Fabrication methods of biopolymeric microgels and microgel-based hydrogels

Biopolymeric microgels made of proteins and/or polysaccharides provide a renewable source for enteral nutrition, interface stabilization, controlled release applications and etc. These microgels consist of physically, chemically, or enzymatically cross-linked biopolymer molecules that trap and hold water within the particle network. They can be formed from single or mixed biopolymers using a variety of methods based on molecular association mechanisms and mechanical processes. Biopolymer type and microgelation method determine the main properties of resulting microgels. Certain challenges associated with the small dimensions of microgels can be addressed through the development of immobilized microgel matrices, in which individual microgel particles are entrapped inside a hydrogel or cross-linked to form a macroscopic network. Immobilized microgel matrices can provide unique properties and additional applications relative to bulk hydrogels or individual microgels alone. This article reviews manufacturing methods for producing biopolymeric microgels, and describes formation of microgel-based hydrogels via effective immobilization of microgels within a network.