Abstract: Disclosed are apparati for the precise positioning of cells into highly organized tissue structures. In particular, ink jet printers and graphics plotters are modified to allow their use in the preparation of tissue structures which are suitable for use in the treatment of burn patients. Cells are positioned by the use of computer-controlled placement of cell adhesion materials such as fibronectin to a substratum which is suitable for maintaining cell growth, followed by allowing cells to attach to those areas of the substratum where the cell adhesion material has been placed. Alternatively, specific placement of cells onto substrata is obtained by the computer-controlled placement of cells directly. These apparati may be even further modified and improved by providing a controlled biological environment in the area of the substratum, thus providing an integral unit for the production of organized tissues.

Abstract: A process for providing a biological pacemaker for the human heart wherein the sino-atrial (S-A) node cells are removed from the heart and cultured to generate a critical mass of S-A node cells of sufficient quantity to generate a depolarization wave capable of stimulating the cells of the myocardium to ensure normal or near-normal pumping action in the heart. The critical mass of S-A node cells are then implanted in the myocardial tissue of the right ventricle to provide biological pacing for the heart which is sensitive to and variable with normal increase and decrease of output demands on the heart.

Abstract: A method for treating a lesion in an arterial wall having plaque thereon and a luminal surface, the arterial wall having been mechanically injured during an angioplasty procedure, the arterial wall and the plaque including fissures resulting therefrom, the method comprising the steps of positioning an angioplasty catheter adjacent to the lesion being treated; delivering a bioprotective material between the arterial wall and the angioplasty catheter so that the bioprotective material is entrapped therebetween and permeates into the fissures and small vessels of the arterial wall during apposition of the angioplasty catheter to the arterial wall; applying thermal energy to the lesion, thereby bonding the bioprotective material to the arterial wall and within the fissures; and removing the angioplasty catheter, the bioprotective material remaining adherent to the arterial wall and within the fissures, thereby coating the luminal surface of the arterial wall with an insoluble layer of the bioprotective material s

Abstract: The coating process for coating the vascular prosthesis resides in stepwise rotations of the prosthesis, filled with a cell suspension, through fixed angles and in pauses for deposition between the rotations. The length of pauses start at two seconds and are increased in small increments of from 1 to 2 seconds to values of 2 to 3 minutes. The angle of rotation is controlled to ensure a uniform gapless deposition of the living cells.

Abstract: Implants containing a reasonably biocompatible fabric, which is to be exposed to blood flow after implantation, are rendered biocompatible and substantially impervious to blood, by applying a collagen composition containing soluble collagen, and preferably also collagen fibers, to the fabric in such a manner that the collagen composition penetrates into the interstitial spaces of the fabric. The fabric retaining collagen composition is then incubated at elevated temperature for sufficient time to form collagen fibers from the soluble collagen. Thereafter, the implant is dried. The steps of applying collagen composition, incubating and drying are repeated approximately two to four times. The implants, particularly when they comprise tubular vascular grafts, are tested for porosity by placing a pressurized column of aqueous solution, such as saline, into their interior.

Abstract: The invention is an endothelial cell procurement and deposition kit for collecting fat from a patient, processing said fat to produce an endothelial cell deposition product, and depositing said product on the surface of a graft, all under sterile conditions established and maintained within the components of said kit comprised of: fat collection means for collecting subcutaneous fat from a patient; digestion means connectable to said fat collection means to maintain sterility during reception of said fat and for retaining said fat under sterile conditions during rinsing and digestion to produce a digested product; endothelial cell isolation means connectable to said digestion means for maintaining sterile conditions during reception of said digested product and for separating and isolating microvessel endothelial cells from said digested product to produce an endothelial cell product; cell deposition means connectable to said isolation means for maintaining sterile conditions during reception of said endothel

Abstract: A soft tissue implant device such as a catheter, heart valve, or plastic or reconstructive surgical material, to be at least partially embedded in an implantation site in soft organic tissue of a living organism includes a body defining a surface layer extending over the portion of the body contacting the organic tissue. The surface layer defines a three-dimensional pattern with an exterior surface defining a plurality of spaces and a plurality of solid surface portions. The spaces have a mean bridging distance ranging from greater than 1.0 micron to less than 4.0 microns and the solid surfaces portions have mean breadths ranging from 0.10 micron to 2.0 microns. The mean bridging distance is preferably greater than 1.4 microns and less than 1.9 microns. The exterior surface is substantially free of indentations having a bridging distance measuring in a range from between 10.0 microns and 1,000 microns.

