Abstract
Intelligent polymeric micelles with fluorescence imaging feature have been emerged as promising tools for theranostics. However, conventional fluorescent dyes are limited by short wavelength excitation, interference of tissue autofluorescence, limited imaging depth and quenched emission in aggregation state. Methods: We synthesized a novel mPEG-SS-Poly (AEMA-co-TBIS) (mPEATss) copolymer to develop multifunctional polymeric micelles with great AIE feature for cancer therapy and AIE active two-photon bioimaging. The stimuli-responsive behavior and AIE active two-photon cell and tissue imaging as well as in vitro and in vivo antitumor ability of DOX-loaded mPEATss were studied. Results: mPEATss micelles showed excellent AIE active two-photon cell imaging ability and deep tissue imaging ability. Antitumor drug DOX could be encapsulated to form a drug-loaded micellar system with a small diameter of 65 nm. The disassembly and charge-conversion of mPEATss micelles could be triggered by acidic environment, resulting in accelerated drug release and great antitumor efficacy. In vivo, ex vivo imaging and in vivo pharmacokinetic study demonstrated that mPEATss micelles could efficiently accumulate in tumor sites, which ensured ideal anticancer effect. Conclusions: This pH and redox dual responsive and AIE active two-photon imaging polymeric micelles would be a promising candidate for theranostics.