Used in bioconjugation and drug delivery systems, it serves as a linker molecule to attach therapeutic agents or targeting moieties to biomolecules like proteins or antibodies. Its polyethylene glycol (PEG) spacer enhances solubility and reduces immunogenicity, making it suitable for improving the pharmacokinetics of drugs. Additionally, it is employed in the development of antibody-drug conjugates (ADCs) and other targeted therapies, ensuring precise delivery of drugs to specific cells or tissues. Its carboxylic acid group allows for easy modification and conjugation with various functional groups, expanding its utility in biomedical research and therapeutic applications.