Heparin derivatized and immobilized

Free amine groups on porcine intestinal heparin (Sigma) were first blocked with acetic anhydride to form IV-acetylated heparin (13). This blocking reaction was performed to insure against intermolecular or intramolecular cross-linking during heparin carboxylic activation reactions. The N -acetylated heparin was then dialyzed extensively and freeze-dried. This heparin preparation was used in all further derivatization and immobilization reactions. 

To elucidate heparin anticoagulant effects caused by covalent coupling via specific functional groups, those heparin groups involved in immobilization reactions are first derivatized, and the effect of derivatization on anticoagulant activity is determined. 

This chapter focuses on the effects of anticoagulant activity caused by specific functional group derivatization of heparin, and on preliminary immobilization spacer group evaluations. The functional groups selected for immobilization are hydroxyl and carboxylic heparin groups. 

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