Composite material and laminate

Abstract

A composite material (10) comprising: an expanded polytetrafluoroethylene layer (12); a densified expanded polytetrafluoroethylene layer (16a) connected to the expanded polytetrafluoroethylene layer; a porous expanded polytetrafluoroethylene layer (16b) connected to the densified expanded polytetrafluoroethylene layer; a binder (16c); and a densified intumescent polyethylene layer (14), the adhesive bonding the intumescent polyethylene layer to the porous intumescent polytetrafluoroethylene layer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 433,143, filed December 16, 2022, which is incorporated herein by reference in its entirety for all purposes. Technical Field

[0003] The present disclosure generally relates to apparatus, systems, and methods for providing composite materials operable to resist wear. More particularly, the present disclosure relates to apparatus, systems, and methods including wear-resistant materials that can be used in implantable medical devices. Background Art

[0004] The materials used in manufacturing are important because they provide specific qualities necessary for the manufactured article to perform for its intended purpose. Materials can be selected based on a variety of properties, including, for example, longevity. Material selection is crucial in a variety of industries, including but not limited to the medical device industry, and more specifically, implantable medical devices.

[0005] Implantable devices are often required to remain in the patient's body for extended periods or permanently. Implantable devices are often placed in locations subject to movement and motion, potentially increasing the likelihood of wear and / or failure due to certain movements and motions, including repetitive ones. Failure of implantable devices due to material failure can have numerous adverse consequences, and therefore, materials that maintain their structural integrity over the long term are crucial.

[0006] Many materials are used in multiple industries, and the same properties required in one industry may be important in others. Summary of the Invention

[0007] Composite materials are provided herein that have high wear and abrasion resistance during use. Composite materials achieve wear and abrasion resistance by combining the desirable qualities of different materials into a single composite material (e.g., a laminate) and firmly bonding the different materials to each other to provide wear-resistant qualities throughout.

[0008] According to one example ("Example 1"), a composite material is provided, comprising: an expanded polytetrafluoroethylene layer; a densified expanded polytetrafluoroethylene layer connected to the expanded polytetrafluoroethylene layer; a porous expanded polytetrafluoroethylene layer connected to the densified expanded polytetrafluoroethylene layer; an adhesive; and a densified expanded polyethylene layer, the adhesive bonding the expanded polyethylene layer to the porous expanded polytetrafluoroethylene layer.

[0009] According to another example ("Example 2") based on Example 1, the adhesive is low-density polyethylene.

[0010] According to another example ("Example 3") based on Example 1, the composite material further comprises a thin layer of low-density polyethylene connected to the expanded polyethylene layer.

[0011] According to another example ("Example 4") based on Example 3, a thin layer of low-density polyethylene and an adhesive sandwiched an expanded polyethylene layer.

[0012] According to another example ("Example 5") based on Example 1, the densified expanded polyethylene layer is about 2 microns to about 5 microns thick.

[0013] According to another example ("Example 6") based on Example 1, the adhesive is at least partially imbibed into the porous expanded polytetrafluoroethylene layer.

[0014] According to another example ("Example 7") based on Example 6, the adhesive was processed at about 130°C to about 145°C to adhere the densified expanded polyethylene layer and the porous expanded polytetrafluoroethylene layer.

[0015] According to another example ("Example 8") based on Example 1, the densified expanded polytetrafluoroethylene layer is about 2 microns to about 10 microns thick.

[0016] According to another example ("Example 9") based on Example 1, the porous expanded polytetrafluoroethylene layer is about 10 microns to about 50 microns thick.

[0017] According to another example based on Example 1 ("Example 10"), the adhesive forms a layer having a thickness of about 1 micrometer to about 200 micrometers.

[0018] According to one example ("Example 11"), an implantable device includes: a tubular member formed from a composite material, the tubular member including: a first polymer layer comprising a blood-contacting surface; a densified second polymer layer connected to the first polymer layer; a porous expanded third polymer layer connected to the densified second polymer layer; an adhesive; and a densified expanded polyethylene layer, the adhesive bonding the densified expanded polyethylene layer to the porous expanded third polymer layer.

