Abstract:
Elongated seamless capsules containing biological material are prepared by a method in which a coagulant, which includes a cell suspension or other biologically active factor, and a polymeric casting solution are extruded through a common extrusion port having at least two concentric bores, such that the coagulant is extruded through the inner bore and the polymeric casting solution is extruded through the outer bore. The method involves initiating extrusion of the coagulant subsequent to initiating delivery of the casting solution through the respective bores to form a capsule having a curved and smooth leading edge shape. Delivery of the coagulant is then shut off, and extrusion of the casting solution is terminated either immediately or after some predetermined time.
Abstract:
A medical device is disclosed for use in regenerating a severed nerve, including a tubular, biocompatible, electrically-charged membrane or guidance channel, having openings adapted to receive the ends of the severed nerve and defining a lumen through which the nerve can regenerate. The electrically-charged membrane can further include a polymeric electret material that is electrically poled. A method for repairing a severed nerve is also disclosed and includes placing severed nerve ends in proximity to each other within the lumen of the guidance channel of the present invention and securing the nerve ends to the device.
Abstract:
A medical device is disclosed for use in regenerating a severed nerve. The device includes an implantable, tubular, electrically-charged membrane having openings adapted to receive the ends of the severed nerve and a lumen having a diameter ranging from about 0.5 millimeters to about 2.0 centimeters to permit regeneration of the nerve therethrough. The membrane is fabricated such that an electric charge is exhibited at the inner membrane surface to stimulate regeneration by axonal sprouting and process extension. Also disclosed are methods for repairing a severed nerve and for preparing a medical device for use in regeneration of a severed nerve.
Abstract:
Medical devices and methods employing biocompatible polymers and nerve growth-enhancing active factors are disclosed for use as guidance channels for regenerating nerves. The devices are formed from a porous, tubular membrane containing active factor incorporated within the membrane and having openings adapted to receive the ends of the severed nerve. In one aspect of the invention, the membrane has an impermeable, outer membrane surface and a porous, inner membrane surface through which the active factor can diffuse and which defines the boundary of a lumen through which said nerve may regenerate. Methods for fabricating such devices are also disclosed.
Abstract:
The present invention is directed to devices and methods for in situ delivering an antibody or a fragment thereof to a host. In particular, the invention relates to devices and methods for in situ delivering an antibody or a fragment thereof to patient suffering for a neurodegenerative disorder or other diseases treated by antibody administration.
Abstract:
Methods and devices are provided for gene therapy using encapsulated packaging cell lines to deliver viral particles carrying at least one heterologous gene encoding at least one biologically active molecule.
Abstract:
This invention relates to methods and compositions of controlling cell distribution within a bioartificial organ by exposing the cells to a treatment that inhibits cell proliferation, promotes cell differentiation, or affects cell attachment to a growth surface within the bioartificial organ. Such treatments include (1) genetically manipulating cells, (2) exposing the cells to a proliferation-inhibiting compound or a differentiation-inducing compound or removing the cells from exposure to a proliferation-stimulating compound or a differentiation-inhibiting compound; exposing the cells to irradiation, and (3) modifying a growth surface of the BAO with ECM molecules, molecules affecting cell proliferation or adhesion, or an inert scaffold, or a combination thereof. These treatments may be used in combination.
Abstract:
A method for treating diabetes in a patient comprising subcutaneously implanting in the patient at least one immunoisolatory vehicle comprising a core comprising a volume of at least 1 .mu.l and at least about 10.sup.4 living cells which secrete insulin, said cells being dispersed in a biocompatible matrix comprising a hydrogel or extracellular matrix components, and a surrounding external jacket of a biocompatible thermoplastic or hydrogel free of said cells projecting externally thereof, said jacket being permselective and immunoisolatory, said jacket having a molecular weight cutoff permitting passage of molecules between the patient and core through said jacket wherein the insulin is released from the immunoisolatory vehicle into the patient's body to treat diabetes.
Abstract:
Methods and compositions are provided for controlling cell distribution within an implantable bioartificial organ by exposing the cells to a treatment that inhibits cell proliferation, promotes cell differentiation, or affects cell attachment to a growth surface within the bioartificial organ. Such treatments include (1) genetically manipulating cells, (2) exposing the cells to a proliferation-inhibiting compound or a differentiation-inducing compound or removing the cells from exposure to a proliferation-stimulating compound or a differentiation-inhibiting compound; exposing the cells to irradiation, and (3) modifying a growth surface of the bioartificial organ with extracellular matrix molecules, molecules affecting cell proliferation or adhesion, or an inert scaffold, or a combination thereof. These treatments may be used in combination. The bioartificial organ typically has a semipermeable membrane encapsulating a cell-containing core, and is preferably immunoisolatory. Cells can be grown on microcarriers and then loaded into the bioartificial organ. The microcarriers may be coated with an extracellular matrix component such as collagen to cause decreased cell proliferation or increased cell differentiation. Microcarriers containing cells can be suspended in a proliferation inhibiting hydrogel matrix prior to encapsulation.
Abstract:
A method of making an immunoisolatory vehicle comprised of a core comprising living cells dispersed in a biocompatible matrix is disclosed, the cells being capable of secreting a biologically active product or of providing a metabolic or immunologic function to an individual, and an external jacket surrounding said core which is a biocompatible, permselective thermoplastic or hydrogel, said jacket being free of said cells, comprising coextruding a suspension comprising said cells dispersed in a precursor matrix material comprising extracellular matrix components or a biocompatible hydrogel precursor, and a solution of a biocompatible jacket precursor from a nested dual-bore extrusion nozzle, wherein the suspension of (a) is coextruded from the inner bore and the solution of (b) is coextruded from the outer bore of the nozzle, to form said jacket as the solution of (b) and the suspension of (a) arc coextruded; and exposing the vehicle to a treatment that forms a core comprising a volume of at least 1 .mu.l and at least 10.sup.4 cells and comprising a biocompatible matrix from the precursor matrix of solution (a).