Compression implants for soft tissue repair

Abstract

Implants are disclosed that include one or more biopolymer sheets having compressed and uncompressed portions. The compressed portion has a reduced thickness and increased density compared to the uncompressed portion of the implant. This contributes to modifying the flexibility of the compressed portion compared to the uncompressed portion. The compressed portion can include one or more portions or one or more edges of the implant. The compressed edges help manage the circumferential "sag" that can occur in the high pressure fluid environment used to establish the surgical space at the repair site of damaged tissue.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Provisional Patent Application No. 63 / 300,162, filed January 17, 2022, entitled "Compression Implant for Soft Tissue Repair," which is incorporated by reference in its entirety. [Background technology]

[0002] Generally, implantable scaffolds are used in operating rooms or other acute treatment environments and can be cut and shaped to attach to and support a given soft tissue site. The scaffold may be placed near or in contact with the tissue that has been torn and repaired, for example, with sutures, suture anchors, or surgical adhesives. The scaffold provides support and reinforcement for soft tissues such as tendons and ligaments, including the Achilles tendon, rotator cuff, patellar tendon, biceps tendon, and quadriceps tendon. The scaffold shares some of the mechanical stresses and loads with the tissue to be repaired. Preferably, such a scaffold provides a suitable matrix for tissue growth. The scaffold may be packaged individually or in pairs, or in larger quantities, in a sterile container.

[0003] For example, during arthroscopic surgery to repair a shoulder, pressurized fluids may be used to enhance visibility at the surgical site and provide physical space for implanting and attaching a scaffold to support or repair damaged or injured tissue. However, for relatively flexible scaffolds, pressurized fluids can make the insertion, control and placement of the scaffold more difficult. Summary of the Invention

[0004] In one aspect, an implant includes one or more biopolymer sheets, the implant having first and second portions, the first portion having a first thickness and the second portion having a second thickness that is less than the first thickness, the portion of the implant having the second thickness being present at one or more edges of the implant.

[0005] In another aspect, a method for manufacturing an implant includes providing a biopolymer sheet having an initial sheet thickness, placing a stencil against the biopolymer sheet, the stencil covering a selected portion of the biopolymer sheet, and applying a load by pressing the stencil against the biopolymer sheet to generate a modified biopolymer sheet, the modified biopolymer sheet including at least one uncompressed portion having the initial sheet thickness and at least one compressed portion having a compressed thickness.

[0006] In another aspect, a method for assisting in soft tissue repair using an implant comprising a biopolymer sheet including selectively compressed and uncompressed portions includes implanting the implant within a surgical site including a pressurized fluid environment within a subject's body, manipulating the implant to embed the implant, and securely anchoring the implant to tissue at the surgical site.

[0007] Other systems, methods, features and advantages of the embodiments will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description, and all such additional systems, methods, features and advantages are intended to be included within this specification and this summary, be within the scope of the embodiments, and be protected by the following claims.

[0008] The embodiments may be better understood with reference to the following drawings and description. The components in the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the embodiments. Moreover, in the drawings, like reference numbers represent corresponding parts throughout the different views. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a portion of a biopolymer sheet according to one embodiment. [Diagram 2] FIG. 2 is a schematic diagram of an implant constructed from a biopolymer sheet having compressed edges, according to one embodiment. [Diagram 3] FIG. 3 is a schematic side view of an implant constructed from a biopolymer sheet having compressed edges, according to one embodiment. [Figure 4] FIG. 4 is a schematic side view of an implant constructed from a biopolymer sheet having compressed edges, according to another embodiment. [Diagram 5] FIG. 5 is a schematic close-up view of a compressed edge of an implant, according to one embodiment. [Figure 6] FIG. 6 is a schematic diagram of an embodiment of an implant having compressed portions configured with different geometries. [Figure 7] FIG. 7 is a schematic diagram of an embodiment of an implant having compressed portions configured with different geometries. [Figure 8] FIG. 8 is a schematic diagram of an embodiment of an implant having compressed portions configured with different geometries. [Figure 9] FIG. 9 is a schematic diagram of an embodiment of an implant having compressed portions configured with different geometries. [Figure 10] FIG. 10 is a schematic diagram of an embodiment of an implant having compressed portions configured with different geometries. [Figure 11] FIG. 11 is a schematic diagram of an embodiment of an implant having compressed portions configured with different geometries. [Figure 12] FIG. 12 is a schematic diagram of a method for manufacturing an implant with compressed edges, according to one embodiment. [Figure 13] FIG. 13 is a schematic illustration of steps in a method for making an implant having compressed edges, according to one embodiment. [Figure 14] FIG. 14 is a schematic illustration of steps in a method for making an implant having compressed edges, according to one embodiment. [Figure 15] FIG. 15 is a schematic illustration of steps in a method for making an implant having compressed edges, according to one embodiment. [Figure 16] FIG. 16 is a schematic illustration of steps in a method for making an implant having compressed edges, according to one embodiment. [Figure 17] FIG. 17 is a schematic diagram illustrating an implant having a compressed edge that includes a transition region of gradual thickness, according to one embodiment. [Figure 18] FIG. 18 is a schematic diagram illustrating an implant having a compressed edge that includes a transition region of gradual thickness, according to one embodiment. [Figure 19A] FIG. 19A is a schematic diagram of an implant with compressed edges operating in a dynamic fluid environment. [Figure 19B] FIG. 19B is a schematic diagram of an implant with compressed edges operating in a dynamic fluid environment. [Figure 19C] FIG. 19C is a schematic diagram of an implant with compressed edges operating in a dynamic fluid environment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] definition For reference purposes, various terms used throughout the detailed description and in the claims are collected here.

