Combined anti-calcification treatment of bovine pericardium with amino compounds and solvents

Abstract

The objective of this study was to evaluate the effect of treatment with amino compounds and solvents in vivo on calcifications of glutaraldehyde (GA)-fixed pericardium. Groups of bovine pericardium samples were fixed with 0.5% GA. We used urazole and glutamate to neutralize the free aldehyde and some solvents (ethanol with octanol or octanediol) to reduce the phospholipid content in the bovine pericardial tissue. Tensile strength and thermal stability were evaluated before implantation. Twelve weeks after rat subdermal implantation, the pericardial samples were harvested from eight juvenile rats. Urazole [calcium (Ca(2+)): 11.86 ± 2.85 μg/mg; inorganic phosphorus (IP): 32.59 ± 7.73 μg/mg] or glutamate (Ca(2+): 7.95 ± 1.21 μg/mg; IP: 21.76 ± 3.48 μg/mg) alone significantly decreased the Ca(2+) and IP concentrations (without any anti-calcification treatment, Ca(2+): 277.85 ± 17.51 μg/mg; IP: 147.07 ± 8.32 μg/mg), but when used with organic solvents, the Ca(2+) and IP concentrations were the lowest (Ca(2+): 0.05 ± 0.04 μg/mg; IP: 3.36 ± 0.61 μg/mg). After anti-calcification treatment, the calcifications in microscopic images were dramatically decreased. Anti-calcification treatment with glutamate, urazole, and solvents did not worsen the physical properties of bovine pericardium, and significantly prevented in vivo calcifications compared to GA fixation only. There should be additional studies done to understand the other mechanism underlying xenograft tissue calcification.