In this webinar, we explored the development and characterization of a novel photoacoustic (PA) contrast agent suitable for in vivo applications, that out-performs current conventional PA agents. Translation of transabdominal PA imaging is limited due to high optical attenuation of tissue when imaging at conventional wavelengths from the first near infrared (NIR) window. Though imaging at the NIR-2 window allows deeper light penetration due to minimized tissue scattering, there is a lack of optical contrast from endogenous chromophores at these wavelengths.

Currently, gold nanorods (AuNRs) are conventionally used as exogenous contrast for PA imaging at the NIR-2 window. However, AuNRs have large sizes leading to poor clearance in biological systems with adverse long-term effects due to bioaccumulation. Hence, there is a need for exogenous agents with high optical contrast at NIR-2 suited for in vivo applications. Here, using the TriTom compact PA tomography system, a semiconductor nanocrystal contrast agent was validated in vitro, then demonstrated in a mouse model.

Key Points:

  • Explore enhancement in photoacoustic image contrast using a novel NIR-2 agent
  • Compare increase in image contrast using the novel NIR-2 agent against conventional exogenous photoacoustic contrast agents