SITE SPECIFIC BINDING SYSTEM, NUCLEAR IMAGING COMPOSITIONS AND METHODS

摘要

A method for ligand-based binding of lipid encapsulated particles to molecul ar epitopes on a surface in vivoor in vitrocomprises sequentially administering (a) a site-specific ligand activated with a biotin activating agent; (b) an avidin activating agent; and (c) lipid encapsulated particles activated with a biotin activating agent, whereby the ligand is conjugated t o the particles through an avidin-biotin interaction and the resulting conjuga te is bound to the molecular epitopes on such surface. The conjugate is effecti ve for imaging by x-ray, ultrasound, magnetic resonance, positron emission tomography or nuclear imaging. Compositions for use in ultrasonic imaging of nature or synthetic surfaces and for enhancing the acoustic reflectivity thereof are also disclosed.