PEGYLATION: CONCEPT AND APPLICATIONS IN CANCER THERAPEUTICS

Polyethylene glycol-ylation (PEGylation) is a phenomenon of modification of a protein, peptide, or non-peptide molecule by linking of one or more polyethylene glycol chains. These synthetic polymers have received FDA approval for internal use. It is an effective method of delivering therapeutic proteins as it modifies their pharmacokinetic properties. The PEG-drug conjugates have several advantages - prolonged residence in body, decreased degradation by metabolic enzymes and reduction or elimination of protein immunogenicity. The delivery of several classes of protein drugs (including protein scaffolds, enzymes, cytokines and antibodies) is significantly improved by PEG-drug conjugate and they are useful in treating chronic diseases such as hepatitis C, leukemia, acromegaly, severe combined immunodeficiency disease (SCID), chronic gout, rheumatoid arthritis, and Crohn's disease. This review envisages an overview of PEGylation and its applications in cancer therapeutics. PEGylation technology has proven pharmacological advantages and acceptability and will undoubtedly prove useful for treating many previously difficult-to-treat conditions.