This compound is widely utilized in the field of bioconjugation and drug delivery systems. Its primary application lies in the modification of biomolecules, such as proteins, peptides, and antibodies, to enhance their stability, solubility, and bioavailability. The S-acetyl group serves as a protective moiety for thiols, allowing controlled release in biological environments, while the PEG (polyethylene glycol) spacer improves water solubility and reduces immunogenicity. The t-butyl ester group provides additional protection for carboxylic acids, which can be deprotected under specific conditions. This makes it particularly valuable in the synthesis of prodrugs, targeted therapies, and bioconjugates for cancer treatment, diagnostics, and other therapeutic applications. Its versatility also extends to the development of advanced materials and nanotechnology-based drug delivery platforms.