Inorganic Compositions and Properties of Cardiovascular Calcific Deposits
Calcified deposits (CD) that form in the cardiovascular system are bioapatites with composition comparable to hydroxyapatite Ca5(PO4)3OH. Previous studies have yielded information on the calcium, phosphate, sodium, and magnesium contents of CD samples (1). The present study examined the compositions of three distinctly different types of CD’s that were isolated from: 1) bovine pericardium bioprostheses (bpb); 2) human heart valves (hhv), and 3) human aortas (ha). The present study additionally focused on the fluoride and carbonate contents, specific surface area and thermogravimetric and structural properties of deposits. The three types of CD’s differed significantly in several aspects, notably Ca/P ratios, fluoride and carbonate contents. The Ca/P ratios were ha (1.61) > hhv (1.55) > bpb (1.45) (p<0.01); the fluoride contents (ppm) were ha (1390) > hv (890) > bpb (3.7) (p<0.01). these differences may be attributed to varying locations of formation and different CD resiendce times in the cardiovascular system. In a separate experiment, these CD materials were used as seeds for mineral growth under well defined super-saturation conditions. Preliminary data indicate that the surface properties of the CD have significant effects o the rate of mineral formation. Information on the composition and crystal growth properties of the various CD’s and help elucidate the mechanism of the CD formation, which is not fully understood.
KeywordsCarbonate Content Cardiovascular System Separate Experiment Mayo Clinic Calcify Deposit
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