Photoacoustic imaging with biodegradable plasmonic nanoclusters

Plasmonic nanoparticles have been widely used for various biomedical applications such as biological imaging, sensing, and cancer therapy. Specifically, gold nanospheres, nanorods, and nanoshells are used as contrast agents for photoacoustic imaging due to their strong absorptive property. However, there are concerns about using these nanoparticles in-vivo because they are not biodegradable and cannot be cleared from the body. Recently, biodegradable nanoclusters have been reported. The biodegradable nanoparticles are composed of primary 4-nm gold nanoparticles and stabilized by a biodegradable polymer binder. In this study, we demonstrated the utility of biodegradable nanoclusters as a contrast agent in photoacoustic imaging. The tissue mimicking phantoms were used for ultrasound and photoacoustic imaging. The results show that the biodegradable plasmonic nanoclusters can be used as photoacoustic contrast agent.