Abstract: The immunogenicity of transfused or transplanted, allogeneic tissue is reduced by either directly exposing the tissue to ultraviolet (UV) irradiation prior to administering the tissue to the recipient or by inducing a state of tolerance in the recipient to non-UV or UV-irradiated allogeneic tissue by prior exposure to UV-irradiated allogeneic tissue.

Abstract: Arteries and veins of umbilical cords are treated by processes described, fitted with a biodegradable mesh support and used as tubular prosthesis for vascular reconstructive surgery.

Abstract: A prosthesis for replacing parts of arteries and other blood vessels preferably has an inner tube suitable for use as a vascular graft in combination with external longitudinal ribs and a surrounding wrap which provides radial and longitudinal strength and resistance to kinking. The ribs separate the wrap from the inner tube, providing spaces between the wrap and tube to allow the tube to expand and contact, thus promoting isocompliance of the prosthesis with natural blood vessels.

Abstract: A prosthesis for transluminal implantation comprising a flexible tubular body which has a diameter that is variable by axial movement of the ends of the body relative to each other and which is composed of several individual rigid but flexible thread elements each of which extends in helix configuration with the center line of the body as a common axis, a number of elements having the same direction of winding but being axially displaced relative to each other crossing a number of elements also axially displaced relative to each other but having the opposite direction of winding; and method for transluminal implantation.

Abstract: An artificial vessel having a compliance and a stress-strain curve approximate to those of a vital vessel, which comprises a porous part of an elastomer having pores which communicate between the inside of the vessel and the outside of the vessel and a tubular part of fibers, said tubular part being in contact with and/or bonded to at least one part of the porous part. The artificial vessel can be prevented from breakage and damage at a high blood pressure and has an excellent durability.

Abstract: A synthetic vascular prosthesis comprises a hollow tubular base member having a multitude of continuous pores and formed of an elastomer material, and a hydrogel layer formed on the inner surface of the base member. The hydrogel layer is partly embedded in the inner portion of the base member at the pores, thereby permitting anchoring adhesion between the hydrogel layer and the base member. A method for manufacturing the synthetic vascular prosthesis is also disclosed, in which the formation of pores in the base member is effected by two separate steps and the hydrogel layer is formed after formation of an inner porous portion of the base member.

Abstract: A method for treating porous polytetrafluoroethylene and other types of synthetic materials having low surface tension to render the material suitable for use in bonding to living tissue. The synthetic material is enveloped with a liquid of sufficiently low surface tension to permit the liquid to enter the pores of the material. The liquid has a sufficiently low gas content to enable the liquid to absorb or displace essentially all gas nuclei held in the pores of the material as the liquid fills essentially all pores. After the low surface tension liquid has permeated all pores of the porous material, such liquid is replaced with a solution compatible with the body fluid and in which proteins have a low solubility to render the material suitable for implant. When such material is placed in contact with exposed tissue, an immediate bond is formed which permits implanting the material without the need of sutures to hold the material in place.

Abstract: Methods for attaching prostheses to natural vessels are disclosed. Prosthetic vessels having improved resistance to occlusion by tissue reaction upon implantation by reducing transmural stresses are also disclosed. Prostheses having elliptical cross-sections governed by the maximum strain expected in the natural vessel and possessing a higher bulk compliance than previous designs are provided. Additionally, novel methods are presented for implanting improved prostheses by using angled bias cuts to produce an elliptical cross-section at each end of the natural vessel section receiving the prosthesis. In accordance with preferred embodiments, vessels are provided where the cross-sectional geometry is approximated by the equations:a=r.sub.0 [1+2.epsilon.(2+.epsilon.)].sup.1/2andb=r.sub.0.

Abstract: A method and composition of regenerating tissue. More specifically, a method for regenerating pancreatic islet tissue having the histological and insulin-containing properties of islets typically found in neonatal or adult animals is described. The regenerated islet tissue is produced by fetal mesenchyme acting upon an epithelium such that an inductive message causes the epithelium to differentiate into islet tissue.

Abstract: A method for fabricating human tissue prosthesis. The method produces a prosthesis that has mechanical compliance properties similar to that of body tissue. The prosthesis fabrication method utilizes, for example, a polyurethane urea-linked block copolymer system which in the cured state is a thermoset elastomer which has lumen surface qualities which are essentially optically flat. The formulation is essentially a single a single step process. A clean mandrel is horizontally clasped in the jaws of a variable speed motor and slowly rotated. The pre-polymer solution is placed on the rotating mandrel and thickness adjusted by a mechanical wiper. The rotating mandrel having pre-polymer of desired thickness is placed in a sub-atmospheric environment to remove dissolved gasses and permitted to initially cure while rotating. The final cure is achieved in a sub-atmospheric environment.

