OPTICAL PROPERTIES OF SKIN,SUBCUTANEOUS,AND MUSCLE TISSUES:A REVIEW

The development of optical methods in modern medicine in the areas of diagnostics,therapy,and surgery has stimulated the investigation of optical properties of various biological tissues,since the efficacy of laser treatment depends on the photon propagation and fluence rate distribution within irradiated tissues.In this work,an overview of published absorption and scattering properties of skin and subcutaneous tissues measured in wide wavelength range is presented.Basic principles of measurements of the tissue optical properties and techniques used for processing of the measured data are outlined.

Quantification of glucose and glycerol diffusion in myocardium

The results on determination of glucose and glycerol difusion cofficients in myocardium tissuse are presented.The method is based on the measurement and analysis of temporal dependence of tissue optical collimated transmittance umder action of a hyperosmotic agent.This temporal tissue response is related to the rate of the agent and water diffusion in a tissue.The diffusion coefficients for tssue fAuid fluxes at glucose and glycerol application to the myocardium at 20℃ have been estimated as(4.75±3.40)×10^(-7) and(7.71±4.63)×10^(-7) cm^(2)/s,respectively.

Glycerol effects on optical,weight and geometrical properties of skin tissue

Complex study of glycerol effects on the skin tissue was performed.The change in optical,weight and geometrical parameters of the rat skin under the action of the glycerol solutions was studied ex vivo.Possible mechanisms of the skin optical clearing under the action of glycerol solutions of different concentrations were discussed.The results can be helpful for refinement of models developed to evaluate the effective diffusion coefficients of glycerol in tissues.

OPTICAL MEA SUREMENTS OF RAT MUSCLE SAMPLES UND ER TREATMENT WITH ETHYLENE GLYCOL AND GLUCOSE

With the objective to study the variation of optical properties of rat muscle during optical clearing,we have performed a set of optical measurements from that kind of tissue.The.measurements performed were total tr ansmittance,ollimated transmit tance,specular reflec-tance and total reflectance.This set of measurements is suficient to determine diffuse reflectance and absorbance of the sample,also necessary to est imate the optical properties.All the per formed measurements and calculated quantities will be used later in inverse Monte Carlo(IMC)simu-lations to determine the evolution of the optical properties of muscle during treatments with ethylene glycol and glucose.The results obt ained with the measurements already provide some information about the optical c learing treatments applied to the muscle and translate the mechanisms of turning the tissue more transparent and sequence of regimes of optical clearing.

The morpho-functional assessment of plasmonic photothermal therapy effects on transplanted liver tumor

The antitumor efficiency of gold nanorod plasmonic photothermal therapy(PPTT)was evalu-ated experimentally.The rat cholangiocarcinoma line PC-1 was used as a tumor model.Exposureof tumors to S08-nm laser radiation was performed,and the noninvasive temperature monitoring of the tumor tissue was carried out using infrared imager.The growth rate kinetics and mor-phological alterations of transplanted liver tumors,as wll as indicators of lipid peroxidation activity and autointoxication in rat serum,were studied,The activation of lipid peroxidation andthe development of autointoxication were detected after PPTT.The results not only demonstratethe antitumor ficacy of the proposed therapeutic technology but also reveal the side effectsin the presence of peroxidation products in systemic circulation.

PHOTOTHERAPY OF GINGIVITIS:PILOT CLINICAL STUDY

The goal of this work was to evaluate the safety and efficacy of the Red Light Emitted Toothbrush(R-LETB)emitting at wavelength of 663 nm with power density of 3.3mW/cm2 in combination with 0.1%-methylene blue(MB)solution for the reduction of plaque and treatment of gingivitis.A microbiological in vitro study and a pilot clinical study were conducted.The microbiological study has shown total suppression of pathogenicflora after a 3-min exposure to the dye solution followed by a 20-sec treatment with the R-LETB.For the clinical study,37 subjects of both sexes with gingivitis were enrolled and randomly assigned to one of two groups.Subjects in thefirst(treatment)group were instructed to rinse their mouth with MB solution provided for 1 min and then brush the teeth with the R-LETB and standardized toothpaste.The second(control)group used only the toothpaste and a regular toothbrush.Subjects in both groups followed their respective procedures 2 times a day(morning and evening)for 30 days.Indices of plaque,gingival bleeding,and inflammation were evaluated at 14-day and 30-day timepoints.In the both groups,all indices improved in comparison with baseline.However,the treatment group demonstrated more pronounced improvement of the studied indices that was attributed to additional anti-microbial action of red light and MB on gum tissue.Thus,the use of R-LETB with MB appears to have a multifactor therapeutic action on oral pathological microflora:mechanical removal of the bacteria and suppressing action on microorganisms due to photodynamic reaction.

Foreword to the Special Issue on Optical Technologies in Biophysics and Medicine

We are pleased to present the third issue of JIOHS,which focuses on optical technologies of diagnosticsand therapy,These are selected papers presented during Saratov Fall Meeting,1t International Sym-posium on Optics and Biophotonics(September 24-28,2013,Saratov,Russia)in the framework of the Workshops:"Optical Technologies in Biophysics_and Medicine,"Nanobiophotonics,"and"Internet Biophotonics."

