MPEG4-Mal is widely used in the field of bioconjugation and drug delivery due to its ability to link with various biomolecules. It serves as a crucial component in modifying proteins, peptides, and other therapeutic agents to enhance their solubility, stability, and circulation time in the body. This chemical is particularly valuable in the development of targeted drug delivery systems, where it helps in attaching drugs to specific carriers or ligands for precise delivery to diseased tissues. Additionally, it is employed in the creation of biocompatible hydrogels and nanoparticles, which are used in regenerative medicine and diagnostic imaging. Its role in improving the pharmacokinetic properties of therapeutic agents makes it a key tool in advancing modern medicine.