pH-Responsive Biocompatible Fluorescent Core-Shell Nanogel for Intracellular Imaging and Control Drug Release

This study reports a fluorescence iron core-carbonized biocompatible hybrid poly(ethylene glycol) (PEG)-oriented nanogel (Fe₂O₃@C@PEG-COOH nanogel). The fluorescence Fe₂O₃@C@PEG-COOH nanogel is prepared using a facile one-pot polycondensation reaction without organic solvents or catalysts. The properties of the fluorescenceFe₂O₃@C@PEG-COOH nanogel are investigated by fluorescence spectroscopy, transmission electron microscopy, X-ray diffraction, and thermogravimetric analysis. A change in pH as a stimulus can trigger the release of loaded doxorubicin (DOX). Under acidic conditions, the nanogel releases the highly loaded drug slowly compared to the neutral and basic conditions, which is important for cancer treatment. The synthesized fluorescenceFe₂O₃@C@PEG-COOH nanogel is well dispersed in water and shows fluorescence with high photostability, good biocompatibility with a paramagnetic nature. Furthermore, the nanogel can act as a potential fluorescent probe for cell imaging.