Abstract: Method and apparatus are disclosed for removing biopolymer constructs from support structures used to impart a selected shape to the biopolymer. The biopolymer construct and the support structure are in intimate at an interface and adhere to each other. The support structure includes an endcap adapted for introducing a fluid to the interface for reducing adhesion between the biopolymer structure and the support structure by applying a separating force at the interface, thereby facilitating removal between the support structure and the biopolymer construct.

Abstract: A biopolymer solution is polymerized to form a gel which is freeze-dried and crosslinked with ultraviolet radiation to form a biopolymer foam. The foam is filled with a collagen solution and the combination is freeze-dried or the foam is filled with a collagen solution containing extracellular matrix particulates and that combination is freeze-dried, thereby forming a foam to which extracellular matrix particulates are attached.

Abstract: An apparatus for forming a collagen fiber having microparticulates coated on the surface of the fiber and the method for forming the fiber are disclosed.

Abstract: Using connective tissues as starting materials, a method is described for producing matrix particulates. The invention includes an embodiment wherein the matrix particulate are seeded with living human cells or with cells of other species. Further, the invention encompasses fusing the particulates to constitute composites of various shapes, or holding them together in a porous container made of membranous biopolymers. The particulates or composites can be used as tissues for grafting or as model systems for research and testing. The invention also encompasses the spinning of threads in which the matrix particulates are components.

Abstract: Single and double density biopolymer foams, composite biopolymer foams including both single and double density foams, and methods of preparing these foams and composite foams are described. Also described are biocompatible constructs which include single or double density biopolymer foams and extracellular matrix particulates and methods of preparing these constructs. The foams, composite foams, and biocompatible constructs of the invention can be used in tissue repair and reconstruction.

Abstract: Apparatus and methods are disclosed for maturing a biopolymer tissue construct in vitro prior to use as a replacement construct in vivo as, for example, a graft, implant, or prosthesis. The tissue is seeded with specific cells, exposed to a maturation fluid, such as a synovial-like fluid containing hyaluronic acid, and subjected to selected conditioning and maturation forces, which can include frictional forces, shear forces, and compressive pressure. The tissue is mounted on a first support element and a second surface applies a selected force to the tissue. This maturation process occurs within a maturation chamber. The resultant matured replacement tissue construct is intended to provide a replacement tissue that is more readily integrable in vivo to produce a more durable and functional replacement tissue.

Abstract: An apparatus for forming a collagen fiber having microparticulates coated on the surface of the fiber and the method for forming the fiber are disclosed.

Abstract: Microfibrillar collagen and a superabsorbent polymer are combined in a hemostatic bandage which both absorbs blood and induces clotting.

Abstract: Using animal tissues as starting materials, a method is described for producing extracellular matrix particulates. The invention includes an embodiment wherein the matrix particulates are applied to collagen scaffolds, which can be seeded with living cells or the particulates may alone be seeded with living cells. Further, the invention encompasses bonding the particulates to collagen foams, or collagen threads made into fabrics or to foams combined with threads. The particulates, with or without scaffolding, can be used as tissues for grafting or as model systems for research and testing. The invention also encompasses the spinning of threads on which the matrix particulates are components and the freeze drying of foams to whose surfaces the matrix particulates are attached.

Abstract: A biopolymer solution is polymerized to form a gel which is freeze-dried and crosslinked with ultraviolet radiation to form a biopolymer foam. The foam is filled with a collagen solution and the combination is freeze-dried or the foam is filled with a collagen solution containing extracellular matrix particulates and that combination is freeze-dried, thereby forming a foam to which extracellular matrix particulates are attached.

Abstract: An apparatus for forming a collagen fiber having microparticulates coated on the fiber surface includes a device for forming a continuous stream of liquid collagen, a coagulation bath wherein the continuous liquid collagen stream can be formed into a continuous collagen gel fiber, a dehydrating bath, wherein the continuous collagen gel fiber can be partially dehydrated and further polymerized, and a device for coating particulates on the surface of the fiber. The method includes directing a liquid collagen solution into a coagulating bath to form a continuous collagen gel fiber, transferring the fiber to a dehydrating bath so that the fiber is partially dehydrated and further polymerized, removing the dehydrated fiber from the dehydrating bath, coating the surface of the fiber with microparticulates, and stretching and drying the coated fiber.

Abstract: Tissue equivalents are produced by applying a solution of collagen without cells to a permeable membrane, gelling to produce a collagen gel on the membrane, applying a mixture of collagen and a contractile agent to the collagen gel, gelling the mixture and allowing the resultant gel to undergo radial contraction which is controlled by the collagen gel on the membrane. A suitable contractile agent is fibroblast cells. A skin tissue equivalent is produced by disposing human epidermal cells on the contracted collagen gel and allowing epidermalization to occur. A nutrient medium can be supplied to the cells. An absorbent member may be disposed adjacent the permeable membrane opposite the collagen gel on the membrane. The permeable membrane can be the bottom of an inner well disposed in an outer well for containing a nutrient medium in contact with the membrane. The nutrient medium may be contained in the outer well in an agarose gel in contact with the membrane.

Abstract: This invention relates to collagen compositions and methods of preparing such compositions. This invention also relates to a novel source of collagen, the common digital extensor tendon.

Abstract: The present invention provides methods of, apparatus for, and kits for determining the interaction of tissue and at least one agent by use of at least one tissue equivalent. Tissue equivalent includes, but is not limited to, equivalents of epithelial tissue, connective tissue, cartilage, bone, blood, organs, glands and blood vessels, which are composed of living cells and extracellular matrix molecules, principally collagen. Agent includes, but is not limited to, various substances such as chemicals, cosmetics, pharmaceuticals, stimuli, e.g., light or physical injury; and tissue protective agents.

Abstract: An improvement in the preparation of living skin-equivalents from contracted hydrated collagen lattices having keratinocyte cells on the surface is disclosed herein. In this improvement, punch biopsies of skin are employed to provide a source of keratinocyte cells to the lattices.

Abstract: A method and apparatus for producing a vessel-equivalent prosthesis is described. A contractile agent such as fibroblast cells, smooth muscle cells or platelets is incorporated into a collagen lattice and contracts the lattice axially around an inner core. After the structure has set, additional layers may be formed in an ordered manner depending on the intended function of the prosthesis. Alternatively, all the layers may be formed concurrently. A plastic mesh sleeve is sandwiched between layers or embedded within the smooth muscle cell layer to reinforce the structure and provide sufficient elasticity to withstand intravascular pressure.

Abstract: A method and apparatus for producing a vessel-equivalent prosthesis is described. A contractile agent such as fibroblast cells, smooth muscle cells or platelets is incorporated into a collagen lattice and contracts the lattice axially around an inner core. After the structure has set, additional layers may be formed in an ordered manner depending on the intended function of the prosthesis. Capillary beds, blood vessels and glandular structures may be formed by this process.

Abstract: A bone-equivalent, useful in the fabrication of prostheses, is disclosed which is prepared from a hydrated collagen lattice contracted by fibroblast cells and containing demineralized bone powder.

Abstract: A tissue-equivalent, useful in the treatment of burns or other skin wounds and in the fabrication of prostheses, is disclosed which is prepared from a hydrated collagen lattice contracted by a contractile agent, such as fibroblast cells or blood platelets, to form tissue-equivalent. In one embodiment, a skin-equivalent can be fabricated by growing a layer of keratinocyte cells thereon. Both the keratinocyte cells and contractile agent may be derived from the potential recipient of the skin-equivalent.