FIELD OF THE INVENTION

[0001] The present invention relates to medical barriers including a flexible membrane and removably insertable reinforcement members held in place therein by pockets and or apertures.

BACKGROUND OF THE INVENTION

[0002] In the field of periodontics and oral surgery, regeneration of bone continues to be a challenge. In particular, ingrowth of gingival tissue into grafted boney defects hinders bone regeneration. In an effort to foster bone regeneration, membranes having a pore size that allow fluids to cross but prevent cells from crossing were developed. Such membranes, placed at the site of a bone graft during surgery, act as a barrier to prevent gingival cells (which are relatively fast-growing) from migrating into the site of a bone graft and allow host bone cells (which are relatively slow-growing) a chance to penetrate the bone graft and regenerate bone. Notably, the host bone cells use the bone graft as a matrix. Depending on the size and type of boney defect, such barrier membrane needs to be in place for 6 weeks to 6 months to effectively foster bone regeneration.

[0003] Where boney defects are small and surrounded on all sides by boney walls, barrier membranes do not need structural support as the bone graft material and the boney walls of the boney defect provide sufficient structural integrity. However, barrier membranes that drape well are desirable such that the barrier membrane adapts to the bone to more effectively prevent in-growth of gingival cells. In contrast, where boney defects are large or where there are incomplete boney walls that need to be regenerated, barrier membranes that both drape well and have structural support are needed. Furthermore, barrier materials with space-making ability are also required in some instances. Such barrier membranes which provide these advantages and structural features are not currently available. [0004] Barrier membranes made of polytetrafluoroethylene (PTFE) provide structural support and have space-making ability but drape poorly. Although barrier membranes made of PTFE with permanently embedded titanium struts allow the barrier membranes to adapt to limited boney defects, such barrier membranes still have limited draping ability. Poor draping may result in gingival cells penetrating a bone graft site onto which the barrier membrane is placed. Furthermore, barrier membranes made of PTFE often become exposed to the oral environment and thus require premature removal by a second surgical procedure. In contrast, barrier membranes made of materials which drape well and are resorbable (e.g., collagen, polylactic acid and polyglycolic acid) are also effective at preventing ingrowth of gingival cells to a bone graft site and advantageously avoid the need for a second surgical procedure to remove them. Furthermore, resorbable barrier membranes remain covered by gingiva during the healing process. There are clear draw-backs to using resorbable membranes, however, including, the fact that many of them lack sufficient structural support and space-making ability as sometimes required at the site of a boney defect.

[0005] Moreover, due to the variability of boney defects, it is often difficult for the practitioner using commercially available barrier membranes to tailor and customize the membrane to the specific defect. Practitioners often attempt to cut, trim and shape the membrane in order to properly form an effective barrier for the specific defect. One of the difficulties with current commercially available membranes having structural supports associated with them is that they do not permit customization of the structural support. The location of the support relative to the membrane is fixed, making tailoring difficult and often not acceptable from a standard of care point of view. Currently, practitioners often fabricate make-shift designs due to the lack of the existence of membrane barrier designs which have the ability to selectively structurally support the tailored membrane to accommodate the tailored fit.

[0006] Thus, there remains a need for improved barrier membranes with desirable draping ability as well as structural support and space-making properties and which are designed to permit selective tailoring of these properties. SUMMARY OF THE INVENTION

[0007] The present invention solves the above-mentioned problems as well as other problems associated with customization of barrier membranes to specific boney defects. Barrier membranes of the present invention permit an array of possible support configurations which can be selected by the practitioner to support the customized shaping and fitting of the membrane at the boney defect site.

[0008] In one aspect of the invention, there is provided medical barriers including a flexible membrane and removably insertable reinforcement members which are held in place in the flexible membrane by pockets and or apertures. Additionally, there is provided medical barriers including a flexible membrane including pockets and/or apertures for releasably holding reinforcement members as well as a kit to form such medical barriers. Advantageously, the medical barriers of the present invention can be customized to a particular shape by selectively configuring reinforcement members in the flexible membrane as desired. Cutting of the membrane to properly drape the defect can be accomplished without having to also cut the structural support members along with the membrane material. Once the size and shape of the membrane is determined, the structural support members can be inserted in the membrane pockets and/or apertures built into the membrane structure. Various sizes of support members may be used, as desired to span the membrane at locations determined to best provide the shaped support necessary for proper bone growth and healing.

