Abstract: The present invention provides an irradiated crosslinked polyethylene containing reduced free radicals, preferably containing substantially no residual free radical. Disclosed is a process of making irradiated crosslinked polyethylene by irradiating the polyethylene in contact with a sensitizing environment at an elevated temperature that is below the melting point, in order to reduce the concentration of residual free radicals to an undetectable level. A process of making irradiated crosslinked polyethylene composition having reduced free radical content, preferably containing substantially no residual free radicals, by mechanically deforming the polyethylene at a temperature that is below the melting point of the polyethylene, optionally in a sensitizing environment, is also disclosed herein.

Abstract: This invention includes a method of producing a thin, oriented layer of polymer material. The material is preferably produced by the method of introducing a shearing flow to a free surface in a predominantly monomeric solution of the self-assembling polymer sub-units, and inducing polymerization or growth of the monomer while in this shearing flow. The system for forming the oriented layer of material provides relative movement between a delivery system and the substrate on or over which the material is deposited. The rate of flow of the material from the delivery system and the relative velocity between the deposition surface and the material as it is developed to the surface are controlled to properly orient the material and desired thickness. These rates can be adjusted to vary the properties of the film in a controlled manner. Preferred embodiments include either angular or linear relative movement between the delivery system and the substrate.

Abstract: This invention includes a method of producing a thin, oriented layer of polymer material. The material is preferably produced by the method of introducing a shearing flow to a free surface in a predominantly monomeric solution of the self-assembling polymer sub-units, and inducing polymerization or growth of the monomer while in this shearing flow. The system for forming the oriented layer of material provides relative movement between a delivery system and the substrate on or over which the material is deposited. The rate of flow of the material from the delivery system and the relative velocity between the deposition surface and the material as it is delivered to the surface are controlled to properly orient the material at the desired thickness. These rates can be adjusted to vary the properties of the film in a controlled manner. Preferred embodiments include either angular or linear relative movement between the delivery system and the substrate.

Abstract: The present invention provides an irradiated crosslinked polyethylene containing reduced free radicals, preferably containing substantially no residual free radical. Disclosed is a process of making irradiated crosslinked polyethylene by irradiating the polyethylene in contact with a sensitizing environment at an elevated temperature that is below the melting point, in order to reduce the concentration of residual free radicals to an undetectable level. A process of making irradiated crosslinked polyethylene composition having reduced free radical content, preferably containing substantially no residual free radicals, by mechanically deforming the polyethylene at a temperature that is below the melting point of the polyethylene, optionally in a sensitizing environment, is also disclosed herein.

Abstract: The present invention provides a system and a method for reducing pores, or air pockets, that form at the interface between the material used to attach or adhere the surface of a component, such as a prosthesis, to a site. A preferred embodiment of the invention includes an actuator that controls a coupler which transmits energy to a prosthesis being inserted into a material to reduce porosity at an interface between the prosthesis and the material. The system of the present invention can include an oscillating hand-held device that vibrates the stem component of an orthopedic prosthesis at a particular frequency and amplitude. The device is typically held by the hand of the surgeon, who guides the vibrating prosthesis into the cement-filled medullary cavity.

Abstract: The present invention provides an irradiated crosslinked polyethylene containing reduced free radicals, preferably containing substantially no residual free radical. Disclosed is a process of making irradiated crosslinked polyethylene by irradiating the polyethylene in contact with a sensitizing environment at an elevated temperature that is below the melting point, in order to reduce the concentration of residual free radicals to an undetectable level. A process of making irradiated crosslinked polyethylene composition having reduced free radical content, preferably containing substantially no residual free radicals, by mechanically deforming the polyethylene at a temperature that is below the melting point of the polyethylene, optionally in a sensitizing environment, is also disclosed herein.

Abstract: In preferred embodiments, the present invention provides methods of controllably making a vinyl polymer hydrogel having desired physical properties without chemical cross links or radiation. The gelation process is modulated by controlling, for example, the temperature of a resultant vinyl polymer mixture having a gellant or using active ingredients provided in an inactive gellant complex.

Abstract: The preferred embodiments of the present invention provide polymer compositions and methods for controlling a property of a resultant gel. A preferred method includes dissolving a vinyl polymer in a first solvent to form a solution; and contacting the vinyl polymer solution in a suitable volume of at least one immersion solvent comprising a second solvent to cause gelation. In preferred embodiments, the invention provides poly(vinyl alcohol) compositions and methods that produce physically crosslinked hydrogels that have tunable physical properties. Also provided are articles of manufacture such as prosthetic intervertebral disks and contact lenses.

Abstract: Apparatus and methods for evaluating the rheological properties of Newtonian and non-Newtonian liquids and melts employs the principle of capillary breakup following rapid stretching of the fluid between two plates. The apparatus includes opposed surfaces defining a sample site disposed therebetween. A liquid sample undergoes an extensional deformation between the opposed surfaces which separate using a user-defined motion profile. The time profile of the diameter of the liquid filament is monitored and recorded as a function of time. Preferred embodiments of the present invention include data analysis of the diameter of the filament as a function of time which provides information regarding rheological parameters including, but not limited to, extensional viscosity versus strain.

Abstract: This invention includes a method of producing a thin, oriented layer of polymer material. The material is preferably produced by the method of introducing a shearing flow to a free surface in a predominantly monomeric solution of the self-assembling polymer sub-units, and inducing polymerization or growth of the monomer while in this shearing flow. The system for forming the oriented layer of material provides relative movement between a delivery system and the substrate on or over which the material is deposited. The rate of flow of the material from the delivery system and the relative velocity between the deposition surface and the material as it is delivered to the surface are controlled to properly orient the material at the desired thickness. These rates can be adjusted to vary the properties of the film in a controlled manner. Preferred embodiments include either angular or linear relative movement between the delivery system and the substrate.

Abstract: The present invention provides a system and a method for reducing pores, or air pockets, that form at the interface between the material used to attach or adhere the surface of a component, such as a prosthesis, to a site.