Microfluidic Fabrication of Monodisperse Microcapsules for Thermo-Triggered Release of Liposoluble Drugs

Here, we report a novel thermo-triggered-releasing microcapsule for liposoluble drug delivery. Monodisperse microcapsules with a poly(N-isopropylacrylamide-co-methacrylic acid) hydrogel shell and an oil core were successfully fabricated by a double coaxial microfluidic device. Fluorescent dye Lumogen Red F300 as a model liposoluble drug was dissolved in the oil core with controllable loading capacity. The volume phase transition temperature (VPTT) of the microcapsule was adjusted by copolymerizing with the hydrophilic methacrylic acid. The in vitro release study demonstrates that the shells shrink, leading to the thermo-triggered release of the model drug from the microcapsules at the environmental temperature above the VPTT, while the swollen hydrogel shells can protect the encapsulated drug from leakage and contamination below the VPTT. The proposed microcapsule is a promising liposoluble drug delivery system with controllable loading and smart thermo-triggered release.