We report our pilot results on quantification of glucose (G) diffusion permeability in human normal esophagus and ESCC tissues in vitro by using OCT technique. The permeability coefficient of 40% aqueous solution of G was found to be (1.74±0.04)×10-5 cm/s in normal esophagus and (2.45±0.06)×10-5 cm/s in ESCC tissues. The results from this study indicate that ESCC tissues had a higher permeability coefficient compared to normal esophageal tissues, and the light penetration depths gradually increase with the increase of applied topically with G time for the normal esophageal and ESCC tissues. The results indicate that the permeability coefficient of G in cancer tissues was 1.41-fold than that in normal tissues, and the light penetration depth for the ESCC tissues is significantly smaller than that of normal esophagus tissues in the same time range. These results demonstrate that the optical clearing of normal and cancer esophagus tissues are improved after application of G.

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)×10-5 cm/s in breast cancer tissues, and (0.89±0.02)×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.

No abstract

The absorption coefficients, the reduced scattering coefficients and the optical penetration depths for native and coagulated human normal and adenomatous colon tissues in vitro were determined over the range of 400-1,100 nm using a spectrophotometer with an internal integrating sphere system, and the inverse adding-doubling method was applied to calculate the tissue optical properties from diffuse reflectance and total transmittance measurements. The experimental results showed that in the range of 400-1,100 nm there were larger absorption coefficients (P < 0.01) and smaller reduced scattering coefficients (P < 0.01) for adenomatous colon tissues than for normal colon tissues, and there were smaller optical penetration depths for adenomatous colon tissues than for normal colon tissues, especially in the near-infrared wavelength. Thermal coagulation induced significant increase of the absorption coefficients and reduced scattering coefficients for the normal and adenomatous colon tissues, and significantly reduced decrease of the optical penetration depths for the normal and adenomatous colon tissues. The smaller optical penetration depth for coagulated adenomatous colon tissues is a disadvantage for laser-induced thermotherapy (LITT) and photodynamic therapy (PDT). It is necessary to adjust the application parameters of lasers to achieve optimal therapy.

Abstract. Previous studies have demonstrated the ultrasound-induced skin optical clearing enhancement with topical application of 60% glycerol ͑G͒ on in vitro porcine skin and in vivo human skin. Our purpose was to find the relation between the effect of optical skin clearing and different concentrations of glycerol and to find more effective ultrasound-glycerol combinations on optical skin clearing. The enhancement effect of ultrasound ͓Sonophoresis ͑SP͒ delivery͔ in combination with 40% G, 60% G, and 80% G on in vitro human skin optical clearing was investigated. Light imaging depths of skin were measured using optical coherence tomography. Different concentrations of glycerol and ultrasound with a frequency of 1 MHz and an intensity of 0.5 W / cm 2 was simultaneously applied for 15 min. The results show that with the increase of concentration of glycerol, the optical clearing of skin is much improved. Optical clearing capability of glycerol was more enhanced with simultaneous application of ultrasound compared with glycerol alone. The attenuation coefficients of skin tissues after application of 40% G/SP, 60% G/SP, and 80% G/SP decreased approximately 11.8%, 18.5%, and 20.0% at 15 min compared with 40% G, 60% G, and 80% G alone, respectively. The greatest decrease in attenuation coefficients at 60 min was approximately 52.3% and 63.4% for 80% G ͑without ultrasound͒ and 80% G/SP ͑with ultrasound͒, respectively, which are 2.1-fold and 2.6-fold to that in the 40% G.

Here we examined the effect of human normal breast (NB) and breast cancer (BC) tissues in vitro after treatment with glycerol in conjunction with ultrasound (surgeonperformed, SP) by OCT for functional imaging to monitor. 60% glycerol (G) and SP was simultaneously applied for 5 min. Depth-and time-resolved profiles for OCT signal enhancement were presented. The results show that OCT imaging depth of breast tissues after treatment with 60% G in combined with SP more obviously improved than that after application of glycerol alone. The permeability coefficient of 60% glycerol in 60% G/NB, 60% G/BC, 60% G/SP/NB, and 60% G/SP/BC were (0.91±0.02)×10 cm/s, (1.63±0.04)×10−5 cm/s, and (7.98±0.19)×10 −5 cm/s, respectively. The permeability coefficient of glycerol in 60% G/SP/NB was 1.84-fold than that in 60% G/NB, but there was 2.54-fold on permeability coefficient comparing 60% G/SP/BC with that in 60% G/BC. The results from this study indicated that the permeability coefficient of glycerol not only in normal breast tissues, but also in breast cancer tissues after treatment with ultrasound is larger than that in tissues without ultrasound. The relative permeability coefficient of 60% glycerol diffusion of normal breast and breast cancer treatment with ultrasound than without ultrasound for 5 min

The purpose of the study is to analyze and compare differences in the optical properties between normal and adenomatous human colon tissues in vitro at 630-, 680-, 720-, 780-, 850-, and 890-nm wavelengths using a Ti:sapphire laser. The optical parameters of tissue samples are determined using a double integrating sphere setup at seven different laser wavelengths. The inverse Monte Carlo simulation is used to determine the optical properties from the measurements. The results of measurement show that the optical properties and their differences vary with a change of laser wavelength for normal and adenomatous colon mucosa/submucosa and normal and adenomatous colon muscle layer/chorion. The maximum absorption coefficients for normal and adenomatous human colon mucosa/submucosa are 680 nm, and the minimum absorption coefficients for both are 890 nm. The maximum difference of the absorption coefficients between both is 56.8% at 780 nm. The maximum scattering coefficients for normal and adenomatous colon mucosa/submucosa are 890 nm, and the minimum scattering coefficients for both are 780 nm. The maximum difference of the scattering coefficients between both is 10.6% at 780 nm. The maximum absorption coefficients for normal and adenomatous colon muscle layer/chorion are 680 nm, and the minimum absorption coefficients for both are 890 nm. The maximum difference of the absorption coefficients between both is 47.9% at 780 nm. The maximum scattering coefficients for normal and adenomatous colon muscle layer/chorion are 890 nm, and the minimum scattering coefficients for both are 680 nm. The maximum difference of the scattering coefficients between both is 9.61% at 850 nm. The differences in absorption coefficients between normal and adenomatous tissues are more significant than those in scattering coefficients.

The objective of this work is to quantify and compare the optical clearing efficacy of glucose, propylene glycol, glycerol solutions through the human skin tissue in vivo by calculating permeability coefficient of three solutions. Currently, the permeability coefficient of agent in tissues was extracted from optical coherence tomography (OCT) amplitude data mainly through the OCT signal slope and the OCT amplitude methods. In this study, we report the OCT attenuation coefficient method which is a relatively novel and rarely reported methodology to measure the permeability coefficient during the optical skin clearing procedure. The permeability coefficients for 40% propylene glycol, glucose and glycerol were (2.74 ± 0.05) × 10(-6) cm s(-1), (1.78 ± 0.04) × 10(-6) cm s(-1) and (1.67 ± 0.04) × 10(-6) cm s(-1), respectively. It could be clearly seen that the permeability coefficient of the 40% propylene glycol solution is higher than that of 40% glucose solution, and the permeability coefficient of the 40% glucose solution is higher than that of the 40% glycerol solution. These indicate 40% propylene glycol solution is more effective than others in the human skin in vivo. We then compare and prove consistency of optical clearing efficacy figured out by three different methods.