[0019] According to another example ("Example 12") based on Example 11, the first polymer layer is an expanded polytetrafluoroethylene layer.

[0020] According to another example ("Example 13") based on Example 11, the densified second polymer layer is a densified polytetrafluoroethylene layer.

[0021] According to another example ("Example 14") based on Example 11, the porous expanded third polymer layer is a porous expanded polytetrafluoroethylene layer.

[0022] According to another example ("Example 15") based on Example 11, the adhesive is low-density polyethylene.

[0023] According to another example ("Example 16") based on Example 15, low-density polyethylene was imbibed into the porous expanded third polymer layer.

[0024] According to another example ("Example 17") based on Example 11, the tubular member is a graft.

[0025] According to another example ("Example 18") based on Example 17, the implantable device further includes a stent connected to the tubular member.

[0026] According to one example ("Example 19"), an implantable medical device includes: a first polytetrafluoroethylene layer; and a second polyethylene layer coupled to the first polytetrafluoroethylene layer, wherein the second polyethylene layer is operable to be positioned against a structure that is non-stationary relative to the second polyethylene layer.

[0027] According to another example ("Example 20") based on Example 19, the first polytetrafluoroethylene layer and the second polyethylene layer are included in one of a graft, a tag, a cartilage substitute, an implantable medical device, and a removable medical device.

[0028] The foregoing examples are merely examples and should not be construed as limiting or otherwise narrowing the scope of the inventive concepts otherwise provided by this disclosure. Although a number of examples are disclosed, other embodiments will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative examples. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive in nature.

[0029] BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0031] Figure 1 is a cross-sectional view of a composite material according to one embodiment, the composite material including various polytetrafluoroethylene layers and polyethylene layers; and

[0032] Figure 2 is a cross-sectional view of another composite material according to one embodiment, the composite material comprising various polytetrafluoroethylene layers including an outer layer of low-density polyethylene;

[0033] Figures 3A-3E are wear images of various composite materials according to various embodiments;

[0034] Figure 4 is a diagram of an implantable medical device embodying a composite material according to an embodiment;

[0035] Figure 5 is an illustration of an implantable medical device including a composite tag located in a potential high wear location, according to one embodiment;

[0036] Figure 6 is an implantable medical device according to one embodiment, the implantable medical device being formed of a composite material of expanded polytetrafluoroethylene and expanded polyethylene;

[0037] Figure 7 is an implantable medical device according to one embodiment, comprising a graft attachment band formed of a composite material; DETAILED DESCRIPTION

[0038] Definitions and Terminology

[0039] This disclosure is not meant to be read in a limiting sense. For example, the terms used in this application should be read broadly within the context of the meanings ascribed to these terms in the art.

[0040] For imprecise terms, the terms "about" and "approximately" can be used interchangeably to indicate that a measurement value includes the stated measurement value and also includes any measurement value that is reasonably close to the stated measurement value. As understood and readily determined by a person of ordinary skill in the relevant art, a measurement value that is reasonably close to the stated measurement value has a fairly small deviation from the stated measurement value. For example, such deviations may be due to measurement errors, differences in calibration of measurement and / or manufacturing equipment, human error in reading and / or setting measurements, fine-tuning to optimize performance and / or structural parameters due to measurement differences related to other components, specific implementation scenarios, imprecise adjustment and / or manipulation of an object by a person or machine, etc. If it is determined that a person of ordinary skill in the relevant art cannot easily determine the value of such a reasonably small difference, the terms "about" and "approximately" can be understood to mean plus or minus 10% of the stated value.

[0041] As used herein, "connect" means to join, engage, attach, adhere, affix, or bond directly or indirectly, permanently or temporarily.

[0042] As used herein, the term "composite material" refers to a material comprising two or more material components having one or more material properties that differ from one another. In some examples, a composite material comprises at least a first material component in the form of a film and a second material component in the form of a polymer that is combined with the film (e.g., by a coating and / or imbibition process). The term "laminate" as used herein refers to a multilayer film, composite material, or other material, such as, but not limited to, a polymer, such as, but not limited to, an elastomer, an elastomeric or non-elastomeric material, and combinations thereof.

[0043] As used herein, the term "film" generally refers to one or more of a membrane, a composite material, or a laminate.

