PEG polymers contain numerous inherent favorable biological characteristics including high water solubility and a lack of toxicity and immunogenicity. Thus, the chemical modification of biologically active compounds, such as peptides, antibody fragments, enzymes, or small molecules with polyethylene glycol chains, referred to as “PEGylation”, often leads to improved pharmacokinetics and biological function in many applications.
Drugs can especially benefit from PEGylation, and a continuously growing number of PEG conjugated drugs are on the market. By increasing the molecular mass of proteins and peptides and shielding them from proteolytic enzymes, PEGylation often improves bioavailability. After the first therapeutic PEG-protein conjugate (PEG-adenosine deaminase, PEG-ADA3) was approved by the FDA in 1991, a large number of PEG-protein conjugates have been described for therapeutic use against a range of diseases.
In addition, PEGylation can be used as a tool to facilitate drug delivery of nanocarrier systems, nanoparticles, and microparticles. Also, in contrast to increasing the water solubility of certain compounds and materials, PEG-enzyme complexes have been shown to increase the solubility, stability, and activity of the enzymes in hydrophobic organic solvents.
Sigma-Aldrich offers a broad portfolio of homobifunctionalized, heterobifunctionalized, and mono-methoxy endcapped PEG reagents with molecular weights up to 20 kDa to suit all of your PEGylation needs.