1851results about "General culture methods" patented technology

A freeze dried biocompatible matrix comprising plasma proteins, useful as implants for tissue engineering as well as in biotechnology, and methods of producing the matrix are provided. Mechanical and physical parameters can be controlled by use of auxiliary components or additives which may be removed after the matrix is formed in order to improve the biological properties of the matrix. The matrices according to the present invention may be used clinically per se, or as a cell-bearing implant.

The present invention relates to collagenous membranes produced from amnion, herein referred to as a collagen biofabric. The collagen biofabric of the invention has the structural integrity of the native non-treated amniotic membrane, i.e., the native tertiary and quaternary structure. The present invention provides a method for preparing a collagen biofabric from a placental membrane, preferably a human placental membrane having a chorionic and amniotic membrane, by decellularizing the amniotic membrane. In a preferred embodiment, the amniotic membrane is completely decellularized. The collagen biofabric of the invention has numerous utilities in the medical and surgical field including for example, blood vessel repair, construction and replacement of a blood vessel, tendon and ligament replacement, wound-dressing, surgical grafts, ophthalmic uses, sutures, and others. The benefits of the biofabric are, in part, due to its physical properties such as biomechanical strength, flexibility, suturability, and low immunogenicity, particularly when derived from human placenta.

The present invention provides a method of extracting and recovering embryonic-like stem cells, including, but not limited to pluripotent or multipotent stem cells, from an exsanguinated human placenta. A placenta is treated to remove residual umbilical cord blood by perfusing an exsanguinated placenta, preferably with an anticoagulant solution, to flush out residual cells. The residual cells and perfusion liquid from the exsanguinated placenta are collected, and the embryonic-like stem cells are separated from the residual cells and perfusion liquid. The invention also provides a method of utilizing the isolated and perfused placenta as a bioreactor in which to propagate endogenous cells, including, but not limited to, embryonic-like stem cells. The invention also provides methods for propagation of exogenous cells in a placental bioreactor and collecting the propagated exogenous cells and bioactive molecules therefrom.

Tissue engineering devices for use in the repair or regeneration of tissue made of support scaffolds and cell sheets.

The present invention provides a method of extracting and recovering embryonic-like stem cells, including, but not limited to pluripotent or multipotent stem cells, from an exsanguinated human placenta. A placenta is treated to remove residual umbilical cord blood by perfusing an exsanguinated placenta, preferably with an anticoagulant solution, to flush out residual cells. The residual cells and perfusion liquid from the exsanguinated placenta are collected, and the embryonic-like stem cells are separated from the residual cells and perfusion liquid. The invention also provides a method of utilizing the isolated and perfused placenta as a bioreactor in which to propagate endogenous cells, including, but not limited to, embryonic-like stem cells. The invention also provides methods for propagation of exogenous cells in a placental bioreactor and collecting the propagated exogenous cells and bioactive molecules therefrom.

The invention features polymeric biomaterials formed by nucleophilic addition reactions to conjugated unsaturated groups. These biomaterials may be used for medical treatments.

A nanofibrillar structure for cell culture and tissue engineering is disclosed. The nanofibrillar structure can be used in a variety of applications including methods for proliferating and / or differentiating cells and manufacturing a tissue. Also disclosed is an improved nanofiber comprising a lipid, lipophilic molecule, or chemically modified surface. The nanofibers can be used in a variety of applications including the formation of nanofibrillar structures for cell culture and tissue engineering.

Cells grown on a microcarrier are separated from the microcarrier by enzymatically digesting the microcarrier. More specifically, chondrocytes may be grown on dextran microcarrier beadlets and then the beadlets digested using dextranase to separate the chondrocytes from the carrier. Cells can also be grown on chitosan microcarriers to be used for implantation. In addition, cells can be grown on polysaccharide polymers to be used as implant devices. Various polymers serve as scaffolds for cells to be used for implantation. The polymers can be used for cell culture as well as for preparing scaffolds useful for tissue replacement such as cartilage tissue.

The present invention provides a class of interpenetrating polymeric networks (IPNs) and semi-interpenetrating polymeric networks (sIPNs) which include a covalently grafted growth factor or differentiation factor for a stem cell.

