Smart microcapsule membranes for stimuli-responsive controlled- release

The target of a controlled drug delivery system is for an improved drug treatment (outcome) through rate-/time-programmed and/or site-specific drug delivery. Environmental stimuli-responsive controlled-release systems have been developed specifically for this purpose. These environmental stimuli-responsive release systems can release specified chemicals or drugs at a particular site where an environmental condition, such as temperature, pH or other information, is different from that at other sites. In developing environmental stimuli-responsive controlled-release systems, one of the important parameters is to reduce the response time of the release rate to stimuli. As the release rate from microcapsules is generally controlled by the thin microcapsule membrane, an increase in the release rate in response to stimuli may be expected when compared to gels and microspheres. Therefore, microcapsules with a thin membrane are suitable for stimuli-responsive controlled-release systems. Recently, the authors’ group has developed efficient approaches to fabricate monodisperse microcapsules with stimuli-responsive membranes. For different application purposes, smart microcapsules with thermo-responsive, pH-responsive, ion-recognizable membranes are designed and successfully fabricated with either oil-in-water-in-oil double emulsions or water-in-oil-in-water-in-oil triple emulsions that generated via microfluidic approached as synthesis templates. In this presentation, the design, fabrication and performance of monodisperse smart microcapsules with stimuliresponsive membranes will be introduced and discussed.