Optical Clearing of Ex Vivo Adipose Tissue.

Objectives: The paper focuses on the development of technology of adipose tissue optical clearing using different complex hyperosmotic optical clearing agents and tissue permeability enhancers.

Methods: To quantify optical clearing efficiency, reduced scattering coefficient was estimated from the ex vivo spatially resolved backreflectance measurements using a multi-distant fiber optical device. Tissue morphology modification was monitored with the help of histological studies.

Delivery and kinetics of immersion optical clearing agents in tissues: Optical imaging from ex vivo to in vivo.

Advanced optical imaging provides a powerful tool for the structural and functional analysis of tissues with high resolution and contrast, but the imaging performance decreases as light propagates deeper into the tissue. Tissue optical clearing technique demonstrates an innovative way to realize deep-tissue imaging and have emerged substantially in the last two decades. Here, we briefly reviewed the basic principles of tissue optical clearing techniques in the view of delivery strategies via either free diffusion or external forces-driven advection, and the commonly-used optical techniques for monitoring kinetics of clearing agents in tissue, as well as their ex vivo to in vivo applications in multiple biomedical research fields.

Stereoscopic spatial graphical method of Mueller matrix: Global-Polarization Stokes Ellipsoid.

A Mueller matrix covers all the polarization information of the measured sample, however the combination of its 16 elements is sometimes not intuitive enough to describe and identify the key characteristics of polarization changes. Within the Poincaré sphere system, this study achieves a spatial representation of the Mueller matrix: the Global-Polarization Stokes Ellipsoid (GPSE). With the help of Monte Carlo simulations combined with anisotropic tissue models, three basic characteristic parameters of GPSE are proposed and explained, where the V parameter represents polarization maintenance ability, and the E and D parameters represent the degree of anisotropy.

Unpaired fundus image enhancement based on constrained generative adversarial networks.

Fundus photography (FP) is a crucial technique for diagnosing the progression of ocular and systemic diseases in clinical studies, with wide applications in early clinical screening and diagnosis. However, due to the nonuniform illumination and imbalanced intensity caused by various reasons, the quality of fundus images is often severely weakened, brings challenges for automated screening, analysis, and diagnosis of diseases. To resolve this problem, we developed strongly constrained generative adversarial networks (SCGAN).

Gold/cobalt ferrite nanocomposite as a potential agent for photothermal therapy.

The study encompasses an investigation of optical, photothermal and biocompatibility properties of a composite consisting of golden cores surrounded by superparamagnetic CoFeO nanoparticles. Accompanied with the experiment, the computational modeling reveals that each adjusted magnetic nanoparticle redshifts the plasmon resonance frequency in gold and nonlinearly increases the extinction cross-section at ~800 nm. The concentration dependent photothermal study demonstrates a temperature increase of 8.

Biodegradable calcium carbonate carriers for the topical delivery of clobetasol propionate.

Inflammatory dermatoses represent a global problem with increasing prevalence and recurrence among the world population. Topical glucocorticoids (GCs) are the most commonly used anti-inflammatory drugs in dermatology due to a wide range of their therapeutic actions, which, however, have numerous local and systemic side effects. Hence, there is a growing need to create new delivery systems for GCs, ensuring the drug localization in the pathological site, thus increasing the effectiveness of therapy and lowering the risk of side effects.

Analysis of the experimental absorption spectrum of the rabbit lung and identification of its components.

The broadband absorption coefficient spectrum of the rabbit lung presents some particular characteristics that allow the identification of the chromophores in this tissue. By performing a weighted combination of the absorption spectra of water, hemoglobin, DNA, proteins and the pigments melanin and lipofuscin, it was possible to obtain a good match to the experimental absorption spectrum of the lung. Such reconstruction provided reasonable information about the contents of the tissue components in the lung tissue, and allowed to identify a similar accumulation of melanin and lipofuscin.

Optimized reconstruction of the absorption spectra of kidney tissues from the spectra of tissue components using the least squares method.

With the objective of developing new methods to acquire diagnostic information, the reconstruction of the broadband absorption coefficient spectra (μ [λ]) of healthy and chromophobe renal cell carcinoma kidney tissues was performed. By performing a weighted sum of the absorption spectra of proteins, DNA, oxygenated, and deoxygenated hemoglobin, lipids, water, melanin, and lipofuscin, it was possible to obtain a good match of the experimental μ (λ) of both kidney conditions. The weights used in those reconstructions were estimated using the least squares method, and assuming a total water content of 77% in both kidney tissues, it was possible to calculate the concentrations of the other tissue components.

Transcranial photobiomodulation for brain diseases: review of animal and human studies including mechanisms and emerging trends.

The brain diseases account for 30% of all known diseases. Pharmacological treatment is hampered by the blood-brain barrier, limiting drug delivery to the central nervous system (CNS). Transcranial photobiomodulation (tPBM) is a promising technology for treating brain diseases, due to its effectiveness, non-invasiveness, and affordability.

Berberine mediated fluorescent gold nanoclusters in biomimetic erythrocyte ghosts as a nanocarrier for enhanced photodynamic treatment.

Photodynamic therapy (PDT) is a well-established cancer treatment method that employs light to generate reactive oxygen species (ROS) causing oxidative damage to cancer cells. Nevertheless, PDT encounters challenges due to its oxygen-dependent nature, which makes it less effective in hypoxic tumor environments. To address this issue, we have developed a novel nanocomposite known as AuNC@BBR@Ghost.

Multimodal Method for Differentiating Various Clinical Forms of Basal Cell Carcinoma and Benign Neoplasms In Vivo.