[0011] "Biopolymer" means naturally occurring protein-based macromolecules found naturally in connective and other soft tissues and in the extracellular matrix, such as collagen, fibrin, fibrinogen, gelatin, and laminin.

[0012] By "biocompatible polymer" is meant a synthetic polymer that has the ability to be mixed or blended with biopolymers to add various properties, such as strength or stiffness, that would otherwise be provided by the biopolymer alone.

[0013] By "high strength collagen fibers" is meant fibers comprising collagen that have an ultimate tensile strength of at least 80 MPa.

[0014] By "scaffold" is meant a construct formed from biopolymers and / or copolymers. It is contemplated that a scaffold can include linear structures, such as sutures, two-dimensional structures, such as patches, ribbons, or sheets, and any suitable three-dimensional structures. In some embodiments, such constructs are substantially aligned fibers formed into layers, mats, sheets, and tubes.

[0015] By "substantially aligned fibers" is meant that approximately at least half of the fibers within 15 to 20 degrees of a datum in a scaffold are oriented along a common axis, which should be interpreted in contrast to randomly oriented fibers.

[0016] A "compressed" portion of an implant, scaffold, component, or layer of material means a portion that has been pressed, squeezed, molded, or crimped under mechanical load. The compression process reduces the thickness and increases the density of the compressed portion. Compression can also reduce inter-fiber movement. Thus, compared to an otherwise similar "uncompressed" portion of an implant, the compressed portion may be substantially thinner than the uncompressed portion and may have a higher density. Higher density is the result of compressing a given amount of material into a smaller volume. Furthermore, increased density generally reduces the flexibility of the compressed portion compared to the flexibility of the uncompressed portion. Moreover, an implant having a compressed portion generally has a lower overall flexibility compared to its pre-compressed configuration, despite retaining some uncompressed portion.

[0017] Biopolymer Sheet The embodiments provide implantable biocompatible scaffolds in the form of surgical implants, preferably including sheet-like or pad-like structures, and surgical and orthopedic devices utilizing such scaffolds, and associated methods for their manufacture and use to aid in the repair of damaged soft and hard tissues and to stabilize and support various body structures, including ligaments, tendons, and joints. For example, the implants can be used in surgical procedures for tendons and ligaments, including but not limited to the Achilles tendon, rotator cuff, patellar tendon, biceps tendon, quadriceps tendon, gluteus medius, and plantar ligament. Thus, the implants of the present invention may be applied and used by medical practitioners in pressurized and non-pressurized repair sites.

[0018] In a preferred embodiment, the scaffold (or implant) comprises a sheet-like or pad-like construct, wherein the scaffold is further comprised of biopolymer fibers, preferably formed of collagen or a collagen blend and a biocompatible (or biodegradable) polymer, preferably PLLA, PDLA, PDLLA, PLGA, poly(glycolic acid) and blends thereof. A preferred polymer blend in the scaffold for aiding in the repair of soft tissue injuries in humans or other mammals comprises about 10 to 40% by weight of type I collagen and about 60% to 90% by weight of such a biocompatible copolymer.

[0019] In such embodiments, the terms "sheet" or "biopolymer sheet" may be used to refer to the scaffold. Optionally, the scaffold may be formed of multiple individual sheets of differing composition and porosity held together by conventional means such as laser tacking, stitching, or sutures.

[0020] The scaffold is designed to be resorbed over time and replaced with the patient's own tissue during the healing process. The implantable biocompatible scaffold is designed to promote healing in tissue (e.g., ligaments, tendons, or other suitable tissue) and aid in earlier return to activity by allowing for earlier physical therapy compared to alternative traditional recovery and rehabilitation treatments.

[0021] As an example, Figure 1 shows a biopolymer sheet 100 (sheet 100) comprised of collagen fibers. In some embodiments, the outer surface 102 of the sheet 100 is comprised of unaligned fibers designed for isotropic suture retention, strength and structural integrity. In contrast, the bulk (bulk interior 104) and inner surface 106 of the sheet 100 may be comprised of porous microfibers and substantially aligned fibers with consistent microarchitecture. The sheet 100 may be constructed to be fully absorbed during the remodeling process as it promotes tissue ingrowth.

[0022] The biopolymer sheets of the embodiments preferably have a non-woven structure, and those skilled in the art will appreciate that implants having woven and non-woven components may be used in the devices and methods of the present invention.

[0023] The implants of the present invention can be constructed of any suitable biopolymer composition and blend of biopolymers, and optionally biocompatible polymers. In some embodiments, the sheets can be constructed from an electrospun blend of type I collagen and poly-d,l-lactic acid (PDLLA). Preferred examples are described in U.S. Pat. No. 10,617,787 to Francis et al., entitled "Biopolymer Compositions, Scaffolds and Devices," which is incorporated herein by reference in its entirety. Additionally, as additional preferred examples, the implants and collagen fibers can be produced using any of the methods and components described in U.S. Pat. No. 11,213,610 to Francis et al., entitled "Biopolymer Scaffold Implants and Methods for Producing Them," U.S. Pat. No. 11,020,509 to Francis et al., entitled "Microfluidic Extrusion," and U.S. Patent Application Publication No. 2021 / 0275716 to Francis et al., entitled "Braided Surgical Implants," which are incorporated herein by reference in their entireties.

