scholarly journals CELL SURFACE CHANGES DURING DEDIFFERENTIATION IN THE METAPLASTIC TRANSFORMATION OF IRIS INTO LENS

1972 ◽  
Vol 55 (1) ◽  
pp. 134-146 ◽  
Author(s):  
Sara E. Zalik ◽  
Vi Scott
Keyword(s):  
Cell Surface ◽  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Cell Periphery ◽  
Notophthalmus Viridescens ◽  
Taricha Granulosa ◽  
Electrophoretic Mobilities ◽  
Cell Surface Changes ◽  
Surface Changes

Changes at the cell periphery during the dedifferentiative phase of the metaplastic transformation of iris into lens have been studied in Notophthalmus viridescens and Taricha granulosa using cell electrophoresis. Cell surface charge density increases as early as 1–3 days after lens removal. Cells of regenerates at 10–15 days after lentectomy have significantly lower electrophoretic mobilities than those of the irises of nonlentectomized newts. Decrease in surface charge density is due, at least in part, to the loss of ribonuclease- and neuraminidase-sensitive groups from the cell periphery. Loss of negatively charged groups from the cell surface appears to occur as cells go through dedifferentiation. Loss of cell surface components also occurs in the cells of the ventral iris which also undergo dedifFerentiation but do not regenerate a lens.

Cell Electrophoresis of the Cellular Slime Mould Dictyostelium Discoideum

1972 ◽  
Vol 10 (1) ◽  
pp. 249-265
Author(s):  
K.-C. LEE
Keyword(s):  
Cell Adhesion ◽  
Cell Surface ◽  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Cell Aggregation ◽  
Cellular Slime Mould ◽  
Cell Electrophoresis ◽  
Electrophoretic Mobilities ◽  
Cellular Slime

The reduction in the cell surface charge density of Dictyostelium discoideum during differentiation has been studied by the technique of cell electrophoresis. It was abolished under conditions in which cell aggregation was inhibited (e.g. low temperature, the presence of actinomycin D or cycloheximide). In the presence of nutrients incapable of supporting growth, cell aggregation occurred without a reduction in surface charge density. Cell adhesion in these aggregates was impaired, and a reduction in surface charge density appeared to be necessary for further development. Brief treatment of exponential phase and aggregating cells with agents which disaggregate slugs failed to alter their electrophoretic mobilities. Low concentrations of magnesium chloride caused extensive agglutination, especially in aggregating cell suspensions, but little change in their electrophoretic mobilities. Magnesium chloride could agglutinate cells by association with cell surface components undetectable by cell electrophoresis. This, together with immunological evidence from other workers, supports the possibility of involvement of specific surface macromolecules in cellular slime mould aggregation. It was concluded that changes in surface charge density, though important for cell adhesion and morphogenesis, cannot account for all aspects of cell interactions in D. discoideum.

scholarly journals Mapping Surface Charge Distribution of Single-Cell via Charged Nanoparticle

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1519
Author(s):  
Leixin Ouyang ◽  
Rubia Shaik ◽  
Ruiting Xu ◽  
Ge Zhang ◽  
Jiang Zhe
Keyword(s):  
Cell Surface ◽  
Charge Density ◽  
Surface Charge ◽  
Charge Distribution ◽  
Surface Charge Density ◽  
Single Cells ◽  
Fluorescent Light ◽  
Fluorescent Nanoparticles ◽  
Cell Surface Charge ◽  
Surface Charge Distribution

Many bio-functions of cells can be regulated by their surface charge characteristics. Mapping surface charge density in a single cell’s surface is vital to advance the understanding of cell behaviors. This article demonstrates a method of cell surface charge mapping via electrostatic cell–nanoparticle (NP) interactions. Fluorescent nanoparticles (NPs) were used as the marker to investigate single cells’ surface charge distribution. The nanoparticles with opposite charges were electrostatically bonded to the cell surface; a stack of fluorescence distribution on a cell’s surface at a series of vertical distances was imaged and analyzed. By establishing a relationship between fluorescent light intensity and number of nanoparticles, cells’ surface charge distribution was quantified from the fluorescence distribution. Two types of cells, human umbilical vein endothelial cells (HUVECs) and HeLa cells, were tested. From the measured surface charge density of a group of single cells, the average zeta potentials of the two types of cells were obtained, which are in good agreement with the standard electrophoretic light scattering measurement. This method can be used for rapid surface charge mapping of single particles or cells, and can advance cell-surface-charge characterization applications in many biomedical fields.