[0044] As used herein, the term "biocompatible material" broadly refers to any material having biocompatible properties, including synthetic materials, such as but not limited to biocompatible polymers, or biological materials, such as bovine pericardium. The biocompatible material may include the first membrane and the second membrane as described herein for each embodiment.

[0045] As used herein, the term "polyethylene" (PE) includes all types of polyethylene including, but not limited to, expanded polyethylene (ePE).

[0046] As used herein, the term "polytetrafluoroethylene" (PTFE) includes all types of polytetrafluoroethylene, including but not limited to expanded polytetrafluoroethylene (ePTFE).

[0047] As used herein, the term "graft attach tape" includes all types of tapes used to attach graft material or implemented on stent grafts.

[0048] Description of each embodiment

[0049] Those skilled in the art will understand that various aspects of the present disclosure may be implemented by any number of methods and devices configured to perform the desired effects. It should also be noted that the drawings referenced herein are not necessarily drawn to scale, but may be exaggerated to illustrate various aspects of the present disclosure, and in this regard, the drawings should not be considered limiting.

[0050] Figure 1 The composite materials shown in the drawings are provided as examples of various features of the composite materials, and although combinations of these shown features are clearly within the scope of the invention, the examples and their illustrations do not mean that the inventive concepts provided herein are limited to fewer features, additional features, or alternative features. Figure 1 One or more of those features shown. For example, in various embodiments, Figure 1 The composite material layers shown may include reference Figure 2 It should also be understood that the reverse is also true. Figure 1 One or more of the components / parts shown may be used as Figure 2 Supplement or replacement of the components / parts shown. Figure 1 and Figure 2 The composite material can be implemented in various devices and components, such as Figure 4-6 As shown. Figure 4-6The apparatus shown in FIG. 4 can implement the composite materials described herein, but it should be understood that the composite materials can be implemented with respect to various apparatuses, systems, and methods.

[0051] Figure 1 An exemplary composite material 10 is shown that implements various polymer layers to provide a durable, wear-resistant material that can be implemented in a variety of situations, including but not limited to implantable medical devices. The various polymer layers are connected together to provide specific properties, thereby improving the durability of the material and preventing the material from breaking due to repeated movement / motion that may cause the material to wear. Each layer can perform various functions, such as durability in a specific direction (e.g., X, Y, and Z or compression, tension, etc.). By providing a wear-resistant material that can withstand repeated movement / motion with only limited degradation or damage, the life of the implantable device is improved, resulting in fewer surgeries, reduced risk of device failure, and increased confidence in the device's efficacy.

[0052] The composite material 10 includes a plurality of layers. For example, the composite material 10 includes a base layer 12, an outer layer 14, and at least one intermediate layer 16. The base layer 12 and the outer layer 14 may include materials having properties suitable for implantation into the human body, for example, materials that are biologically stable and suitable for contact with or direct exposure to biological tissue. In some embodiments, the base layer 12 may include a material suitable for blood contact (e.g., polytetrafluoroethylene or polyethylene). The various layers may be connected to each other in various ways, including but not limited to bonding, adhesion, absorption / infiltration / imbibe, etc. For example, the composite material 10 may include: a first polymer layer (e.g., base layer 12); a densified second polymer layer (e.g., first intermediate layer 16a) connected to the first polymer layer; a porous expanded third polymer layer (e.g., second intermediate layer 16b) connected to the densified second layer; an adhesive (e.g., third intermediate layer 16c); and a densified expanded polymer layer (e.g., outer layer 14, wherein the outer layer is formed of a polymer different from that of the base layer 12).

[0053] In a more specific example, the base layer 12 is formed of polytetrafluoroethylene (PTFE) and the outer layer 14 is formed of polyethylene (PE). The PTFE base layer 12 provides Z-axis strength, and the PE outer layer 14 provides XY-axis strength, which increases resistance to material particulation during friction (which can result in the release of loose material into the body and thinning of the material at locations of contact). The PTFE base layer 12 is operable to provide Z-axis strength (e.g., by compression) to the PE outer layer 14 (which may have relatively low Z-axis strength), while the PE outer layer 14 limits damage caused by friction or wear).

