Molecular targeting of imaging and drug delivery probes in Atherosclerosis

Precise and selective targeting of biomolecules specifically expressed in atherosclerotic tissues can offer substantial advantages in the design of novel diagnostic tools and drug delivery systems, discriminating unstable plaques at risk of rupturing from stable ones. Efforts of design of synthetic ligands targeting vascular integrins, adhesion molecules, proteolytic enzymes, markers of apoptosis and necrosis, and of their chemical conjugation with radionuclides for single photon emission computed tomography (SPECT) and positron emission computed tomography (PECT), with paramagnetic magnetic resonance imaging (MRI) detectors, or with near infrared (NIR) fluorophores have provided a panel of opportunities. The use of nano- and micro-sized particles can provide enhanced capacity for loading of drug delivering or imaging entities, as well as specific imaging modalities by gas-filled microbubbles, intravascularly detectable by contrast ultrasound techniques. Some of these opportunities, up to now supported by investigations in animal models, appear to deserve further efforts of research and development for validation and translation in innovative clinical applications.