Estimating transparency and penetration depth enhancement induced by clearing tissue using optical coherence tomography

Optical Coherence Tomography (OCT) technology offers numerous advantages, including non-contact imaging, rapid imaging capabilities, and high resolution. Although the enhancement of optical transparency through ultrasound is limited, the application of alcohol-based optical clearing agents (OCAs) combined with CaCO3 microspheres significantly improves the optical imaging of skin tissue. Using OCT, it has been demonstrated that the imaging depth of optically cleared skin tissue increases by approximately 14% due to the inclusion of CaCO3 microspheres. Molecular simulations reveal the hydrogen bonding interactions between collagen receptors, which are linked to the strong scattering characteristics of skin tissue, and four commonly used alcohol-based OCA small-molecule ligands. These simulation results correlate with the variations in imaging depth observed in experiments with different OCAs, thereby establishing the relevance and differences among various OCAs in enhancing the optical imaging effectiveness of biological tissues.