Alginate hydrogel microcapsules produced by coaxial electrohydrodynamic method

Abstract

Microencapsulation of biological cells has a broad range of applications in pharmacy and biomedicine. This paper introduces generation of core-shell microcapsules based on a coaxial electrohydrodynamic method. For the core and shell materials, RPMI-1640 culture medium and alginate are used respectively. The generated micro-droplets become hydrogel capsules with RPMI-1640 trapped, by reacting with CaCl2 solution in the collector electrode. It is found that ejection frequency can be increased by either increasing the outer flow rate or field strength. However, sufficiently high outer flow rate or sufficiently strong electric field will change the shape of the core of the microcapsule. Fluorescence stained human peripheral blood mononuclear cells (PBMC) are added to RPMI-1640 medium. Fluorescence imaging showed that the cells are effectively encapsulated.