HO-PEG-COOtBu

HO-PEG-COOtBu has two different activated end groups, hydroxyl and carboxylate tert-butyl ester, which is a linear heterofunctional PEG derivative. The protected carboxyl (COOH) prevents self coupling or polymerization under standard acid/amine or acid/hydroxyl coupling conditions. The protected acid can be regenerated by acidic or basic hydrolysis. HO-PEG-COOtBu is used in cell culture, drug research, drug delivery and release, nanotechnology and new materials. It can also be attached to different molecules or materials to extend the richness of different molecular combinations. PEG modification can form a spatial barrier around the drug, reduce enzymatic hydrolysis of the drug, avoid rapid elimination of kidney metabolism, and allow the drug to be recognized by immune system cells.