Used as a hydrophilic linker in pharmaceutical and polymer chemistry, particularly in the synthesis of antibody-drug conjugates (ADCs). Its polyethylene glycol (PEG)-like structure enhances solubility and improves the pharmacokinetic properties of conjugated drugs. The terminal carboxylic acid group allows for easy coupling to amines or alcohols, while the ketone functionality can be further modified for bioconjugation. Commonly employed as spacer molecules in diagnostic probes and targeted therapies, reducing aggregation and increasing stability in biological environments.