Biochemical properties of heat-treated valvular bioprostheses.
BACKGROUND
Preliminary studies showed that heat treatment of glutaraldehyde preserved valvular bioprostheses mitigates calcification. This study was carried out to define the physicochemical characteristics of the heat-treated tissues to elucidate the mechanism involved in the mitigation.


METHODS
Glut bovine pericardium or porcine valve samples were treated at 50 degrees C in a 0.625% glutaraldehyde solution for 2 months. Some samples underwent assay for shrinkage temperature, moisture content, ninhydrin test, and acid hydrolysis, and other samples were incubated in human serum for 3 days and then analyzed by electrophoresis to study protein adsorption.


RESULTS
Heat treatment mitigated calcification without adversely affecting shrinkage temperature (84.81 degrees C versus 83.95 degrees C) and moisture content (78.68% versus 78.71%). A significant reduction in free amino groups (0.15 versus 0.37 mol NH2/mol collagen) and a significant increase in resistance to acid hydrolysis were observed. Total protein content was similar, but significant differences were found for four proteins adsorbed in the tissues (167, 45, 11.6, and 10 kDa).


CONCLUSIONS
The anticalcification effect of heat treatment may be attributed to structural changes, lipid extraction, increased resistance, and modifications of the type and concentration of the proteins adsorbed in the tissue.
Carpentier
S M
SM
Laboratoire d'Etude des Greffes et Prothèses Cardiaques, Hĵpital Européen Georges Pompidou, Paris, France. labo.legpc@brs.ap-hop-paris.fr
Shen
M
M
Chen
L
L
Cunanan
C M
CM
Martinet
B
B
Carpentier
A
A
D000327:Adsorption; D000818:Animals; D001705:Bioprosthesis; D002114:Calcinosis / Q000473:pathology; D002417:Cattle; D019544:Equipment Failure Analysis; D006350:Heart Valve Prosthesis; D006361:Heating; D006801:Humans; D011506:Proteins / Q000032:analysis; D013552:Swine
D011506:Proteins