MPEG-maleimide is widely used in bioconjugation and drug delivery applications due to its ability to react selectively with thiol groups. It is commonly employed to modify proteins, peptides, and antibodies, enhancing their stability, solubility, and circulation time in the body. In drug delivery systems, it is utilized to create PEGylated conjugates, which improve the pharmacokinetics and reduce immunogenicity of therapeutic agents. Additionally, it plays a critical role in the development of targeted therapies, where it is used to link drugs to specific targeting molecules, ensuring precise delivery to diseased tissues. Its applications also extend to nanotechnology, where it is used to functionalize nanoparticles for improved biocompatibility and targeted delivery.