[0024] The embodiments provide implants with features that help overcome a variety of technical problems that may be encountered when attempting to manipulate implants in a pressurized fluid environment, including undesirable deflection at the edges of the implant (including bending, twisting, and folding), delamination (or separation) of sheets, dye retention, and possible tearing.

[0025] To help overcome at least these problems, embodiments provide a biopolymer sheet that includes both compressed and uncompressed portions. As used herein, a compressed portion of a sheet is a portion of the sheet that is pressed or squeezed along its thickness against any uncompressed portions of the sheet. The compressed portion is thinner, denser, less flexible, and less prone to tearing than the uncompressed portions of the sheet. In some embodiments, the formation of the compressed portion is achieved by applying a mechanical load to the uncompressed areas of the biopolymer sheet.

[0026] Thus, implant embodiments can be characterized as having at least two distinct portions (or regions) having substantially different thicknesses. Similarly, implant embodiments can be characterized as having at least two distinct portions (or regions) having substantially different densities.

[0027] Sheet having compressed portions 2 and 3 respectively illustrate bottom and side views of implant 200. Implant 200 is comprised of a biopolymer sheet including an uncompressed inner portion 202 and a compressed peripheral portion 204. It can be seen that uncompressed inner portion 202 and compressed peripheral portion 204 are comprised of the same continuous biopolymer sheet such that at least some of the fibers within uncompressed inner portion 202 extend into compressed peripheral portion 204.

[0028] In this exemplary embodiment, the peripheral portion 204 completely surrounds the uncompressed inner portion 202, thereby providing a compressed outer edge to the implant 200. In other words, the entire periphery of the implant 200 is compressed. However, in other embodiments, the periphery of the implant 200 may be comprised of both compressed and uncompressed portions (see, e.g., FIGS. 8 and 9).

[0029] 2-3, implant 200 has a puffed or pillow-like shape with uncompressed inner portion 202 extending or "bulging" away from a planar surface coinciding with compressed peripheral portion 204. More specifically, uncompressed inner portion 202 extends outwardly along inner side 210 and outer side 212, with compressed peripheral portion 204 generally lying in a plane between the outer and inner sides of implant 200.

[0030] In another embodiment, one side of the implant is relatively flat, such that the compressed peripheral portion is generally planar with a relatively flat side. Referring to FIG. 4, the implant 400 has a "ravioli-like" shape. In this case, the uncompressed inner portion 402 is relatively flat on the outer side 412. Furthermore, the compressed peripheral portion 404 lies generally in the same plane as the uncompressed inner portion 402 on the outer side 412. In contrast, the uncompressed inner portion 402 bulges outward on the inner side 410. More specifically, the uncompressed inner portion 402 bulges outward from the planar surface defined by the compressed peripheral portion 404 and the uncompressed inner portion 402 on the outer side 412.

[0031] In other embodiments, an implant having compressed portions can have other suitable geometries, including quilted or paneled geometries. As another example, an implant having compressed edges can have a trapezoidal geometry.

[0032] Usefulness of compressed parts As already mentioned, the use of implants comprised of one or more biopolymer sheets, preferably having compressed portions, including compressed edges, addresses, or at least substantially solves, various technical problems commonly encountered when implanting such scaffolds in environments characterized by the presence and use of pressurized fluids.

[0033] For example, when inserting a flexible sheet-like implant during a procedure at a surgical site in the presence of a pressurized fluid, such as saline, characterized by having dynamic fluid flow, a sheet-like implant without a compressed portion will flex at its edges, making it more difficult to properly position, align and / or secure the implant. In an exemplary embodiment, the compressed portion of the implant helps to control the flexing by reducing the relative flexibility of the implant along its edges. This reduced flexibility may be due in part to an increased density of the implant within the compressed portion. As detailed in more detail below, flexibility may also be affected by the overall shape and size (e.g., width and thickness) of the compressed portion. The reduced flexibility helps provide a more stable configuration for the implant. In this way, the tendency of the implant to bend, fold, twist and / or flutter under dynamic fluid flow is reduced, which allows for easier placement, alignment and fixation of the implant within a surgical site within the body of a human or other animal requiring such surgical treatment.

[0034] Because the (uncompressed) biopolymer sheets of the embodiments tend to be highly porous, any dyes or colors optionally applied to the sheets, for example to mark edges and / or indicate proper alignment for implantation, may be partially washed away by fluids present at the repair site during the surgical procedure, making visibility of the sheet relatively more difficult throughout the duration of the procedure. In contrast, the compressed portions of the exemplary implants have a relatively high density, and thus dye retention may be improved by modifying fluid flow through the compressed portions compared to uncompressed portions. For example, if the peripheral edges of a dyed implant are compressed, the dye may be retained longer on the peripheral edges, allowing the surgeon improved visibility of the implant edges throughout the procedure.