The invention relates to cells or tissues having an increased amount of regulatory proteins, including cytokines, growth factors, angiogenic factors and / or stress proteins, and methods of producing and using those cells or tissues. The invention is based on the discovery that the production of regulatory proteins is induced in cells or tissue constructs following cryopreservation and subsequent thawing of the cells or constructs. The compositions and methods of this invention are useful for the treatment of wound healing and the repair and / or regeneration of other tissue defects including those of skin, cartilage, bone, and vascular tissue as well as for enhancing the culture and / or differentiation of cells and tissues in vitro.

The assemblies of the invention can comprise a fine fiber layer having dispersed within the fine fiber layer an active particulate material. Fluid that flows through the assemblies of the invention can have any material dispersed or dissolved in the fluid react with, be absorbed by, or adsorbed onto, the active particulate within the nanofiber layer. The structures of the invention can act simply as reactive, absorptive, or adsorptive layers with no filtration properties, or the structures of the invention can be assembled into filters that can filter particulate from a mobile fluid while simultaneously reacting, absorbing, or adsorbing materials from the mobile fluid.

Biocompatible polyhydroxyalkanoate compositions with controlled degradation rates have been developed. In one embodiment, the polyhydroxyalkanoates contain additives to alter the degradation rates. In another embodiment, the polyhydroxyalkanoates are formed of mixtures of monomers or include pendant groups or modifications in their backbones to alter their degradation rates. In still another embodiment, the polyhydroxyalkanoates are chemically modified. Methods for manufacturing the devices which increase porosity or exposed surface area can be used to alter degradability. For example, as demonstrated by the examples, porous polyhydroxyalkanoates can be made using methods that creates pores, voids, or interstitial spacing, such as an emulsion or spray drying technique, or which incorporate leachable or lyophilizable particles within the polymer. Examples describe poly(4HB) compositions including foams, coatings, meshes, and microparticles. As demonstrated by the examples, these polyhydroxyalkanoate compositions have extremely favorable mechanical properties, as well as are biocompatible and degrade within desirable time frames under physioogical conditions. These polyhydroxyalkanoate materials provide a wider range of polyhydroxyalkanoate degradation rates than are currently available. Methods for processing these materials, particularly for therapeutic, prophylactic or diagnostic applications, or into devices which can be implanted or injected, are also described.

This disclosure provides an improved system for culturing human pluripotent stem cells. Traditionally, pluripotent stem cells are cultured on a layer of feeder cells (such as mouse embryonic fibroblasts) to prevent them from differentiating. In the system described here, the role of feeder cells is replaced by components added to the culture environment that support rapid proliferation without differentiation. Effective features are a suitable support structure for the cells, and an effective medium that can be added fresh to the culture without being preconditioned by another cell type. Culturing human embryonic stem cells in fresh medium according to this invention causes the cells to expand surprisingly rapidly, while retaining the ability to differentiate into cells representing all three embryonic germ layers. This new culture system allows for bulk proliferation of pPS cells for commercial production of important products for use in drug screening and human therapy.

The present invention provides compositions and methods that combine the initial patterning capabilities of a direct cell printing system with the active patterning capabilities of magnetically labeled cells, such as cells labeled with superparamagnetic nanoparticles. The present invention allows for the biofabrication of a complex three-dimensional tissue scaffold comprising bioactive factors and magnetically labeled cells, which can be further manipulated after initial patterning, as well as monitored over time, and repositioned as desired, within the tissue engineering construct.

The present invention relates to injectable compositions comprising biocompatible, hydrophilic, non-toxic and substantially spherical microspheres associated with stem cells useful for tissue construction and generation. The invention also relates to methods of tissue construction and generation, for the treatment of various tissue damage and defects, using the injectable compositions.

New methods for producing tissue engineered constructs and engineered native tissues are disclosed. The methods include producing a tissue engineered construct by growing cells in vitro on a substrate and then decellularizing the construct to produce a decellularized construct consisting largely of extracellular matrix components. The construct can be used immediately or stored until needed. The decellularized construct can be used for further tissue engineering, which may include seeding the construct with cells obtained from the intended recipient of the construct. During any of the growth phases required for production of the construct, the developing construct may be subjected to various tissue engineering steps such as application of mechanical stimuli including pulsatile forces. The methods also include producing an engineered native tissue by harvesting tissue from an animal or human, performing one or more tissue engineering steps on the tissue, and subjecting the tissue to decellularization. The decellularized, engineered native tissue may then be subjected to further tissue engineering steps.

