Visualisation of distribution of gold nanoparticles in liver tissues ex vivo and in vitro using the method of optical coherence tomography

Abstract. The possibility of visualising the distribution of gold nanoparticles in liver by means of the method of optical coherence tomography is studied experimentally in model samples of beef liver in vitro and rat liver ex vivo. In the experiments we used the gold nanoparticles in the form of nanocages with resonance absorption in the near-IR spectral region. In the model studies the suspension of nanoparticles was applied to the surface of the sample, which then was treated with ultrasound. In the ex vivo studies the suspension of nanoparticles was injected to the laboratory rats intravenously. The image contrast and the optical depth of detection of blood vessels and liver structure components are calculated, as well as the depth of liver optical probing before and after the injection of nanoparticles. It was shown that the administration of the nanoparticle increases significantly the imaging contrast of liver blood vessels owing to the localisation of the nanoparticles therein

A robust ex vivo method to evaluate the diffusion properties of agents in biological tissues

A robust method is presented for evaluating the diffusion properties of chemicals in ex vivo biological tissues. Using this method that relies only on thickness and collimated transmittance measurements, the diffusion properties of glycerol, fructose, polypropylene glycol and water in muscle tissues were evaluated. Amongst other results, the diffusion coefficient of glycerol in colorectal muscle was estimated with a value of 3.3 × 10−7 cm2/s. Due to the robustness and simplicity of the method, it can be used in other fields of biomedical engineering, namely in organ cryoprotection and food industry

Optical properties of human skin, subcutaneous and mucous tissues in the wavelength range from 400 to 2000 nm,"

Abstract The optical properties of human skin, subcutaneous adipose tissue and human mucosa were measured in the wavelength range 400-2000 nm. The measurements were carried out using a commercially available spectrophotometer with an integrating sphere. The inverse adding-doubling method was used to determine the absorption and reduced scattering coefficients from the measurements

In vivo optical monitoring of transcutaneous delivery of calcium carbonate microcontainers

We have developed a method for delivery of biocompatible CaCO3 microcontainers (4.0 ± 0.8 µm) containing Fe3O4 nanoparticles (14 ± 5 nm) into skin in vivo using fractional laser microablation (FLMA) provided by a pulsed Er:YAG laser system. Six laboratory rats have been used for the microcontainer delivery and weekly monitoring implemented using an optical coherence tomography and a standard histological analysis. The use of FLMA allowed for delivery of the microcontainers to the depth about 300 μm and creation of a depot in dermis. On the seventh day we have observed the dissolving of the microcontainers and the release of nanoparticles into dermis

Laser therapy of acute and chronic maxillary sinusitis

ABSTRACT The clinical results of photodynamic therapy of maxillary sinusitis have been presented. 0.1 %-Methylene Blue aqueous solution in combination with He-Ne laser irradiation (632.8 nm) has been used for treatment of patients with acute and chronic maxillary sinusitis. Efficacy of the photodynamic therapy was estimated with the use of the following criteria: the state of respiration, olfaction, duration of purulent discharge, reconstruction of transport function of ciliary epithelium, etc. The obtained results have shown that the photodynamic therapy is effective in comparison with conservative methods of treatment of the diseases

Study of the possibility of increasing the probing depth by the method of reflection confocal microscopy upon immersion clearing of near-surface human skin layers.

The possibility of increasing the human-skin probing depth by the method of reflection confocal microscopy (RCM) upon decreasing the amplitude of spatial fluctuations of the refractive index of the upper skin layers is considered. A change in the probing depth is estimated by analysing the spatial distribution of the probability density of the effective optical paths of detected photons calculated by the Monte Carlo method. The results of the numerical simulation are interpreted within the framework of the possible application of RCM to the study of the human skin exposed to an immersion liquid compatible to it. A diffusion of the immersion agent into the skin depth involves the equalising of the refractive indices of the structural elements of near-surface skin layers, which in turn causes a decrease in the scattering intensity and a certain increase in the transparency of the upper tissue layers. It is shown that a decrease in the light scattering in the near-surface skin layers leads to a significant increase in the probing depth obtained with the RCM technique

The Enhancement of Confocal Images Of Tissues at Bulk Optical Immersion.

