Nanoparticles for photoacoustic imaging of cancer

Abstract

Photoacoustic imaging is a complementary modality to ultrasound imaging with potential for several clinical applications, including cancer imaging. Photoacoustic contrast is derived from optical absorption by intrinsic tissue constituents such as oxygenated and deoxygenated hemoglobin, melanin, and lipid. However, the use of exogenous contrast agents, including nanoparticle-based contrast materials, allows for a wide range of cancer-specific imaging uses. Nanoparticles, including noble metal (gold, silver), carbon nanotubes, and custom mixed composition nanoparticles, are exogenous contrast agents that exhibit excellent optical absorption and can be optimized for specific cancer applications through surface targeting. Their small size enables them to not only circulate in vasculature but also extravasate to reach tumor sites. In this chapter, after an introduction to the basics of photoacoustic imaging, we present an overview of the most common nanoparticles used in photoacoustic imaging of cancer, their general synthesis methods, and applications.