Polyhydroxyalkanoates (PHAs) from which pyrogen has been removed are provided for use in numerous biomedical applications. PHAs which have been chemically modified to enhance physical and / or chemical properties, for targeting or to modify biodegradability or clearance by the reticuloendothelial system (RES), are described. Methods for depyrogenating PHA polymers prepared by bacterial fermentation processes are also provided, wherein pyrogens are removed from the polymers without adversely impacting the polymers' inherent chemical structures and physical properties. PHAs with advantageous processing characteristics, including low melting points and / or solubility in non-toxic solvents, are also described. PHAs are provided which are suitable for use in in vivo applications such as in tissue coatings, stents, sutures, tubing, bone and other prostheses, bone or tissue cements, tissue regeneration devices, wound dressings, drug delivery, and for diagnostic and prophylactic uses. Properties which are selected for include degradability, elasticity, inclusion of functional groups or derivatized groups, which can in turn be used to attach targeting agents, and bioadhesion.

Cells derived from human umbilical cords are disclosed along with methods for their therapeutic use. Isolation techniques, culture methods and detailed characterization of the cells with respect to their cell surface markers, gene expression, and their secretion of trophic factors are described.

A composite product is disclosed as a collagen support comprising at least one porous collagen layer covered on at least one side with an essentially compact collagen membrane consisting either of a collagen film prepared by drying a collagen gel, preferably in air or a gaseous fluid, or of a very highly compressed collagen sponge. At least one of the two layers, i.e. the porous layer and the essentially compact membrane, may comprise normal, genetically modified or malignant living cells originating particularly from young or elderly subjects. This composite product is used as a collagen support for the manufacture of artificial skin intended especially for performing in vitro tests on the efficacy of potentially active substances or for reconstructing damaged areas of skin in vivo.

The present invention relates to an in vivo method of promoting the growth of autologous tissue and its use to form corrective structures, including tissue that can be explanted to other locations in the animal. In particular, the invention relates to methods and systems for (a) the site-specific regeneration of tissue, and (b) the synthesis of neotissue for transplantation.

The present invention relates to the development of new porous particulate collagen sponges, combining the desirable features of low toxicity, resorbability, and satisfactory porosity, particularly when wetted in an aqueous medium. Accordingly, the present invention is directed to new porous, particulate, dehydrothermally cross-linked, wetted sponges, as well as a process for making them.

The present invention relates to methods for producing carbon-based molded bodies. In particular, the present invention relates to methods for producing porous carbon-based molded bodies by carbonizing organic polymer materials mixed with non-polymeric fillers and subsequently dissolving the fillers out from the carbonized molded bodies. The present invention further relates to methods for producing porous carbon-based molded bodies by carbonizing organic polymer materials mixed with non-polymeric fillers which are substantially completely decomposed during the carbonization. The present invention also relates to a method for producing porous carbon-based molded bodies by carbonizing organic polymer materials, the carbon-based molded bodies being partially oxidized following carbonization so as to produce pores. In addition, the present invention relates to porous molded bodies produced according to one of said methods and the use thereof, especially as cell culture carriers and / or culture systems.

A cell transfection / culture device is disclosed which includes a solid support coated with a degradable polymer cation as a transfection reagent. The transfection / culture device is conveniently stored at room temperature until use. Cell transfection is accomplished easily by adding the nucleic acid of interest and the cells to be transfected to the transfection / culture device. Cell transfection is completed in less than one hour by using the transfection / culture device described herein.

The present invention provides engineered tissue scaffolds, engineered tissues, and methods of using them. The scaffolds and tissues are derived from natural tissues and are created using non-thermal irreversible electroporation (IRE). Use of IRE allows for ablation of cells of the tissue to be treated, but allows vascular and neural structures to remain essentially unharmed. Use of IRE thus permits preparation of thick tissue scaffolds and tissues due to the presence of vasculature within the scaffolds. The engineered tissues can be used in methods of treating subjects, such as those in need of tissue replacement or augmentation.

Compositions and methods for manufacturing polymers are disclosed. Compositions include novel plastics, including films and shaped forms comprising polymer matrices that are biologically compatible and biodegradable. Such plastics may comprise polymers derived from natural sources. Further, such plastics are useful in biological systems for wound repair, implants, stents, drug encapsulation and delivery, and other applications. The disclosed methods comprise mild manufacturing processes such that various additives, such as biologically active proteins, sugars, lipids, and the like may be incorporated into the polymer matrix without subsequent loss of bioactivity during processing. Additionally, methods of manufacture for controlling mechanical properties, such as elasticity, pliancy, and the porosity of such plastics are disclosed.