Complement factor H in molecular regulation of angiogenesis.

Angiogenesis, the process of formation of new capillaries from existing blood vessels, is required for multiple physiological and pathological processes. Complement factor H (CFH) is a plasma protein that inhibits the alternative pathway of the complement system. Loss of CFH enhances the alternative pathway and increases complement activation fragments with pro-angiogenic capacity, including complement 3a, complement 5a, and membrane attack complex.

Mechanical properties of blood exosomes and lipoproteins after the rat whole blood irradiation with X-rays in vitro explored by atomic force microscopy.

Unlabelled: Blood is a two-component system with two levels of hierarchy: the macrosystem of blood formed elements and the dispersed system of blood nanoparticles. Biological nanoparticles are the key participants in communication between the irradiated and non-irradiated cells and inducers of the non-targeted effects of ionizing radiation. The work aimed at studying by atomic force microscopy the structural, mechanical, and electrical properties of exosomes and lipoproteins (LDL/VLDL) isolated from rat blood after its exposure to X-rays in vitro.

Mechanical Properties and Nanomotion of BT-20 and ZR-75 Breast Cancer Cells Studied by Atomic Force Microscopy and Optical Nanomotion Detection Method.

Cells of two molecular genetic types of breast cancer-hormone-dependent breast cancer (ZR-75 cell line) and triple-negative breast cancer (BT-20 cell line)-were studied using atomic force microscopy and an optical nanomotion detection method. Using the Peak Force QNM and Force Volume AFM modes, we revealed the unique patterns of the dependence of Young's modulus on the indentation depth for two cancer cell lines that correlate with the features of the spatial organization of the actin cytoskeleton. Within a 200-300 nm layer just under the cell membrane, BT-20 cells are stiffer than ZR-75 cells, whereas in deeper cell regions, Young's modulus of ZR-75 cells exceeds that of BT-20 cells.

Cadmium, von Willebrand factor and vascular aging.

Vascular aging is a major contributing factor to cardiovascular disease. The aged blood vessels, characterized by vascular wall thickening and stiffening, are instigated by endothelial cell dysfunction induced by oxidative stress and inflammation. von Willebrand Factor (vWF) is a glycoprotein known for its role in coagulation, and plasma levels of vWF are increased with age.

Modulation of the nanoscale motion rate of by X-rays.

Introduction: Patients undergoing cancer treatment by radiation therapy commonly develop infections (candidiasis). Such infections are generally treated by antifungals that unfortunately also induce numerous secondary effects in the patient. Additional to the effect on the immune system, ionizing radiation influences the vital activity of cells themselves; however, the reaction of to ionizing radiation acting simultaneously with antifungals is much less well documented.

CD109-regulated mechanical properties of endothelial cells.

CD109 antigen on the endothelial cell surface plays an important role in vascular pathology. The aim of the work was to investigate the effect of the immobilization of CD109 antigen with specific antibodies on nanomechanical properties of human umbilical endothelial cells (HUVECs) using atomic force microscopy in quantitative nanomechanical property mapping mode (PeakForce QNM). Anti-CD109 antibodies induced significant stiffening of the cell surface Me(LQ; UQ): in 1.

The Effects of Intravitreal Administration of Antifungal Drugs on the Structure and Mechanical Properties Peripheral Blood Erythrocyte Surface in Rabbits.

Background: Fungal infections can pose great threat to sight. Immediate treatment is usually required; antifungal agents are widely accepted and are effective in most cases. The present experimental study aims to investigate the probable effects of intravitreal injection of antifungal agents on the structure and mechanical properties of the surface of peripheral blood erythrocytes.

Nanomechanical characterization of exosomes and concomitant nanoparticles from blood plasma by PeakForce AFM in liquid.

Background: To date, EVs characterization techniques are extremely diverse. The contribution of AFM, in particular, is often confined to size distribution. While AFM provides a unique possibility to carry out measurements in situ, nanomechanical characterization of EVs is still missing.

Heterogeneity of nanomechanical properties of the human umbilical vein endothelial cell surface.

