Controlled Electrospray Generation of Non-Spherical Aqueous Microparticles

Abstract

Production of aqueous polymeric microparticles has attracted increasing interest because they benefit a variety of new biomedical applications such as cell encapsulation. Here we present a technique based on the application of electrospray to generate aqueous non-spherical microparticles using sodium alginate as emulsion phase and calcium chloride for continues phase. This approach allows the formation of calcium alginate microbeads with tunable sizes and shapes. We use a high voltage power supply to form the electric field, we apply a charge to the alginate solution that flows through a glass capillary with a tapered tip, and we ground a metallic ring that is positioned beneath the capillary tip. We investigate the effects of changing various parameters such as voltage, flow rate, capillary tip size, reagent concentration, and the distance from the capillary tip to the free interface of the calcium chloride bath, and discover parameter spaces that yield a variety of different shape and size particles. This technique of aqueous microparticles may have applications in drug delivery, enzyme immobilization, cell encapsulation and drug screening and further investigation of this technique can lead to a simple but high throughput method for generation of three-dimensional culture system in cancer studies.