[0054] The performance of the combined properties of PTFE base layer 12 and PE outer layer 14 is enhanced by the firm connection between PTFE base layer 12 and PE outer layer 14. Intermediate layer 16 can be implemented to provide firm bonding, thereby reducing the possibility of composite material 10 delamination, particularly for the material that may comprise different material properties (such as hydrophobicity). By comprising firm bonding between the layer, each layer is given the base material of whole combination with its effect separately. Intermediate layer can also give base material other characteristics, includes but not limited to z-axis strength. Any number of intermediate layers can be implemented to realize firm bonding, and other performances are provided, including the intensity and durability that increase.

[0055] With further reference to the example including the PTFE base layer 12 and the PE outer layer 14, the intermediate layer 16 may include a layer formed of the same or similar material as the PTFE base layer 12 and / or the PE outer layer 14. In other embodiments, the intermediate layer 16 may include a layer formed of different materials, such as the PTFE base layer 12 and the PE outer layer 14, wherein the different materials are capable of being firmly bonded to the PTFE base layer 12 and / or the PE outer layer 14.

[0056] In one example, Figure 11 shows a composite material 10 having a PTFE base layer 12, a PE outer layer 14, and a PTFE and PE intermediate layer 16. For example, the PTFE base layer 12 is formed from expanded PTFE (ePTFE), the PE outer layer 14 is formed from expanded polyethylene (ePE), and the intermediate layer 16 includes a densified ePTFE intermediate layer 16a, an ePTFE intermediate layer 16b, and a low-density PE (LDPE) intermediate layer 16c (implemented as an adhesive). In this example, the ePTFE base layer 12 can be a blood-contacting surface because ePTFE is stable to blood contact; the densified ePTFE intermediate layer 16a bonded to the ePTFE base layer 12 can provide Z-axis strength to the composite material 10; the ePTFE intermediate layer 16b is bonded to the densified ePTFE intermediate layer 16a, and the ePTFE intermediate layer 16b includes a porous open network; the LDPE intermediate layer 16c is bonded to the ePTFE intermediate layer 16b; and the PE outer layer 14 is bonded to the LDPE intermediate layer 16c. The LDPE middle layer 16c acts as an adhesive between the PE outer layer 14 and the ePTFE middle layer 16b. For example, the LDPE middle layer 16c can be imbibed into the ePTFE middle layer 16b. Due to the open, porous nature of the ePTFE middle layer 16b, the LDPE middle layer 16c is able to at least partially penetrate or imbibe into the pores of the ePTFE middle layer 16b, which can occur at low processing temperatures (e.g., approximately 130°C). In some embodiments, the PE outer layer 14 can be a wear-resistant, densified ePE material. The PE outer layer 14 can be applied to the LDPE middle layer 16c at a low processing temperature (e.g., approximately 130°C). It should be understood that various types of films can be used for the base layer, middle layer, and outer layer. For example, these layers can be reversed, such that the PE is applied to the base layer 12 and the ePTFE is applied to the outer layer 14. It should be understood that the layers discussed herein may include one or more layers (e.g., a layer may include multiple films of the same or similar material, which are joined together to form a single layer).

[0057] Still refer to Figure 1The densified ePTFE intermediate layer 16a may comprise a densified ePTFE membrane operable to provide hoop and creep strength to the composite material 10. For examples of densified ePTFE membranes, see US Pat. No. 7,521,010 to Kennedy and Hollenbaugh Jr. The densified ePTFE intermediate layer 16a may be from about 1 micron to about 200 microns thick. In some embodiments, the intermediate layer 16a is from about 1 micron to about 2 microns, from about 2 microns to about 3 microns, from about 3 microns to about 4 microns, from about 4 microns to about 5 microns, from about 5 microns to about 6 microns, from about 6 microns to about 7 microns, from about 7 microns to about 8 microns, from about 8 microns to about 9 microns, from about 9 microns to about 10 microns, from about 10 microns to about 15 microns, from about 15 microns to about 20 microns, from about 20 microns to about 25 microns, from about 25 microns to about 30 microns, from about 30 microns to about 35 microns, from about 35 microns to about 40 microns, from about 40 microns to about 45 microns, from about 45 microns to about 50 microns, from about 50 microns to about 100 microns, from about 100 microns to about 150 microns, and from about 100 microns to about 200 microns. In one example, the densified ePTFE intermediate layer 16a is formed of densified ePTFE with fluorinated ethylene propylene (FEP) used as a binder operable to maintain a solid bond or adhesion.

