Biology subjects

Chester, A. H.

Publications and source records attributed to Chester, A. H..

3 recordsLinked to original sources

bioRxiv2022

Alizarin Red fluorescence imaging for nano calcification

The formation of calcium phosphate (calcification) has been observed in a variety of healthy and diseased tissues and contributes to a wide range of pathologies. In physiological and pathological mechanisms, calcification begins at the nano scale and then develops into structures that range from a few micrometres to several centimetres. Fluorescence microscopy can be an efficient way to visualise such early calcification and its interaction with cells and proteins. The limited shelf life and high cost of commercial dyes for staining calcification, however, can be problematic when using this imaging method. Here, we aim to evaluate the effectiveness and stability of Alizarin Red (AR) as a fluorescent staining agent for nano and micro calcified structures. Our results show that AR staining for nano and micro calcified structures is a simple, reliable, effective, and quite inexpensive method to visualize calcification at the nano and micro scale in biological samples.

pathology↗

bioRxiv2022

Density-Dependent Color Scanning Electron Microscopy (DDC-SEM) for calcified tissue and pathological calcification.

Scanning electron microscopy (SEM) is widely used for materials characterization. It has also been successfully applied to the imaging of biological samples, providing invaluable insights into the topography, morphology and composition of biological structures, including pathological minerals, in diseases affecting cardiovascular, kidney and ocular tissues. Here we provide a comprehensive and detailed guide on how to use colored SEM to aid the visualization and characterization of pathological calcification, and identify the effects of different sample preparation protocols for the visualisation of these minerals.

pathology↗

bioRxiv2019

Electron microscopy characterization of minerals formed in vitro by human bone cells and vascular smooth muscle cells

Soft tissue mineralization has been found to be a major component of diseases such as aortic valve stenosis and rheumatic heart disease. Cardiovascular mineralization has been suggested to follow mechanisms similar to those of bone formation with several cell culture models been developed over the years to provide mechanistic insights. These cell models have been characterized by a wide range of biochemical and molecular methods, which identified the presence of osteogenic markers and bone-like cells. However, there is a surprisingly small number of studies where the mineral formed in these cell culture models has been characterized by physico-chemical methods, and even fewer studies have compared this mineral to the one produced by bone cells in cultures. Here we investigated the morphology and composition of the minerals formed in cell cultures of vascular smooth muscle cells and bone cells. Electron microscopy and traditional cell mineralization assays were applied, revealing that vascular cells are indeed able to form calcified nodules of elemental composition similar to bone, however with different morphology. Comparison of morphologies of the two minerals to that found in cardiovascular tissue shows that some of tissue calcification resembles the calcified fibers produced by bone cells in vitro. These results suggest that the characterization of the mineral is of utmost importance and its morphology and chemical properties can contribute an important piece of information in the comprehensive analysis of soft tissue mineralization mechanisms, both in in vitro cell culture as well as in clinical samples.

pathology↗