This chemical is widely used in bioconjugation and drug delivery systems due to its hydrophilic polyethylene glycol (PEG) chain and reactive carboxyl group. The PEG segment enhances solubility, stability, and biocompatibility of conjugated molecules, making it ideal for modifying proteins, peptides, and nanoparticles. The terminal carboxyl group allows for easy attachment to amino groups via amide bond formation, enabling the creation of targeted drug delivery systems or diagnostic probes. It is also employed in surface modification to reduce immunogenicity and improve the pharmacokinetics of therapeutic agents. Additionally, its properties make it suitable for use in hydrogel formation and as a linker in prodrug design.