Nanosecond pulsed electric field induced changes in cell surface charge density

Micron ◽  
2017 ◽  
Vol 100 ◽  
pp. 45-49 ◽  
Author(s):  
Diganta Dutta ◽  
Xavier-Lewis Palmer ◽  
Anthony Asmar ◽  
Michael Stacey ◽  
Shizhi Qian
Keyword(s):  
Cell Surface ◽  
Electric Field ◽  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Pulsed Electric Field ◽  
Cell Surface Charge ◽  
Nanosecond Pulsed Electric Field ◽  
Induced Changes

scholarly journals Electrophoretic Mobility and N-Acetyl Neuraminic Acid Content of Human Normal and Leukemic Lymphocytes and Granulocytes

Blood ◽  
1970 ◽  
Vol 35 (1) ◽  
pp. 12-22 ◽  
Author(s):  
MARSHALL A. LICHTMAN ◽  
ROBERT I. WEED
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Surface Area ◽  
Electrophoretic Mobility ◽  
Surface Charge Density ◽  
Human Leukocyte ◽  
Neuraminic Acid ◽  
Cell Periphery ◽  
Neuraminidase Treatment ◽  
Molecular Arrangement

Abstract Studies have been conducted to determine the electrophoretic mobility and the N-Acetyl Neuraminic Acid (NANA) content of different human leukocyte types. Leukemic granulocytes and lymphocytes do not differ significantly from their normal counterparts in rate of electrophoretic mobility. An absolute comparison between leukemic and normal myeloblasts could not be made; however, populations of leukemic myeloblasts were often similar in mobility to normal immature granulocytes. Immature granulocytes had a significantly higher surface-charge density than PMNGs, and this is due primarily to differences in NANA carboxyl groups contributing to the electro-kinetic surface of the cell. The small lymphocyte has a surface-charge density more similar to that of immature granulocytes and myeloblasts than to that of PMNGs. The surface-dependent behavior of different leukocyte types may be related, in part, to the density or arrangement of NANA molecules at the cell periphery; alternatively, the distribution of surface NANA may be a reflection of other differences in molecular arrangement of the cell membrane which are important in determining functional capacities. Total cellular NANA is greater in the PMNG than the lymphocyte, and this is likely to be a reflection of the larger surface area of external and internal membranes of the PMNG. These data also suggest that the surface area of the PMNG and lymphocyte is not reflected by the assumption of a smooth sphere. Neither total NANA nor neuraminidase-susceptible NANA can be used as an estimate of comparative NANA-dependent surface-charge density which must depend on electrophoretic mobility measurements with and without neuraminidase treatment.

scholarly journals Mapping Surface Charge Distribution of Single-Cell via Charged Nanoparticle

2021 ◽  
Author(s):  
Leixin Ouyang ◽  
Rubia Shaik ◽  
Ruiting Xu ◽  
Ge Zhang ◽  
Jiang Zhe
Keyword(s):  
Cell Surface ◽  
Charge Density ◽  
Surface Charge ◽  
Charge Distribution ◽  
Surface Charge Density ◽  
Single Cells ◽  
Cell Behaviors ◽  
Cell Surface Charge ◽  
Surface Charge Distribution ◽  
Fluorescence Light

Abstract Background: Many bio-functions of cells can be regulated by their surface charge characteristics. Mapping surface charge density in a single cell’s surface is vital to advance the understanding of cell behaviors. Results: This article demonstrates a method of cell surface charge mapping via electrostatic cell–nanoparticle interactions. Nanoparticles with fluorescence were used as the marker to investigate single cells’ surface charge distribution. The nanoparticles with opposite charges were electrostatically bonded to the cell surface; a stack of fluorescence distribution on a cell’s surface at a series of vertical distances was imaged and analyzed. By establishing a relationship between fluorescence light intensity and surface charge density, cells’ surface charge distribution was quantified from the fluorescence distribution. Two types of cells, HUVECs and Hela cells, were tested. From the measured surface charge density of a group of single cells, the average zeta potential of the two types of cells was obtained, which is in good agreement with the standard electrophoretic light scattering measurement. Conclusions: This method can be used for rapid surface charge mapping of single particles or cells and can advance cell-surface-charge characterization applications in many biomedical fields.

