Acryloyl PEG NHS (NHS PEG Acrylate) is heterobifunctional PEG crosslikers that have an acrylate group one one PEG terminus and a NHS (succinimidyl ester) group on the other PEG end. Acrylate group can be used for acrylic polymer synthesis while NHS can be used to react with amine group at alkaline pH. PEGylation can increase solubility and stability and reduce immunogenicity of peptides and proteins. It can also suppress the non-specific binding of charged molecules to the modified surfaces.