Immobilized enzymes and cells in poly(N-vinyl caprolactam)-based hydrogels: Preparation, properties, and applications in biotechnology and medicine
A one-step mild method for entrapping animal cells and enzymes in macroporous composite poly(N-vinyl caprolactam)-calcium alginate (PVCL-CaAlg) hydrogels is described. Some properties of immobilized enzymes, such as thermal and storage stabilities and stability in water/ organic media were investigated. Composite PVCL-CaAlg gels were successfully applied to immobilize a number of proteases, namely, trypsin, α-chymotrypsin, carboxypeptidase B, and thrombin. Thermal stability of the immobilized preparations obtained by entrapment in hydrogel beads allowed us to use them at 65-80°C, while the native enzymes were completely inactivated at 50-55°C. Various applications of enzymes and cells immobilized in beads were demonstrated. Immobilized trypsin and carboxypeptidase B were applied to prepare human insulin from recombinant proinsulin. The hydrogel beads with entrapped α-chymotrypsin were used in enantioselective hydrolysis of Shiff's base of D,L-phenylalanine ethyl ester (SBPH) in acetonitrile/water medium. Thrombin immobilized in PVCL-based hydrogel films was shown to be a promising compound for wound treatment. To prepare pure preparations of monoclonal antibodies (MAb) several hybridoma cell lines, including hybridoma cell lines producing MAb to interleukin-2, were successfully cultivated in the hydrogel beads.