Abstract: Neurological therapy devices are disclosed for the local and controlled delivery of a neurotransmitter to the brain of a subject suffering from neurotransmitter deficiency or dysfunction. In one embodiment the device includes a biocompatible, implantable, and retrievable polymeric insert including a source of neurotransmitter embedded therein. In another embodiment, the device includes a retrievable source of neurotransmitter including at least one neurotransmitter-secreting cell encapsulated within a semipermeable membrane allowing the diffusion therethrough of the neurotransmitter, and further includes a source of growth factor in close proximity to the neurotransmitter-secreting cells.

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: Methods and devices are disclosed for the delivery of a neurotransmitter from an implanted, neurotransmitter-secreting cell culture to a target region in a subject. The cell culture is maintained within a biocompatible, semipermeable membrane which permits the diffusion of the neurotransmitter therethrough while excluding viruses, antibodies, and other detrimental agents present in the external environment from gaining access. Implantable cell culture devices are disclosed, some of which may be retrieved from the subject, replaced or recharged with new, neurotransmitter-secreting cell cultures, and reimplanted.

Abstract: Medical devices employing semipermeable materials, such as acrylic copolymers, polyurethane isocyanate, and other biocompatible semipermeable polymers, are disclosed for use as guidance channels in regenerating nerves. The devices can be formed by tubular semipermeable conduits adapted to receive the ends of a severed or damaged nerve. The tubular conduits define lumens through which axons can regenerate to restore motor and/or sensory functions. The guidance materials are chosen such that they are capable of allowing the diffusion of nutrients and other metabolites to the regenerating nerve site while excluding fibroblasts and other scar-forming cells. In particular, tubular channels which have a smooth inner surface and longitudinally oriented trabeculae result in significantly larger regenerated nerve cables and higher numbers of regenerated myelinated axons.