[0058] The ePTFE intermediate layer 16b can be formed from an open, porous ePTFE material. The ePTFE intermediate layer 16b provides an attachment surface into which other layers (e.g., the LDPE intermediate layer 16c) can be imbibed. The ePTFE intermediate layer 16b can also provide burst strength, suture retention strength, longitudinal strength, and creep resistance to the overall construction (e.g., composite material 10). The ePTFE intermediate layer 16b can be about 1 micron to about 200 microns thick. In some embodiments, the ePTFE intermediate layer 16b is about 1 micron to about 2 microns, about 2 microns to about 3 microns, about 3 microns to about 4 microns, about 4 microns to about 5 microns, about 5 microns to about 6 microns, about 6 microns to about 7 microns, about 7 microns to about 8 microns, about 8 microns to about 9 microns, about 9 microns to about 10 microns, about 10 microns to about 15 microns, about 15 microns to about 20 microns, about 20 microns to about 25 microns, about 25 microns to about 30 microns, about 30 microns to about 35 microns, about 35 microns to about 40 microns, about 40 microns to about 45 microns, about 45 microns to about 50 microns, about 50 microns to about 100 microns, about 100 microns to about 150 microns, and about 100 microns to about 200 microns. Some embodiments of the ePTFE intermediate layer 16b can include FEP as a binder within a single film including the ePTFE intermediate layer 16b.

[0059] LDPE middle layer 16c is used as an adhesive to bond the layers together. In some embodiments, the LDPE middle layer 16c forms a layer having a thickness of 0.1 to about 200 microns. In some embodiments, the LDPE middle layer 16c is from about 1 micron to about 2 microns, from about 2 microns to about 3 microns, from about 3 microns to about 4 microns, from about 4 microns to about 5 microns, from about 5 microns to about 6 microns, from about 6 microns to about 7 microns, from about 7 microns to about 8 microns, from about 8 microns to about 9 microns, from about 9 microns to about 10 microns, from about 10 microns to about 15 microns, from about 15 microns to about 20 microns, from about 20 microns to about 25 microns, from about 25 microns to about 30 microns, from about 30 microns to about 35 microns, from about 35 microns to about 40 microns, from about 40 microns to about 45 microns, from about 45 microns to about 50 microns, from about 50 microns to about 100 microns, from about 100 microns to about 150 microns, and from about 100 microns to about 200 microns. The LDPE middle layer 16c is also operable to provide some stiffness as a backing to the other layers, resulting in improved abrasion and puncture / tear resistance of the composite material 10. Although see Figure 1 While the example provided is formed of LDPE, it should be understood that the intermediate layer 16c can also be formed of various other materials that function as adhesives. For example, the intermediate layer 16c can include fluoropolymers, polyurethane copolymers, silicone wet lay-up, polyurethane, etc. Such adhesives can be selected based on their low melting temperatures, thereby allowing the adhesive to be applied without damaging the properties of other layers through heat treatment.

[0060] In some embodiments, the materials discussed herein can be selected based on their molecular weight, which can be a strong indicator of strength and density and is understood to play a role in toughness or compressibility. It should be understood that the materials used can be selected based on the pre-processing that has occurred (including heat treatment before incorporation into the composite material) as well as the effects during the composite material construction (such as through heat treatment). It should also be understood that the temperature at which the material is implemented may have an impact on the performance of the composite material (e.g., the level of creep resistance at room temperature versus body temperature).

[0061] Figure 2 is similar to Figure 1 The composite material 10 is an example of a composite material of the type discussed above, but further comprising an LDPE layer 18 connected to a PE outer layer 14, such that the PE outer layer 14 is sandwiched between two LDPE layers. It should be understood that various layers may be positioned as the base layer 12 and the outer layer 14, depending on the specific properties that may be desired on the surface. Various characteristics that may be selected include porosity, texture, biocompatibility, coatability, processability, coefficient of friction, etc. In some embodiments, the PE outer layer 14 (e.g., densified PE) is 2 microns to about 10 microns thick.

