Methoxy Linear PEG (mPEG)

BOC Sciences is a leading supplier of mPEG compounds with a range of molecular weights and functional groups. Because of the high purity and quality of our mPEG products, we are guaranteed to meet the most exacting requirements of the pharmaceutical and biomedical industries. Global distribution capabilities of BOC Sciences allow prompt and effective shipping of mPEG products to clients all over the world.

Methoxy Polyethylene Glycol

Methoxy linear PEG (mPEG) is a type of PEG that has methoxy (CH₃O) groups attached to its linear chain. It includes monofunctional or heterobifunctional mPEG derivatives with various functional groups, such as Amine (NH₂), Thiol (SH), Azide (N₃), NHS ester, Maleimide (Mal), Carboxylic acid (COOH), Alkyne, Silane, Biotin, DBCO, DSPE, etc. mPEG is a water-soluble and biocompatible high-molecular polymer. It is frequently employed in the domains of medical research, drug release, nanotechnology, cell culture, and new materials because of its special qualities, including low toxicity, non-immunogenicity, and high solubility.

Methoxy Polyethylene Glycol Structure

Methoxy (CH₃O) groups are joined to the end of a linear chain of repeating ethylene glycol units to form the structure of mPEG. mPEG's general formula is HO(CH₂CH₂O)_nCH₂CH₂OCH₃, where n is the number of ethylene glycol units in the chain and varies based on the polymer's molecular weight. The methoxy groups attached to the end of the PEG chain provide steric hindrance and reduce protein adsorption, making it a useful polymer for various biomedical and pharmaceutical applications. Methoxypolyethylene glycol typically has an average molecular weight of 350-5000. An average molecular weight number is assigned to each mPEG. While mPEG 750 and 1000 require temperatures above 40 °C, mPEG 350 and 500 are transparent, viscous liquids at ambient temperature. mPEG 2000, 3000, and 5000 are white, waxy solids, typically supplied in flake form.

Fig. 1. Schematic structure of linear PEG, methoxy linear PEG (mPEG), and branched monomethoxy-PEG (mPEG2).

Methoxy Polyethylene Glycol Uses

The molecular weights of mPEG, which range from a few hundred to several thousand Daltons, can be adjusted to satisfy the demands of various applications. It is frequently employed as a surface modification to lessen the immunogenicity and toxicity of pharmaceuticals as well as to increase their stability, solubility, and bioavailability. In order to avoid biofouling and increase the biocompatibility of medical equipment like implants and catheters, mPEG is also applied as a coating. In order to promote cell adhesion and proliferation, it is also utilized in tissue engineering and regenerative medicine.

mPEG for Drug Delivery

Linear mPEG can be used for PEGylation and cross-linking in drug delivery systems. PEGylation with linear mPEG can alter the pharmacokinetic properties of drugs, resulting in increased circulation half-life, decreased renal clearance, and immunogenicity. This is because attaching linear mPEG chains to drug molecules increases their hydrodynamic size and decreases their clearance by the reticuloendothelial system. In addition, PEG chains are highly water soluble and can increase the solubility of poorly water soluble drugs and prevent protein aggregation or denaturation. Cross-linking with linear mPEG is another important application in drug delivery systems. Cross-linking refers to the formation of covalent bonds between linear mPEG chains and drug molecules or between different linear mPEG chains. This can lead to the formation of drug-loaded nanoparticles or hydrogels, which can improve drug stability, bioavailability, and targeted delivery.

mPEG for Bioconjugation

Linear mPEG can also be used for bioconjugation of nucleic acids, oligonucleotides, peptides, and proteins to optimize pharmacokinetic properties. In addition, linear mPEG-conjugated peptides or proteins can be used to target specific receptors or tissues to enhance therapeutic effects. Bioconjugation of PEG requires PEG with active terminal groups, such as n-hydroxysuccinimide esters, sulfhydryls, or carboxyls. The nature of the conjugation chemistry determines the number of binding sites and PEG per molecule. Generally, high molecular weight PEG (≥5k Da) is usually used for conjugation of small molecules, siRNA, and peptides. Low molecular weight PEG (≤5kDa) is often used for protein PEGylation.

Methoxy Polyethylene Glycol Benefits

Because of its numerous benefits, the chemistry of mPEG makes it a valuable and popular polymer for usage in numerous biological and pharmaceutical applications. For instance, mPEG is a perfect polymer for use in a variety of biomedical applications like medication delivery and tissue engineering since it is biocompatible and non-toxic. In addition, mPEG is highly water-soluble, which makes it easy to handle and formulate into different drug delivery systems such as micelles, liposomes, and nanoparticles. Our mPEG product features include:

• Biocompatibility
• Water solubility
• Low immunogenicity
• Resistance to protein adsorption
• Tailored molecular weights
• Chemical versatility

How to Use Methoxy Polyethylene Glycol?

Functional Groups

• Monofunctional polyethylene glycol, containing one chemically reactive end, can be used for PEGylation, surface conjugation, and nanoparticle coating.
• Bifunctional polyethylene glycol, PEG with two active ends, including homobifunctional PEG and heterobifunctional PEG. It is conducive to the conjugation and cross-linking of hydrogels.

Reaction Types

• Covalent conjugation: PEG with active terminal groups, such as n-hydroxysuccinimide ester, sulfhydryl or carboxyl, can be covalently conjugated to the corresponding functional groups.
• Click chemistry requires PEG with azide or alkyne reactive groups. Click chemistry is a rapid, selective, bioorthogonal conjugation or hydrogel formation method.
• Polyethylene glycol with acrylate end-linked can be rapidly polymerized and photopolymerized under mild reaction conditions.

Polymer Structure

• Linear PEG is commonly used for PEGylation, bioconjugation, and cross-linking.
• Multi-arm PEG (4-arm, 6-arm, 8-arm) can be used for cross-linking into hydrogels and scaffolds in drug delivery or tissue engineering.
• Y-type PEG is often used for PEGylation because its branched structure can improve in vivo stability.

Molecular Weight

• Bioconjugation: High molecular weight (≥5k Da) PEG is often used for coupling small molecules, siRNA and peptides. Low molecular weight PEG (≤5kDa) is often used for protein PEGylation.
• Surface conjugation and cross-linking usually use PEG<40k Da.
• Hydrogel formation: PEG molecular weight affects the mesh size and mechanical properties of the hydrogel. Typically, PEG with a molecular weight of ≥5k Da is used.

Overall, methoxy linear PEG is a versatile and biocompatible polymer with a wide range of applications in the biomedical and pharmaceutical fields. Its unique properties, such as biocompatibility, water solubility, and tunable drug release profiles, make it an ideal material for drug delivery, tissue engineering, and other medical applications. As researchers continue to explore the potential of methoxy linear PEG, we can expect to see more innovative uses for this versatile polymer in the future. If you are interested in our PEG products and PEGylation services, please contact us now for more information.