CHEMICAL MODIFICATION OF POLYMERS WITH PHYSIOLOGICALLY ACTIVE SPECIESUSING WATER-SOLUBLE CARBODIIMIDES

The covalent immobilization of some proteins (ovomucoid from duck egg white, human serum albumin, aldolase and thiroglobulin) on the surface of polyethylene grafted with polyacrylic acid has been studied. Water -soluble carbodiimide was (1-ethyl-3-(3-dimethylaminoprophyl carbodiim ide) used as a condensing agent. It was shown that three different rea ctions can occur in the reaction mixture during immobilization: the re action between carboxy groups of graft copolymer and amino groups of p rotein (the immobilization reaction itself) and reactions between carb oxy and amino groups of protein molecules (reactions of intra- and int ermolecular cross-linking). The reaction of intramolecular cross-linki ng leads to a decrease in the physiological activity of the immobilize d substance, while other reactions do not affect it. The preliminary a ctivation of this surface by carbodiimide before the modification allo ws to maintain the activity after immobilization on the insoluble surf aces. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.