Treating biological tissues to mitigate post-implantation calcification

A method of treating a biological tissue including crosslinking with glutaraldehyde; immersing the biological tissue in a first solution containing glutaraldehyde and heat in the first solution to a temperature of about 50° C. for a first period of time; immersing the biological tissue in a second solution containing a mixture of a crosslinking agent, a denaturing agent and a surfactant; and immersing the biological tissue in a sterilizing solution containing glutaraldehyde and heating the sterilizing solution to a temperature of 37.5±2.5° C. for a sterilizing period of time. The method may include a terminal sterilization step in a method for fixation of biological tissues, and bioprosthetic devices may be prepared by such fixation method. The fixation method may include the steps of A) fixing the tissue, B) treating the tissue with a mixture of i) a denaturant, ii) a surfactant and iii) a crosslinking agent, C) fabricating or forming the bioprosthesis (e.g., forming the tissue and attaching any non-biological components thereto) and D) subjecting the bioprosthesis to the terminal sterilization method.