[0035] The use of compressed sections along some, or optionally substantially all, of the periphery of the biopolymer sheet can also reduce fiber delamination or separation that can occur when the edges of the biopolymer sheet are subjected to dynamic fluid flow. Specifically, within the compressed section of the implant, contact between the biopolymer fibers can be increased compared to the fibers within the uncompressed section of the implant. Furthermore, movement between the fibers can be reduced within the compressed section compared to the uncompressed section of the implant. This closer packing and reduced movement of adjacent fibers at the edge of the implant limits the ingress of fluid into the edges, which can eliminate or slow down the process of fiber separation.

[0036] The compressed portion may also reduce accidental tears and / or prevent tears, if any, from spreading or propagating to the edges of the implant, since the compressed portion may have increased fiber-to-fiber contact and reduced fiber separation compared to the uncompressed portion. In some cases, the compressed portion may have increased suture or anchor retention compared to the uncompressed portion, since the stiffness and / or strength of the compressed portion may be higher compared to the uncompressed portion.

[0037] The compressed edges can also have a reduced frontal area to fluid flow compared to uncompressed portions of the implant, which can ultimately help improve placement of the implant at the surgical repair site, since the edges are less subject to fluid forces that would tend to push, bend, or otherwise interfere with placement of the implant.

[0038] The extent to which the compressed portion can limit implant flexibility, reduce separation, enhance dye retention, and / or limit / reduce tearing can depend on the relative dimensions of the compressed portion to the dimensions of the uncompressed portion, including the relative thickness, relative width (and / or length), and relative area of ​​the compressed and uncompressed portions.

[0039] Relative Thickness The relative thickness between the compressed and uncompressed portions of an implant constructed from biopolymer sheets can best be understood with reference to Figures 4 and 5, which show an enlarged view of a portion of an implant 400. With reference to both Figures 4 and 5, the uncompressed inner portion 402 has an uncompressed thickness 420 (see Figure 4), while the compressed peripheral portion 404 has a compressed thickness 422 (see Figure 5). It will be appreciated that for purposes of illustration, some of these dimensions are not shown to scale.

[0040] In different embodiments, the relative thickness of the compressed and uncompressed portions can be varied. Changing the relative thickness of the compressed and uncompressed portions can result in a change in the relative flexibility between the compressed and uncompressed portions, as well as a change in the overall flexibility of the entire implant. In some embodiments, the compressed thickness 422 can be approximately 0.5% to 25% of the original uncompressed thickness. In other embodiments, the compressed thickness 422 can be approximately 1% to 3% of the uncompressed thickness 420. In some embodiments, for example, the value of the compressed thickness 422 can be approximately 95% less than the value of the uncompressed thickness 420. In other embodiments, the value of the compressed thickness 422 can be approximately 60, 65, 70, 75, 80, 85, 90, 95, or 99% less than the value of the uncompressed thickness 420.

[0041] For reference, exemplary thickness measurements for compressed and uncompressed portions are provided herein. However, it can be appreciated that different absolute thicknesses can be used while still providing a relative thickness within the ranges described above. With reference to FIG. 4, in some embodiments, the uncompressed thickness 420 can have a value in the range of approximately 2 mm to 10 mm. In other embodiments, the uncompressed thickness 420 can have a value in the range of approximately 2 mm to 6 mm. In yet other embodiments, the uncompressed thickness 420 can have a value in the range of approximately 3 mm to 5 mm.

[0042] 5, in some embodiments, the compressed thickness 422 may have a value of less than approximately 1 mm. In some embodiments, the compressed thickness 422 may have a value within the range of approximately 20 μm to 1000 μm (0.02 mm to 1 mm). In other embodiments, the compressed thickness 422 may have a value within the range of approximately 200 μm to 800 μm (0.2 mm to 0.8 mm).

[0043] Periphery Width A compressed peripheral portion may be characterized by the width of one or more edges. With reference to Figure 2, for example, compressed peripheral portion 204 may have a peripheral width 250. In this case, peripheral width 250 is the width of one of the four peripheral edges that together make up compressed peripheral portion 204. If the compressed portion extends around the entire perimeter of the implant (see Figure 2), the peripheral width may be referred to as a "border zone width."

[0044] The uncompressed peripheral portion 202 can have an interior width 260. In a non-rectangular configuration, the peripheral portions 202 can have different interior lengths.

[0045] In "wide edge" embodiments, the perimeter width 250 may have a value approximately within the range of about 2.5 mm to 4 mm. As an example, for an implant having an overall dimension of approximately 30 x 30 mm, this corresponds to an internal width of approximately 22 mm to 24 mm. This in turn corresponds to a perimeter width that is approximately 10% to 13% of the total implant width. In "narrow edge" embodiments, the perimeter width 250 may have a value approximately within the range of about 0.5 mm to 2.5 mm. For a 30 x 30 mm implant, this corresponds to an internal width of approximately 26 mm to 29 mm. This in turn corresponds to a perimeter width that is approximately 1% to 7% of the total implant width.

[0046] flexibility As previously discussed, the use of compressed edges can reduce the flexibility of the implant, which will reduce the tendency of the implant to bend, fold, and stick on itself during arthroscopic implantation. As one measure of this reduced flexibility, the implant can be hydrated and draped onto an object such as a glass rod to determine how the compressed and uncompressed (or non-compressed) portions may tend to deform relative to one another. Specific measures include the bend angle, or "drape angle," between the two sides of a portion of the implant as it is draped onto the glass rod or similar component. A smaller drape angle means more bending and flexibility around the rod compared to a larger drape angle. In particular, a drape angle close to zero is believed to mean that the portion of the implant is folded approximately in half around the rod, and a drape angle close to 180 degrees is believed to mean that the portion of the implant is not substantially bent or folded around the rod.

