Used in drug delivery systems to improve the circulation time and stability of liposomes and nanoparticles. The PEG-OH component provides a hydrophilic coating that reduces immune recognition and prevents rapid clearance from the bloodstream. This allows therapeutic agents to accumulate more effectively in target tissues, especially in tumor sites via the enhanced permeability and retention (EPR) effect. Commonly employed in the formulation of stealth liposomes for cancer therapy, vaccines, and diagnostic imaging. The terminal hydroxyl group can be further modified or conjugated to attach targeting ligands, drugs, or imaging agents, enabling tailored functionalization for specific biomedical applications. Also used in surface modification of nanocarriers to enhance biocompatibility and reduce protein adsorption.