Metallic and upconversion nanoparticles as photoacoustic contrast agents for biomedical imaging #39

Abstract

Photoacoustic imaging is an emerging biomedical technique. By using nonionized pulsed laser as the excitation source and ultrasound probe as the signal detector, this technique could afford noninvasive imaging for medical diagnostics. In this chapter, current biomedical imaging techniques are discussed and compared in terms of their pros and cons in clinical applications. The basic theory of photoacoustic imaging is elaborated. In order to gain better resolution as well as provide targeted imaging, photoacoustic contrast agents are often employed. Photoacoustic contrast agents such as metallic nanoparticles and upconversion nanoparticles are introduced, revealing promising potentials for clinical uses. Finally, the nanotoxicity of these nanomaterials for practical bioimaging is scrutinized. This chapter presents state-of-the-art research progress of using metallic and upconversion nanoparticles as photoacoustic contrast agents for biomedical imaging.