Three core-shell polymersomes for targeted doxorubicin delivery: Sustained and acidic release

The novel core-shell polymersomes with sustained and pH-responsive drug delivery properties is developed in this work. Doxorubicin hydrochloride (DOX) loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles were prepared as a core, and then modified with polymer shells through electrostatic assembly. Three polymers, amino-terminated poly (ethylene glycol)-folate (NH2-PEG-FA), poly (allylamine hydrochloride) (PAH) and quaternary chitosan (QCS) were selected for constructing the shell layer. The successful modifications of polymer shell on the spherical DOX@PLGA core were characterized by SEM, TEM, particle size and zeta-potential. It was verified that DOX was well dispersed in core of polymersomes. In vitro drug release studies showed that DOX@PLGA core performed well in acidic pH triggered drug release. The core-shell polymersomes, especially for DOX@PLGA@PEG-FA, can be used to form pH-sensitive systems for smart and sustained drug release. FA, as the targeting agent, was exposed onto the polymersomes surface, possible for interacting with folate receptors on many cancer cells membranes. Fitted experimental data with various kinetic models, the drug release mainly follows the Fickian diffusion mechanism in the polymer system, and the erosion mechanism only existed at acidic pH. All the presented results make the proposed polymersomes a promising system for controlled and selected drug delivery. [Display omitted]