Patent ID: 8137411

Claim:
A process of converting a pericardial tissue specimen taken from a bovine, porcine or ovine animal not more than 30 days old and comprised of 95-99% collagen, to a non-antigenic, non-thrombogenic, calcification-resistant implantable material for use in surgical procedures on humans consisting of the following steps performed in order: the pericardial tissue specimen is (i) cleaned, (ii) digested by surfactant, (iii) compressed to approximately 0.002″ (0.0508 mm) to 0.005″ (0.127 mm) in thickness by dehydration in a hyperosmotic solution, followed by mechanical compression, (iv) vapor cross-linked by exposing the tissue to a vapor-phase cross-linking agent selected from the group consisting of aldehydes, epoxides, isocyanates, carbodiimides, isothiocyanates, glycidalethers, and acyl azides, and (v) liquid-phase cross-linked by immersing the tissue in a liquid cross-linking agent selected from the group consisting of aldehydes, epoxides, isocyanates, carbodiimides, isothiocyanates, glycidalethers, and acyl azides.