Abstract: Non-glutaraldehyde fixation of an organ or a prosthesis for implantation in a mammal is based upon carbodiimide treatment. A solution containing a sterilizing agent, such as EDC, in combination with a coupling enhancer, such as Sulfo-NHS, and a high concentration of a diamine cross linking agent is used. As a result, only minimal surface reduction occurs during fixation, and the resultant products show a dramatic increase in resistance to calcification.

Abstract: A bioreactor and a method for growing engineered tissue provide facing surfaces in a vessel for containing cell-culture media. The facing surfaces are equidistant and define a gap therebetween while providing substrates for cell tissue growth. By maintaining conditions within the vessel conducive to cell tissue growth and moving the surfaces relative to one another within such cell culture media, tissue growing thereupon is subjected to physiological flow and shear stress, preferably through the use of oscillating motion, and engineered tissue is produced.

Abstract: An actuable truss with ordered or disordered planar or strut elements or pore walls may be seeded with tissue cells, wherein application of a magnetic field may result in mechanical strain on the cells and increased fluid flow in and out of the truss structure. Modified polymers, such as ?-Fe2O3/PLGA, may be used to form actuable scaffolds suitable for tissue engineering. It is also disclosed a device with a trap-door that may be remotely actuated by applying a magnetic field. Such a device may be employed to deliver and control the release of other micro-devices or materials such as drugs to a specific location inside the body of a human or an animal.

Abstract: The present invention relates, in general, to tissue decellularization and, in particular to a method of treating tissues, for example, heart valves, tendons and ligaments, so as to render them acellular and thereby limit mineralization and/or immunoreactivity upon implementation in vivo.

Abstract: A process and system for compressing bioprosthetic tissue for use in medical implants. The process involves placing the tissue between two compressive surfaces and applying a force to reduce any nonuniformity of thickness in the tissue, while at the same time reduce the overall thickness. One particularly useful application is the compression of bioprosthetic sheet during the preparation of heart valve leaflets. Bovine pericardium may be compressed to reduce its thickness by about 50%, and then formed into heart valve leaflets. The thinned leaflets have substantially the same absolute strength as those made from uncompressed tissue, and are particular desirable for use in minimally invasive valves which must be compressed into a small profile. The thin tissue enables a reduction in the overall size of the minimally invasive heart valve for delivery. For instance, rolled MIS valves may be reduced in size to as small as 20 mm in diameter.

Abstract: A prosthetic valve for placement within a body passage includes at least two valve leaflets made from a first layer of either peritoneal fascia tissue or pleural tissue. Support structure is attached to the first layer to provide structural support for the valve leaflets. A method for producing the prosthetic valve is also provided.

Abstract: In a system for generating tissue by growing cells in a porous and sometimes biodegradable material, a needle punched textile which serves as a scaffold is used for growing any of a variety of anatomical elements, in which the thickness of areas of the anatomical element and thus its strength can be increased by providing layers of mesh which are needled together to form a layerless textile and in which delamination is prevented through the use of the needling. In one embodiment, the needle punched textile is utilized to form a semi-lunar heart valve. In a preferred embodiment for pediatric use, the textile is made from two different biodegradable non-woven meshes. For some adult applications biodegradable meshes are not necessary, thus eliminating the necessity of using two different needled meshes. In one embodiment the needling is done with a single needle which is made to move around the periphery of a mold used in making the scaffold, thus to precisely control the area needled.

Abstract: A replacement heart valve and fixture assembly for limiting longitudinal stretch during fixation of a harvested aortic root including valve leaflets. The assembly includes an inflow plug inserted into the inflow section of the aortic root and having an apertured tube or cannula extending through the valve leaflets to an outflow plug inserted into the outflow section of the aortic root. Apertures in the tube are located on either side of the valve leaflets and the tube is coupled to a fluid inlet, preferably located on the outflow plug. The outflow plug is slidable relative to the tube and is provided with an engagement mechanism such as a setscrew for fixing the location of the outflow plug relative to the tube and the inflow plug.

Abstract: An improved fixative for tissue useful for bioprosthetic heart valves is provided. The tissue can have an elastin content and the elastin can be chemically fixed using a phenolic tannin, for example, tannic acid. The fixed elastin component provides greater mechanical durability and improved resistance to biological degradation following implantation. The tannic acid fixation protocol allows for biological material having a high elastin content, for example, about 30% or more. When used in combination with a glutaraldehyde fixative an additive effect can be seen in increased cross-link density and increased resistance to degradation and calcification.

Abstract: Valved prostheses are described with crosslinked leaflets. At least one of the leaflets has a shape corresponding to a contoured surface. The leaflets are individually attached to the prostheses. Furthermore, in some embodiments, the leaflets do not comprise native leaflet tissue. Methods for forming tissue heart valve prostheses can comprise assembling a plurality of leaflets configured to open and close the valve in response to pressure differentials. Each of the plurality of leaflets is preformed individually when at least partially crosslinked in contact with a contoured surface. The individual crosslinked leaflets can be selected and matched for assembly into a valve. In general, the tissue, when it is crosslinked, has a size and shape approximately the size of a single human heart valve leaflet.

