Patent Publication Number: US-2009222039-A1

Title: Suture with biological material

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/033,246, filed Mar. 3, 2008, the entire disclosure of which is incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to surgical suture materials and, in particular, to sutures comprising biological materials such as collagen. 
     BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 4,470,941 discloses a composite suture prepared by forming a thread comprised of fibers of a first synthetic polymer, the thread further including a second synthetic polymer in intimate association with an present uniformly along the length of the first synthetic polymer, softening the second synthetic polymer to cause it to flow, and applying pressure to the softened polymer to redistribute it throughout the plurality of fibers, and into the interstices. The &#39;941 patent, however, only relates to polymers. The present invention expands upon this by allowing for a different filler material, for example, a biological material such as collagen, to improve healing. 
     SUMMARY OF THE INVENTION 
     The present invention provides a surgical suture made substantially of biological material (such as biopolymers or proteins, for example). 
     The invention also provides a method of suturing comprising the steps of: (i) providing a suture with a core made substantially of biological material such as biopolymers or proteins and, optionally, with a cover surrounding the core; and (ii) delivering the biological material to a surgical repair site. 
     Other features and advantages of the present invention will become apparent from the following description of the invention, which refers to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a suture and/or tape comprising a biological material, and according to an exemplary embodiment of the present invention. 
         FIG. 2  illustrates a partial, cross-sectional view of a suture and/or tape comprising a biological material, and according to another exemplary embodiment of the present invention. 
         FIG. 3  illustrates a schematic view of a suture and/or tape comprising a biological material, and according to another exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following detailed description, reference is made to various specific embodiments in which the invention may be practiced. These embodiments are described with sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be employed, and that structural and logical changes may be made without departing from the spirit or scope of the present invention. 
     The present invention provides a surgical suture made substantially of biological material such as biopolymers or proteins. 
     In an exemplary embodiment only, the surgical suture may comprise a core made substantially of biological material such as biopolymers or proteins and, optionally, may be provided with a cover (for example, a braided cover) surrounding the core. The section comprising the biological material may be provided as a suture tape or as a round or oval suture, or as a combination of tape and suture. Optionally, the section comprising the biological material may be provided adjacent at least a section of suture not comprising biological material. 
     The invention also provides a method of suturing comprising the steps of: (i) providing a suture with a core made substantially of biological material such as biopolymers or proteins; and (ii) delivering the biological material to a surgical repair site. 
     The invention also provides a method of suturing comprising the steps of: (i) providing a suture with a core made substantially of a matrix of biological material such as biopolymers or proteins; (ii) containing at least one biological component such as blood, blood fractions or growth factors within the matrix; and (iii) delivering at least one of the biological material and biological component to a surgical repair site. 
     Referring now to the drawings, where like elements are designated by like reference numerals,  FIGS. 1-3  illustrate exemplary embodiments of suture strands  100 ,  200 ,  300  of the present invention comprising a biological material such as biopolymers or proteins. 
     As shown in  FIGS. 1 and 2 , suture strands  100 ,  200  comprise at least a section or core  10  substantially formed of biological material and, optionally, at least a section or portion  20  provided adjacent the biological material of section  10 . Suture section  10  may preferably comprise biological material throughout its whole length or, alternatively, may comprise biological material provided at localized areas or regions within the section  10 . The biological material (for example, the collagen) may be also provided throughout the entire length and throughout the entire core of the suture, as desired. 
     Section  20  may also comprise biological material (which may be the same as or different from the biological material of section  10 ) and/or may comprise a biological material in an amount different from that of section  10 . In additional embodiments, suture section  20  does not comprise biological material. Section  20  may have a diameter that is constant throughout the whole length of section  20 , or may vary depending on the nature of the surgical application and of the instruments with which the suture is employed. The diameter of section  10  may be similar to or different from the diameter of section  20 . 
     Biological material of suture section  10  may include a biopolymer (for example, a bioabsorbable polymer such as collagen or a collagen-based material, among others), or an extracellular matrix protein (such as fibronectin, elastin or laminin, among others). If collagen is employed, the collagen forming suture section  10  may be cross-linked, with additional materials, to increase the tensile strength of the collagen strands. The collagen, in its natural state or cross-linked, may be provided in the form of a plurality of collagen strips (for example, 4 inch collagen strips) that are bundle together to form the core or suture section  10  of suture  100 . The collagen strips may be braided, for example, or may be provided as parallel strips adjacent to each other, to form the suture  10 . 
