Abstract: This invention is directed to prosthesis, which, when implanted into a mammalian patient, serve as a functioning replacement for a body part, or tissue structure, and will undergo controlled biodegradation occurring concomitantly with bioremodeling by the patient's living cells. The prosthesis of this invention, in its various embodiments, thus has dual properties. First, it functions as a substitute body part, and second, it functions as bioremodeling template for the ingrowth of host cells.

Abstract: A method for improving the tensile strength of wet collagen threads or collagen thread constructs for implantation to replace or repair tissue or organs wherein the strength of the threads is improved by plasticizing the threads with a plasticizing agent, imparting a tensile load to the collagen thread to strain the collagen thread; allowing the load in the thread to decrease by stress-relaxation or by creep conditioning methods and finally, removing the plasticizing agent. Prosthetic devices comprising collagen threads with improved strength characteristics are intended to repair load bearing tissues such as ligaments and tendons.

Abstract: The present invention provides systems, methods and chemically defined media for the cultivation of cells, particularly epithelial cells. Cells may be cultured with a varied calcium concentration. Furthermore, a calcium concentation in excess of 1.00 mM may be used in the practice of the present invention without loss of a proliferative cell population and maintianing high colony forming efficiencies. Population doubling times range from about 16 to about 33 hours. Cells may serially cultivated to achieve from about 20 to about 50 population doublings.

Abstract: An apparatus for ice seeding during cryopreservation of biological samples such as cells, harvested tissues, and cellular biological constructs such as culture tissue equivalents wherein ice seeding is performed by discharging a liquefied or chilled gas from a nozzle to the surface container containing said biological sample in cryopreservative. Inside a freezing chamber, containers are placed on racks that are located proximal to a sprayrail containing nozzles. Ice seeding is performed by discharge of liquefied or chilled gas from the nozzles to the container surface at the solid-liquid equilibrium temperature of the cryopreservative. Localized cooling of the container surface by the discharge results in ice seed formation within the container.

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 is directed to cryopreservation of cultured tissue equivalents made by in vitro technology. The invention involves immersing a cultured tissue equivalent in a cooled cryoprotectant solution, agitating the cryoprotectant solution and the immersed cultured tissue to achieve effective penetration of the cryoprotectant solution into the cultured tissue equivalent, and then freezing the cultured tissue at a high freezing rate. The cryopreserved cultured tissue equivalent may be stored for indefinite periods of time prior to use. The cultured tissue equivalent is an in vitro model of the equivalent human tissue, which, when retrieved from storage can be used for transplantation or implantation in vivo or for screening compounds in vitro.

Abstract: This invention is directed to the sterilization of collagen and collagenous tissue which is to be used for implantation, repair, or use in a mammalian host in the emerging field of tissue engineering. The sterilants are low concentration peracetic acid solutions in either neutral or high ionic strength that prevent or minimizes the swelling of collagen or collagenous tissue so that the sterilized tissue retains its structural integrity and bioremodelable properties.

Abstract: The present invention provides improved collagen threads and methods of making and using such threads, including the production of yarn, as well as braided, knitted, and woven articles of manufacture, comprising such threads.

Abstract: This invention is directed to an organ equivalent of the cornea part of the eye made using tissue culturing systems. The method of constructing the cornea equivalent results in a structure analogous to the eye cornea in vivo. The cornea equivalent is an in vitro model of the eye, which can be used for transplantation or implantation in vivo or for screening compounds in vitro.

Abstract: The present invention provides collagen constructs and methods of making and using such constructs. The present invention also provides tissue equivalents having improved characteristics and methods of making and using such tissue equivalents. This invention also provides methods of producing highly concentrated solutions of collagen.

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 fibrin-collagen tissue equivalents and methods of making and using such tissue equivalents. The present invention also provides methods of forming multi-layer tissue equivalents having improved adherence of the layers. The present invention further provides a method for joining tears in tissue equivalents.