Used in drug delivery systems to improve the solubility and stability of therapeutic agents. Helps prolong circulation time of drugs by reducing immune recognition and preventing rapid clearance from the body. Commonly employed in the development of PEGylated proteins and peptides. Facilitates bioconjugation through the carboxylic acid group, allowing attachment to amines on biomolecules or surfaces. Applied in tissue engineering and hydrogel formation due to its biocompatibility and ability to modify material properties. Widely used in diagnostic imaging and targeted therapies where controlled attachment of molecules is required.