A Novel, Laser-Based Technique to Fabricate and Precisely Pattern Cell-Encapsulated Alginate Microbeads

Microbeads are three-dimensional, generally spherical microstructures that are currently being investigated for applications in tissue engineering and for delivery of drugs, proteins, and DNA [1, 2]. Current microbead fabrication devices such as electrostatic bead generators, microfluidic devices, and micro-vibrators, function by using cross-linkable polymers into a crosslinking solution, such as calcium chloride in the case of alginate. These procedures allow for the controlled manipulation of microbead size, e.g., increasing electric field voltage for the electrostatic bead generator during polymer extrusion. Popular devices such as electrostatic bead generators are limited to polyelectrolyte materials because of the electric field extrusion method [3]. In addition, despite their ability to create monodispersed beads of different size, none of these technologies can precisely control microbead placement.