A method of creating an implantation material from biological and tissue engineered biosynthetic and biological tissue of autogenic, allogenic and xenogenic origin suitable for implantation into humans or animals as surgical and vascular prostheses. The resultant material inhibits in vivo calcification and provides a non-porous biomatrix which is impervious to angiogenesis and tissue ingrowth and suitable for the adhesion and retention of transplanted living cells such as endothelial cells, without the need for additional extracellular matrix protein coating. The method, which incorporates a gradual increase in glutaraldehyde concentration from 0% to no more than 5% weight/volume in a pH which is gradually changed from acid to alkaline at room temperature, maintains the micro-architecture and the cellular lining of the material. Additionally flexibility, compliance and haemo-compatibility along with strength and durability can be varied according to the end use. The glutaraldehyde penetrates the material gradually and completely, cross linking the collagenous components of the tissue.