Entrapment of enzymes into cellulose–biopolymer composite hydrogel beads using biocompatible ionic liquid

For the first time, lipase from Candida rugosa was successfully entrapped into various cellulose–biopolymer composite hydrogels by using a biocompatible ionic liquid, 1-ethyl-3-methylimidazolium acetate ([Emim][Ac]). Lipase-entrapped cellulose and cellulose–biopolymer composite hydrogel beads were simply prepared by co-dissolution of biopolymers in [Emim][Ac] and dispersion of lipase in biopolymer solution followed by formation of biopolymer hydrogel using distilled water. Immobilization yields (specific activity ratio of entrapped lipase to free lipase) of cellulose, cellulose–carrageenan, cellulose–chitosan, cellulose–agarose, and cellulose–agar bead were 35.0, 9.6, 39.7, 41.4, and 52.6%, respectively. Cellulose–biopolymer composite hydrogels proved to be good supports for entrapment of enzymes and have many potential applications, including drug delivery, biosensors, biofuel cells, and tissue engineering due to their inherent excellent biocompatibility and biodegradability.