     Alternatively, biological material of suture section  10  may be formed of a graft material or a combination of graft materials. In yet additional embodiments, biological material of suture section  10  is a spongy biological material which may form a scaffold or matrix containing interstitial spaces and channels that allow cellular invasion and growth (for example, fibroblast proliferation to allow tissue regeneration). The scaffold or matrix may optionally comprise additional components such as blood, proteins, growth factors or chemicals, that may be provided (by injection or impregnation, for example) within the matrix. 
     As such, and in accordance with additional embodiments, suture section  10  may be employed to deliver to the surgical site a biological component which includes at least one of blood, blood components or fractions, PRP, bone marrow aspirate (BMA) or autologous conditioned plasma (ACP). The biological component may be provided (by injection, impregnation or soaking, for example) directly into the suture section  10 , and subsequently to the site or into the anatomical tissue, or in the vicinity of the surgical site (for example, arthroscopic site) or tissue to be repaired. In yet another embodiment, the whole length of suture  100  (including suture sections  10  and  20 , or only suture section  10  if suture section  20  is absent) is soaked or injected with the biological component (for example, PRP, BMA or ACP). If desired, suture section  10  may additionally comprise components such as growth factors, additional antiseptic chemicals and/or antibiotics and/or electrolytes, or hormones or site-specific hybrid proteins (that promote or enhance the wound healing effectiveness of the growth factors), among others. 
     To assist in retention of the biological component by the suture  100 , and if desired, at least one of suture sections  10 ,  20  may be coated (partially or totally) with wax (beeswax, petroleum wax, polyethylene wax, or others), silicone (Dow Corning silicone fluid  202 A or others), silicone rubbers (Nusil Med 2245, Nusil Med 2174 with a bonding catalyst, or others) PTFE (Teflon, Hostaflon, or others), PBA (polybutylate acid), ethyl cellulose (Filodel) or other coatings, to improve lubricity of the braid, knot security, pliability, handleability or abrasion resistance, for example. 
     Suture section  10  may have cross-sections of various forms and geometries, including round, oval, rectangular, or flat, among others, or combination of such forms and geometries. In an exemplary embodiment only, suture section  10  may be provided as a suture tape or as a round suture, or as a combination of tape and round suture. The diameter of suture section  10  may be constant or may vary. In an exemplary embodiment, suture section  10  is about 4 to about 6 inches long and, as shown in  FIG. 1 , is bounded at each end by suture material  20  that does not comprise biological material. In an exemplary embodiment, at least a portion of the suture (for example, about 4 to about 6 inches) comprises a section with a biological material core  10  disposed between sections  20  of the suture without biological material (for example, sections of #5 PET suture). At least one of sections  20  may contain strands of a high strength suture material, such as Arthrex FiberWiret suture disclosed in U.S. Pat. No. 6,716,234, incorporated herein by reference, with optional colored strands to assist surgeons in distinguishing between suture lengths with the biological material and suture lengths without the biological material. If desired, at least one of the tail regions of suture sections  20  (preferably both tail regions) may have a very fine end that is coated, impregnated, or otherwise stiffened with a material such as plastic, for example. 
     In an exemplary embodiment only, surgical suture  100  is formed only of biological material, for example, only of collagen. Surgical suture may be formed of a core made substantially of collagen or collagen strands. The collagen may be provided as a suture tape or as a round, flat, or oval suture, or as a combination of tape and suture. The full length of the suture may include the biological material (for example, the collagen) throughout the entire length and throughout the entire core of the suture. 
     The biological material (for example, the collagen) may form strands and/or a matrix or sponge (i.e., collagen matrix or sponge) that allows suture section  10  to be impregnated, injected or soaked with additional components. For example, the collagen stuffed suture may be injected with at least one biological component such as blood, blood fraction, PRP, BMA or ACP, or may be soaked in a solution containing at least one biological component such as blood, blood fraction, PRP, BMA or ACP, to allow the biological component to be delivered to the surgical repair site. In an exemplary embodiment, suture material  20  (that bounds each end of collagen suture section  10 ) is #5 PET suture about 38 inches long, disposed at each end of the collagen section  10 . The collagen section  10  advantageously delivers biological materials to the surgical repair site. If desired, the collagen stuffed suture may optionally comprise additional components such as growth factors, additional antiseptic chemicals and/or antibiotics and/or electrolytes, or hormones or site-specific hybrid proteins (that promote or enhance the wound healing effectiveness of the growth factors), among others. 
