Abstract: A tissue illumination system and a method for harvesting a section of a blood vessel from a patient's body for further use. The tissue illumination system includes a light catheter inserted into a lumen of the blood vessel section to illuminate the vessel section and vessel side branches with an intensity which is visible to the physician from an exterior of the vessel section and also includes a viewing element insertable into the lumen and capable of viewing the illuminated vessel section. The tissue illumination system also includes at least one tool insertable into the lumen and used to harvest the vessel section.

Abstract: A system (10) for forming and maintaining a biological tissue by which a biological tissue can be artificially formed by culturing cells, which comprises a pulse pump (12), a circulation pathway (13) having such a circuit structure as allowing a liquid cell culture medium discharged from the pulse pump (12) to return into the pulse pump (12), and a cell culture section (14A) and a gas exchange section (14B) provided along the circulation pathway (13). The cell culture section (14A) holds a cell holder (H) in such a manner to form a first channel wherein the liquid cell culture medium flowing in the circulation pathway (13) passes through the cell holder (H) and returns into the circulation pathway (13) and a second channel wherein the liquid cell culture medium flowing in the circulation pathway (13) passes outside the cell holder (H) and returns into the circulation pathway thereby bringing about a difference in pressure between the liquid cell culture medium passing through the respective channels.

Abstract: Systems and methods are provided for controlling the diameter of a mammalian hybrid coronary bypass graft. The system includes a controller having at least one input for receiving information and feedback information and an output for outputting control signals, including at least one steady flow system control signal; and a pressure/flow loop subsystem coupled to the controller. The pressure/flow loop subsystem includes a specimen holder, an external flow loop system coupled to the specimen holder, a steady flow system, and an output for outputting the feedback information. The pressure/flow loop subsystem receives the control signals and is capable of adjusting a diameter of a specimen in accordance with the control signals, when the specimen holder contains the specimen.

Abstract: Developing heart valves are exposed to dynamic strains by applying a dynamic pressure difference over the leaflets. The flow is kept to a minimum, serving only as a perfusion system, supplying the developing tissue with fresh nutrients. Standard heart valves were engineered based on B trileaflet scaffolds seeded with cells isolated from the human saphenous vein. Tissue compaction is constrained by the stent, inducing increasing pre-strain in the tissue. The dynamic strains the tissues are exposed to via the dynamic pressure difference, are estimated using finite element methods based on the mechanical properties of the neo-tissue, in order to get inside into the strain distribution over the leaflet.

Abstract: An organ support apparatus includes: (a) a fluid circuit defining upstream and downstream legs adapted to be connected to an organ to be supported; (b) a circulation pump connected to the fluid circuit for circulating a process fluid through the fluid circuit and the organ; and (c) a first waveform generator connected to the fluid circuit for impressing a preselected pressure waveform on the process fluid.

Abstract: A system for hemodynamic simulation comprises a vessel having properties of a blood vessel, a reservoir containing a quantity of fluid, tubing connecting the vessel and reservoir, and at least one pump for circulating the fluid within the system. Fluid can be tissue culture medium or blood analog fluid, and the vessel may include mammalian cells attached to its inside. A drive system, comprising two reciprocating drive shafts that are coupled by a cam, enables the uncoupling of pulsatile flow and pulsatile pressure to provide independent control over wall shear stress and circumferential strain. The shaft drives two pumps that are 180 degrees out-of-phase and are connected upstream and downstream of the vessel, and effect this uncoupling.

Abstract: Hybrid synthetic grafts and embodiments of systems and methods for producing hybrid vascular grafts that can yield implantable grafts that combine synthetic grafts with living cells. Embodiments of systems can include a pressure/flow loop subsystem having an external flow loop system coupled to a specimen holder, where the pressure/flow loop subsystem is capable of adjusting at least two dynamic conditions in the specimen holder or a diameter of a specimen in the specimen holder. Embodiments of methods can coat a hybrid graft with a confluent monolayer of endothelial cells by immobilizing stem cells on a hybrid hemodialysis access graft or a hybrid femoral artery bypass graft, and placing the hybrid graft in a system embodiment according to the invention under conditions effective to promote the stem cells to form a confluent monolayer on the hybrid graft and in an environment to promote the stem cells to differentiate into endothelial cells.

