Similar Endothelial Glycocalyx Structures in Microvessels from a Range of Mammalian Tissues: Evidence for a Common Filtering Mechanism?

AbstractThe glycocalyx or endocapillary layer on the luminal surface of microvessels has a major role in the exclusion of macromolecules from the underlying endothelial cells. Current structural evidence in the capillaries of frog mesentery indicates a regularity in the structure of the glycocalyx, with a center-to-center fiber spacing of 20 nm and a fiber width of 12 nm, which might explain the observed macromolecular filtering properties. In this study, we used electron micrographs of tissues prepared using perfusion fixation and tannic acid treatment. The digitized images were analyzed using autocorrelation to find common spacings and to establish whether similar structures, hence mechanisms, are present in the microvessel glycocalyces of a variety of mammalian tissues. Continuous glycocalyx layers in mammalian microvessels of choroid, renal tubules, glomerulus, and psoas muscle all showed similar lateral spacings at ∼19.5 nm (possibly in a quasitetragonal lattice) and longer spacings above 100 nm. Individual glycocalyx tufts above fenestrations in the first three of these tissues and also in stomach fundus and jejunum showed evidence for similar short-range structural regularity, but with more disorder. The fiber diameter was estimated as 18.8 (± 0.2) nm, but we believe this is an overestimate because of the staining method used. The implications of these findings are discussed

Europium-Coordinated Gold Nanoparticles on Paper for the Colorimetric Detection of Arsenic(III, V) in Aqueous Solution

The europium-functionalized gold nanoparticle is developed as a sensor for highly sensitive and specific detection of the very low concentration of As^III and As^V ions in water and using the paper strip. The GNP-MMT@Eu nanosensor is synthesized by stepwise chemical conjugations of gold nanoparticle (GNP) with 2-mercapto-4-methyl-5-thiazoleacetic acid (MMT) followed by europium chloride (EuCl₃) in deionized (DI) water. GNP-MMT@Eu shows a visible color change in the presence of both As^III and As^V ions in an aqueous medium, because of arsenic-mediated aggregation through electrostatic attraction and covalent-type interaction that form an inner-sphere arsenic complex between nanoparticles, which is proportional to the concentration of arsenic. The fluorometric properties of the nanosensor are not significant, and thus, only colorimetric and spectroscopic methods that are very much selective for As^III and As^V ions are used with a detection limit of ≤10.0 ppb. GNP-MMT@Eu also shows excellent capabilities for regeneration and quantitative estimation of total dissolved arsenic in a real water sample, signifying the usefulness of the developed nanosensor for field-test applications such as arsenic level screening during the water quality monitoring process

Data for: Peptide Gels of Fully-Defined Composition and Mechanics for Probing Cell-Cell and Cell-Matrix Interactions In Vitro

Supporting data for the Matrix Biology publication 'Peptide Gels of Fully-Defined Composition and Mechanics for Probing Cell-Cell and Cell-Matrix Interactions In Vitro'