[0062] The various layers can include similar thicknesses, can each have different thicknesses, or have a combination of similar and different thicknesses. For example, in some embodiments, the ePTFE layer can be an ultra-thin wall ePTFE layer. In some embodiments, the PTFE base layer 12 (e.g., densified ePTFE) is 10 microns to about 50 microns thick. The PTFE base layer 12 can be provided in various configurations, including but not limited to tubular or sheet-like. When formed into a tubular shape, the PTFE base layer 12 can provide a seamless tube. The PTFE base layer 12 can provide longitudinal strength for the composite material 10. The PTFE base layer 12 provides a porous chamber surface for tissue ingrowth and anti-thrombosis (e.g., by patency).

[0063] In some embodiments, the PE outer layer 14 can be a gel or paste processed ePE film. As discussed, the PE outer layer 14 can be coated with LDPE on one or both sides to provide enhanced adhesion to the other layers and provide strength to the composite material 10. For example, when the PE outer layer 14 is coated with LDPE on the outer surface, the LDPE can provide wear durability by helping to reduce surface tearing and / or damage (e.g., keeping the surface intact).

[0064] In some embodiments, the PE layer can be bonded to the PTFE layer by each layer having at least one surface imbibed with LDPE. Once the PE and PTFE layers have surfaces imbibed with LDPE, the imbibed surfaces of the PE and PTFE are bonded together (e.g., by heat treating at approximately 130°C). The bond between the LDPE imbibed surfaces of the PE and PTFE layers can produce a peel strength of approximately 4 Newtons, indicating a strong bond between the two layers. The stronger bond between the layers results in the individual properties of each layer being combined into the composite material 10. For example, when a strong bond is achieved between the PTFE and PE, the Z-axis strength of the PTFE layer is incorporated into the composite material, and the pilling resistance of the PE layer (e.g., the material being pushed out of place, resulting in layer thinning) is also incorporated into the composite material. When the bond between the PE and PTFE layers is compromised or incomplete (e.g., in a composite material with lower peel strength), the Z-axis strength of the composite material 10 is reduced, and this may result in the material of the composite material 10 stretching and / or ripping and tearing.

[0065] Figures 3A-3E The wear test results of various composite materials are depicted. The wear test performed consisted of applying a 2 Newton force at a frequency of 5 Hz with a 300 second interval and stopping at 1500 cycles. Figure 3AAn ePE membrane with a dense porous structure (e.g., pore size greater than 5 microns) (composite material 10A) is depicted. The ePE membrane was not treated with LDPE. As shown, the ePE membrane experienced pilling and tearing of the top layer and failed after 1500 cycles. Figure 3B Depicted is an ePE film with an LDPE layer (composite material 10b) having a dense porous structure (eg, approximately 3 microns). By incorporating LDPE into the ePE film, pilling was reduced, no tearing occurred, and a relatively smooth surface was maintained after the test cycle. Figure 3C Depicted is a densified ePE film with an LDPE layer (composite 10c), a densified ePE film (ADD measurement). This resulted in no pilling, tearing, or ripping. The densified ePE film showed some signs of material stretching in the Z axis. Figure 3D Composite material 10d is depicted having two densified ePE films and LDPE layers. Composite material 10d did not pill, tear, or rip when subjected to abrasion testing. Composite material 10d showed some evidence of material stretching in the Z axis relative to Figure 3C The stretching is small for composite materials. Figure 3E Composite material 10e is depicted, having a densified ePE membrane and an ePE layer (with a tight porous structure) and an LDPE layer. When subjected to abrasion testing, composite material 10e did not pill, tear, or rip. Composite material 10e showed minimal material stretching in the Z axis and fully retained the ePE layer.

[0066] The various layers of the composite materials described herein can be processed individually or in combination. Various methods can be implemented, including but not limited to the methods described in U.S. Patent No. 9,926,416, issued to Striglia on March 27, 2018, U.S. Patent No. 10,577,468, issued to Striglia on March 3, 2020, PCT Publication No. WO 2020 / 028328, filed on July 30, 2019, by Bell, and PCT Publication No. WO 2020 / 028331, filed on July 30, 2019, by Bell.

