THE CONJUGATION OF PROTEINS WITH POLYETHYLENE-GLYCOL AND OTHER POLYMERS - ALTERING PROPERTIES OF PROTEINS TO ENHANCE THEIR THERAPEUTIC POTENTIAL

The development of protein drugs for therapeutic purposes using recombinant DNA technology has generated a great deal of interest in methods of enhancing their delivery. One method of improving the delivery of proteins, and thereby increasing their therapeutic index, is covalent conjugation to polymers. This paper discusses polymers which are suitable for conjugation, methods of conjugation, the properties of polymer-protein conjugates and possibilities for designing drug delivery systems using these conjugates. The properties of protein-polymer conjugates include a dramatic increase in bioavailability, decreased immunogenicity, and enhanced solubility and stability. These altered properties improve the delivery and efficacy of proteins and impart a flexibility to their clinical usage.