Abstract: Hybrid synthetic grafts and embodiments of systems and methods for producing hybrid vascular grafts that can yield implantable grafts that combine synthetic grafts with living cells. Embodiments of systems can include a pressure/flow loop subsystem having an external flow loop system coupled to a specimen holder, where the pressure/flow loop subsystem is capable of adjusting at least two dynamic conditions in the specimen holder or a diameter of a specimen in the specimen holder. Embodiments of methods can promote endothelialization of a hybrid hemodialysis access graft or a hybrid femoral artery bypass graft by placing the hybrid hemodialysis access graft or the hybrid femoral artery bypass graft in a system embodiment according to the invention under conditions effective to promote endothelial cells to form a confluent monolayer on the surface of the hybrid graft.

Abstract: Hybrid synthetic grafts and embodiments of systems and methods for producing hybrid vascular grafts that can yield implantable grafts that combine synthetic grafts with living cells. Embodiments of systems can include a pressure/flow loop subsystem having an external flow loop system coupled to a specimen holder, where the pressure/flow loop subsystem is capable of adjusting at least two dynamic conditions in the specimen holder or a diameter of a specimen in the specimen holder. Embodiments of methods can promote endothelialization of a hybrid hemodialysis access graft or a hybrid femoral artery bypass graft by placing the hybrid hemodialysis access graft or the hybrid femoral artery bypass graft in a system embodiment according to the invention under conditions effective to promote stem cells to form a confluent monolayer on the hybrid graft.

Abstract: A composite stent and a method for making the same are provided.

Abstract: A method of yielding a functional human hybrid coronary bypass graft is provided. The method includes conditioning a hybrid synthetic tubular structure having stem cells and/or endothelial cells on at least one surface to yield the functional human hybrid coronary bypass graft. Specifically, the method includes placing the hybrid synthetic tubular structure in a system capable of producing three dimensional dynamic conditions for a sufficient time to yield said functional human hybrid coronary bypass graft.

Abstract: A method of yielding a functional human hybrid hemodialysis access graft is provided. The method includes conditioning a hybrid synthetic tubular structure having stem cells and/or endothelial cells on at least one surface to yield the functional human hybrid hemodialysis access graft. Specifically, the method includes placing the hybrid synthetic tubular structure in a system capable of producing three dimensional dynamic conditions for a sufficient time to yield said functional human hybrid hemodialysis access graft.

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: Apparatus and methods for seeding an implantable medical device, such as a vascular prosthesis, with cells, such as endothelial cells, are described. The invention supports techniques for seeding a luminal surface of the device with axial centrifugation. Cells are introduced in suspension into the lumen of the device. The introduction of the cells may occur after a blood centrifugation product, such as platelet-poor plasma, is applied to the luminal surface. After the cells are introduced, the device is then subjected to centrifugation around a longitudinal axis defined by the lumen. Axial centrifugation causes the cells to concentrate toward and adhere to the luminal surface. Shortly after axial centrifugation, the seeded device can be presented for implantation in a patient. The implantable medical device may be inserted into a protective sleeve prior to seeding the device with cells, and the sleeve may or may not be removed prior to implantation.

Abstract: Apparatus and methods for seeding an implantable medical device, such as a vascular prosthesis, with cells, such as endothelial cells, are described. The invention supports techniques for seeding a luminal surface of the device with axial centrifugation. Cells are introduced in suspension into the lumen of the device. The introduction of the cells may occur after a blood centrifugation product, such as platelet-poor plasma, is applied to the luminal surface. After the cells are introduced, the device is then subjected to centrifugation around a longitudinal axis defined by the lumen. Axial centrifugation causes the cells to concentrate toward and adhere to the luminal surface. Shortly after axial centrifugation, the seeded device can be presented for implantation in a patient. The implantable medical device may be inserted into a protective sleeve prior to seeding the device with cells, and the sleeve may or may not be removed prior to implantation.

Abstract: The invention relates to a bioartificial primarily vascularized tissue matrix, a bioartificial primarily vascularized tissue, a method for the production thereof and the use of the same. Said tissue matrix and bioartificial primarily vascularized tissue are obtained by preparing the necessary natural tissue, conserving at least one vessel.

