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

Optical clearing of laser-induced tissue plasma

We studied the effect of optical clearing (OC) by glycerol on laser-induced tissue plasma using the immersion method. The results demonstrated the apparently enhanced effect of glycerol on the molecular spectra of the laser induced plasma. The OC is more sensitive to the molecular bands than atomic lines. After tissue immersion in the glycerol, the electron density of tissue plasma is decreased. The laser plasma temperature of the glycerol treated tissue is higher than for virgin fresh tissue. The tissue plasma after the glycerol application is still in the local thermal equilibrium plasma state. This work presents a new perspective for OC application that can extend from tissue better imaging quality to improvement of laser plasma generation

Detection of melanoma cells in whole blood samples using spectral imaging and optical clearing

Most cancer deaths are associated with metastases resulting from the spread of circulating tumor cells (CTCs) from the primary tumor to vital organs. The existing methods for detection of CTCs as markers of metastasis progression are time consuming with several steps of sample processing, including red blood cell removal, labeling, immunomagnetic capture and isolation, which can lead to loss of CTCs. Here we introduce a method for detection and identification of CTCs using spectral absorption imaging of melanoma cells and optical clearing of whole blood samples. Verification of this approach was performed using phantoms of human melanoma cells and suspensions of mouse melanoma cells of line B16F10 alone and in mixture with blood. A method for improving detection sensitivity has been demonstrated applying optical clearing of mouse blood using biocompatible chemical agents. The findings suggest that the proposed diagnostic platform has the potential to detect quickly CTCs in whole blood samples from patients with melanoma

Light distribution in fat cell layers at physiological temperatures

Abstract 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. It was shown with a cellular tissue phantom, is split into a fan of narrow tracks, originating from the insertion point and representing filament-like light distribution. The development of suitable approaches for describing light propagation in a AT is urgently needed. A mathematical model of the propagation of light through the layers of fat cells is proposed. It has been shown that the sharp local focusing of optical radiation (light localized near the shadow surface of the cells) and its cleavage by coupling whispering gallery modes depends on the optical thickness of the cell layer. The optical coherence tomography numerical simulation and experimental studies results demonstrate the importance of sharp local focusing in AT for understanding its optical properties for physiological conditions and at AT heating

Immersion optical clearing of adipose tissue in rats: ex vivo and in vivo studies

Optical clearing (OC) of adipose tissue has not been studied enough, although it can be promising in medical applications, including surgery and cosmetology, for example, to visualize blood vessels or increase the permeability of tissues to laser beams. The main objective of this work is to develop technology for OC of abdominal adipose tissue in vivo using hyperosmotic optical clearing agents (OCAs). The maximum OC effect (77%) was observed for ex vivo rat adipose tissue samples exposed to OCA on fructose basis for 90 minutes. For in vivo studies, the maximum effect of OC (65%) was observed when using OCA based on diatrizoic acid and dimethylsulfoxide for 120 minutes. Histological analysis showed that in vivo application of OCAs may induce a limited local necrosis of fat cells. The efficiency of OC correlated with local tissue damage through cell necrosis due to accompanied cell lipolysi