Physiochemical principles of cardiovascular calcification.

Objectives: The objectives of this review article are to provide detailed physicochemical information on the nature of pathological cardiovascular deposits, PCD, isolated from different sites of the human cardiovascular system. In order to help to understand the complex mechanism of the formation of PCD, special emphasis is focused on the attempt to recognize early precursor(s) of PCD by utilizing combined in vivo and in vitro studies.

Background: The common idea is that PCD is hydroxyapatite (HAP), Ca5(PO4)3OH; however, this is questionable and deserves critical evaluation.

An in vitro diffusion model for the study of calcification of bovine pericardium tissue.

Bovine pericardium (BP) is extensively used for the production of heart valve bioprostheses. BP has excellent mechanical properties but a limited lifespan because of intrinsic subsurface calcification in vivo. In this study, the in vitro mineralization of BP was investigated by a novel diffusion cell model.

Physicochemical characterization of natural and bioprosthetic heart valve calcific deposits: implications for prevention.

This investigation was performed to provide a comprehensive physicochemical characterization of calcific deposits (CDs) that form on human heart valves under various pathological conditions. We examined and characterized CDs associated with aortic stenosis on congenitally bicuspid valves (n = 10), degenerative aortic stenosis on valves with previously normal anatomy (n = 10), and rheumatic aortic (n = 10) and mitral (n = 10) stenosis. Native and deproteinated CDs underwent chemical analysis and structural characterization, whereas deproteinated CDs were measured for thermodynamic solubility.

Physicochemical properties of calcific deposits isolated from porcine bioprosthetic heart valves removed from patients following 2-13 years function.

The purpose of this study was to characterize the physicochemical properties of calcific deposits that cause the failure of tissue-derived heart valve bioprostheses. This was done in an effort to understand the mechanism of pathologic biomineralization in the cardiovascular system and potentially prevent deterioration of bioprostheses. Calcific deposits taken from 10 failed bioprosthetic valves that had been implanted in patients for 2-13 years were characterized by chemical analysis, x-ray diffraction, FTIR spectroscopy, scanning electron microscopy, polarized light microscopy, and solubility measurements.

A critical evaluation of the purification of biominerals by hypochlorite treatment.

The quantitative deproteination of calcific deposits from surgically explanted heart valve bioprostheses was carried out by both hypochlorite and hydrazine extraction to establish which is the better procedure for preparing purified mineral suitable for detailed chemical and structural characterization. Hypochlorite treatment resulted in a material with a higher Ca/PO4 ratio than that of the untreated deposits. The hydrazine treatment did not produce such an effect.