Used in bioconjugation to link biomolecules such as proteins, peptides, or antibodies through carbonyl groups like aldehydes or ketones. The hydrazide groups react selectively under mild conditions, making it ideal for creating stable bioconjugates in drug delivery systems and diagnostic applications. Its 4-arm structure allows for crosslinking, enabling hydrogel formation for tissue engineering and controlled release formulations. Commonly used in creating biocompatible matrices due to PEG’s non-immunogenic and water-soluble properties. Suitable for surface modification of nanoparticles and medical devices to improve stability and reduce protein adsorption.