The purpose of the present work is a theoretical examination of how localised skin-tissue dehydration affects the depth of the confocal probing and what depth of effective detection can be reached with the chemical administration of skin tissues. A semi-infinite multilayer Monte Carlo model is used to estimate spatial localisation of the output signal offered by a confocal probe. A solution of glycerol is taken in the capacity of innocuous osmotic agent. Diffusion of this bio-compatible chemical agent into the skin temporarily pushes water out of the tissues and results in the matching of the refractive indices of skin structural elements. This temporarily decreases scattering and increases transparency of topical skin layers, which allows for unrestricted light to permeate deeper into the skin. The results of simulation show that signal spatial localization offered by a confocal probe in the skin tissues during their clearing is usable for the monitoring of deep reticular dermis and improving the image contrast and spatial resolution. A discussion of the optical properties of skin tissues and their changes due to diffusion of glycerol into the skin is given. Optical properties of tissues and their changes due to chemical administration are estimated based on the results of experimental in vitro study with rat and human skin

A Highly Conductive and Mechanically Robust OH– Conducting Membrane for Alkaline Water Electrolysis

In an alkaline water electrolysis cell, a membrane is needed between the cathode and the anode to avoid mixing of hydrogen and oxygen products while enabling OH- transport. Hydroxide ion conductivity and membrane mechanical properties are both important parameters that determine material constraints on low electrical resistance of a membrane versus sufficient structural integrity. Herein, we demonstrate a strategy to make membranes with both high OH- conductivity and mechanical strength. A chemically tailored OH- conducting polymer (qPPO) was synthesized via amination and subsequent quaternization of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and was blended with poly(vinyl alcohol) (PVA) to provide an environment analogous to basic water solutions. The -OH groups in PVA provide high-density Grotthuss mechanism conduction sites similar to water, which may be the key reason for the observed high OH- conductivity of the membranes. The PVA backbone was cross-linked to form a semi-interpenetrating network (semi-IPN) of PVA and qPPO; the resulting material contains PVA chemical cross-links and hydrogen bonds between PVA and qPPO and between PVA with itself, all of which are believed to contribute to a high tensile strength. By tuning the PVA/qPPO ratio, the transport and mechanical properties were optimized. The membrane with 30% qPPO possesses both extraordinary conductivity (151 mS/cm at room temperature) - about 2.7 times as high as Nafion 117 in acidic conditions - and high ultimate tensile strength (126 MPa (dry), 41 MPa (wet)). This highly conductive polymer membrane also exhibits stability in alkaline water electrolysis at room temperature, a property that makes qPPO an interesting and potentially translational material for the design of hydroxide-based electrochemical cells.National Science Foundation (Grant CHE-1305124

Efficacy and safety of combined vs. single renin-angiotensin-aldosterone system blockade in chronic kidney disease

Hypertension and proteinuria are well-known predictors of chronic kidney disease (CKD) progression. Therapeutic interventions have different magnitude of albuminuria and hypertension. This study was designed to evaluate the efficacy and safety of combined vs. single renin-angiotensin-aldosterone system (RAAS) blockade in chronic kidney disease. Forty (28 female) patients with chronic kidney diseases were collected from nephrology outpatient clinic, internal medicine department, Beni Suef University hospital. They were divided randomly into 2 groups. Group A was 24 (20 females) patients treated with Enalapril, as angiotensin converting enzyme inhibitor (ACE-I) alone. Group B was 16 (8 females) patients treated with combination of Enalapril and Irbesartan, as angiotensin receptor blocker (ARB). All patients were subjected to full history taking; thorough clinical examination; certain laboratory tests and renal function tests at the start of the study, 1.5 and 3 months later. Proteinuria, urinary albumin/creatinine ratio (UACR), systolic blood pressure (SBP) and glomerular filtration rate (GFR) were significantly (p [Med-Science 2016; 5(3.000): 751-7