Fluorescent turn-on carbon dot-cored pseudo unimolecular prodrug micelles for tumor-specific dual-triggered drug delivery

Abstract

Polymer prodrugs have attracted intense attention in tumor chemotherapy in the form of nanoparticles, nanogels or micelles. However, it is still a challenge to control their particle size and stability. Here, carbon dot-cored star-like copolymer hybrid prodrug (CD-PMHyDOX-ssPEG) has been designed for the tumor-specific fluorescent turn-on and pH/reduction dual-triggered drug delivery. The fluorescence of CDs was almost completely quenched after the surface modification and drug conjugation via both static and dynamic quenching effects. It could easily self-assemble into pseudo unimolecular prodrug micelles in aqueous system with CDs as fluorescent off-on core, acid-labile polymer prodrug block as shell and reduction-triggered detached PEG block as corona, possessing excellent tumor-specific pH and reduction dual-triggered drug release performance. Furthermore, the fluorescence of CDs could be partially recovered after the drug release because of the relief of the dynamic quenching during the drug release.