Used in bioconjugation to link biomolecules like proteins, peptides, or antibodies with polyethylene glycol (PEG) chains. Enhances stability, solubility, and reduces immunogenicity of the conjugated molecules. Commonly applied in drug delivery systems to improve pharmacokinetics and therapeutic efficacy. Also utilized in surface modification of nanoparticles or medical devices to prevent protein adsorption and improve biocompatibility.