Entrapment of Biocatalysts with Photo-Cross-Linkable Resin Prepolymers and Urethane Resin Prepolymers

At present, most of the prepolymers, except for a few kinds of photo-cross-linkable resin prepolymers, are not commercially available. However, the prepolymer methods, which enable gel properties to be easily selected, seem very useful for the bioreactions of a variety of purposes. Prepolymer methods, using synthetic resin prepolymers as gelforming starting materials, have features useful for various purposes. Specific features and advantages of the prepolymer methods are (1) entrapment procedures are very simple under very mild conditions, (2) prepolymers do not contain monomers that may have bad effects on the biocatalysts to be entrapped, (3) the network structure of gels can be controlled by using the prepolymers of optional chain length, and (4) optional physicochemical properties of gels, such as hydrophilicity–hydrophobicity balance and ionic nature, can be changed by selecting suitable prepolymers. The prepolymers utilized were too few in number to cover all the types of bioreactions. New types of prepolymers, which are easy to handle and whose properties can be easily controlled, should be developed for more extensive applications of prepolymer methods to bioindustries.