[0047] In some embodiments, the compressed portion of the implant may tend to have a drape angle that is significantly greater than the uncompressed portion due to the reduced flexibility of the compressed portion compared to the uncompressed portion. That is, the compressed portion may provide greater resistance to bending around the rod than the uncompressed portion. In some embodiments, the uncompressed portion may have a drape angle within the range of approximately 20 degrees to 40 degrees. In some embodiments, the compressed portion may have a drape angle within the range of approximately 40 degrees to 90 degrees. In some embodiments, the compressed portion may have a drape angle that is at least 10 degrees less than the drape angle of the uncompressed portion. In some embodiments, the compressed portion may have a drape angle that is at least 20 degrees less than the drape angle of the uncompressed portion. In some embodiments, the compressed portion may have a drape angle that is at least 25 degrees less than the drape angle of the uncompressed portion. By sizing each implant so that it is slightly larger than the physical area it is to treat, the compressed portions can add sufficient stiffness to the edges of the implant for ease of insertion and placement at the repair or treatment site, while the uncompressed portions inside the edges provide drapeability at the implant site where the implant approximates or contacts.

[0048] Variation along the perimeter The properties of the implant can be modified by adjusting the location and shape of the compressed portions as well. For example, the embodiment of FIG. 6 shows a configuration in which the implant 600 has a compressed peripheral portion 602 and a non-compressed inner portion 604. The compressed peripheral portion 602 has a narrow width along the edge 610 of the implant 600, and also includes compressed corners 612 that are triangular in shape and extend further into the interior of the implant 600 to provide additional reinforcement at the corners. In an exemplary embodiment, the compressed peripheral portion 602 is configured with a border region having a width in the range of about 0.5 mm to 2.5 mm. Each compressed triangular corner may have a hypotenuse in the range of about 2 mm to 6 mm. Using compressed corners with narrow compressed edges, as in FIG. 6, can help maximize the non-compressed area of ​​the implant while preventing delamination and improving dye retention along the entire circumference of the implant.

[0049] 7, only the corners 712 of the implant 700 may be compressed. Using only the compressed corners can help maximize the uncompressed area of ​​the implant while preventing delamination and improving dye retention in the corners of the implant.

[0050] Variation along the interior Figures 8 and 9 illustrate two embodiments of implants where the compressed portions of the implant extend through the interior region of the implant and around the periphery. For example, in Figure 8, implant 800 includes a compressed outer peripheral portion 802 and a compressed inner portion 804. In this example, compressed inner portion 804 has an X-shaped geometry with two narrow compressed lines extending from opposite corners and intersecting at the center of the implant.

[0051] The compressed inner portion 804 has the effect of dividing the interior of the implant into four separate uncompressed portions 810, each having an approximately triangular shape. In an exemplary embodiment, the compressed outer peripheral portion 802 has an approximate border width within the range of about 0.5 mm to 2 mm. Similarly, the lines forming the "X" of the compressed inner portion 804 may each have an approximate width within the range of about 0.5 mm to 2 mm.

[0052] 9, the implant 900 includes a compressed outer peripheral portion 902 and a compressed inner portion 904. In this example, the compressed inner portion 904 is configured as a set of parallel lines. In some embodiments, the parallel lines may be oriented along the alignment of the fibers in the biopolymer sheet.

[0053] The compressed inner portion 904 has the effect of dividing the interior of the implant into four separate uncompressed portions 910, each having an approximately rectangular shape. In an exemplary embodiment, the compressed outer peripheral portion 902 has a thin border and the compressed inner portions 904 each include a line or strip having a width in the range of about 0.5 mm to 2 mm. In some cases, the separation distance between adjacent lines of the compressed inner portions 904 may be approximately in the range of about 4 mm to 6 mm.

[0054] The use of compressed sections within the implant interior can help reduce unwanted deflection within the implant, reduce delamination throughout the interior, and improve dye retention throughout the interior. Additionally, the use of compressed sections to create isolated uncompressed sections within the interior (e.g., uncompressed section 810 and uncompressed section 910) can help reduce tearing. Specifically, if a tear forms in one of the uncompressed sections, it may have a relatively low probability of spreading to other isolated uncompressed sections, thus limiting the likelihood that the tear may extend throughout the entire implant.

[0055] Some embodiments may include compressed portions having curved or otherwise irregular boundaries. In FIG. 10, the implant 1000 has a compressed peripheral portion 1002 and a non-compressed inner portion 1004. In this case, the outer boundary 1010 of the compressed peripheral portion 1002 has a rectangular shape. However, the inner boundary 1012 has a different shape along different edges. Specifically, a first set of opposing edges 1020 are straight along the inner boundary 1012, while a second set of opposing edges 1022 are substantially curved along the inner boundary 1012. In particular, the second set of opposing edges 1022 may have a "scalloped" shape. By scalloping the inner edges of the compressed peripheral portion 1002, this configuration may reduce the amount of stress and shear in the transition region between the compressed and non-compressed portions. Additionally, in the embodiment of FIG. 10, the orientation of the scalloped edges may proceed in parallel with the substantially aligned fibers of the implant. This configuration can help reduce longitudinal or transverse tear propagation.

