Monodisperse PEG Synthesis

BOC Sciences provides customized high purity monodisperse polyethylene-glycols (PEG) synthesis with different functional groups or different molecular weights. Our monodisperse PEG products retain the typicle PEG properties including hydrophilicity, non-toxicity, non-immunogenicity, a high exclusion volume in water, flexibility, high chain mobility and high biocompatibility.

Traditional PEGs are polydisperse polymers. They are polymerized from a large amount of different PEG and their molecular weights are not certain but mostly distributed in a probable range. This oligomeric mix has different chemical and physical properties, which will lead to complex and unpredictable mixtures or products. Therefore, there are some difficulties and challenges when using these PEG compounds for quantitative modification and drug development. The polydispersity in PEGs can downgrade the purity, bioactivity, and safety.

Monodisperse PEG is pure compound with a consistent molecular weight and a clearly defined purity profile. Monodisperse PEG has defined physical properties of one mass, one melting point and one retention time. They are single components with predictable physicochemical properties, much higher bioactivity and safety than traditional polydisperse PEGs. In the past two decades, with the progress of both synthetic and purification chemistry, monodisperse PEG have become more commercially viable.

Monodisperse PEGs have been found to play a role in drug design, especially in the development of safe and effective PEGylated small molecule drugs. There are some problems in the development of small molecules drugs, including low solubility, easy removal from the body and poor target-specificity. Monodisperse PEG can be used to solve these problems. In order to extend drug half-life in the body, monodisperse PEG linkers are introduced to small molecule drugs to increase the solubility and molecular weight of drugs. The solubility and molecular weight are increased by introducing monodisperse PEG linkers to small molecule drugs. Monodisperse PEG can also be used in drug development to produce homogeneous PEGylated drugs with specific molecular weight.

It is not easy to isolate and purify PEG compounds with similar structure. The synthesis of monodisperse PEG is challenging. Specific methods and suitable separation approaches are needed for monodisperse PEG synthesis. At present, there are two common routes for preparing monodisperse PEG. The first route is to use an ethylene glycol linked to the protected group at one end and another ethylene glocol linked to the active group at both ends for condensation reaction. The second route is to use PEG with both an activating group and protecting group to make a condensation reaction with PEG of a specific molecular weight. The principle of the above two processes is simple, but the control of the raw materials and conditions of the condensation reaction is complicated. At present, monodisperse polyethylene glycols are often more expensive in the market.

Figure 1. A comparison between regular polidocanol and monodisperse polidocanol.Figure 1. A comparison between regular polidocanol and monodisperse polidocanol. (Yu, Z., et al., 2017)

BOC Sciences has an excellent technical team to design and synthesize the corresponding monodisperse PEG according to customers' needs, and ensure the purity of monodisperse PEG. From laboratory scale to large commercial scale, we can meet the PEG and PEGylation needs in pharmaceutical, biotechnology, chemical markets, diagnostics and medical device. You will benefit from using our purified products.

If you have any questions or specific needs, please feel free to contact us.


  1. Berna M, et al., 2006. Novel monodisperse PEG−dendrons as new tools for targeted drug delivery: synthesis, characterization and cellular uptake. Biomacromolecules, 7 (1), pp. 146–153.
  2. Dang T D, et al., 2012. Preparation of monodisperse PEG hydrogel microparticles using a microfluidic flow-focusing device. Journal of Industrial and Engineering Chemistry, 18 (4), pp. 1308–1313.
  3. Yu, Z., et al., 2017. Application of Monodisperse PEGs in Pharmaceutics: Monodisperse Polidocanols. Molecular Pharmaceutics, 14 (10), pp. 3473–3479.

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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

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