Poly(ethylene glycol)(PEG), also known as poly(ethylene oxide)(PEO), is an amphiphilic polyether that is soluble both in water and most organic solvents. PEG and its derivatives are among the few polymers approved for medical uses by the U.S. Food and Drug Administration (FDA).

Functionalized PEG, also named active PEG, activated PEG or functional PEG, is a family of PEG derivatives decorated with functional groups. Functionalized PEGs are used broadly for drug pegylation (conjugation of PEG molecule to drug molecules), polymer engineering, nanotechnology, biotechnology, and biomedical engineering. Drug pegylation(conjugation) is illustrated in the following figure.


Pegylation refers to a process of covalent attachment of PEG polymer chains to target molecules, normally small molecule chemical drugs or large bio-molecules like peptides, proteins, carbohydrates, lipids, oligonucleotides, antibody fragments, affinity ligands, cofactors, liposomes, and other bio-related substances.


Pegylation can impart several significant pharmacological advantages over the unmodified counterparts in the following attributes, improving drug performance and its therapeutic effect significantly:
- Extended circulating life;
- Lower maximum plasma concentration;
- Smaller fluctuation of concentration in blood;
- Less enzymatic degradation.


The pegylation of bioengineered protein/peptide drugs (hereinafter referred to as PEG-protein drugs) has received intensive attentions. Future broader applications in interferon, insulin, erythropoietin (EPO), interleukin, and growth hormone, are critical to the treatment on severe diseases including malignant tumors, diabetes and cardiovascular diseases, etc..

So far, about 22 kinds of PEG-drug received U.S. FDA approval to market. The PEG of drugs already on the market showed good therapeutics efficacy, which in turn stimulates the enthusiasm of the major pharmaceutical companies and research institutions PEG. Currently, there are dozens of drugs in clinical or pre-clinical research stage.


Novel Y-shape poly(ethylene glycol) with the functional group at only one terminal (out of three branch chains) is developed on the basis of V-shape PEGs to enhance below performance attributes:


o Ease of pegylation vs traditional branched structure:

Relatively, 2-arm (or V-shape) traditional branched PEG has greater steric hindrance in pegylation, when compared to Y-shape PEG molecule where the distance between the functional group and the branch point can be regulated to balance the steric effect and the reactivity.

o Branched structure can provide an “umbrella-like” protective coverage around protein surface and maintain the reactivity of protein drugs in vivo effectively. Now, our Y-shape product is one of the popular products preferred by our customers in exploring differentiation in next-generation drug designs.