Fluorophore Nanogold Particle-Based Optical Breast Cancer Locator

摘要

We report synthetic routes for modifying the fluorophore cypate, an indocyanine green (FDA approved) derivative, with custom thiol-terminated peptide and poly(ethylene glycol) (PEG) substrates. We selected the amino acid sequence of the peptide to serve as a recognition element for the enzyme urokinase plasminogen activator (uPA), a serine protease synthesized within cancer cells. In collaboration with Dr. Kang (partnering award W81XWH-08-1- 0460), the peptide and PEG conjugates are attached via the thiol functionality to nanogold particles for evaluation of their fluorescence properties. We also describe the synthesis of a novel cypate derivative that possesses two pendant aldehyde groups. This derivative will be useful for performing straightforward coupling reactions with aminooxy substrates via oximation (oxime ether formation). In this way, we aim to conduct the loading of cypate onto nanogold particles fitted with aminooxy-functionalized peptide or PEG fragments by simple mixing in water.