Synthesis, self-assembly and pH sensitivity of PDEAEMA–PEG–PDEAEMA triblock copolymer micelles for drug delivery

In this study, well-defined double-hydrophilic triblock copolymers, consisting of hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(N,N-diethylamino-2-ethylmethacrylate) (PDEAEMA), were synthesized and characterized. The molecular weights of the copolymers were controllable. In the basic environments, the copolymers can self-assemble into the PDEAEMA core and PEG corona micelles in aqueous solution with an average size of 40–180 nm. The low critical micelle concentration (CMC, about 10− 3 mg mL− 1) of copolymers investigated in pH 7.4 aqueous solution confirmed the adequate thermodynamic stability of their self-assembly. As shown in the cytotoxicity assay, the copolymers have good biocompatibility. Doxorubicin (DOX) was encapsulated into the triblock copolymer micelles. The drug loading efficiency and entrapment efficiency values of DOX-loaded micelles reached 8.14% and 88.6%, respectively. The DOX release of the drug-loaded micelles depends on the pH values. These phenomena indicated that the double-hydrophilic PDEAEMA–PEG–PDEAEMA triblock copolymers have a potential application in the drug delivery.