Custom Synthesis PEG Derivatives

BOC Sciences provides many types of activated PEGs with wide variety of functional groups, whereby can be further introduced into drugs, enzymes, peptide, proteins, nanoparticles and other biologics, playing important roles in the augmentation the targeting ability, stabilization of conjugates, reduction of their antigenicity and/or decrease in the drug doses.

PEG, as obtained by ethylene oxide polymerization, presents one or two terminal hydroxyl groups (mPEG-OH or HO-PEG-OH) depending upon the initiator of polymerization: methanol or water, respectively. Because the repeating ethylene oxide units of PEG possess no reactive side moieties, PEG is bound to other compounds through terminal functional groups to realize activation.

Below are the application of PEG Derivatives

Versatility of PEG modification Fig. 1 Versatility of PEG modification. (Expert opinion on drug delivery, 2009, 6(1): 1-16)

How to Modify?

Two approaches are commonly used:

  1. Alteration of the terminal hydroxyl group through a series of reactions to a more active functional group
  2. Through reaction of PEG under controlled conditions with difunctional compounds so that one of the functional groups reacts with PEG and the other remains active.

*In most cases, several steps are conducted to achieve the expected derivatization.

PEG Derivatives We Can Offer Including but Not Limited to:

  • Mono-functional Linear PEGs

The mono-functional linear PEGs contain highly purified methoxy groups, which can effectively prevent the occurrence of bridging reactions (side reactions) that hinder PEGylation.

Mono-functional linear PEGs

Bifunctional PEG is the most popular starting point for cross-linking reaction between proteins, enzymes and other small molecule drugs. Moreover, it can also be utilized to prepare hydrogels for tissue engineering.

Bi-functional PEGs

Forked PEGs provide multi-proximal reactive groups at one or both ends of a linear PEG chain. It can be applied in biobetters’ design attached to Fab’ antibody fragments to produce a conjugate similar in structure to the full-length antibody.

Forked PEGs

Multi-arm PEGs can be used not only as the starting materials for hydrogels, but also are indicated to enhance the loading of low molecule drugs.

Multi-arm PEGs

Y-shaped PEG is more effective in protecting the conjugated protein from degradative enzymes and antibodies. Moreover, enzymes modified with this PEG retain more activity with those counterparts modified by linear PEGs.

Y-shaped PEGs

These derivatives present two different functional groups, one for each extreme, which simplify the linking of different molecules to the same PEG chain.

Heterobifunctional PEGs

  • PEG with linkers designed for the controlled release

This kind of PEG derivative has pH-cleavable acetyl linkers, which can be recognized and cleaved by lysosomal enzymes when the conjugates reach the intracellular compartment.

Monodisperse PEG is a pure compound with unique, specific and single molecular weight. Inserting monodisperse PEGs into small molecule drugs can well increase the hydrodynamic volume and solubility of the drugs, reduce aggregation and immunogenicity, as well as extend the half-life of drugs in the body.

Why Us?

Advantage of BOC Sciences

How to Order?

How to order


  1. Bailon P, Won C Y. PEG-modified biopharmaceuticals. Expert opinion on drug delivery, 2009, 6(1): 1-16.
  2. Santos, J. H. P. M.; Torres-Obreque, K. M.; et al. Protein PEGylation for the design of biobetters: from reaction to purification processes. Brazilian Journal of Pharmaceutical Sciences 2018, 54 (SPE).

Why BOC Sciences?

  • Large Stock

    More than 2000+ products in inventory

  • Global Delivery

    Warehouses in multiple cities to ensure fast delivery

  • mg to kg

    Multi specification for academic research and industrial production

  • 24/7 Technical Support

    Strict process parameter control to ensure product quality



Our Feature

BOC Sciences supplies a unique variety of PEG derivatives and functional PEG polymers. Our products offer the most diverse collection of reactivity, ready-to-use functionality, and molecular weight options that you will not find anywhere else.

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PEGylation of Peptides and Proteins

PEGylation of Peptides
and Proteins

Reduce the Immunogenicity of Peptide/Protein Drugs

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PEG linkers For Drug

Improved Circulation Half-Life

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