m-PEG-CM

mPEG-CM (mPEG-Carboxymethyl) is a linear carboxylic acid functionalized methoxy polyethylene glycol. A methylene (CH2) bond exists between the PEG and COOH groups. Carboxyl groups can not only undergo esterification with hydroxyl groups to form ester bonds, but also undergo affinity substitution reactions with amino groups to form amides, which are one of the excipients for COVID-19 vaccines.