Multimodal Diagnostics of Microrheologic Alterations in Blood of Coronary Heart Disease and Diabetic Patients

Correlation between the Capillary Blood Flow Characteristics and Endothelium Function in Healthy Volunteers and Patients Suffering from Coronary Heart Disease and Atrial Fibrillation: A Pilot Study

Coronary heart disease (CHD) and atrial fibrillation (AF) pose significant health risks and require accurate diagnostic tools to assess the severity and progression of the diseases. Traditional diagnostic methods have limitations in providing detailed information about blood flow characteristics, particularly in the microcirculation. This study's objective was to examine and compare the microcirculation in both healthy volunteers and patient groups with CHD and AF. Furthermore, this study aimed to identify a relationship between blood microcirculation parameters and endothelial function. Digital capillaroscopy was employed to assess the microcirculation parameters, for example, such as capillary blood flow velocity, the size of red blood cell aggregates, and the number of aggregates per min and per running mm. The results indicate significant alterations in blood flow characteristics among patients with CHD and AF compared to healthy volunteers. For example, capillary blood flow velocity is statistically significantly decreased in the case of CHD and AF compared to the healthy volunteers (p < 0.001). Additionally, the correlation between the measured parameters is different for the studied groups of patients and healthy volunteers. These findings highlight the potential of digital capillaroscopy as a non-invasive tool for evaluating blood flow abnormalities (red blood cell aggregates and decreased capillary blood flow velocity) in cardiovascular diseases, aiding in early diagnosis and disease management.

Analysis of Polarization Images in the Microphysical Blood Parameters Research for the Hematocrit Diagnostics

The development of non-invasive optoelectronic technologies for human blood monitoring is one of the important research areas for medicine. A critical analysis of optoelectronic methods of blood research and the micromechanical systems based on them is carried out in this article. A design realization of a polarizing portable system for non-invasive monitoring of hematocrit as one of the basic homeostatic constants of the human body containing information about the microphysical parameters of blood cells has been substantiated. A physical model of polarized radiation conversion in a video information system of laser sensing of a biological research object has been formed. Visual and quantitative differences in the spatial distribution of polarization parameters of the scattered radiation for the states of the body with different hematocrit levels have been revealed. A scheme of a multichannel imaging portable system, based on a smartphone using miniature optical and microelectronic components of information conversion for non-invasive monitoring of microphysical blood parameters, has been created. The system implements the principle of polarimetric blood photometry and a multiparametric analysis of the polarization properties of the laser radiation scattered by blood. The developed portable optoelectronic system, based on a smartphone, can be used for rapid blood diagnostics in disaster medicine and the presence of clinical contraindications to the formation of invasive tests. The proposed polarization-based approach is a promising automated alternative to traditional devices and systems for the research of microphysical blood parameters.

Probing Red Blood Cell Membrane Microviscosity Using Fluorescence Anisotropy Decay Curves of the Lipophilic Dye PKH26

Red blood cell (RBC) aggregation and deformation are governed by the molecular processes occurring on the membrane. Since several social important diseases are accompanied by alterations in RBC aggregation and deformability, it is important to develop a diagnostic parameter of RBC membrane structural integrity and stability. In this work, we propose membrane microviscosity assessed by time-resolved fluorescence anisotropy of the lipophilic PKH26 fluorescent probe as a diagnostic parameter. We measured the fluorescence decay curves of the PKH26 probe in the RBC membrane to establish the optimal parameters of the developed fluorescence assay. We observed a complex biphasic profile of the fluorescence anisotropy decay characterized by two correlation times corresponding to the rotational diffusion of free PKH26, and membrane-bounded molecules of the probe. The developed assay allowed us to estimate membrane microviscosity ηm in the range of 100-500 cP depending on the temperature, which paves the way for assessing RBC membrane properties in clinical applications as predictors of blood microrheological abnormalities.

Application of optical tweezers in cardiovascular research: More than just a measuring tool

Recent advances in the field of optical tweezer technology have shown intriguing potential for applications in cardiovascular medicine, bringing this laboratory nanomechanical instrument into the spotlight of translational medicine. This article summarizes cardiovascular system findings generated using optical tweezers, including not only rigorous nanomechanical measurements but also multifunctional manipulation of biologically active molecules such as myosin and actin, of cells such as red blood cells and cardiomyocytes, of subcellular organelles, and of microvessels in vivo. The implications of these findings in the diagnosis and treatment of diseases, as well as potential perspectives that could also benefit from this tool, are also discussed.

Problems of Red Blood Cell Aggregation and Deformation Assessed by Laser Tweezers, Diffuse Light Scattering and Laser Diffractometry

This study aims to highlight the problems with implementing optical techniques (laser tweezers, diffuse light scattering and laser diffractometry) in clinical hemorheological practice. We provide the feasibility of these techniques to assess microrheological effects of various molecular mechanisms affecting RBC aggregation and deformability. In particular, we show that they allow assessment of changes in RBC aggregation in whole blood samples both on the level of single cells and on the level of large ensembles of cells. Application of these methods allows for studying the mechanisms of RBC aggregation because they are sensitive to changes in the medium which surrounds the RBC (i.e., blood plasma, serum or model solutions of blood plasma proteins) and to changes in the cellular properties of RBCs (i.e., effects on the cell membrane due to glycoprotein inhibition).

A New In Vitro Blood Hyperviscosity Model

We developed a model of blood hyperviscosity avoiding extreme impact on the blood. The model shows reproducibility in rat blood under common storage conditions (4±1°C; stabilization with citrate-phosphate-glucose additive solution). Storage of rat blood under these condition leads to impairment of its rheological properties, which manifested in an increase in blood viscosity in a wide range of shear rates (3-300 sec^-1). An increase in blood viscosity appeared the first day of storage and reached a maximum on the third day. During further 11-day storage, the blood viscosity did not change significantly. A hybrid macromolecular compound O-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl)-(1→6)-α-D-glucan improved the hemorheological properties during storage. The most pronounced effect was observed on the third day of storage and manifested in a decrease in blood viscosity in the range of shear rates of 50-300 sec^-1. Thus, storage of rat blood with citrate-phosphate-glucose additive solution for 3 days at 4±1°C reproduces the phenomenon of blood hyperviscosity; this model can be used to screen agents with hemorheological activity.

A fluorescence color card for point-of-care testing (POCT) and its application in simultaneous detection

Diabetes mellitus has received much attention because its complications include liver, kidney, eye, heart and cerebrovascular diseases. Thus, it would be highly significant to develop a rapid and efficient method for glucose detection in biological samples. In this work, a point-of-care testing (POCT) method of glucose detection was proposed using a standard colorimetric card for semi-quantitative determination patterns. In the prepared fluorescence color card for glucose, a good linear relationship was acquired by plotting the ratio of the grayscale value (I/I0) versus the logarithm of glucose concentration within 100.0 to 1000.0 μmol L-1, and the LOD of glucose detection was 1.1 μmol L-1. A large number of actual samples (30 serum and 7 urine) were analyzed and the results demonstrated that this method had good potential to be applied in the primary screening of diabetic patients. In addition, this method is universal and can be applied in the simultaneous detection of multiple small molecules. It provides a new strategy for the primary screening of multiple diseases simultaneously, which presents excellent application potential.