Radio-labeled Nanoparticles for Biomedical Imaging - Nanotechnology for Biomedical Imaging and Diagnostics - page 189

7

Radio-labeled NaNopaRticles
foR biomedical imagiNg

Tolulope Aweda, Deborah Sultan, and Yongjian Liu
Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA

7.1 iNtRoductioN

In the field of biomedical imaging, developing delivery systems specific to the target
site is an ongoing objective for both therapeutic and imaging applications. Cancer
targeting systems have utilized monoclonal antibodies (mAbs) [1-3] or peptides that
bind antigens or receptors, which are expressed on the targeted cell surface [4-6].
Other strategies have included the use of antibody-fused streptavidin with a biotin-
probe [7-9] engineered proteins that bind specifically to synthetic tags [10-12]. These
imaging systems are often limited by suboptimal pharmacokinetics, low sensitivity,
and poor targeting efficiency, especially for disease models with low biomarker
expression [11]. An alternative is the fast-growing field of nanomedicine, which offers
advantages including tuned in vivo biodistribution, enhanced targeting efficiency,
greater imaging sensitivity, and potential for identification of diseases at an early
stage [13, 14]. It is becoming increasingly clear that nanomedicine holds tremendous
potential for personalized diagnosis and treatment [15, 16].
Typically, nanoparticles range in size from 1 to 100 nm, exhibiting unique size-
dependent physical and chemical properties including optical, magnetic, catalytic,
thermodynamic, and electrochemical traits [17]. Nanoparticles can generally be
grouped into one of three constructs based on their structure: (1) inorganic nanopar-
ticles including quantum dots, iron oxide nanoparticles, gold nanostructures, and
upconversion nanophosphors [18-22]; (2) polymer nanoparticles such as core-shell