Nanoparticles as Contrast Agents for Optoacoustic Imaging - Nanotechnology for Biomedical Imaging and Diagnostics - page 135

5.5 coNclusioNs

from this short review where we briefly analyzed the design, characterizations, and
application of different types of OA imaging contrast agents, we can summarize that
nanoparticle-based contrast agents greatly extend OA as an imaging technique.
Nanoparticles are best designed with peak absorption in the NIR region, where
optical attenuation of tissue is relatively low, affording deep light penetration.
Targeting peptides and antibodies can be conjugated to the nanoparticle surface for
cell-specific contrast and molecular imaging. some types of contrast agents are non-
photobleaching and provide a long-circulating lifetime with good optical absorption.
OA imaging could be combined with PT therapy, since both techniques share similar
mechanisms of interaction with light.
certain aspects of OA imaging with nanoparticles need further investigation. A
comparison between contrast agents of different materials, shapes, and sizes on OA
imaging is lacking. Presently, we are unable to specify which kind of nanoparticle is
best for each OA modality (imaging, tomography, or sensing). Another challenge is
an analysis of nanoparticles in vivo , for example, in the blood stream after in vivo
administration, in tumors, or in other tissues. future study should be directed toward
optimization of the size and shape of nanoparticle-based OA contrast agents to ensure
the most efficient transformation of light energy into high pressure.
Overall, this review presents OA imaging contrast agents and amplifiers, which
show a significant promise for preclinical research in cancer and cardiovascular diag-
nostics, as the OA research community continues to discover new approaches and
invent new technologies.

ackNowledgmeNts

This work was supported by the National Institutes of Health, grants: 1R43es021629,
R44cA110137, and R44cA110137-s1.

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