A Tumor‐Acidity‐Activated Charge‐Conversional Nanogel as an Intelligent Vehicle for Promoted Tumoral‐Cell Uptake and Drug Delivery

A positive (or negative) chameleon: A nanogel that is negatively charged at physiological pH values and activated to be positively charged at tumor extracellular pH values was internalized efficiently by tumor cells both in vitro and in vivo (see illustration). Intracellular drug release was also enhanced, probably as a result of a decrease in the interaction between the drug and the nanogel in its protonated state.