       FIG. 2  illustrates another exemplary embodiment of suture  200  of the present invention. Suture  200  is substantially similar to suture  100  of  FIG. 1  but differs in that the suture section or core  10  of suture  200  is covered (partially or totally) by cover  50 . In an exemplary embodiment only, suture section  10  is totally covered by cover or jacket  50 . 
     As in the previously-described embodiment, suture section  10  may be in the form of a suture tape or a suture with the core replaced by biological material. As detailed above, suture core  10  may be formed substantially of biological material which may be optionally treated with additional materials such as blood, blood fractions, PRP, BMA, ACP, growth factors, antiseptic chemicals, antibiotics, electrolytes and various chemicals, among many others. 
     Cover  50  of suture  200  may be formed of suture materials, such as PET, UHMWPE, PEEK, silk nylon, and absorbable polymers, among many others. Cover  50  may also contain a bioabsorbable material, such as PLLA or one of the other polylactides, for example, and/or may be formed of twisted fibers having strands of a contrasting color added to the braided threads, to make the suture more visible during surgical procedures. The colored strands, preferably, may be dyed filaments or strands. 
     In exemplary embodiments, cover  50  may be a braided suture cover containing strands of a high strength suture material, such as Arthrex FiberWire suture disclosed in U.S. Pat. No. 6,716,234, incorporated herein by reference, with optional colored strands to assist surgeons in distinguishing between suture lengths with the biological material and suture lengths without the biological material. 
     As in the previously-described embodiment, at least one of cover  50  and suture section  20  may be coated (partially or totally) with wax (beeswax, petroleum wax, polyethylene wax, or others), silicone (Dow Corning silicone fluid  202 A or others), silicone rubbers (Nusil Med 2245, Nusil Med 2174 with a bonding catalyst, or others) PTFE (Teflon, Hostaflon, or others), PBA (polybutylate acid), ethyl cellulose (Filodel) or other coatings, to improve lubricity of the braid, knot security, pliability, handleability or abrasion resistance, for example. 
       FIG. 3  illustrates another exemplary embodiment of suture construct  300  comprising a biological material  310  (for example, collagen  310 ) provided as a strip inserted into the core of suture body  320 . Strip  310  of suture construct  300  has similar characteristics as those of section or core  10  substantially formed of biological material of structures  100 ,  200 . Suture body  320  of suture construct  300  has similar characteristics as those of section or portion  20  of structures  100 ,  200 . 
     In the exemplary embodiment of  FIG. 3 , two suture tails  330  are provided adjacent each splice  340 . Suture body  320  may be formed of polyester (for example, braided polyester) and the suture tails  330  may be also formed of polyester or a similar material. Strip  310  may be formed of collagen. 
     In an exemplary embodiment only, suture body  320  may be formed of braided polyester with polyester core and collagen strip  310  inserted into the core of suture. Suture tails  330  may be braided polyester with a polyester core and spliced to the suture. 
     As in the previously-described embodiment, suture construct  300  may be coated (partially or totally) with wax (beeswax, petroleum wax, polyethylene wax, or others), silicone (Dow Corning silicone fluid  202 A or others), silicone rubbers (Nusil Med 2245, Nusil Med 2174 with a bonding catalyst, or others) PTFE (Teflon, Hostaflon, or others), PBA (polybutylate acid), ethyl cellulose (Filodel) or other coatings, to improve lubricity of the braid, knot security, pliability, handleability or abrasion resistance, for example. For example, a coating may be provided to the yarns forming the braided suture construct  300  before braiding. Polyester yarns for the braided construct of the suture body may be coated using a silicone elastomer (or a similar material as detailed above) prior to braiding. Similarly, the suture tails may be coated using the same or different coating material after braiding and before splicing. 
     The suture construct of the present invention has applicability to suture applications that may be employed in surgical procedures such as rotator cuff repair, Achilles tendon repair, patellar tendon repair, ACL/PCL reconstruction, hip and shoulder reconstruction procedures, and applications for suture used in or with suture anchors. In exemplary embodiments only, the suture construct of the present invention may be employed in suture applications that do not involve knot tying, for example, for use with suture anchors (such as PushLock™ suture anchor) or for knotless arthroscopic suture repairs (such as knotless single row rotator cuff repair, or SpeedBridge™ repair using no knots and only suture passing steps), among many others. 
     Although the present invention has been described in connection with preferred embodiments, many modifications and variations will become apparent to those skilled in the art. While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Accordingly, it is not intended that the present invention be limited to the illustrated embodiments, but only by the appended claims.