Used in bioconjugation and targeted drug delivery systems, DSPE-PEG-N3 enables efficient coupling of biomolecules such as peptides, proteins, or fluorescent dyes to liposomes or nanoparticles via click chemistry. The azide group reacts selectively with alkynes under copper catalysis or strain-promoted conditions, allowing modular and site-specific modifications. It is commonly applied in the development of stealth liposomes for prolonged circulation in vivo, enhancing tumor targeting in cancer therapy. Its PEGylated structure reduces opsonization and clearance by the reticuloendothelial system. Widely used in diagnostic imaging, theranostics, and vaccine delivery platforms due to its biocompatibility and functional versatility.