Patent ID: 7129035

Claim:
A method of preparing a preserved tissue, comprising providing an uncrosslinked tissue selected from the group consisting of heart valve leaflets, aortic roots, aortic walls, pulmonary valves, pulmonary conduits, non-valved conduits, mitral valves, monocusps, tendons, ligaments, fascia, blood vessels, arteries, veins, ureters, diaphragm, pericardium, umbilical cords, dura mater, and tympanic membranes; providing an aqueous solution comprising between 15 mM and 100 mM bio-compatible buffer; between 5% and 30% polyvinylpyrrolidone (v/v); between 5% and 30% isopropanol (v/v); and between 0.1 M and 1.5 M ascorbate; combining the aqueous solution with the uncrosslinked tissue; lowering the temperature of the resulting composition to at least the freezing point of the aqueous solution; and irradiating the tissue with ionizing radiation to produce a preserved tissue, wherein the denaturation temperature of the preserved tissue, when thawed, is reduced or increased by no more than 3° C. as compared to the uncrosslinked tissue prior to combination with the aqueous solution.