Hollow Microcapsules with Enhanced Stability via Stereocomplex Assemblies

This paper presents a microfluidic approach for fabricating stereocomplexed hollow microcapsules that uses water-in-oil-in-water double-emulsion droplets as templates. The poly-lactides functionalized with 2-ureido-4[1H]-pyrimidinone (UPy) end groups are intermolecularly stereocomplexed by polylactides with opposite configurations to promote their self-assembly at a water-chloroform interface. This intermolecular interaction can significantly enhance the stability of resulting hollow microcapsules so that they preserve their shape and size after drying. Moreover, because these stimuli-responsive polylactides can assemble and disassemble into superstructures, they can be made to release their cargo by varying the pH values. The interfacially assembled supramolecular microcapsules, which possess stimuli-responsiveness and longterm stability, are potentially useful for encapsulation and delivery of drugs.