A Tumor‐Specific Cascade Amplification Drug Release Nanoparticle for Overcoming Multidrug Resistance in Cancers

A cascade amplification release nanoparticle (CARN) is constructed by the coencapsulation of β-lapachone and a reactive-oxygen-species (ROS)-responsive doxorubicin (DOX) prodrug, BDOX, in polymeric nanoparticles. Releasing β-lapachone first from the CARNs selectively increases the ROS level in cancer cells via NAD(P)H:quinone oxidoreductase-1 (NQO1) catalysis, which induces the cascade amplification release of DOX and overcomes multidrug resistance (MDR) in cancer cells, producing a remarkably improved therapeutic efficacy against MDR tumors with minimal side effects.