Gated mesoporous carbon nanoparticles as drug delivery system for stimuli-responsive controlled release

Mesoporous carbon nanoparticles (MCNs) show low toxicity suitable for drug delivery carriers but are limited to strong hydrophobic property. Carboxylation and subsequent amination of MCNs were beneficial to drug delivery and release. Gated channel-interconnected MCN vehicles were constructed to realize stimuli-responsive controlled release of drugs. N-(3-Trimethoxysilylpropyl)ethylenediamine triacetate-functionalized ZnO quantum dots (QDs) as gatekeepers were covalently linked with carboxylated MCNs (ca. 115 nm in diameter and 3–3.5 nm in pore size) via dual amide linkages encapsulated drugs within the interconnected channels. The gating of the MCN vehicles not only improved the drug loading capacity but also introduced the stimuli-responsive performance. The controlled release of the drugs could be achieved by lowering pH (acidic microenvironment of tumor cells) to dissolve the ZnO QD gatekeepers and further promoted at elevated temperatures. The ZnO-gated MCN drug delivery system exhibits prospective applications for tumor therapy.