Microfluidic Formation of Monodispersed Spherical Microgels Composed of Triple-Network Crosslinking

A microfluidic emulsification method for producing monodispersed microgels from a triple interpenetrating network (3XN) hydrogel was reported. This 3XN system is comprised of minimally modified natural GRAS materials, partially oxidized dextran (Odex), Teleostean, and N-carboxyethyl chitosan (CEC), without the need of utilizing extraneous crosslinkers or photo-initiators, which has been proved to be a novel biodegradable and mechanically strong in-situ gelable hydrogel systems. A microfluidic chip was specifically designed to produce microgels from the 3XN hydrogel system. The study shows that microfluidic emulsification method could yield microgels with better size and morphology than the conventional in-emulsion-crosslinking method, and the size of microgels could be modulated by simply adjusting the flow rates of the oil and/or the individual precursor fluids. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 3093-3100, 2011