[0056] Other embodiments may use other shapes along the inner or outer boundaries of the compressed portion. Other example shapes may include, but are not limited to, wavy, zigzag, dentil edges, and / or irregular curves or varying radii.

[0057] 11 illustrates an alternative embodiment for an implant 1100. In this example, an uncompressed inner portion 1104 extends to the outermost edge 1110 of the implant 1100 in several regions. These uncompressed regions are separated by distinct compressed peripheral portions 1102. This configuration can facilitate reduced stress and shear in the transition regions, as in the embodiment of FIG. 10, while also increasing the surface area of ​​the uncompressed portions compared to the embodiment of FIG. 10.

[0058] The relative area of ​​the compressed and uncompressed portions can vary depending on the shape and size of the compressed and uncompressed portions. Depending on the presence and width of the border zone, the presence, shape and size of the inner portion, and the dimensions of the biopolymer sheet, the relative surface area of ​​the compressed portion (along one side of the implant) can vary between about 0.1% and 50% of the total implant area, and is preferably about 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.25%, 1.5%, 1.75%, 2.0%, 2.25%, 2.5%, 2.75%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 7.5%, 10%, 15%, 20%, 25%, 30%, 35%, 40% and 45% of the total implant area.

[0059] By varying the relative thickness, width, and area of ​​the compressed versus uncompressed portions, and adjusting the placement and shape of the compressed portions, the implant can be tailored to achieve the desired properties of flexibility, delamination, dye retention, and tear mitigation. For example, generally increasing the relative width and / or area of ​​the compressed versus uncompressed portions will result in a less flexible implant compared to a completely uncompressed implant of the same shape and size. In this way, flexing of the implant during surgery will be minimized, facilitating easier positioning, alignment, and attachment of the implant to the target fibers (e.g., tendons).

[0060] Manufacturing method Embodiments provide methods for compressing a biopolymer sheet to produce an implant having compressed and uncompressed portions. In some embodiments, selective portions of the biopolymer sheet can be compressed using a stencil. The stencil can include a material having openings. When pressed against the biopolymer sheet, the solid portions of the stencil press down on the underlying biopolymer sheet portions to produce the compressed portions. The openings in the stencil correspond to areas where the biopolymer sheet is not compressed, such that such portions remain uncompressed after the load is removed.

[0061] Figure 12 illustrates a schematic method 1200 for forming an implant by modifying a biopolymer sheet, several steps of which are illustrated in Figures 13 to 15.

[0062] In step 1202, the biopolymer sheet may be stained. As discussed above, staining the sheet may facilitate increased visualization of the implant during the surgical procedure. Any suitable method for applying the dye to the biopolymer sheet may be used.

[0063] Next, in step 1204, a stencil can be placed against the biopolymer sheet. The stencil can be made of any suitable material, including soft or hard plastic, or other suitable materials. Some specific examples of materials that may be used for the stencil include polylactide (PLA) and silicone cord. In some embodiments, an additional layer of rubber and / or a thin ultra-high molecular weight polyethylene (UHMWPE) sheet can be used to promote more uniform compression. Here, the entire biopolymer sheet provided may be in an uncompressed state and may have an approximately constant thickness (also referred to as the "initial thickness" of the biopolymer sheet). FIG. 13 shows a schematic diagram of an uncompressed biopolymer sheet 1300 placed on a support surface 1302. A stencil 1304 is shown in cross-section. The stencil can be seen to include a solid material portion 1306 that acts to press the biopolymer sheet downward, and an opening 1308 that prevents the underlying portion of the biopolymer sheet from being pressed. Although shown in cross section, it can be appreciated that in an exemplary embodiment, the openings have a square or roughly rectangular geometry. In other embodiments, the openings in the stencil can have any suitable geometry. In step 1206, a load can be applied to the stencil against the biopolymer sheet. In the example shown in FIG. 14, a downward force is applied to the stencil 1304 using a press 1402. This causes the stencil 1304 to compress the biopolymer sheet 1300 at selected portions. In one embodiment, a mechanical arm configured to press down on the stencil is used. The load applied can be sufficient to achieve the desired compression but not so high that the fibers of the biopolymer sheet are damaged. In one exemplary embodiment, a load of approximately 50 pounds can be applied to achieve the desired level of compression. One skilled in the art will adjust the pressure to create the desired amount of compression of the implant.

[0064] For clarity, only a support surface 1302 and a stencil 1304 are shown to facilitate compression of the biopolymer sheet 1300. However, in some embodiments, layers of UHMWPE and rubber can be used on either side of the biopolymer sheet for added cushioning to facilitate uniform compression. In one embodiment, the biopolymer sheet and stencil can be sandwiched between two cushioning assemblies. Each cushioning assembly can further comprise a rubber sheet (approximately 1 / 8 inch thick) sandwiched between two thin UHMWPE sheets (approximately 0.25 inch thick). That is, one cushioning assembly (rubber sheet sandwiched between UHMWPE sheets) can be placed on the support surface, and then the biopolymer sheet can be placed on top of that assembly. The stencil can be placed on the biopolymer sheet, and then another cushioning assembly (rubber sheet sandwiched between UHMWPE sheets) can be placed on the stencil. A press can then be applied.