ASSESSMENT OF TISSUE OPTICAL CLEARING AS A FUNCTION OF GLUCOSE CONCENTRATION USING OPTICAL COHERENCE TOMOGRAPHY

One of the major challenges in imaging biological tissues using optical techniques,such as optical coherence tomography(OCT),is the lack of light penetration due to highly turbid structures within the tissue.Optical clearing techniques enable the biological samples to be more optically homogeneous,allowing for deeper penetration of light into the tissue.This study investigates the effect of optical clearing utilizing various concentrations of glucose solution(10%,30%,and 50%)on porcine skin.A gold-plated mirror was imaged beneath the tissue and percentage clearing was determined by monitoring the change in reflected light intensity from the mirror over time.The ratio of percentage clearing per tissue thickness for 10%,30% and 50% glucose was determined to be 4.7±1.6%mm^(−1)(n=6),10.6±2.0%mm^(−1)(n=7)and 21.8±2.2%mm^(−1)(n=5),respectively.It was concluded that while higher glucose concentration has the highest optical clearing effect,a suitable concentration should be chosen for the purpose of clearing,considering the osmotic stress on the tissue sample.

Gold nanorods with a hematoporphyrin-loaded silica shell for dual-modality photodynamic and photothermal treatment of tumors in vivo

由一个金 nanorod 核心和与 hematoporphyrin (HP ) 做的 mesoporous 硅石壳组成的 Nanocomposites (NC ) 被制作了以便由在 vivo 联合 photothermal 和光力学的治疗(太平洋夏季时间 + PTT ) 改进癌症治疗的效率。除了 810830 nm 附近的长波长的电浆子回声，制作 NC 展出了相应的一座 400-nm 吸收度山峰围住 HP，在 632.5-nm Q 乐队附近在 633-nm 刺激下面产生了汗衫氧，并且生产了在 808-nm 下面的热在红外线附近(NIR ) 激光照耀。这些形式被用于联合太平洋夏季时间 + PTT 治疗大(大约 3 cm3 ) 在有一只 xenorafted 肿瘤老鼠的 vivo 的稳固的肿瘤当模特儿。NC 直接被注入肿瘤并且与 633-nm 和 808-nm 激光同时照耀刺激联合光力学并且 NC 的 photothermal 活动。联合治疗的效率被光连贯断层摄影术评估，组织学的分析，并且由肿瘤体积生长的大小在一个 21 天的时期期间。调停 NC 的太平洋夏季时间在组织组织学并且到导致了弱变化一中等在肿瘤体积的 20% 减少。相反，联合太平洋夏季时间 + PTT 处理导致了大区域的肿瘤坏死并且在肿瘤体积导致了戏剧的减少。

Histogram analysis of laser speckle contrast image for cerebral blood flow monitoring

激光点缀对比成像(LSCI ) 是为血流动印射的一个强大的工具。在这份报纸，我们基于激光点缀对比图象的直方图分析描述了一个简单算法提供在宏之间的快速的区别 -- 并且 microcirculations。算法被血流动的学习成功地在功能的激活下面在老鼠外皮验证。

PHOTONIC CRYSTAL WAVEGUIDE BIOSENSOR

The hollow core photonic crystal waveguide biosensor is designed and described.The biosensor was tested in experiments for artificial sweetener identifcation in drinks.The photonic crystal waveguide biosensor has a high sensitivity to the optical properties of liquids flling up the hollow core.The compactness,good integration ability to different optical systems and compatibility for use in industrial settings make such biosensor very promnising for v arious biomedical applicat ions.

FOREWORD

Special Issue Optical Technologies in the Study of Tissues and Biological Fluids We are pleased to present this special issue of JIOHS,which focuses on optical technologies in the study of tissues and biological liquids.The selected papers were presented during Saratov Fall Meeting—XII International School for Junior Scientists and Students on Optics,Laser Physics and Biophotonics(September 23–26,2008,Saratov,Russia)in the framework of the following workshops:“Optical Technologies in Biophysics and Medicine,”“Nanostructures and Nanoparticles,”“Microscopic and Low-Coherence Methods in Biomedical Applications,”and“Internet Biophotonics.”All eight papers in this special issue are research papers.

A special issue on Biomedical Photonics

During the last decades, there have been significant developments in the field of biomedical photonics. We are pleased to present a special issue of Frontiers of Optoelectronics on Biomedical Photonics, which assembles one letter, three reviews, and eight original research articles. Optical coherence tomography （OCT） has the ability to image tissues in vivo. Polarization-sensitive optical coherence tomography （PSOCT） is a functional extension of OCT. By measuring the polarization state of light reflecting or scattering back from tissue, PSOCT enables depth-resolved mapping of sample polarization information, such as phase-retardation and optical axis orientation. In this issue, Zhenyang Ding et al. gave a review of technology developments and biomedical applications of PSOCT. Fourier domain optical coherence tomography （FDOCT） provides cross-sectional images of tissuematerial microstructures by spectral analysis of the low-coherence interference fringe pattern. Zhihua Ding et al. developed two novel systems with ultralong depth range. One is the orthogonal dispersive spectral domain optical coherence tomography （SDOCT）, and the other is the recirculated swept source interferometer/OCT. No compromise between depth range and depth resolution is required in both systems. With their SDOCT system, Jian Gao et al. imaged mouse model with dorsal skin window chamber, they obtained a series of real-time OCT images and reconstructed 3D images of the specific area inside the dorsal skin window chamber by Amira.