A pH-responsive amphiphilic chitosan-pyranine core-shell nanoparticle for controlled drug delivery, imaging and intracellular pH measurement.

A pH-responsive multifunctional core-shell nanoparticle, named CHC-PY nanoparticle, was successfully synthesized through electrostatic interaction of a thin shell of fluorescent pyranine dye (PY) with amphiphilic carboxymethylhexanoyl chitosan (CHC) nanoparticles. Upon encapsulating an anticancer drug, camptothecin (CPT), the CHC-PY nanoparticles exhibited an excellent drug loading efficiency (>95%). The resulting CPT-loaded CHC-PY nanoparticles also exhibited efficient cell internalization and good pH-responsive behavior.