BRIEF DESCRIPTION OF THE FIGURES

[0009] Figure 1 is a cross section of a boney defect surrounded on all sides by boney walls. Specifically, a jaw bone with a tooth socket space having a bone graft therein which is covered by a membrane to prevent in-growth of gingival cells from the surrounding gum tissue.

[0010] Figure 2 is a side view of a boney defect lacking boney walls on all sides. Specifically, a jaw bone with a tooth socket space having a bone graft therein which is covered by a membrane having reinforcement members therein which adapts the membrane to the bone and thus prevents in-growth of gingival cells from the surrounding gum tissue. [0011] Figure 3 is a perspective view of a membrane having sleeves which hold reinforcement members therein.

[0012] Figure 4 is a perspective view of a membrane having a series of slits therein whereby reinforcement members are held within the membrane.

[0 13] Figure 5 is a perspective view of a membrane having a series of loops therein some of which are employed to hold reinforcement members within the membrane.

[0014] Figure 6 is a perspective view of a membrane having a series of slits therein some of which are employed to hold reinforcement members within the membrane. Notably, the paths of the reinforcement members cross each other.

[0015] Figure 7 is a top view of a membrane having a series of blind pockets facing each other designed to hold reinforcement members therein and a series of loops designed to guide the reinforcement members between blind pockets.

[0016] These and other features of the invention will be better understood through a study of the following detailed description.

DETAILED DESCRIPTION OF THE INVENTION

[0017] As used herein the following terms shall have the definitions set forth below.

[0018] As used herein, the phrase "rod-like shaped" with reference to reinforcement members refers to having a form or shape that resembles a rod in that it is curved and somewhat round in shape rather than jagged.

[0019] As used herein, the phrase "pocket" with reference to a flexible membrane refers to a sleeve or other means for releasably housing a reinforcement member.

[0020] As used herein, the phrase "aperture" with reference to a flexible membrane refers to a tubular protrusion, a loop, a slit or other means for releasably holding a reinforcement member inserted therethrough.

[0021] As described herein, the term "non-degradable" includes substantially non-degradable materials which are, from a practical standpoint, not degradable to any appreciable extent during their useful life, i.e., while used in the patient. [0022] As described herein, the term "degradable" means substantially degradable in the patient such that the material which is degradable is resorbed by the body. Desirably, membranes made from degradable materials do not require removal once placed in the body.

Barrier Membranes

[0023] In one aspect, the present invention provides medical barriers including (i) a flexible membrane having a length, a width, and top and bottom surfaces; (ii) a plurality of pockets on at least one of said surfaces for releasably housing reinforcement members; and (iii) a plurality of reinforcement members selectively removably insertable within one or more pockets to permit selective positioning and repositioning of said reinforcement members with respect to said surfaces, thereby permitting multiple reinforcement arrangements. In certain embodiments, the aforementioned medical barrier further includes one or more apertures on at least one of said surfaces to selectively releasably position and reposition one or more reinforcement members inserted therethrough.

[0024] In another aspect, the present invention provides medical barriers including (i) a flexible membrane having a length, a width and top and bottom surfaces; (ii) a plurality of apertures on at least one of said surfaces for releasably holding reinforcement members to be inserted therethrough; and (iii) a plurality of reinforcement members selectively removably insertable within said apertures to permit selective positioning and repositioning of said reinforcement members with respect to said surfaces, thereby permitting multiple reinforcement arrangements. In certain embodiments, the aforementioned medical barrier further includes a plurality of pockets on at least one of said surfaces for releasably housing said reinforcement members.

[0025] In yet another aspect, the present invention provides a medical barrier including (i) a flexible membrane having a length, a width and top and bottom surfaces; and (ii) a plurality of apertures and/or pockets on at least one of said surfaces for releasably holding reinforcement members.

[0026] The aforementioned medical barriers of the present invention may include any of the following embodiments. Active Agent(s)

[0027] In certain embodiments, the aforementioned medical barriers of the present invention further include at least one active agent releasable held on or within the flexible membrane. In one embodiment, at least one active agent is a pharmaceutical or a biological agent. In certain embodiments, the pharmaceutical agent is selected from the group consisting of anti-infective agents, analgesics, anti-inflammatory agents and combinations of two or more thereof. In certain other embodiments, the biological agent is a protein (e.g., a growth factor) or a cell.

