620 results about "Fibril" patented technology

The implant includes an outer layer of ePTFE which exhibits extensibility normally not associated with ePTFE. The ePTFE is reduced in length by deforming the fibrils between the nodes while maintaining the nodes in a substantially flat configuration. Various implant configurations that can include the outer layer described are also disclosed.

Graphitic nanotubes, which includes tubular fullerenes (commonly called "buckytubes") and fibrils, which are functionalized by chemical substitution or by adsorption of functional moieties. More specifically the invention relates to graphitic nanotubes which are uniformly or non-uniformly substituted with chemical moieties or upon which certain cyclic compounds are adsorbed and to complex structures comprised of such functionalized fibrils linked to one another. The invention also relates to methods of introducing functional groups onto the surface of such fibrils.

Graphitic nanofibers, which include tubular fullerenes (commonly called "buckytubes"), nanotubes and fibrils, which are functionalized by chemical substitution, are used as electrodes in electrochemical capacitors. The graphitic nanofiber based electrode increases the performance of the electrochemical capacitors. Preferred nanofibers have a surface area greater than about 200 m2/gm and are substantially free of micropores.

A medical balloon composed of a micro-composite material which provides for radial expansion of a balloon to a predetermined extent, but which has minimal longitudinal growing during balloon inflation. The micro-composite material includes a fibril component, a matrix component, and optionally, a compatibilizer. The fibril component may preferably be liquid crystal polymer fibers randomly scattered through out the balloon material. The liquid crystal polymers are created by extrusion at high speed. An alternative fibril component may be a PET fibers which are uniformly spaced about the balloon material and extend through out the length of the balloon material tube.

A tubular tissue scaffold is described which comprises a tube having a wall, wherein the wall includes biopolymer fibrils that are aligned in a helical pattern around the longitudinal axis of the tube where the pitch of the helical pattern changes with the radial position in the tube wall. The scaffold is capable of directing the morphological pattern of attached and growing cells to form a helical pattern around the tube walls. Additionally, an apparatus for producing such a tubular tissue scaffold is disclosed, the apparatus comprising a biopolymer gel dispersion feed pump that is operably connected to a tube-forming device having an exit port, where the tube-forming device is capable of producing a tube from the gel dispersion while providing an angular shear force across the wall of the tube, and a liquid bath located to receive the tubular tissue scaffold from the tube-forming device. A method for producing the tubular tissue scaffolds is also disclosed. Also, artificial tissue comprising living cells attached to a tubular tissue scaffold as described herein is disclosed. Methods for using the artificial tissue are also disclosed.

An intraluminal catheter, such as a guiding catheter, employed for intravascular procedures and having an inner liner formed of expanded Ultra High Molecular Weight Polyethylene (UHMWPE) is disclosed. The expanded UHMWPE is microporous and has an oriented microstructure structure characterized by nodes interconnected by fibrils. The inner liner formed of expanded UHMWPE is very thin to maximize the inner lumen diameter and has excellent mechanical properties.

Disclosed is a knitted article, and a method of producing such an article, having at least one PTFE fiber with oriented fibrils forming multiple fiber cross-over points wherein PTFE fiber is self-bonded in at least one of the cross-over points.

A method of forming a composite textile and ePTFE implantable device includes the steps of (a) providing an ePTFE layer having opposed surfaces comprising a microporous structure of nodes interconnected by fibrils; (b) providing a textile layer having opposed surfaces; (c) applying a coating of an elastomeric bonding agent to one of the opposed surfaces of the ePTFE layer or the textile layer; (d) providing a hollow member having an open end and an opposed closed end defining a fluid passageway therebetween and having a wall portion with at least one hole extending therethrough, the hole being in fluid communication with the fluid passageway; (e) concentrically placing the ePTFE layer and the textile layer onto the hollow member and over the at least one hole of the hollow member to provide an interior composite layer and an exterior composite layer, thereby defining a composite assembly, wherein the interior composite layer is one of the ePTFE layer or the textile layer and the exterior composite layer is the other of the ePTFE layer or the textile layer; (f) placing the hollow member with the composite assembly within a pressure chamber; (g) applying a pressure differential so that the pressure within the chamber is greater than a pressure within the fluid passageway of the hollow member; and (h) applying heat to the bonding agent to adhesively bond the textile layer and the ePTFE layer to provide a laminated composite assembly.

