Title: Molecular imaging with targeted quantum dot bioconjugates: the need for contrast optimisation studies

Authors: Mathieu Roy, Brian C. Wilson

Addresses: Department of Medical Biophysics, Ontario Cancer Institute, University of Toronto, 610 University Ave., Toronto, ON, M5G2M9, Canada. ' Department of Medical Biophysics, Ontario Cancer Institute, University of Toronto, 610 University Ave., Toronto, ON, M5G 2M9, Canada

Abstract: Quantum dots have the potential to be used as contrast agents for molecular imaging in vivo, but there are many challenges in optimising such procedures, both in pre-clinical animal models and in the potential clinical applications. In particular, it is critical to obtain the optimal target-to-background contrast to achieve maximum diagnostic accuracy. However, available data are insufficient to determine the optimal parameters for this objective. Here, we explore the factors that affect imaging contrast with quantum dots, including time, dosage, emission and excitation wavelengths, and instrumentation. This includes a brief review of the published work. In addition, we present initial studies with tissue-simulating phantoms that allow the optimum excitation wavelength to be determined for visible-emitting quantum dots used to image surface or near-surface lesions, as found in endoscopic diagnosis of early cancer. We also suggest needed areas for future research for optimisation of quantum dot-based bio-imaging applications.

Keywords: quantum dots; fluorescence imaging; medical imaging; contrast optimisation; contrast agent; tissue phantoms; molecular imaging; autofluorescence; signal-to-background; excitation spectra; emission spectra; molecular imaging; bioconjugates; nanotechnology; endoscopic diagnosis; early cancer; surface lesions.

DOI: 10.1504/IJNT.2009.024639

International Journal of Nanotechnology, 2009 Vol.6 No.5/6, pp.442 - 455

Published online: 13 Apr 2009 *

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