[0065] In step 1208, the stencil is removed and the resulting modified biopolymer sheet (modified sheet 1500 in FIG. 15) can be collected. The resulting sheet has both compressed and uncompressed portions. The resulting modified sheet will include both compressed and uncompressed portions. As an example, FIG. 15 shows one embodiment of a modified sheet 1500 having compressed portions 1502 and uncompressed portions 1504.

[0066] In step 1210, the modified biopolymer sheet can be cut along the compressed portions to generate multiple implants having both compressed and uncompressed portions. In some cases, laser cutting can be used.

[0067] 16 is a schematic diagram of a modified biopolymer sheet 1602 that includes both compressed portions 1604 and uncompressed portions 1606. Cut lines 1610 indicate where biopolymer sheet 1602 can be cut to separate the sheet into four separate implants: implant 1620, implant 1622, implant 1624, and implant 1626. The final implants may be similar to each other, with each implant including a compressed peripheral portion and an uncompressed inner portion.

[0068] Thus, embodiments provide an efficient method for manufacturing implants having compressed and uncompressed portions that minimizes damage to fibers that may be caused by the application of heat or other substances. Moreover, because the cut is made along the compressed portion, the resulting cut edges may be "cleaner" or more regular than cuts that may be made through the uncompressed portion.

[0069] As previously discussed, implants manufactured in this manner can aid in better deflection control, improved dye retention and visualization during surgery, reduced edge and / or corner delamination, and reduced tearing and / or propagation of existing tears.

[0070] Transition Thickness For clarity, the embodiments of Figures 12-15 depict configurations using stencils with generally vertical opening sidewalls. The resulting implant geometry may be like that depicted in Figure 5, where the thickness of the implant changes abruptly in the transition region between the compressed and uncompressed portions. In some embodiments, the manufacturing process may be amendable to produce an implant with a more gradual change in thickness within this transition zone. This alternative geometry may help reduce (or distribute) stresses in these transition regions.

[0071] As an example, Figure 17 illustrates an embodiment in which the stencil 1710 has curved interior aperture walls 1712. In this embodiment, the aperture walls 1712 have a convex curvature that results in a concave geometry for the transition region 1722 of the implant 1720. Moreover, as can be seen in Figure 18, which shows a close-up of the transition region, this concave geometry corresponds to a more gradual change in thickness of the implant 1710 between the fully compressed peripheral portion 1704 and the uncompressed portion 1702 (see Figure 17). The resulting implant can have regions with a fully uncompressed thickness, regions with a fully compressed thickness, and variable thickness within the transition region.

[0072] In other embodiments, the curvature of the transition region of the implant may be convex rather than concave. Such a geometry may be achievable by using a stencil with internal opening walls that have a concave curvature.

[0073] Dynamic fluid flow results Figures 19A-C show how biopolymer sheets with compressed sections can help overcome various technical problems mentioned above in the context of dynamic fluid flow. In particular, Figure 19A shows a portion of a biopolymer sheet with compressed edges after vigorous shaking in a fluid in a test tube. As can be seen in Figure 19A, the compressed edges show no signs of delamination.

[0074] Similarly, Figures 19B-19C show an implant with compressed edges that was successfully deployed and secured in an arthroscopic shoulder implantation under fluid pressures of 25-50 mmHg. Figures 19B-19C also show how the compressed edges of the implant retain staining better than the uncompressed interior of the implant, thereby improving visualization throughout the procedure compared to a sheet without any compressed portions.

[0075] How to use The implant can be used to assist in the repair of soft tissue. In one embodiment, the implant can be collapsed and inserted through a cannula into a surgical space in the body. Such techniques are described, for example, in U.S. Patent Application Publication No. 2021 / 0275220, entitled "Surgical Cannula with Removable Pressure Seal," the entire contents of which are expressly incorporated by reference. In some cases, the implant is inserted in a pressurized fluid environment. Once the implant has passed the distal end of the cannula, it returns to a non-collapsed configuration. At this point, the surgeon can manipulate the implant to embed it on the surgical field (which may include, for example, the tendon to be repaired). Finally, the surgeon can secure the implant at the surgical site as appropriate. For example, the implant can be secured using sutures, staples, anchors, and other fasteners known to those skilled in the art.

[0076] The use of implants having compressed portions as described above may allow for better visibility and manipulation of the implant by reducing edge deflection under fluid flow and extending the time that dye remains visible on the implant. The compressed edges may also reduce the tendency of the implant to separate or delaminate into layers under fluid pressure, maintaining distinct edges that the surgeon can visualize and manipulate.

[0077] While various embodiments have been described, the description is intended to be illustrative rather than restrictive, and it will be apparent to one skilled in the art that many more embodiments and implementations are possible that fall within the scope of the embodiments. While many possible feature combinations are illustrated in the accompanying drawings and discussed in this detailed description, many other combinations of the disclosed features are possible. Unless specifically constrained, any feature of any embodiment can be used in combination with or substituted for any other feature or element in any other embodiment. Thus, it is to be understood that any features shown and / or discussed in this disclosure can be implemented together in any suitable combination. Thus, the embodiments should not be limited except in light of the appended claims and their equivalents. Similarly, various modifications and variations are possible within the scope of the appended claims.

Claims

1. 1. An implant comprising one or more biopolymer sheets, The implant has a first portion and a second portion; the first portion has a first thickness; the second portion has a second thickness that is less than the first thickness; the portion of the implant having the second thickness is at one or more edges of the implant; Implant.

