Anticoagulant hydrogels derived from crosslinked dextran. Part I: Synthesis, characterization and antithrombic activity.

Hydrogels have been prepared by binding various amino acids to Sephadex derivatives bearing carboxymethyl and sulphonated benzylamide groups. Depending on the chemical nature and content of the amino acid substituent, these insoluble strongly hydrophilic materials may absorb 7 to 19 volumes of buffer per volume of dry material. These hydrogels present antithrombic activity in relation to their swelling ratio. The adsorption of thrombin might partially explain the anticoagulant effect as shown by the evaluated affinity constants between the hydrogels and the enzyme i.e. 1 to 2 X 10(6) I/M.