Polymersomes with singlet oxygen-labile poly(β-aminoacrylate) membrane for NIR light-controlled combined...

Engineering the membrane of the polymersomes with biologically relevant stimuli-responsive units enables spatial and temporal controlled drug release for effective therapy. Herein, we introduce a new-type of polymersomes featuring reactive oxygen species singlet oxygen (¹O₂)-labile membrane by employing a versatile stereoregular amphiphilic poly(ethylene glycol)-block-poly(β-aminoacrylate)-block-poly(ethylene glycol) copolymers, which are synthesized through a facile one pot modular amino-alkynoate click polymerization between secondary amines and activated alkynes. These polymersomes readily co-encapsulate an anticancer drug doxorubicin (DOX) and a near infrared (NIR) photosensitizer IR-780 with hydrophobic characteristics in the membrane, and the resulting polymersomes show efficient uptake by the tumor cells. NIR light irradiation on the tumors, following intraperitoneal injection of the IR-780/DOX co-encapsulated polymersomes, facilitates tumor-specific release of DOX through disassembly of the polymersome nanostructure via ¹O₂-mediated photocleavage of the membrane. Moreover, IR-780 dye can convert NIR light energy into heat in addition to the generation of ¹O_2, thus allows to realize both photothermal and photodynamic therapy. Accordingly, the NIR light-mediated on demand chemotherapy, in combination with appreciable phototherapy, of IR-780/DOX co-loaded polymersomes demonstrate an efficient tumor suppression in vivo.