Advances in PEGylation of important biotech molecules: delivery aspects

Abstract

Background: Although various injected peptide and protein therapeutics have been developed successfully over the past 25 years, several pharmacokinetic and immunological challenges are still encountered that can limit the efficacy of both novel and established biotech molecules. Objective and method: PEGylation is a popular technique to address such properties. PEGylated drugs exhibit prolonged half-life, higher stability, water solubility, lower immunogenicity and antigenicity, as well as potential for specific cell targeting. Although PEGylated drug conjugates have been on the market for many years, the technology has steadily developed in respect of site-specific chemistry, chain length, molecular weights and purity of conjugate. These developments have occurred in parallel to improvements in physicochemical methods of characterization. Conclusion: This review will discuss recent achievements in PEGylation processes with an emphasis on novel PEG-drugs constructs, the unrealized potential of PEGylation for non-injected routes of delivery, and also on PEGylated versions of polymeric nanoparticles, including dendrimers and liposomes.

Keywords::

• drug delivery
• PAMAM dendrimers
• PEG
• PEGylation
• PEGylated liposomes

Acknowledgments

We are grateful to Science Foundation Ireland (Investigator Grant 04 IN3 B575 to DB) for funding for the PEGylated sCT work and to Warwick Effect Polymers Ltd. for providing polymer conjugates.