Monitoring of interaction of low-frequency electric field with biological tissues upon optical clearing with optical coherence tomography

et al. 2016

J. Biomed. Opt

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Skin optical clearing can significantly enhance the ability of biomedical optical imaging. Some alcohols and sugars have been selected to be optical clearing agents (OCAs). In this work, we paid attention to the optical clearing potential of disaccharides. Sucrose and maltose were chosen as typical disaccharides to compare with fructose, an excellent monosaccharide-OCA, by using molecular dynamics simulation and an ex vivo experiment. The experimental results indicated that the optical clearing efficacy of skin increases linearly with the concentration for each OCA. Both the theoretical predication and experimental results revealed that the two disaccharides exerted a better optical clearing potential than fructose at the same concentration, and sucrose is optimal. Since maltose has an extremely low saturation concentration, the other two OCAs with saturation concentrations were treated topically on rat skin in vivo, and optical coherence tomography imaging was applied to monitor the optical clearing process. The results demonstrated that sucrose could cause a more significant increase in imaging depth and signal intensity than fructose.

Section: Optical Coherence Tomography For Assessingmentioning

confidence: 99%

Skin optical clearing potential of disaccharides

Feng

et al. 2016

J. Biomed. Opt

Self Cite

“…An OCT angiography (Angio‐OCT) was applied to monitor in vivo skin optical clearing efficacy to obtain the quantitative comparisons, including imaging performances optimization, changes of skin optical properties and RI mismatching extent, and permeability rate as well. The Angio‐OCT used here not only has the capacity to produce high‐resolution 3‐dimention (3‐D) images of the in vivo tissues in different depth noninvasively completely with labelling free , but also can obtain the blood flow distribution information additionally .…”

Section: Introductionmentioning

confidence: 99%

A useful way to develop effective in vivo skin optical clearing agents

Journal of Biophotonics

Zhang

et al. 2016

Skin optical clearing has shown tremendous potential in improving various optical imaging performances, but there is some certain blindness in screening out high-efficiency in vivo optical clearing methods. In this work, three optical clearing agents: sucrose (Suc), fructose (Fruc) and PEG-400 (PEG), and two chemical penetration enhancers: propylene glycol (PG) and thiazone (Thiaz) were used. PEG was firstly mixed with the two penetration enhancers, respectively, and then mixed with Fruc and Suc, respectively, to obtain six kinds of skin optical clearing agents (SOCAs). Optical coherence tomography angiography was applied to monitor SOCAs-induced changes in imaging performances, skin optical properties, refractive index mismatching extent, and permeability rate. Experimental results demonstrated that PEG+Thiaz+Suc has the optimal capacity in enhancing the imaging performances, decreasing the scattering and the refractive index mismatching since Thiaz is superior to PG, and Suc is superior to Fruc. This study indicates that the optimal SOCA can be obtained directly by means of additionally adding or replacing the similar category substance in preexisting SOCAs with some more effective reagents. It not only provides an optimal SOCA, but also provides a useful way to develop more effective SOCAs. Cross-section skin structural texture (a), reconstructed blood flow distribution information (b), before or after treated with different SOCAs.

“…3,4 In a previous study, we found a mixture of fructose with PEG-400 and thiazone (FPT) allows in vivo blood flow imaging with higher contrast and resolution. 16 Currently, evaluation of a newly developed OCA is usually performed by imaging the blood flow in vivo 5,16 or by measuring the optical properties via integration sphere, 17 diffuse reflectance spectroscopy, 18 and OCT 7,[19][20][21] separately. LSCI allows a fullfield imaging of the cutaneous blood flow using speckle dynamics and has been used for evaluating the OCA-induced improvement in both the contrast and resolution of blood flow imaging.…”

Section: Introductionmentioning

confidence: 99%

“…7,19,21,26 The depth-resolved OCT signal offers an approach for measuring optical properties. 7,[19][20][21] Thus, the attenuation coefficient, refractive-index mismatching extent, and permeation rate of different tissue compounds can be quantified, which has played a vital role in evaluating the changes of tissue optical properties in previous studies. 21 OCA processing, skin optical properties, and blood flow imaging performances are closely correlated, but their relationship has seldom been reported.…”

Section: Introductionmentioning

confidence: 99%

Optical coherence tomography angiography offers comprehensive evaluation of skin optical clearingin vivoby quantifying optical properties and blood flow imaging simultaneously

Zhang

et al. 2016

J. Biomed. Opt

Abstract. Tissue optical clearing (TOC) is helpful for reducing scattering and enhancing the penetration depth of light, and shows promising potential in optimizing optical imaging performances. A mixture of fructose with PEG-400 and thiazone (FPT) is used as an optical clearing agent in mouse dorsal skin and evaluated with OCT angiography (Angio-OCT) by quantifying optical properties and blood flow imaging simultaneously. It is observed that FPT leads to an improved imaging performance for the deeper tissues. The imaging performance improvement is most likely caused by the FPT-induced dehydration of skin, and the reduction of scattering coefficient (more than ∼40.5%) and refractive-index mismatching (more than ∼25.3%) in the superficial (epidermal, dermal, and hypodermal) layers. A high correlation (up to ∼90%) between the relative changes in refractive-index mismatching and Angio-OCT signal strength is measured. The optical clearing rate is ∼5.83 × 10 −5 cm∕s. In addition, Angio-OCT demonstrates enhanced performance in imaging cutaneous hemodynamics with satisfactory spatiotemporal resolution and contrast when combined with TOC, which exhibits a powerful practical application in studying microcirculation. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.