Abstract: The present invention provides for compositions and methods for the preservation of tissues and organs ex vivo and in situ. In addition, the present invention provides for kits that may be used in the preparation of the solutions of the present invention. The present invention also provides a device for perfusing tissues and organs with the solutions of the present invention.

Abstract: A microprocessor controlled and instrumented bioreactor for conditioning intravascular tissue engineered medical products. One bioreactor design including an integrated pump to provide a relatively small volume of fluid nutrient. The microprocessor control providing measurement and control of the fluid flow and tissue displacement and subsequent determination of material properties. One design includes a flexible joint providing motion of the treated tissue in the axial, bending and torsional direction.

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 system and a method for harvesting a section of a blood vessel from a patient's body for further use. The system includes an expandable hood that creates a workspace for the dissection and removal of the vessel and a telescoping device that has tools at its distal end. The blood vessel is cut at a distal location and a light catheter inserted to illuminate the area of dissection. The system can remove a section of the saphenous vein for use in coronary bypass surgery.

Abstract: A system for hemodynamic simulation comprises a vessel having properties of a blood vessel, a reservoir containing a quantity of fluid, tubing connecting the vessel and reservoir, and at least one pump for circulating the fluid within the system. Fluid can be tissue culture medium or blood analog fluid, and the vessel may include mammalian cells attached to its inside. A drive system, comprising two reciprocating drive shafts that are coupled by a cam, enables the uncoupling of pulsatile flow and pulsatile pressure to provide independent control over wall shear stress and circumferential strain. The shaft drives two pumps that are 180 degrees out-of-phase and are connected upstream and downstream of the vessel, and effect this uncoupling.

Abstract: The present invention provides an ex vivo vascular remodeling methods and system by which an excised, small diameter blood vessel can be harvested and expanded to provide viable vascular grafts, as demonstrated at the physical and molecular levels, and as optimized in vivo. The tissue-engineered vessels generated by the present invention closely resemble native vessels in terms of structure, histologically, including endothelial coverage and intricate structural components such as the internal elastic lamina, viability (as measured with the MTT assay and TUNEL analysis), and function (vasoactivity, mechanical and biomechanical properties). Thus, the resulting vascular grafts behave in a manner similar to native arteries in terms of mechanical integrity, and provide clinically relevant patency rates when implanted in vivo.

Abstract: An apparatus and method that allows the visualization of leakage of cell culture media through a conduit wall of a tissue-engineered biological construct such as a semilunar heart valve or valve graft under controlled physiologic conditions. The apparatus and method also allows for the assessment of valve function and intraluminal flow using conventional imaging modalities such as ultrasonic and magnetic resonance imaging. The apparatus allows the qualitative and quantitative evaluation of structural and functional characteristics of a condition tissue engineered construct prior to implantation using a valve housing and chamber and a flow-pressure simulator.

Abstract: The invention features a bioreactor system. The system includes components, which exert physiologically relevant translational and rotational strains on a growing bioengineered tissue.

Abstract: A system and a method for harvesting a section of a blood vessel from a patient's body for further use. The system includes an expandable hood that creates a workspace for the dissection and removal of the vessel and a telescoping device that has tools at its distal end. The blood vessel is cut at a distal location and a light catheter inserted to illuminate the area of dissection. The system can remove a section of the saphenous vein for use in coronary bypass surgery.

Abstract: The present invention relates to decellularized vascular prostheses that are resistant to thrombus occlusion and have a low level of immunogenicity. The vascular prostheses are denuded of cells, and coated with an anti-thrombogenic agent and a growth factor that promotes recellularization and further reduces the immunogenicity. The prostheses have high mechanical strength, resist aneurysm rupture, and allow for secure surgical sutures while maintaining structural integrity. The present invention provides vascular prostheses that are blood vessels, valves or portions of vessels containing valves. The present invention is also useful for coating synthetic vascular stents.

Abstract: Cardiovascular cell proliferation in a blood vessel subjected to trauma, such as angioplasty, vascular graft, anastomosis, or organ transplant, can be inhibited by contacting the vessel with a polymer consisting of from 6 to about 30 amino acid subunits, where at least 50% of the subunits are arginine, and the polymer contains at least six contiguous arginine subunits. Exemplary polymers for this purpose include arginine homopolymers 7 to 15 subunits in length.

