Photoacoustic microscopy for cells in a 3D microenvironment: Systems and applications

Abstract

Imaging of living cells in a three-dimensional (3D) culture system is of critical importance in order to understand the interplay between cells and the surrounding matrix components. However, the use of conventional imaging methods, such as optical microscopy, is limited due to the lack of penetration. To overcome the limitation, optical-resolution photoacoustic microscopy (OR-PAM) has been proposed and widely investigated. The OR-PAM is based on the photoacoustic effect with which high frequency acoustic waves are generated when the medium absorbs light energy within a short pulse duration. It, therefore, takes advantages of the high optical absorption contrast with low acoustic scattering, allowing non-invasive visualization the cells at depths with optical resolution. With the advance of targeted contrast agents, the OR-PAM is also capable of facilitating molecular characterization for pre-clinical research on personalized diagnostics or guided therapeutics. In this presentation, the applications and challenges of photoacoustic microscopy in a 3D cellular microenvironment are covered. Potential future development of photoacoustic microscopy in pre-clinical applications is also discussed.