Process for preparing biological mammalian implants

A process for preparing biological material for implant in mammal's cardiovascular system, respiratory system or soft tissue by removing cellular membranes, nucleic acids, lipids and cytoplasmic components and forming an extracellular matrix having as major components collagens and elastins, said process comprising the following sequence of steps:

• (1) isolating from a suitable donor a desired tissue sample of said biological material;
• (2) extracting said tissue sample with a hypotonic buffer solution at a mild alkaline pH for rupturing cells of said tissue sample, said hypotonic buffer solution including active amounts of proteolytic inhibitors and active amounts of antibiotic;
• (3) extracting said tissue sample with a buffered solution having a high concentration of salt, said solution being at a mild alkaline pH and including a non-ionic detergent and the proteolytic inhibitors and active amounts of antibiotic;
• (4) subjecting said tissue sample to enzymatic digestion in a buffered saline solution, said enzymes consisting of purified protease-free deoxyribonuclease and ribonuclease;
• (5) extracting said tissue sample with an anionic detergent at a mild alkaline pH, and
• (6) storing said tissue sample in physiologic buffered solutions.