Alginate hydrogel microspheres and microcapsules prepared by spinning disk atomization.

Our spinning disk atomization (SDA) can, relative to other existing techniques, produce micron-sized particles with very narrow size distribution. The aim of this work is to present this technology for the production of alginate microspheres and microcapsules. We atomized and gelled aqueous alginate solutions into very narrowly dispersed microspheres with sizes ranging from 300 to 600 microm. Here, the interest is to produce, at high rate, particles of a given size with a narrow size distribution and also to show a new method of encapsulation using SDA. The viscosity and flow rate contributions in the drop formation is qualitatively analyzed to show how they affect droplet size. In addition, a technique for high degree of encapsulation is presented in which yeast is used as a model system. The production of yeast-loaded microspheres by SDA shows the potential of the technique for biotechnology applications. Copyright 2000 John Wiley & Sons, Inc.