[0067] Example

[0068] The composite material 10 discussed herein can be implemented on a variety of devices and in a variety of environments. Provided below are examples of how the composite material 10 can be implemented. The following examples should not be construed as limiting.

[0069] Example 1

[0070] Composite material 10 may be implemented as an implantable stent graft 100. Figure 4The stent graft 100 includes a graft member 102 and a stent member 104 connected thereto. The graft member 102 is formed of a composite material 10. The composite material 10 is formed into a tubular member. The graft member 102 includes a PTFE base layer 12 (as a blood contact surface) and a PE outer layer 14 connected to the stent member 104 (see FIG. Figure 1 and Figure 2 ). The PE outer layer 14 is operable to resist wear caused by movement / motion of the stent component 104 during implantation and use. This is relevant in many situations, including when the stent graft 100 is implanted in a tortuous vessel (e.g., in or near the aortic arch) or a vessel that is subject to high pressure or repeated movement / motion (e.g., the aorta). By implementing the composite material 10 discussed, repeated movement / motion is less likely to cause wear of the graft component 102 of the stent graft 100.

[0071] The biocompatible materials used for the graft components discussed herein can be used together with the composite material 10 discussed herein, or used in combination or as a layer of the composite material 10. In some cases, the graft can include a fluoropolymer. In some cases, the graft can be formed of, for example, but not limited to, polyester, silicone, urethane, polyethylene terephthalate, or another biocompatible polymer or a combination thereof. In some cases, a bioresorbable or bioabsorbable material can be used, such as a bioresorbable or bioabsorbable polymer. In some cases, the graft can include Dacron, polyolefins, carboxymethyl cellulose fabrics, polyurethanes, or other woven, nonwoven, or film elastomers.

[0072] In addition, Nitinol (NiTi) can be used as the material of the frame or stent (and any frame discussed herein), but other materials can also be used as the material of the frame, such as, but not limited to: stainless steel, L605 steel, polymer, MP35N steel, polymer material, Pyhnox, Elgiloy non-magnetic alloy (Elgiloy) or any other suitable biocompatible material and combination thereof. The superelasticity and softness of NiTi can improve the compliance of the stent. In addition, NiTi can be shaped into a desired shape. That is, NiTi can be shaped so that when the frame is unconstrained, such as when the frame is deployed from a delivery system, the frame tends to self-expand into a desired shape.

[0073] Example 2

[0074] The composite material may be implemented in locations of a patch or label 200 on an implantable medical device where repeated movement / motion may cause wear on the surface of the implantable medical device. Figure 5 As shown, stent graft 300 is provided with label 200, which is located at a location that may wear due to abrasion. For example, stent graft includes stent component 302 and graft component 304 connected together. Stent component 302 includes multiple tips 306. Label 200 is located between the tips 306 of stent component 302 and graft component 304 (e.g., the abluminal surface of graft component 302). Label 200 can be connected to graft component 304 by various methods. For example, label 200 can be attached by adhesive or applied by heat treatment (e.g., heat gun). In other embodiments, label can be formed from PE or IPA, which is applied as a slurry over the entire mask (e.g., by imbibing). It should be understood that label 200 can be applied to various locations on stent graft 300 where wear or abrasion may occur.

[0075] Example 3

[0076] See also Figure 6 , shows prosthetic cartilage 400. Prosthetic cartilage 400 is formed from composite material 10. Composite material includes a PE outer layer 14 and a PTFE base layer 12. PTFE base layer 12 may include hydrogel 402, which helps provide cushioning for composite material 10. As previously mentioned, PE outer layer 14 provides high wear resistance or abrasion resistance. Prosthetic cartilage 400 can be implemented in a variety of locations, including, but not limited to, use as a replacement prosthetic meniscus.

