pH-Dependent disruption of giant polymer vesicles: a step towards biomimetic membranes

Giant unilamellar polymer vesicles (GUPVs) capable of selectively delivering protected payloads into intracellular environments and releasing them in stimuli-triggered, precise spatially and temporally controlled manners are attractive bioactive cargo delivery tools. Herein, we present highly size-defined and monodisperse (42.1 +/- 1.2, 60.5 +/- 1.0, 80.4 +/- 1.4 and 97.9 +/- 1.2 mu m in diameter, respectively) pH-responsive giant GUPVs prepared via microfluidic droplet generation using a flow-focusing poly(dimethylsiloxane) (PDMS)-based microfluidic device. Poly(ethylene oxide)-block-poly[2-(diisopropylamino)ethyl methacrylate] (PEO-b-PDPA) is a pH-responsive polymer that was synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization and used in combination with poly(ethylene oxide)-block-poly(1,2-butadiene) (PEO-b-PBD) to produce homogeneous pH-responsive giant GUPVs. To demonstrate the spatiotemporal control provided by this approach, we studied in detail the pH-responsiveness of GUPVs according to the disruption and release of dye cargo under distinct acidic conditions using fluorescence confocal microscopy. This approach can be utilized to fabricate pH-responsive delivery systems for various active compounds, microreactors, and artificial organelles, thereby paving the way towards cell mimicry.