scholarly journals Alteration of the Cell Periphery During Granulocyte Maturation: Relationship to Cell Function

Blood ◽  
1972 ◽  
Vol 39 (3) ◽  
pp. 301-316 ◽  
Author(s):  
Marshall A. Lichtman ◽  
Robert I. Weed
Keyword(s):  
Bone Marrow ◽  
Charge Density ◽  
Surface Charge ◽  
Functional Capacity ◽  
Surface Charge Density ◽  
Cell Spreading ◽  
Cell Periphery ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Immature Granulocyte

Abstract Physiologic characteristics of the surface of human granulocytes may be important determinants of functional capacity. Studies of immature granulocytes and polymorphonuclear neutrophils (PMN’s) from marrow and blood indicated that immature granulocytes are characterized by a high, neuraminidase-susceptible, negative surface charge density; a high degree of cellular rigidity, as measured by an elastimeter with a micropipette orifice size that approximated estimates of average bone marrow basement membrane pore size (3.5µ); low adhesiveness to glass and plastic; low propensity to aggregate; a slow rate of cell spreading, pseudopod extension, and motility; and a very low rate of phagocytosis. At the myelocyte stage, adhesiveness and phagocytosis, although not prominent, became evident. In contrast PMN’s had a lower negative surface charge density, a higher degree of surface deformability (the entire PMN readily deforming to enter a 3.5µ micropipette whereas the immature granulocyte would not so deform), higher adhesiveness (plastic > glass), a higher propensity to aggregate, a higher rate of cell spreading, pseudopod formation and motility, and a higher rate of phagocytosis. The increased deformability and adhesiveness of the PMN as compared to the immature granulocyte may be a reflection of an altered relationship between relaxing and contracting systems at the cell periphery during maturation and/or changes in the sol-gel state of macromolecules at the cell periphery. This concept is supported by the change in surface properties of the PMN toward those of the immature granulocyte at cold temperature (4°C). The increased deformability and reduced surface negative charge of the PMN could facilitate adhesiveness and pseudopod formation and, thereby, increase cell-surface and cell-particle contact with enhancement of motility and phagocytosis. Hence the exit of PMN from bone marrow and circulation and the functional capacity of the PMN may be determined by a process of cytoplasmic maturation during granulopoiesis that adapts the PMN for its essential cell-extracell interactions.

Triboelectrification of nanocomposites using identical polymer matrixes with different concentrations of nanoparticle fillers

2021 ◽  
Author(s):  
Linards Lapčinskis ◽  
Artis Linarts ◽  
Kaspars Mālnieks ◽  
Hyunseung Kim ◽  
Kristaps Rubenis ◽  
...  
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Polymer Layers

In this study, we investigate triboelectrification in polymer-based nanocomposites using identical polymer matrixes containing different concentrations of nanoparticles (NPs). The triboelectric surface charge density on polymer layers increased as the...

scholarly journals Effect of Selected Anionic and Cationic Drugs Affecting the Central Nervous System on Electrical Properties of Phosphatidylcholine Liposomes: Experiment and Theory

2021 ◽  
Vol 22 (5) ◽  
pp. 2270
Author(s):  
Joanna Kotyńska ◽  
Monika Naumowicz
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Barbituric Acid ◽  
Membrane Surface ◽  
Adsorption Equilibria ◽  
Two Component ◽  
The Central Nervous System

Interactions between phospholipid membranes and selected drugs affecting the central nervous system (CNS) were investigated. Small, unilamellar liposomes were used as biomimetic cell membrane models. Microelectrophoretic experiments on two-component liposomes were performed using the electrophoretic light scattering technique (ELS). The effect of both positively (perphenazine, PF) and negatively (barbituric acid, BA) charged drugs on zwitterionic L-α-phosphatidylcholine (PC) membranes were analyzed. Experimental membrane surface charge density (d) data were determined as a function of pH. Quantitative descriptions of the adsorption equilibria formed due to the binding of solution ions to analyzed two-component membranes are presented. Binding constants of the solution ions with perphenazine and barbituric acid-modified membranes were determined. The results of our research show that both charged drugs change surface charge density values of phosphatidylcholine membranes. It can be concluded that perphenazine and barbituric acid are located near the membrane surface, interacting electrostatically with phosphatidylcholine polar heads.

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