Near-infrared fluorescent nanocapsules with reversible response to thermal/pH modulation for optical imaging.

ABSTRACT: Polymeric near-infrared (NIR) fluorescent nanocapsules were developed, of which the fluorescence exhibited reversible response to local thermal/pH modulation. Our strategy was to use polymeric micelles made of temperature-sensitive Pluronic F-127 to encapsulate an amphiphilic NIR fluorescent dye-indocyanine green (ICG)-within the core and then cross-link the micelle corona by pH-sensitive poly(ethylenimine) (PEI). The size swelling/shrinking property of the micelles induced by temperature decrease/increase was used as a switch to control the fluorescence yield of the nanocapsules. It was found that the fluorescence yield significantly increased with the increase in temperature. The PEI cross-link made the fluorescence yield also sensitive to local pH change and enhanced intracellular deliv

SUBMITTER: Chen Y 

PROVIDER: S-EPMC5972015 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature