Single molecular weight discrete PEG compounds: Emerging roles in molecular diagnostics, imaging and therapeutics

摘要

PEGylation is the process of covalently attaching polyethylene glycol (PEG) chains to various biomolecules, such as oligo-nucleotides, peptides, proteins and antibody fragments. The PEGylation process was first described in 1977 by Frank Davis and Abraham Abuchowski. It is noteworthy that the first US FDA-approved PEGylated biopharmaceutical became commercially available in 1990. The use of PEGylation has subsequently become commonplace in the development and modification of numerous biophar-maceuticals and has led to many advancements in molecular diagnostics, imaging and therapeutics. Any given PEG chain is made up of a repeating backbone of ethylene oxide units. This backbone can be flanked by terminal methoxy groups and functional groups that match the chemistry on the intended biomolecule. This basic construct of the PEG chain is essential for allowing the creation of a modified or conjugated biopharmaceutical product. The molecular construct of the ethylene glycol backbone of PEG is nonionic, hydrophilie, nontaxic, nonimmunogenic and nonantigenic. The goal of PEGylating various biomolecules is to increase their hydrodynamic volume, water solubility and systemic circulatory half-life, while decreasing their proteolytic enzyme degradation and immunogenicity.