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A Smart Nanoprobe Based On Fluorescence‐Quenching PEGylated Nanogels Containing Gold Nanoparticles for Monitoring the Response to Cancer Therapy
Author(s) -
Oishi Motoi,
Tamura Atsushi,
Nakamura Takahito,
Nagasaki Yukio
Publication year - 2009
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200801164
Subject(s) - nanoprobe , förster resonance energy transfer , materials science , fluorescein isothiocyanate , biophysics , fluorescence , colloidal gold , in vivo , microbiology and biotechnology , nanotechnology , nanoparticle , biology , physics , quantum mechanics
A biocompatible, caspase‐3‐responsive, and fluorescence‐quenching smart apoptosis nanoprobe based on a PEGylated nanogel that contains gold nanoparticles (GNPs) (fluorescence quenchers) in the cross‐linked polyamine gel core and fluorescein isothiocyanate (FITC)‐labeled DEVD peptides at the tethered PEG chain ends is prepared for monitoring the cancer response to therapy. FITC–DEVD–nanogel–GNP shows very little fluorescence in the absence of activated caspase‐3 (normal cells) through the fluorescence resonance energy transfer (FRET) process between the GNPs and the FITC molecules, while pronounced fluorescence signals are observed in apoptotic cells because of the cleavage of the DEVD peptide by activated caspase‐3 present in the cells, which results in the release of FITC molecules. Thus, remarkable quenching and dequenching of fluorescence signals in response to activated caspase‐3 is observed. Apoptotic cells are detected in human hepatocyte (HuH‐7) multicellular tumor spheroids (MCTSs), a commonly used three‐dimensional in vitro model mimicking the in vivo biology of tumors, as early as one day post‐treatment with staurosporine, an apoptosis‐inducing agent; while growth inhibition (i.e., change in size) of the HuH‐7 MCTSs is only observed after a delay of three days (i.e., on day 4). This demonstrates the effectiveness of the FITC–DEVD–nanogel–GNP probe as a smart nanoprobe for real‐time monitoring as well as a more rapid assessment of the early response to cancer therapy.