Centrifugal microfluidics for ultra-rapid fabrication of versatile hydrogel microcarriers

Alginate hydrogel beads/fibers and core-shell structured capsules/fibers as microcarriers for cells or therapeutic agents have been widely used in 3D cell culture, tissue engineering, and regenerative medicine. However, the fabrication of such microcarriers, especially core-shell structured capsules/fibers mainly relies on conventional microfluidics and electrostatic spraying. This process is complicated, labor-intensive and less efficient. Here, a novel and efficient centrifugal microfluidic system is presented for controllable fabrication of simple structured alginate hydrogel beads/fiber and core-shell structured capsules/fibers. Stable and repeatable fabrication of multiple hydrogel microcarriers is accomplished by assembling and refitting standardized metal nozzles to overcome poor repeatability caused by the use of hand-made capillaries. The fabrication process can be precisely controlled to produce beads/capsules/fibers with different diameters by changing the nozzle configuration, solution properties, and centrifugal conditions. The synergy of each factors affecting the construction of microcarriers using the centrifugal method are investigated, and the potential use of these microcarriers is also explored for 3D cell culture. The high efficiency and simplicity of this novel centrifugal microfluidics may facilitate advances in cell-delivery based therapy, tissue engineering, and other biomedical fields. (C) 2018 Elsevier Ltd. All rights reserved.