Abstract: An improved method of implanting cells in the body of a patient includes positioning viable cells on a support structure. One or more blood vessels may be connected with the support structure to provide a flow of blood through the support structure. A support structure may be positioned at any desired location in a patient's body. The support structure may be configured to replace an entire organ or a portion of an organ. An organ or portion of an organ may be removed from a body cells and/or other tissue is removed to leave a collagen matrix support structure having a configuration corresponding to the configuration of the organ or portion of an organ. Alternatively, a synthetic support structure may be formed. The synthetic support structure may have a configuration corresponding to a configuration of an entire organ or only a portion of an organ.

Abstract: A system and a method for harvesting a section of a blood vessel from a patient's body for further use. The system includes an expandable hood that creates a workspace for the dissection and removal of the vessel and a telescoping device that has tools at its distal end. The blood vessel is cut at a distal location and a light catheter inserted to illuminate the area of dissection. The system can remove a section of the saphenous vein for use in coronary bypass surgery.

Abstract: The present invention is directed to novel, less invasive and improved methods of tissue-engineering of constructs that require an endothelial surface such as blood vessels and heart valves. The constructs of the present invention possess long-term patency. The method of the present invention is particularly suited for making small diameter vessels to replace clogged or damaged coronary blood vessels, for making trileaflet heart valve conduits to replace damaged or malformed pulmonic and aortic valves, and for other vascular structures that require an endothelial surface.

Abstract: An apparatus (10) for grafting of a blood vessel (12) and a method of forming the apparatus (10) is provided. The apparatus (10) comprises an expandable support member (16) having inner and outer surfaces (36 and 34). The outer surface (34) of the expandable support member (16) is for engaging and adhering to an inside surface (68) of the blood vessel (12). A layer of biological tissue (14) is attached to the inner surface (36) of the support member (16). The layer of biological tissue (14) has an uninterrupted inwardly facing surface (50) for extending confluently with the inside surface (68) of the blood vessel (12) to provide resistance to thrombosis and platelet deposition.

Abstract: Disclosed are tissue implant materials for use in grafting procedures. More particularly non-vascular tissue for use as vascular graft material and a method of vascular grafting using non-vascular tissue is disclosed. The tissue is preferably autologous relative to the recipient of the graft and is conveniently prepared around or on a molding support inserted into a body cavity of the intended recipient of the graft. These tissues and methods are particularly useful in the treatment or prophylaxis of diseased or damaged blood vessels such as in atherosclerosis.

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 invention is a tissue engineered blood vessel (TEBV) made from a cultured fibroblast sheet rolled into a multilayer vessel which has sufficient burst strength to withstand physiological blood pressure without the inclusion of smooth muscle cells or synthetic scaffolding. The TEBV is made in a bioreactor having an enclosed chamber, a sheet growth module, a rollable mandrel and a clamp for holding the sheet to the mandrel for rolling.

Abstract: A tissue composition includes the subendothelial layer, the elastica interna, and at least a portion of the tunica media of a blood vessel harvested from a mammal, with the endothelial cells removed from the blood vessel. The tissue composition can also include a portion of the tunica adventitia of a blood vessel harvested from a mammal. The tissue composition can be formed into a graft, a patch, a connective tissue for surgical repair, an orthopedic graft, and a substrate for cell growth, among other applications. The tissue composition can also be fluidized, or made into powdered form.

Abstract: A stent cover useful as a barrier between an expandable stent and the vascular surface. The cover provides an optimal combination of such properties as thickness, physical characteristics and biocompatability. The cover can be formed to and positioned upon the size and shape of the unexpanded stent, and to then be expanded in situ upon expansion of the stent itself. The cover is prepared from natural tissues such as umbilical arteries, bovine pericardium, and porcine peritoneum.

Abstract: The invention provides a device and process for recellularizing essentially acellular or devitalized tissue grafts, including for example essentially acellular or devitalized vascular tissue grafts, derived from human or animal sources, or as constructed using any number of tissue engineering methodologies. The process includes repopulating and reendothelializing an essentially acellular or devitalized tissue graft. The device is useful for producing a repopulated tissue graft from an essentially acellular or devitalized tissue, as well as for producing an essentially acellular or devitalized tissue graft.