Flexible Membranes

[0028] In certain embodiments, flexible membranes of the present invention are non-degradable. For example, non-degradable flexible membranes may be made of non-absorbable materials. In another embodiment, flexible membranes of the present invention are degradable. For example, degradabie flexible membranes may be made of bioabsorbable materials.

[0029] In certain embodiments, flexible membranes of the present invention include a material selected from the group consisting of synthetic polymers (e.g., polylactic acid and polyglycolic acid), collagen, artificial dermis and combinations of two or more thereof. In some embodiments, flexible membranes of the present invention include a material selected from the group consisting of polytetrafluoroethylene, fluorinated ethylene propylene, silicone, silicone rubber, polyurethane, polyethylene, polyethylene teraphthalate, polysulfone, non-degradable polycarboxylate, non-degradable polycarbonate, non-degradable polyester, polypropylene, polyacrylic, poly(hydroxymethacrylate), polymethylmethacrylate, and polyamides such as polyesteramide, and copolymers, block copolymers and combinations of two or more thereof. In another embodiment, flexible membranes of the present invention include a material selected from the group consisting of collagen, hyaluronic acid, polylactic acid, polyglycolic acid, copolymers of polylactic acid and polyglycolic acid, polyorthoesters, degradable polycarbonate, degradable polycarboxylate, degradable polycaprolactone, polyanhydride, and copolymers, block copolymers and combinations of two or more thereof. In one embodiment, flexible membranes of the present invention include collagen.

[0030] In some embodiments, flexible membranes of the present invention can be trimmed as needed (e.g., to the size and/or shape of the boney defect). Nonetheless, one or more reinforcement members of an appropriate size can be attached selectively and releasably to the trimmed flexible membrane, such that the flexible membrane can be shaped and sized as needed. In some embodiments, the flexible membrane may include perforations for tacking purposes. Such perforations may be used in conjunction with sutures, staples, pins, tacks or other stabilizing materials to anchor the barrier membrane in place in order to serve its purpose. Such anchoring materials may be pre-set on the membrane for convenience, i.e., the membrane may be "pre-tacked" for ready-use by the practitioner. The anchoring materials (e.g., pins, tacks) may be separate from the membrane initially and inserted by the practitioner, desirably, but not necessarily, using pre-punched or preformed holes in the membrane. Further, in some embodiments, perforations can readily be made in the flexible membrane as needed for fixation thereof, for example, by using a punch tool or a small pilot drill.

[0031] In some embodiments, barrier membranes of the present invention include permanently embedded reinforcement materials in addition to the reinforcement materials that are releasably attached as described herein. For example, a thin bar of titanium, stainless steel or other metal, collagen, or other resorbable and/or degradable material, or a polymeric reinforcement member, may be additionally embedded in the membrane at selective locations which do not interfere with those members which are releasably attached. The relative rigidity of the reinforcement material allows one to pre- shape the membrane to cover the area of the bone graft. In one embodiment, both the flexible membrane and reinforcement member(s) include collagen.

[0032] In certain embodiments, barrier membranes of the present invention are adapted for use with an additional separate layer of reinforcement material which covers at least a portion of the barrier membrane. Suitable reinforcement material includes, but is not limited to, a sheet of metal mesh, such as titanium mesh or a collagen layer. In one instance, the reinforcement material could be added on top of the barrier membrane before the peeled back gum tissue is sutured back in place to cover the barrier membrane. In one embodiment, the sheet of reinforcement material is pre-shaped to conform to the boney defect site. For example, the sheet of reinforcement material may be pre-shaped into a curved configuration (e.g., saddle-shaped) to more readily conform to the boney defect site.

Reinforcement Members

[0033] In some embodiments, reinforcing members of the present invention are placed, at least, on the inside (bone-facing) surface of the flexible membrane. In another embodiment, the reinforcing members are placed, at least, on the outside (gum tissue-facing) surface of the flexible membrane. In yet another embodiment, the reinforcing members may be placed, at least, between the inside (bone-facing side) and outside (gum tissue-facing) surfaces of the flexible membrane.

[0034] In one embodiment, the reinforcement members may be made from one or more materials of metal, polymer, collagen or a combination thereof. In one embodiment, the reinforcement members include a material selected from the group consisting of titanium, stainless steel, nitinol, carbon fiber, polyimide, polyethylene, polypropylene, polytetrafluoroethylene, collagen and combinations of two or more thereof. In one embodiment, the reinforcement members include collagen.

