Advances in the Development of Immobilized Enzymes for Future Extracorporeal Liver Support

Abstract

For an extracorporeal enzymatic detoxification the following enzymes have been prepared for in vitro and in vivo application in the experimental animal: UDP-glucuronyltransferase, methyl-transferase, glutathione transferase, cytochrome-p-450, and NADPH-cytochrome-p-450 reductase. Three immobilization techniques have been developed which have promising qualities. Binding of enzymes to agarose beads by the cyanogen bromide technique produces acceptable enzyme activities and allows inclusion of cofactor loaded adsorbents. Copolymerization of enzymes with acrylamide results in good enzyme activities and also allows cofactor supply via included adsorbents. Inclusion of enzyme into liquid lipid membrane vesicles produces optimal enzyme activities, selectivity toward lipid soluble toxins, and allows inclusion of cofactors in optimal concentrations. Hemocompatibility of all three materials is excellent.