One-step fabrication of multiphasic Janus microparticles with programmed degradation properties based on a microfluidic chip

This work aimed to develop a multiphasic Janus particle system for programmed drug delivery. A phase separation based one-step microfluidic preparation process was demonstrated to generate triple-phase Janus microparticles with different degradation properties in each phase. In this system, particles with a series of complicated structures were generated, and programmed degradation behaviors according to the structures were achieved. Partial degradation of the particles and cargo release triggered by change of ambient temperature or pH could be realized as well. Further, graphene nanosheets and silica nano -spheres were modified in the microparticles by using the principle of Pickering emulsion to enrich the functions of the particles. To reveal the potential of the particles in drug delivery applications, doxoru-bicin and curcumin were co-loaded in triple-phase microparticles, and zonal drug loading was achieved. In vitro drug release profiles and tumor cell apoptosis study indicated that the particles provided pro-grammed release behavior as well as enhanced tumor inhibition efficacy compared with free drug admin-istration and monophasic particles. This study proposed a facile and one-step fabrication method of multiphasic particles possessing programmed and triggered drug release kinetics, and may be the first attempt to generate triple-phase particles with phase separation method in a droplet microfluidic chip.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).