Correct classification of skin lesions is a key step in skin cancer screening, which requires high accuracy and interpretability. This paper proposes a multimodal method for differentiating various clinical forms of basal cell carcinoma and benign neoplasms that includes machine learning. This study was conducted on 37 neoplasms, including benign neoplasms and five different clinical forms of basal cell carcinoma.

Monitoring of optical properties of tumors during laser plasmon photothermal therapy.

We studied grafted tumors obtained by subcutaneous implantation of kidney cancer cells into male white rats. Gold nanorods with a plasmon resonance of about 800 nm were injected intratumorally for photothermal heating. Experimental irradiation of tumors was carried out percutaneously using a near-infrared diode laser.

Multimodal optical clearing to minimize light attenuation in biological tissues.

The biggest obstacle to optical imaging is light attenuation in biological tissues. Conventional clearing techniques, such as agent-based clearing, improve light penetration depth by reducing scattering, but they are hampered by drawbacks including toxicity, low efficiency, slowness, and superficial performance, which prevent them from resolving the attenuation problem on their own. Therefore, quick, safe, and effective procedures have been developed.

Multimodal Diagnostics of Changes in Rat Lungs after Vaping.

(1) Background: The use of electronic cigarettes has become widespread in recent years. The use of e-cigarettes leads to milder pathological conditions compared to traditional cigarette smoking. Nevertheless, e-liquid vaping can cause morphological changes in lung tissue, which affects and impairs gas exchange.

Impact of e-cigarette liquid on porcine lung tissue-Ex vivo confocal Raman micro-spectroscopy study.

Ex vivo porcine lung immersed in e-liquid was investigated in-depth using confocal Raman micro-spectroscopy to assess the e-liquid influence on the lung. It was found that lung-related Raman band intensities at 1002, 1548, 1618 and 1655 cm increased after first and second treatments except the surface, which was attributed to the well-known optical clearing (OC) effect due to alveoli filling with e-liquid resulting in light scattering reduction. The autofluorescence enhancement was explained by oxidative stress induced in lung during exposure to e-liquid.

Correction: Verkhovskii et al. The Influence of Magnetic Composite Capsule Structure and Size on Their Trapping Efficiency in the Flow. 2022, , 6073.

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Optimization of machine learning classification models for tumor cells based on cell elements heterogeneity with laser-induced breakdown spectroscopy.

The rapid and accurate diagnosis of cancer is an important topic in clinical medicine. In the present work, an innovative method based on laser-induced breakdown spectroscopy (LIBS) combined with machine learning was developed to distinguish and classify different tumor cell lines. The LIBS spectra of cells were first acquired.

Effect of pulsed laser parameters on photoacoustic flow cytometry efficiency in vitro and in vivo.

Photoacoustic flow cytometry is one of the most effective approaches to detect "alien" objects in the bloodstream, including circulating tumor cells, blood clots, parasites, and emboli. However, the possibility of detecting high-amplitude signals from these objects against the background of blood depends on the parameters of the laser pulse. So, the dependencies of photoacoustic signals amplitude and number on laser pulse energy (5-150 μJ), pulse length (1, 2, 5 ns), and pulse repetition rate (2, 5, 10 kHz) for the melanoma cells were investigated.

skin optical clearing efficacy quantification of clinically compatible agents using line-field confocal optical coherence tomography.

Significance: The clinical use of optical methods for skin imaging is limited by skin strong scattering properties, which reduce image contrast and probing depth. The efficiency of optical methods can be improved by optical clearing (OC). However, for the use of OC agents (OCAs) in a clinical setting, compliance with acceptable non-toxic concentrations is required.

The Glycerol-Induced Perfusion-Kinetics of the Cat Ovaries in the Follicular and Luteal Phases of the Cycle.

The method of immersion optical clearing reduces light scattering in tissues, which improves the use of optical technologies in the practice of clinicians. In this work, we studied the optical and molecular diffusion properties of cat ovarian tissues in the follicular (F-ph) and luteal (L-ph) phases under the influence of glycerol using reflectance spectroscopy in a broad wavelength range from 200 to 800 nm. It was found that the reflectance and transmittance of the ovaries are significantly lower in the range from 200 to 600 nm than for longer wavelengths from 600 to 800 nm, and the efficiency of optical clearing is much lower for the ovaries in the luteal phase compared to the follicular phase.

Measurement of tissue optical properties in a wide spectral range: a review [Invited].

A distinctive feature of this review is a critical analysis of methods and results of measurements of the optical properties of tissues in a wide spectral range from deep UV to terahertz waves. Much attention is paid to measurements of the refractive index of biological tissues and liquids, the knowledge of which is necessary for the effective application of many methods of optical imaging and diagnostics. The optical parameters of healthy and pathological tissues are presented, and the reasons for their differences are discussed, which is important for the discrimination of pathologies and the demarcation of their boundaries.

Light distribution in fat cell layers at physiological temperatures.

Adipose tissue (AT) optical properties for physiological temperatures and in vivo conditions are still insufficiently studied. The AT is composed mainly of packed cells close to spherical shape. It is a possible reason that AT demonstrates a very complicated spatial structure of reflected or transmitted light.

Reconstruction of fluorophore absorption and fluorescence lifetime using early photon mesoscopic fluorescence molecular tomography: a phantom study.

Significance: Fluorescence molecular lifetime tomography (FMLT) plays an increasingly important role in experimental oncology. The article presents and experimentally verifies an original method of mesoscopic time domain FMLT, based on an asymptotic approximation to the fluorescence source function, which is valid for early arriving photons.

Aim: The aim was to justify the efficiency of the method by experimental scanning and reconstruction of a phantom with a fluorophore.