Quantification of glycerol diffusion in human normal and cancer breast tissues in vitro with optical coherence tomography

Optical coherence tomography (OCT) holds great promise as a routine research tool for analysis of identifying the boundaries between normal and diseased breast tissue in vitro and in vivo. However, despite the depth penetration afforded by this imaging modality, light attenuation in tissues imposes limitations. Here we studied the optical clearing effect of glycerol in human cancer and normal breast tissues with OCT for functional imaging to monitor. Depth- and time-resolved profiles for OCT signal enhancement were presented. The results show that the OCT imaging depth and imaging contrast of breast tissues have been improved after application of 60% glycerol in the 2-D OCT images. The OCT slope signals of breast tissues decreased as glycerol diffusion into tissues, therefore, the water and intercellular fluids were drawn out from tissues. Then the reverse process due to water was drawn back into the cells as a result of its affinity for water. The permeability coefficient of 60% glycerol was (3.14 +/- 0.07)x 10(-5) cm/s in breast cancer tissues, and (0.89 +/- 0.02) x 10(-5) cm/s in normal breast tissues, respectively. The permeability coefficient of glycerol in cancer tissues was 3.54-fold than that in normal tissues. These results demonstrate that the optical clearing of normal and cancer breast tissues are improved after application of glycerol. [GRAPHICS] OCT signal slope graph as a function of time from human breast cancer tissues treatment with 60% glycerol (C) 2010 by Astro Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA