Used in bioconjugation and drug delivery systems, it serves as a protective group for amines during peptide synthesis. The PEG spacer enhances solubility and reduces immunogenicity, making it valuable in creating biocompatible materials. It is also employed in the development of prodrugs and targeted therapies, where controlled release of active compounds is essential. Additionally, it finds application in surface modification of nanoparticles to improve stability and bioavailability in biomedical research.