Used as a hydrophilic linker in drug delivery systems, particularly in the synthesis of antibody-drug conjugates (ADCs) and peptide conjugates. Its long polyethylene glycol chain enhances solubility and reduces aggregation, improving the pharmacokinetic profile of conjugated molecules. Commonly employed in bioconjugation to attach drugs, imaging agents, or targeting moieties to proteins or nanoparticles while maintaining biocompatibility and circulation time. Also utilized in surface modification of nanocarriers to increase stability and reduce immune recognition.