Designable Polymeric Microparticles from Droplet Microfluidics for Controlled Drug Release

Drug delivery systems that can control drug release profile to ensure a high therapeutic efficacy and reduced side effects are highly desired in pharmaceutical and biomedical fields. Microparticles are the most commonly used drug delivery systems, because they can be easily administrated to patients, and be engineered with different structures and functions for keeping drug stability, delivering drugs to a desired location, and releasing drugs with a predetermined rate in a well-controlled manner. Microfluidic techniques show great power for controllable generation of highly monodisperse multiple emulsion droplets with unprecedented structural diversity. Microfluidics-templated emulsions allow elaborately design and controllable generation of highly uniform microparticles with well-controlled sizes, shapes, compositions, and structures, and integrated functions for controlled drug release. This review highlights recent progress on controllable microfluidic fabrication of monodisperse emulsion templates and the resultant polymeric microparticles with well-tailored structures and functions for flexible encapsulation and controlled release of drugs. Especially, a comprehensive overview of the recent biomedical applications of these microparticles with diverse release mechanisms is provided. Finally, perspectives on further advancing the microfluidic techniques for fabricating functional microparticles from lab scale to industrial scale are discussed.