Responsive Contrast Agents: Synthesis and Characterization of a Tunable Series of pH-Sensitive Near-Infrared Pentamethines.

ABSTRACT: The demand for responsive dyes in optical imaging is high to achieve a better signal-to-noise ratio and, more specifically, to visualize acidic compartments of the endocytic pathway. Herein, we present a new synthetic route, with a step-by-step synthesis of water-soluble pH-sensitive cyanine dyes exhibiting pK_a values in the region of physiological pH, as confirmed by absorption and fluorescence spectra. Moreover, modification of pK_a values was achieved by two different substitution patterns, creating tunable pH-sensitive dyes. We demonstrated the functionality of the pH-sensitive dyes and their suitability as contrast agents for cellular uptake studies by preparing dye-labeled cetuximab and transferrin conjugates. Sulfonated head chains increased water

SUBMITTER: Wycisk V 

PROVIDER: S-EPMC6044694 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature