Bis-(m-PEG4)-amidohexanoic acid is widely used in bioconjugation and drug delivery systems due to its PEGylation properties. The PEG chains enhance solubility, stability, and bioavailability of therapeutic compounds, making it valuable in pharmaceutical formulations. It is also employed in the development of targeted drug delivery systems, where it helps in reducing immunogenicity and prolonging circulation time in the body. Additionally, it serves as a linker in antibody-drug conjugates (ADCs), enabling precise delivery of cytotoxic agents to cancer cells while minimizing off-target effects. Its application extends to nanotechnology, where it is used to modify surfaces of nanoparticles for improved biocompatibility and reduced aggregation.