Abstract: The holder contains a sealed chamber in which a vein segment is clamped centrally with a slight axial prestress. For storage and transportation, the interior of the vein segment and the surrounding peripheral portions of the chamber housing the vein segment can be filled with a physiological common salt solution via flow channels. For removal of endothelial cells, an enzyme solution can be passed through the flow channels aligned with the vein segment to entrain the endothelium cells therein for subsequent processing.

Abstract: A vascular tubular graft of a woven fabric with a single velour outside (external) surface and a smooth interior surface, said outside surface having a plurality of loops, each loop extending around a portion of the circumference thereof and each loop formed by fill yarn positioned about warp yarn.

Abstract: An aorto-coronary bypass graft comprising a plate portion and at least one tube portion extending from the plate portion, the opening in the tube portion communicating with a corresponding opening in the plate portion.

Abstract: A method of fabricating frozen fine liver pieces for an artificial liver which comprises cutting a liver removed from a human being or an animal, from which blood has been removed, into fine pieces of square shape and freezing the liver pieces with helium gas. A freezing apparatus for an artificial liver which has gas phase pressurizing means for pressurizing liquid helium coupled to a chamber for storing the liquid helium, a helium gas conduit dipped in the liquid helium passed through the chamber to be closed and contained, to which the liver fine pieces are telescopic, and an exhaust conduit provided with a control valve coupled to the freezing chamber.

Abstract: A method is provided for forming a mold surface with microscopic upstanding pillars for molding the inside surface of a vascular prostheses (synthetic blood vessel). The mold article is formed from a quantity of Teflon (polytetrafluoroethylene) which has a polished, flat surface on which a gold film has been sputter deposited. A photoresist layer, which cannot adhere directly to Teflon, adheres to the gold. The photoresist is exposed and developed leaving a sputter resistant mask defining the desired pillar locations, and the resulting workpiece is ion etched to form the pillars in the Teflon. A synthetic blood vessel material is cast against the Teflon mold to form blind recesses on the inside of the synthetic blood vessel, with the recesses being of predetermined uniform cross section and present in a predetermined uniform pattern.

Abstract: A collagen impregnated synthetic vascular graft including a synthetic vascular graft substrate and cross-linked collagen fibril is formed by depositing an aqueous slurry of collagen fibrils in the lumen of the graft and massaging to insure intimate mixing of the fibrils into the porous structure of the substrate. After massaging, the collagen is dried and cross-linked. Repeated applications and massaging and drying further reduce porosity of the graft.

Abstract: An artificial vessel made of an elastomer having a network structure over the entire thickness of the vessel wall with small pores having a maximum diameter of from 1 to 100 .mu.m which communicate between the inner surface and the outer surface, and having a porosity of 75 to 87.5% by volume and a compliance of 0.1 to 0.8.

Abstract: A surgical method of reconstructing damaged cardiac muscle via latissimus dorsi autograft. The latissimus dorsi is dissected from its origin and insertion while maintaining the neurovascular bundle intact. The dissected muscle flap is passed into the thorax through a rib resection in the corresponding axilla. After appropriate midsternotomy, cardiopulmonary bypass, etc., the muscle flap and its preserved neurovascular bundle may be used as graft muscle in the reconstruction of cardiac muscle. The latissimus dorsi autograft minimizes or eliminates the problems of histoincompatibility associated with cardiac transplantation. A subsequent protocol of suitable pacing of the autograft enables it to contribute to the overall cardiac function, and the structural presence of the grafted muscle tissue permits cardiac muscle repair without distorting the shape of the heart in the area(s) of excised cardiac muscle.

Abstract: An expandable intraluminal vascular graft is expanded within a blood vessel by an angioplasty balloon associated with a catheter to dilate and expand the lumen of a blood vessel. The graft may be a wire mesh tube, having a biologically inert coating thereon.

Abstract: A method and apparatus for producing a graft for a patient consisting of foreign skin provided with openings and segments of a piece of the patient's original skin inserted into the openings are disclosed. A piece of the patient's original skin is cut into segments arranged at specific locations in a system of coordinates. A backing, carrying foreign skin, is also placed within the system of co-ordinates and openings are cut into the foreign skin at similarly defined locations. The segments of the patient's original skin are then placed by mechanical means into the openings of the foreign skin.