Processes for removing cells and cell debris from tissue and tissue constructs used in transplantation and tissue reconstruction

Methods for decellularizing mammalian tissue for use in transplantation and tissue engineering. The invention includes methods for simultaneous application of an ionic detergent and a nonionic detergent for a long time period, which may exceed five days. One method utilizes SDS as the ionic detergent and Triton-X 100 as the nonionic detergent. A long rinse step follows, which may also exceed five days in length. This long duration, simultaneous extraction with two detergents produced tissue showing stress-strain curves and DSC data similar to that of fresh, unprocessed tissue. The processed tissue is largely devoid of cells, has the underlying structure essentially intact, and also shows a significantly improved inflammatory response relative to fresh tissue, even without glutaraldehyde fixation. Significantly reduced in situ calcification has also been demonstrated relative to glutaraldehyde fixed tissue. Applicants believe the ionic and non-ionic detergents may act synergistically to bind protein to the ionic detergent and may remove an ionic detergent-protein complex from the tissue using the non-ionic detergent. The present methods find one exemplary use in decellularizing porcine heart valve leaflet and wall tissue for use in transplantation.