2. 10. The implant of claim 1, wherein the first portion has a first density and the second portion has a second density, the second density being greater than the first density.

3. The implant of claim 1 , wherein the biopolymer sheet has a non-woven structure.

4. 4. The implant of claim 3, wherein the biopolymer sheet is composed of collagen fibers, optionally composed of fibers comprising collagen and a bioreceptive polymer.

5. the first portion of the biopolymer sheet is uncompressed; the second portion of the biopolymer sheet is compressed; 2. The implant of claim 1.

6. The implant of claim 1 , wherein the second thickness is less than about 10% of the first thickness.

7. The implant of claim 1 , wherein the second portion comprises a compressed peripheral portion of the biopolymer sheet.

8. The sheet has a sheet width, 7. The implant of claim 6, wherein the peripheral edge has a peripheral width, said peripheral width being about 1% to 13% of the sheet width.

9. 2. The implant of claim 1, wherein the second portion has a second partial surface area on the first side of the implant, the second partial surface area being approximately 0.5% to 50% of a total implant surface area on the first side.

10. The implant of claim 1 , wherein the second portion includes at least one corner of the biopolymer sheet.

11. The implant of claim 10 , wherein the second portion forms a border around a perimeter of the biopolymer sheet.

12. The implant of claim 1 , wherein the biopolymer sheet includes a compressed inner portion separating two or more uncompressed portions of the biopolymer sheet.

13. The implant of claim 12 , wherein the compressed inner portion is substantially X-shaped.

14. The implant of claim 12 , wherein the compressed inner portion is configured as a plurality of substantially parallel lines.

15. 15. The implant of claim 14, wherein the substantially parallel lines are substantially parallel to aligned fibers of the biopolymer sheet.

16. the second portion forms a border around a perimeter of the biopolymer sheet; At least one portion of the second portion has a curved geometry.

2. The implant of claim 1.

17. the at least one portion having the curved geometry is oriented in a direction that is substantially parallel to aligned fibers of the biopolymer sheet.

17. The implant of claim 16.

18. The implant of claim 1 , wherein the second portion is less flexible than the first portion.

19. 20. The implant of claim 18, wherein the second portion extends around a circumference of the implant, and the reduced flexibility of the second portion compared to the first portion reduces deflection of the circumference of the implant.

19. (Duplication) 2. The implant of claim 1, wherein when the first portion is uncompressed and the second portion is compressed and the implant is subjected to a fluid pressure, the second portion provides the implant with a higher strength against delamination compared to the first portion.

20. 10. The implant of claim 1, wherein the first portion is uncompressed and the second portion is compressed, the second portion having improved dye retention compared to the first portion.

21. 12. The implant of claim 11, wherein the first portion is uncompressed and the second portion is compressed, the second portion having a higher tear resistance than the first portion.

22. A method for producing an implant, comprising: providing a biopolymer sheet having an initial sheet thickness; placing a stencil against the biopolymer sheet, the stencil covering a selected portion of the biopolymer sheet; applying a load to press the stencil against the biopolymer sheet to produce a modified biopolymer sheet, the modified biopolymer sheet including at least one uncompressed portion having the initial sheet thickness and at least one compressed portion having a compressed thickness; The method includes:

23. 23. The method of claim 22, wherein the compressed thickness of the at least one compressed portion is about 0.5% to 10% of the initial sheet thickness.

24. 23. The method of claim 22, wherein the compressing process occurs at about room temperature.

25. 23. The method of claim 22, wherein the biopolymer sheet has a non-woven structure.

26. 23. The method of claim 22, wherein the biopolymer sheet is formed from high strength collagen fibers.

27. 23. The method of claim 22, wherein the at least one compressed portion is less flexible than the at least one uncompressed portion.

28. 23. The method of claim 22, wherein the biopolymer sheet has an initial flexibility prior to the step of applying the load to the stencil against the polymer sheet, and the modified biopolymer sheet has a final flexibility after applying the load to the stencil against the polymer sheet, the final flexibility being less than the initial flexibility.

29. 23. The method of claim 22, wherein the modified biopolymer sheet includes a first uncompressed portion and a second uncompressed portion separated by the at least one compressed portion, the method including cutting the biopolymer sheet along the at least one compressed portion to produce a first sheet-like implant and a second sheet-like implant.

30. 30. The method of claim 29, wherein the cutting comprises laser cutting the biopolymer sheet along the at least one compressed portion.

31. 1. A method of assisting soft tissue repair with an implant, the implant comprising a biopolymer sheet including selectively compressed and uncompressed portions, the method comprising: implanting the implant within a surgical site including a pressurized fluid environment within a subject's body; manipulating the implant to position the implant; anchoring the implant to tissue at the surgical site; A method comprising:

32. 32. The method of claim 31, wherein implanting the implant further comprises inserting the implant through a cannula to the surgical site while the implant is in a collapsed configuration.

33. 32. The method of claim 31, comprising delivering the implant over a distal end of the cannula such that the implant returns to an uncollapsed configuration after being inserted through the cannula and into the body.

34. 31. The method of claim 30, further comprising the step of applying a dye to the implant.

35. 31. The method of claim 30, wherein the dye is retained in a pressurized fluid environment for a longer period on the compressed portions of the implant than on the uncompressed portions of the implant.

36. 15. The implant of claim 14, wherein the compressed inner portion configured as a plurality of substantially parallel lines is stained.

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