Microfluidic synthesis of chitosan-coated magnetic alginate microparticles for controlled and sustained drug delivery.

The present work aimed to assemble a simple, portable and economical L-junction microfluidic device to realize the adjustment and tunability of homogeneous round-shaped particles synthesis. In this study, we synthesize two kind of microparticles, including magnetic alginate microparticles (MAM) and chitosan-coated magnetic alginate (CMAM) used for controlling the drug release under a mild condition. Comparing to the traditional method, the MAM synthesized via this microfluidic approach has uniform size distribution, adjustable diameter as well as tunable magnetism. By exploring the amoxicillin as model drug, the MAM displays excellent pH-sensitive release, the effect of particle size on the drug release rate was investigated as well. The results show the smaller particles (220 μm) show a faster release rate than the bigger materials (1000 μm) due to their larger specific area, providing more frequency to interact with the reaction solution. The positive polyelectrolyte, chitosan, coated on the magnetic alginate surface endows CMAM time extension in drug release by two times, successfully achieving drug controlled and sustained release via the kinetics analysis. In summary, this microfluidic approach provides a convenient and efficient fluidic design for the well-controlled synthesis of micro-and nanoscale particles, which is a potential choice used for controlled and sustained drug release.