Abstract: In some embodiments, a method for processing tissue comprises the application of a directional load to modify the properties of the tissue. In particular, the directional force is sufficient to increase the rigidity of the tissue asymmetrically relative to an unaligned tissue equivalently processed without being subjected to a load. In some embodiments, a sufficient directional load is applied to increase the rigidity of the tissue relative to an unaligned tissue equivalently processed that is not subjected to the load, in which the load is applied with a load applicator. A connector transfers the load from the load applicator to the tissue. Selectively aligned tissue having asymmetric mechanical properties can be used to form a prosthetic valve. The leaflets are matched with respect to each of their properties to have improved coaptation relative to corresponding tissue leaflets with symmetrical mechanical properties.

Abstract: A process and system for compressing bioprosthetic tissue for use in medical implants. The process involves placing the tissue between two compressive surfaces and applying a force to reduce any nonuniformity of thickness in the tissue, while at the same time reduce the overall thickness. One particularly useful application is the compression of bioprosthetic sheet during the preparation of heart valve leaflets. Bovine pericardium may be compressed to reduce its thickness by about 50%, and then formed into heart valve leaflets. The thinned leaflets have substantially the same absolute strength as those made from uncompressed tissue, and are particular desirable for use in minimally invasive valves which must be compressed into a small profile. The thin tissue enables a reduction in the overall size of the minimally invasive heart valve for delivery. For instance, rolled MIS valves may be reduced in size to as small as 20 mm in diameter.

Abstract: A method an apparatus for limiting longitudinal stretch during fixation of a harvested aortic root including valve leaflets and the product produced. The apparatus includes an inflow plug inserted into the inflow section of the aortic root and having an apertured tube or cannula extending through the valve leaflets to an outflow plug inserted into the outflow section of the aortic root. Apertures in the tube are located on either side of the valve leaflets and the tube is coupled to a fluid inlet, preferably located on the outflow plug. The outflow plug is slidable relative to the tube and is provided with an engagement mechanism such as a setscrew for fixing the location of the outflow plug relative to the tube and the inflow plug. After assembly of the aortic root to the apparatus, the fluid inlet is coupled to a source of defined pressure and the root is inflated.

Abstract: The present invention is directed to methods for obtaining heart valves from a donor animal that have a reduced tendency to cause inflammation when implanted into a human patient. The valves produced by this method should be less likely to undergo post-surgical degeneration.

Abstract: The present invention comprises a percutaneously implantable replacement heart valve device and a method of making same. The replacement heart valve device comprises a stent member made of stainless steel or self-expanding nitinol, a biological tissue artificial valve means disposed within the inner space of the stent member. An implantation and delivery system having a central part which consists of a flexible hollow tube catheter that allows a metallic wire guide to be advanced inside it. The endovascular stented-valve is a glutaraldehyde fixed bovine pericardium which has two or three cusps that open distally to permit unidirectional blood flow.

Abstract: A tissue equivalent and method of making and using same is provided herein. The tissue equivalent disclosed herein is particularly useful in the repair or replacement of mitral valve chordae, and is prepared by combining collagen with living tissue cells to form a collagen gel and controlling shrinkage of the collagen gel to cause collagen fibrils in the collagen gel to align along a single axis in an unbranched configuration or multiple paths in a branched configuration.

Abstract: A process of applying thermal energy using a controlled regimen is described to reduce the size of biological xenograft and allograft heart and vascular tissue, particularly heart valves, which are used for implants by applying a controlled regimen of thermal energy, and the related implant products, apparatuses and systems. In a particular embodiment, a xenograft or allograft heart valve experiences size reduction and fits the size requirements of a recipient into whom the heart valve is being implanted.

Abstract: A method for producing a non-immunogenic and durable living graft involves the recellularization of a decellularized heart valve allograft or xenograft by recipient cells after implantation of such graft into a living patient. Decellularized allograft or xenograft grafts which have not been exposed to a cytotoxic environment are treated with either chemotactic factors or cell adhesion factors, or both, to retain desirable recipient cells into the tissue graft after implantation.

Abstract: The invention provides a replacement heart valve which contains an acellular matrix as a structural scaffold. The scaffold is seeded with isolated myofibroblasts and/or endothelial cells prior to implantation into a recipient mammal.

Abstract: The present invention relates, in general, to tissue decellularization and, in particular to a method of treating tissues, for example, heart valves, tendons and ligaments, so as to render them acellular and thereby limit mineralization and/or immunoreactivity upon implementation in vivo.

Abstract: A minimally invasive approach for surgery on portions of the heart and great vessels located between a point approximately three centimeters above supra annular ridge and the mid ventricular cavity. A parasternal incision is made extending across a predetermined number of costal cartilage, e.g., a right parasternal incision extending from the lower edge of the second costal cartilage to the superior edge of the fifth costal cartilage. One or more costal cartilages, e.g., the third and fourth, are then excised to provide access to the portion of the heart or great vessels of interest, and a desired procedure completed. The minimally invasive approach enables repair or replacement of the mitral or aortic valve.

Abstract: A method for preparing vascular valves from submucosal tissue is described. Both bicuspid and tricuspid valve constructs are described. The bicuspid constructs can be formed with or without a supporting stent. The tricuspid constructs are formed by fixing submucosal tissue to a supporting stent, folding the submucosal tissue, and forming the valve commissures from the folded submucosal tissue by cutting along the folds. The artificial vascular valves are useful for replacing damaged or diseased valves of a warm-blooded vertebrate.