloidal semiconductor quantum dots for cancer diagnostic. We have prepared and applied different core-shell semiconductor quantum dots such as Cadmium Teluride-Cadmium Sulfide (CdTe-CdS) and Cadmium Sulfide - Cadmium Hydroxide (CdS/Cd(OH)2). For the purpose of diagnostic with living cells, the CdS/Cd(OH)2 presented best results, maintaining high levels of luminescence as well high stability in biological media. The quantum dots were obtained in aqueous medium, by reacting Cd2+ and S2- in the presence of sodium polyphosphate as the stabilizing agent. Subsequent surface passivation with Cd(OH)2 was carried out to improve luminescence. At a pH of 7.2 the quantum dots were functionalized with a 0.01% glutaraldehyde solution and then, incubated with living healthy and neoplastic cells (glial, glioblastoms and cervical) and tissues (breast) in culture medium. Tissue and cell staining were evaluated by the laser scanning confocal microscopy. Fluorescence Microscopy was used as a primary tool in order to explore the labeling of the samples. The procedure presented in this work, shown to be very efficient as a potential tool for fast and precise cancer diagnostic. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.31140014008Borchert, H., Talapin, D.V., McGinley, C., (2003) J. Chem. Phys, 271, pp. 1800-1807Alivisatos, A.P., (1996) Science, 271, pp. 933-937Nowak, C., Döllefeld, H., Eychmüller, A., (2001) J. Chem. Phys, 114, pp. 489-494Eychmüller, A., (1996) J. Phys. Chem. B, 59, pp. 13226-13239Bruchez Jr., M.P., Moronne, M., Gin, P., Weiss, S., Alivisatos, A.P., (1998) Science, 281, pp. 2013-2016Chan, W.C.W., Nie, S., (1998) Science, 281, pp. 2016-2018Ballou, B., Lagerholm, B.C., Ernst, L.A., Bruchez, M.P., Waggoner, A.S., (2004) Bioconjug. Chem, 15, pp. 79-86Gao, X., Nie, S., (2003) Trends Biotech, 21 (9), pp. 371-373Äkerman, M.E., Chan, W.C.W., Laakkonen, P., Bhatia, S.N., Ruoslahti, E., (2002) Appl. Biol. Sci, 99 (20), pp. 12617-12621W. C. W. Chan, D. J. Maxwell, X. Gao, R. E. Bailey, M. Han, and S. Nie, Curr. Op. Bioteh. 13(1), 40-46 (2002)Mattheakis, L.C., Dias, J.M., Choi, Y., Gong, J., Bruchez, M.P., Liu, J., Wang, E., (2004) Anal Biochem, 327, pp. 200-208Petrov, D.V., Santos, B.S., Pereira, G.A.L., Donegá, C.M., (2002) J. Phys. Chem. B, 106 (21), pp. 5325-5334Farias, P.M.A., Santos, B.S., Menezes, F.D., Ferreira, R.C., Barjas-Castro, M.L., Castro, V., Lima, P.R.M., Cesar, C.L., (2005) J. Microscopy, 219 (3), pp. 103-108Farias, P.M.A., Santos, B.S., Menezes, F.D., Ferreira, R.C., Barjas-Castro, M.L., Castro, V., Lima, P.R.M., Cesar, C.L., (2005) J. Biom. Opt, 10 (4), pp. 44023-4402