The PEG-fluorochrome shielding approach for targeted probe design.

J Am Chem Soc

Center for Translational Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, 149 13th Street, Charlestown, Massachusetts 02129, USA.

Published: November 2012

We provide a new approach for fluorescent probe design termed "PEG-fluorochrome shielding", where PEGylation enhances quantum yields while blocking troublesome interactions between fluorochromes and biomolecules. To demonstrate PEG-fluorochrome shielding, fluorochrome-bearing peptide probes were synthesized, three without PEG and three with a 5 kDa PEG functional group. In vitro, PEG blocked the interactions of fluorochrome-labeled peptide probes with each other (absorption spectra, self-quenching) and reduced nonspecific interactions with cells (by FACS). In vivo, PEG blocked interactions with biomolecules that lead to probe retention (by surface fluorescence). Integrin targeting in vivo was obtained as the differential uptake of an (111)In-labeled, fluorochrome-shielded, integrin-binding RGD probe and a control RAD. Using PEG to block fluorochrome-mediated interactions, rather than synthesizing de novo fluorochromes, can yield new approaches for the design of actively or passively targeted near-infrared fluorescent probes.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3518033PMC
http://dx.doi.org/10.1021/ja309085bDOI Listing

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The PEG-fluorochrome shielding approach for targeted probe design.

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Center for Translational Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, 149 13th Street, Charlestown, Massachusetts 02129, USA.

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