mPEG-NCO (Methoxy Polyethylene Glycol Isocyanate) is a polyethylene glycol (PEG) derivative with an isocyanate (-NCO) active group at the end, and is widely used in fields such as biocoupling, drug delivery, and material modification. Its core features are the hydrophilicity of the PEG chain and the high reactivity of the -NCO group, making it an important tool in biomedicine and materials science.
1. Structure and Characteristics
Chemical structure
mPEG end: Methoxy-terminated polyethylene glycol (mPEG), providing excellent water solubility and biocompatibility.
The -NCO terminal: isocyanate group (-N =C=O), which has high reactivity and can covalently bond with molecules containing -NH ₂ (amino group) or -OH (hydroxyl group).
Physical and chemical properties
Molecular weight (MW) : Common specifications include 350 Da, 500 Da, 1 kDa, 2 kDa, 5 kDa, 10 kDa, etc. (Customization available upon request).
Solubility: Readily soluble in water (PEG chains are hydrophilic), and also soluble in organic solvents (such as DMF, DMSO, THF).
Reactivity
React with -NH ₂ → form urea bonds (-NH-CO-NH -) (stable covalent bonds).
React with -OH → form carbamate bonds (-NH-CO-O -).
React with water → Decompose into amine (-NH ₂) + CO₂ (avoid damp environment).
(1) Biological coupling (PEGylation)
Protein/polypeptide modification
Improve stability and extend half-life (such as PEG interferon, antibody drugs).
Reduce immunogenicity (decrease clearance by the immune system).
Nanoparticle modification
It is used for surface PEG of liposomes and polymer nanoparticles to enhance the blood circulation time (such as mPEG-NCO modified PLGA nanoparticles).
(2) Materials Science
Hydrogel synthesis: Cross-linking with polyamine compounds (such as chitosan, polyethyleneimine) to form injectable hydrogels.
Surface coating: Modify the substrate containing -NH ₂ (such as silicon wafers, gold nanoparticles) to improve biocompatibility.
(3) Drug delivery system
Prodrug synthesis: Link the drug molecule (containing -NH ₂ or -OH) with mPEG-NCO to improve solubility and controlled-release performance.
