Lipid-Based Pharmaceutical Nanocarriers for Imaging Applications - Nanotechnology for Biomedical Imaging and Diagnostics - page 47

3

Lipid-Based pharmaceuticaL
NaNocarriers for imagiNg
appLicatioNs

Tamer Elbayoumi
Department of Pharmaceutical Sciences, Midwestern University, Glendale, AZ, USA

Vladimir Torchilin
Department of Pharmaceutical Sciences and Center for Pharmaceutical Biotechnology and
Nanomedicine, Northeastern University, Boston, MA, USA

3.1 iNtroductioN

A quite actively growing area in current experimental and clinical medicine is the
application of lipid-based vesicles, mostly liposomes and micelles, as pharmaceu-
tical carriers for biomedical and diagnostic imaging agents.
Conditional on the contrast agent, sensitivity, and resolution limit of the scanning
method, specific minimum amounts of the contrast agent have to be delivered into the
area of interest. While conventional nonenhanced imaging techniques are useful only
when relatively large tissue areas are involved in the pathological process, in
the majority of cases, this may not be feasible due to the variable ability of different
tissues to attenuate contrast signal, like X-rays, sound waves, radiation, or radio
frequency. Hence, in order to achieve sufficient attenuation, contrast agents are
utilized to discriminate target tissue, owing to their capability to absorb signal and
irradiation, much stronger than surrounding tissue.