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

Complex study of glycerol e®ects 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 di®erent concentrations were discussed. The results can be helpful for re¯nement of models developed to evaluate the e®ective di®usion coe±cients of glycerol in tissues

Refractive properties of human adipose tissue at hyperthermic temperatures

The refractive index (RI) of human adipose tissu

Laser speckle contrast imaging for monitoring of acute pancreatitis at ischemia-reperfusion injury of the pancreas in rats

The in°uence of ischemia–reperfusion (I/R) action on pancreatic blood °ow (PBF) and the development of acute pancreatitis (AP) in laboratory rats is evaluated in vivo by using the laser speckle contrast imaging (LSCI). Additionally, the optical properties in norm and under condition of AP in rats were assessed using a modi¯ed integrating sphere spectrometer and inverse Monte Carlo (IMC) software. The results of the experimental study of microcirculation of the pancreas in 82 rats in the ischemic model are presented. The data obtained con¯rm the fact that local ischemia and changes in the blood °ow velocity of the main vessels cause and provoke acute pancreatitis

Kinetics of rat skin optical clearing at topical application of 40%glucose: ex vivo and in vivo studies

Optical, molecule diffusion, and mechanical properties of skin and blood microcirculation in the underlying tissues at topical application of 40%-glucose solution in rats were investigated. Optical clearing of ex vivo and in vivo skin was measured within the wavelength range of 400-900 nm using standard spectrometer, and blood microcirculation alterations was measured with laser speckle contrast imaging. Increase of skin collimated transmittance, transverse, and along skin shrinkage and weight loss was observed for the first 20-60 min of immersion, for the longer time, tissue swelling was found. The glucose diffusion coefficients in ex vivo and in vivo rat skin were evaluated as (1.11 ± 0.78) × 10 -6 and (1.54 ± 0.28) × 10 -6 cm 2 /s, respectively. The decrease of average rate of microcirculation in 2.2 fold was observed. The results received allow one to evaluate glucose impact on skin tissue optical and mechanical properties and blood microcirculation

Investigation of the change of tumor optical properties after laser-induced plasmon-resonant photothermal treatment of transplanted tumors in rats

The paper presents the investigation of change of tumor optical properties of the rat tumor doped by gold nanoparticles after laser-induced plasmon-resonant photothermal treatment. To obtain the model tumors the rats have been implanted by suspension of alveolar kidney cancer cells. An hour before the experiment the animals have been injected by the suspension of gold nanorods intratumorally. For irradiation a diode laser with wavelength 808 nm has been used. After the irradiation the tumor has been removed and sliced. Spectra of total and collimated transmission and diffuse reflectance of the samples of different layers of the tumors have been measured in the wavelength range 350-2500 nm. Absorption, scattering, reduced scattering coefficients and scattering anisotropy factor of tumor tissues have been calculated with inverse adding-doubling method. The results of the experiment have shown that after doping the tumor tissue by the plasmon resonant nanoparticles and NIR laser irradiating, there is the decreases of absorption as well as scattering properties of the tumor and surrounding tissues. However, despite the sufficiently high temperature on the surface (about 80°C), the changes in the center of the tumor are insignificant

The assessment of effectiveness of plasmonic resonance photothermal therapy in tumor-bearing rats after multiple intravenous administration of gold nanorods

To assess the effectiveness of plasmonic photothermal therapy (PPT) multiple intravenous strategy of gold nanorods (GNRs) administration was used before laser exposure. The model of alveolar liver cancer PC-1 was used in male outbred albino rats, which were intravenously administrated by single and multiple injections of GNRs and then were treated by PPT. The gold dosage was 400 μg (single injection group), 800 μg (double injection group), 1200 μg (triple injection group), and absorption maximum of gold nanorods suspension was at the wavelength of 808 nm. 24 hours after last injection the tumors were irradiated by the 808-nm diode laser during 15 min at power density 2.3 W/cm2. Temperature control of the tumor heating was provided by IR imager. 24 hours after the PPT the half of animals from each group was withdrawn from the experiments and the sampling tumor tissue for morphological study was performed. In survived animals the growth of tumors was evaluated during 21 days after the PPT. The antitumor effects of PPT after triple intravenous injection were comparable with those obtained at direct intratumoral administration of similar total dose of GNRs. The effectiveness of PPT depended on gold accumulation in tumor, probably, due to sufficient vascularizTation of tumor tissue

Monte Carlo study of skin optical clearing to enhance light penetration in the tissue: implications for photodynamic therapy of acne vulgaris

ABSTRACT Result of Monte Carlo simulations of skin optical clearing is presented. The model calculations were carried out with the aim of studying of spectral response of skin under immersion liquids action and calculation of enhancement of light penetration depth. In summary, we have shown that: 1) application of glucose, propylene glycol and glycerol produced significant decrease of light scattering in different skin layers; 2) maximal clearing effect will be obtained in case of optical clearing of skin dermis, however, absorbed light fraction in skin dermis changed insignificantly, independently on clearing agent and place it administration; 3) in contrast to it, the light absorbed fraction in skin adipose layer increased significantly in case of optical clearing of skin dermis. It is very important because it can be used for development of optical methods of obesity treatment; 4) optical clearing of superficial skin layers can be used for decreasing of power of light radiation used for treatment of acne vulgaris

Tissue optical clearing as a diagnostic tool for tissue pathology differentiation

With the objective of developing a diagnostic tool

The morphological changes in transplanted tumors of rats at plasmonic photothermal therapy

The aim of work was to study the morphological changes in transplanted liver tumors of rats after plasmonic photothermal therapy (PPTT). The gold nanorods functionalized with thiolated polyethylene glycol were injected intravenously to rats with transplanted liver cancer PC-1. A day after injection the tumors were irradiated by the infrared 808-nm diode laser. The withdrawal of the animals from the experiment and sampling of tumor tissue for morphological study were performed 24 hours after the laser exposure. The standard histological and immunohistochemical staining with antibodies to proliferation marker Ki-67 and apoptosis marker BAX were used for morphological study of transplanted tumors. The plasmonic photothermal therapy had pronounced damaging effect in rats with transplanted liver tumors expressed in degenerative and necrotic changes in the tumor cells. The decrease of proliferation marker Ki-67 and increase of expression of apoptosis marker BAX were observed in tumor cells after PPTT

Model of optical phantoms thermal response upon irradiation with 975 nm dermatological laser

We have developed a numerical model describing the optical and thermal behavior of optical tissue phantoms upon laser irradiation. According to our previous studies, the phantoms can be used as substitute of real skin from the optical, as well as thermal point of view. However, the thermal parameters are not entirely similar to those of real tissues thus there is a need to develop mathematical model, describing the thermal and optical response of such materials. This will facilitate the correction factors, which would be invaluable in translation between measurements on skin phantom to real tissues, and gave a good representation of a real case application