Used extensively in liposome-based drug delivery systems, this compound enhances circulation time and targeted delivery of therapeutic agents. The polyethylene glycol (PEG) chain provides steric stabilization, reducing recognition and clearance by the immune system. Biotin allows for specific binding to streptavidin or avidin conjugates, enabling targeted delivery to cells overexpressing biotin receptors or facilitating attachment in diagnostic assays. Commonly employed in the formulation of nanomedicines, including cancer therapies and imaging agents, it supports the development of stealth liposomes that accumulate preferentially in tumor tissues due to the enhanced permeability and retention (EPR) effect. Also used in research settings for cell labeling, receptor targeting, and surface immobilization of liposomes on biosensors or microarrays.