Endothelial cells, due to heterogeneity in the cell structure, can potentially form an inhomogeneous on structural and mechanical properties of the inner layer of the capillaries. Using quantitative nanomechanical mapping mode of atomic force microscopy, the parameters of the structural, elastic, and adhesive properties of the cell surface for living and glutaraldehyde-fixed human umbilical vein endothelial cells were studied. A significant difference in the studied parameters for three cell surface zones (peripheral, perinuclear, and nuclear zones) was established.

Biomechanical Properties of Blood Plasma Extracellular Vesicles Revealed by Atomic Force Microscopy.

While extracellular vesicles (EVs) are extensively studied by various practical applications in biomedicine, there is still little information on their biomechanical properties due to their nanoscale size. We identified isolated blood plasma vesicles that carried on biomarkers associated with exosomes and exomeres and applied atomic force microscopy (AFM) to study them at single particle level in air and in liquid. Air measurements of exosomes revealed a mechanically indented internal cavity in which highly adhesive sites were located.

Nano- and microscale mechanical properties of erythrocytes in hereditary spherocytosis.

Hereditary spherocytosis (HS), an erythrocyte membranopathy, is a heterogeneous disease, even at the level of the erythrocyte population. The paper aims at studying the mechanical properties (the Young's modulus, median and RMS roughness of friction force maps; fractal dimension, lacunarity and spatial distribution parameters of lateral force maps) of the cell surface layer of the erythrocytes of two different morphologies (discocytes and spherocytes) in HS using atomic force microscopy. The results of spatial-spectral and fractal analysis showed that the mechanical property maps of the HS spherocyte surface were more structurally homogeneous compared to the maps of HS discocytes.

Novel fractal characteristic of atomic force microscopy images.

Fractal dimension (D) is one of the important parameters in the description of object's properties in different fields including biology and medicine. The present paper is focused on the application of the fractal dimension (the box counting dimension) in the analysis of the properties of cell surface on the base of its images obtained by atomic force microscopy (AFM). Fractal dimension of digital 3D AFM images depends on interpoint distances determined by the scanning step in the XY-plane and Z-scale factor t.

Thermo-mechanical properties of the cell surface assessed by atomic force microscopy.

Atomic force microscopy (AFM) in lateral force mode was applied to assess the microscale thermo-mechanical (frictional) properties of the air-dried cell surface in the wide temperature range (288-363K/15-90°C). AFM-investigated cell surface layer can be represented as a biocomposite composed of several layers including the glycocalyx, the membrane and the intercellular layer containing membrane (cortical) cytoskeleton. The cells with two different cytoskeleton structures, erythrocytes and thymocytes, were studied.

Mechanical properties of cells and ageing.

Mechanical properties are fundamental properties of the cells and tissues of living organisms. The mechanical properties of a single cell as a biocomposite are determined by the interdependent combination of cellular components mechanical properties. Quantitative estimate of the cell mechanical properties depends on a cell state, method of measurement, and used theoretical model.

Structural and functional changes in the membrane and membrane skeleton of red blood cells induced by peroxynitrite.

The changes in passive ion permeability of the red blood cell membrane after peroxynitrite action (3 microM-3 mM) have been studied by biophysical (using radioisotopes of rubidium, sodium and sulphur (sulphate)) and electrophysiological methods. The enhancement of passive membrane permeability to cations (potassium and sodium ions) and the inhibition of anion flux through the anion exchanger in peroxynitrite-treated red blood cells were revealed. In patch-clamp experiments the whole-cell conductance after peroxynitrite (80 microM) treatment of red blood cells increased 3-3.

Atomic force microscopy probing of cell elasticity.

Atomic force microscopy (AFM) has recently provided the great progress in the study of micro- and nanostructures including living cells and cell organelles. Modern AFM techniques allow solving a number of problems of cell biomechanics due to simultaneous evaluation of the local mechanical properties and the topography of the living cells at a high spatial resolution and force sensitivity. Particularly, force spectroscopy is used for mapping mechanical properties of a single cell that provides information on cellular structures including cytoskeleton structure.

Atomic force microscopy observation of peroxynitrite-induced erythrocyte cytoskeleton reorganization.

Atomic force microscopy (AFM) was used to study surface layers of fixed intact erythrocytes. Advantages of simultaneous analysis of surface topography and lateral force maps in the investigation of cytoskeleton structure were shown. Fractal analysis was applied to the lateral force maps of erythrocyte surfaces to evaluate the complexity of the cytoskeleton.