Functional PEG has huge potentials in different scenarios. A number of compounds, such as proteins, peptides, oligonucleotides, drugs and liposomes, after being modified by PEG covalent bonding, can effectively extend the circulation time in the body, increase stability, optimize pharmacokinetics and reduce side effects.
A Brief Introduction to Functional PEGs
Due to its biological inertness and good biocompatibility, polyethylene glycol (PEG) has a wide
range of applications in the pharmaceutical industry, biological materials, cosmetics, and analytical
science. A number of compounds, such as proteins, peptides, oligonucleotides, drugs and
liposomes, after being modified by PEG covalent bonding, can effectively extend the circulation
time in the body, increase stability, optimize pharmacokinetics and reduce side effects.
Functional PEG has huge potentials in different scenarios. According to MarketsandMarkets, the
global PEG-modified drug market in 2017 was 10.388 billion U.S. dollars, and is expected to reach
17.813 billion U.S. dollars by 2025, with a significant growth rate. As of the end of 2019, 26
PEGylated drugs have been approved by the FDA or the European Union. Except for 2 small
molecule drugs and 1 liposome drug, the remaining 23 are all PEGylated protein/peptide drugs.
On the whole, PEGylation can be used for PEGylated protein drugs, PEGylated peptide chain
compounds, PEGylated small molecule drugs, PEGylated liposomes, etc. At the earliest, it was also
used for producing long-acting protein and peptide drugs. Generally speaking, the common
techniques for the long-lasting potency of protein and peptide drugs include polyethylene glycol
modification, fusion proteins, microspheres, liposomes, and site-directed mutagenesis.
In addition, amphiphilic block-terminated copolymers (BCPs) synthesized based on PEG initiators
are widely used to construct nanocarriers for drug delivery. Via the terminal functionalization of
PEG, longer blood circulation time can be achieved.
Conventional protein and peptide drugs are composed of multiple amino acids. Such drugs are
often excreted quickly through the kidneys after acting on the human body, or are deactivated by
enzymes and proteins that are abundant in the human body. Therefore, the effective time of such
drugs is short, and the concentration of the