[0077] Example 4

[0078] See also Figure 7 , a graft attachment strip 500 is provided using the composite material 10 discussed herein. For example, the graft attachment strip 500 can be implemented on a stent graft, wherein the stent structure 510 includes a first apex 512 and a second apex 514. The graft attachment strip 500 can be implemented so as to attach the first apex 512 to the graft material 520. In some embodiments, the graft attachment strip 500 can include a width such that the graft attachment strip is positioned between the second apex 514 and the graft material 520, thereby providing a wear resistant barrier between the second apex 514 and the graft material 520. For example, the graft attachment strip 500 can be used in ultra-thin wall devices that can benefit from increased wear resistance at locations that may experience increased wear during use. For clarity, Figure 7Only one row of tips 512, 514 is shown with the graft attachment strip 500, and it will be appreciated that the graft attachment strip 500 may be positioned over or between the tips 512, 514 of the device.

[0079] The invention of the present application has been described above generally and in conjunction with specific embodiments. It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments described herein without departing from the scope of the present invention. Therefore, the embodiments are intended to cover such modifications and variations of the present invention as long as such modifications and variations come within the scope of the appended claims and their equivalents.

Claims

1. A composite material comprising: Expanded polytetrafluoroethylene layer; a densified expanded polytetrafluoroethylene layer connected to the expanded polytetrafluoroethylene layer; a porous expanded polytetrafluoroethylene layer connected to the densified expanded polytetrafluoroethylene layer; Adhesives; and The expanded polyethylene layer is densified and the adhesive bonds the expanded polyethylene layer to the porous expanded polytetrafluoroethylene layer.

2. The composite material according to claim 1, wherein The adhesive is low-density polyethylene.

3. The composite material of claim 1, further comprising a thin layer of low density polyethylene connected to the expanded polyethylene layer.

4. The composite material according to claim 3, wherein Thin layers of low-density polyethylene and adhesive sandwich the expanded polyethylene layer.

5. The composite material according to claim 1, wherein The densified expanded polyethylene layer is about 2 microns to about 5 microns thick.

6. The composite material according to claim 1, wherein The adhesive at least partially imbibes into the porous expanded polytetrafluoroethylene layer.

7. The composite material according to claim 6, wherein The adhesive is processed at a temperature of about 130°C to about 145°C to adhere the densified expanded polyethylene layer and the porous expanded polytetrafluoroethylene layer.

8. The composite material according to claim 1, wherein The densified expanded polytetrafluoroethylene layer is about 2 microns to about 10 microns thick.

9. The composite material according to claim 1, wherein The porous expanded polytetrafluoroethylene layer is about 10 microns to about 50 microns thick.

10. The composite material according to claim 1, wherein The adhesive forms a layer having a thickness of about 1 micron to about 200 microns.

11. An implantable device, comprising: A tubular member formed of a composite material, the tubular member comprising: a first polymer layer comprising a blood contacting surface; a densified second polymer layer connected to the first polymer layer; a porous expanded third polymer layer connected to the densified second polymer layer; Adhesives; and A densified expanded polyethylene layer is provided, and an adhesive bonds the densified expanded polyethylene layer to the porous expanded third polymer layer.

12. The implantable device of claim 11, wherein: The first polymer layer is an expanded polytetrafluoroethylene layer.

13. The implantable device of claim 11, wherein: The densified second polymer layer is a densified polytetrafluoroethylene layer.

14. The implantable device of claim 11, wherein: The porous expanded third polymer layer is a porous expanded polytetrafluoroethylene layer.

15. The implantable device of claim 11, wherein: The adhesive is low-density polyethylene.

16. The implantable device of claim 15, wherein: The low density polyethylene is imbibed into the porous expanded third polymer layer.

17. The implantable device of claim 11, wherein: The tubular member is a graft.

18. The implantable device of claim 17, further comprising a stent coupled to the tubular member.

19. An implantable medical device, comprising: a first polytetrafluoroethylene layer; and A second polyethylene layer is coupled to the first polytetrafluoroethylene layer, wherein the second polyethylene layer is operable to be placed against a structure that is non-stationary relative to the second polyethylene layer.

20. The implantable medical device of claim 19, wherein: The first polytetrafluoroethylene layer and the second polyethylene layer are included in one of a graft, a tag, a cartilage substitute, an implantable medical device, and a removable medical device.

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