Disclosed is a knitted article, and a method of producing such an article, having at least one PTFE fiber with oriented fibrils forming multiple fiber cross-over points wherein PTFE fiber is self-bonded in at least one of the cross-over points.

Single, continuous PTFE layers having lateral zones of varied characteristics are described. Some of the lateral zone embodiments may include PTFE material having little or no nodal and fibril microstructure. Methods of manufacturing PTFE layers allow for controllable permeability and porosity of the layers, in addition to other characteristics. The characteristics may vary from one lateral zone of a PTFE layer to a second lateral zone of a PTFE layer. In some embodiments, the PTFE layers may act as a barrier layer in an endovascular graft or other medical device.

Heat is generated in corneal fibrils in a cornea of an eye according to a selected pattern. The heat causes the corneal fibrils corresponding to the selected pattern to transition from a first structure to a second structure. The second structure provides a desired reshaping of the cornea. A cross-linking agent is then activated in the region of corneal fibrils according to the selected pattern. The cross-linking agent prevents the corneal fibrils from changing from the second structure. Thus, embodiments stabilize corneal tissue and improve its biomechanical strength after desired structural changes have been achieved in the corneal tissue. Accordingly, the embodiments help to preserve the desired reshaping of the cornea.

Medical devices having at least a component, such as a catheter balloon, stent cover and vascular graft, formed of ultrahigh molecular weight polyolefin, such as ultrahigh molecular weight polyethylene. The device component is formed from ultrahigh molecular weight polyethylene that has been processed so that it is microporous and has an oriented node and fibril structure. The device component expands compliantly at low strains and are substantially less compliant at higher strains. The invention also comprises methods for making such medical devices, including the steps of compacting a polyethylene powder and deforming it to impart the oriented structure.

The present invention provides an endoprosthesis comprising a radially distensible, tubular stent comprising opposed open ends and a stent wall structure having opposed exterior and luminal surfaces; and a continuous and seamless ePTFE tubular covering having a node and fibril structure securably disposed to at least one of the stent surfaces, the graft covering comprising at least two laminated layers, wherein the laminated layers include at least one region where the laminated layers are not securely bonded; and the at least one region has a different bending flexibility from the tubular graft covering.

A method for modifying an ePTFE surface by plasma immersion ion implantation includes the steps of providing an ePTFE material in a chamber suitable for plasma treatment; providing a continuous low energy plasma discharge onto the sample; and applying negative high voltage pulses of short duration to form a high energy ion flux from the plasma discharge to generate ions which form free radials on the surface of the ePTFE material without changing the molecular and/or physical structure below the surface to define a modified ePTFE surface. The step of applying the high voltage pulses modifies the surface of the ePTFE without destroying the node and fibril structure of the ePTFE, even when the step of applying the high voltage pulses etches and/or carburizes the surface of the ePTFE. The modified surface may have a depth of about 30 nm to about 500 nm. The ions are dosed onto the ePTFE sample at concentrations or doses from about 10¹³ ions/cm² to about 10¹⁶ ions/cm².

A composite multilayer implantable material having a first inner tubular layer formed of expanded polytetrafluoroethyene having a porous microstructure defined by nodes interconnected by fibrils, wherein said first layer has a plurality of pleated folds, a second tubular layer formed of textile material circumferentially disposed exteriorly to said first layer; and having an elastomeric bonding agent applied to one of said first layer or second layer and disposed within the pores of said microstructure for securing said first layer to said second layer.