APPLICANT: INTERNATIONAL CENTRE FOR CARDIO THORACIC AND VASCULAR DISEASES ABSTRACT: The invention relates to implantable xenografts intended for human recipients for correcting cardiovascular abnormalities. The xenografts are prepared from a non-human native tissue portion and are completely sterilized, acellular and exhibit a tensile strength generally higher than that of the native tissue- The uniqueness of the xenografts of the present invention is that the outer surface of the tissue portion is impregnated with collagen nano-fibers. The implantable xenograft exhibits excellent storage stability, non-immunogenicity, non-thrombogenicity, non-cytotoxicity and non-calcifying propperty.[IN-CHE-2009-00818A]