Medical applications of enzymes are found in various areas, such as diagnosis, prognosis, and therapy. They are used as soluble or immobilized forms in replacement and detoxification therapies, as scavengers and as antineoplasic drugs, and also for the prevention of clot formation (1 ). When immobilized enzyme systems are needed for in vivo or ex vivo applications, the use of a biocompatible and a nonthrombogenic immobilization support is an important requirement.