[0035] In some embodiments, the reinforcement members may be rod-like shaped. In certain embodiments, the reinforcement members may have two substantially parallel planar surfaces, such as thin, flat and elongate stays. The reinforcement members may have varying widths or diameters along their lengths to provide for degrees of stiffness and/or flexibility along the length. The reinforcement members may be made from a combination of materials, such as a composite material.

[0036] In some embodiments, the reinforcement members are about 1 to about 3 millimeters in width and about 10 to about 50 millimeters in length. In other embodiments, the reinforcement members are about 1 to about 3 millimeters in width and about 10 millimeters to greater than 50 millimeters in length. Desirably, the reinforcement members can be formed to the shape and length needed. For example, as desired to adapt the flexible membrane to a bone graft filled tooth socket space. In some embodiments, reinforcement members are obtained from a selection of pre-shaped reinforcement members. Additionally, reinforcement members can have perforations for tacking purposes to further stabilize the membrane. Such perforations can be used in conjunction with sutures, staples, pins, tacks, screws or other stabilizing materials to hold the membrane in place in order to serve its purpose. Further, in some embodiments, perforations may readily be made in reinforcement members as needed for fixation thereof, for example, by using a punch tool or a small pilot drill. In one embodiment, a self drilling self tapping screw is utilized to affix the barrier membrane to the boney defect site. Naturally, one or more fixation points are utilized to affix the barrier membrane to the boney defect site for the purposes of ensuring stability of the membrane and graft.

Kits

[0037] In still yet another aspect, the present invention provides kits including

(a) a medical barrier including (i) a flexible membrane having a length, a width and top and bottom surfaces; and (ii) a plurality of apertures and/or pockets on at least one of said surfaces for releasably holding reinforcement members; (b) a plurality of reinforcement members; and (c) instructions for use. Optionally, anchoring members such as sutures, staples, pins, tacks or screws may also be included.

[0038] Referring now to the Figures, in the field of oral surgery, a surgeon generally uses a barrier membrane 1 to cover an area where a bone graft 2 fills a tooth socket space 3 (e.g., an extracted tooth socket) in the jaw bone 10. See, Figure 1. At times, the barrier membrane is desirably shaped and reinforced to adapt to the filled tooth socket space 3 in order to prevent in-growth of gingival cells from the surrounding gum tissue 4 and provide structural support as well as space-making.

[0039] As reflected in Figure 2, reinforcement members 5 are used to shape and support the membrane 1 as desired to adapt to the surface of the bone graft.

[0040] In some embodiments, the membrane 1 includes a series of sleeves 6 designed to house reinforcement members 5 therein. Additionally, any of the embodiments may include pre-drilled holes 11 in the membrane and or reinforcement members as shown. See, Figure 3. [0041] In some embodiments, the membrane 1 includes a series of slits 7 in the membrane through which reinforcement members 5 are held within the membrane 1. See, Figure 4.

[0042] In some embodiments, the membrane 1 includes a series of loops 8 therein designed to hold reinforcement members 5 in place in the membrane 1. As depicted in Figure 5, a plurality of the loops 8 may be employed to hold reinforcement members 5 within the membrane 1.

[0043] In some embodiments, the membrane 1 includes a series of slits 7 therein designed to hold reinforcement members 5 in place in the membrane 1. As depicted in Figure 6, a plurality of the slits 7 may be employed to hold reinforcement members 5 within the membrane 1.

[0044] In some embodiments, the membrane 1 includes a series of blind pockets 9 designed to hold reinforcement members 5 therein as well as a series of loops 8 designed to guide the reinforcement members 5 between the blind pockets 9. See, Figure 7.

[0045] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. Although specific example embodiments have been described, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings that form a part hereof, show by way of illustration, and not of limitation, specific embodiments in which the subject matter may be practiced. The embodiments illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. [0046] Such embodiments of the inventive subject matter may be referred to herein, individually and/or collectively, by the term "invention" merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed. Thus, although specific embodiments have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b) and will allow the reader to quickly ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

[0047] In the foregoing description of the embodiments, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. Any of the materials, components and embodiments described herein may be used in any combination in the practice of this invention and such combinations are included herein. This method of disclosure is not to be interpreted as reflecting that the claimed embodiments have more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may lie in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Description of the Embodiments, with each claim standing on its own as a separate example embodiment. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but is intended to cover modifications that are within the spirit and scope of the invention, as defined by the appended claims.