Sericin extracted fabrics

Abstract

Silk is purified to eliminate immunogenic components (particularly sericin) and is used to form fabric that is used to form tissue-supporting prosthetic devices for implantation. The fabrics can carry functional groups, drugs, and other biological reagents. Applications include hernia repair, tissue wall reconstruction, and organ support, such as bladder slings. The silk fibers are arranged in parallel and, optionally, intertwined (e.g., twisted) to form a construct; sericin may be extracted at any point during the formation of the fabric, leaving a construct of silk fibroin fibers having excellent tensile strength and other mechanical properties.

1 . A fabric comprising one or more individual yarns comprised of sericin-extracted native fibroin fibers. 
     
     
         2 . The fabric of  claim 1 , wherein the fibroin fibers are biocompatible and biodegradable. 
     
     
         3 . The fabric of  claim 1 , wherein the yarn(s) are intertwined to form a 2-dimensional mesh. 
     
     
         4 . The fabric of  claim 1 , wherein the yarn(s) are intertwined by weaving, knitting or stitch bonding. 
     
     
         5 . The fabric of  claim 4 , wherein knitting is by warp-knitting. 
     
     
         6 . The fabric of  claim 1 , wherein the fabric has one or more biomechanical properties of soft tissue selected from the group consisting of ultimate tensile strength, linear stiffness, yield point, percent elongation at break, and combinations thereof. 
     
     
         7 . The fabric of  claim 1 , wherein the fabric has one or more biomechanical properties of body wall connective tissue selected from the group consisting of ultimate tensile strength, linear stiffness, yield point, percent elongation at break, and combinations thereof. 
     
     
         8 . The fabric of  claim 7 , wherein the body wall is a chest wall. 
     
     
         9 . The fabric of  claim 7 , wherein the body wall connective tissue is a ligament or tendon. 
     
     
         10 . The fabric of  claim 1 , wherein the fabric has one or more biomechanical properties of organ supporting connective tissue selected from the group consisting of ultimate tensile strength, linear stiffness, yield point, percent elongation at break, and combinations thereof. 
     
     
         11 . The fabric of  claim 10 , wherein the organ supporting connective tissue is ligament or tendon. 
     
     
         12 . The fabric of  claim 1 , wherein one or more of the yarns comprise fibroin fibers obtained from  Bombyx mori  silkworm. 
     
     
         13 . The fabric of  claim 1  that is non immunogenic. 
     
     
         14 . The fabric of  claim 1 , wherein the fibroin fibers contain less than 20% sericin by weight. 
     
     
         15 . The fabric of  claim 1 , wherein the fibroin fibers contain less than 10% sericin by weight. 
     
     
         16 . The fabric of  claim 1 , wherein the fibroin fibers contain less than 1% sericin by weight. 
     
     
         17 . The fabric of  claim 1 , wherein one or more of the yarns comprise fibroin fibers that are parallel or intertwined. 
     
     
         18 . The fabric of  claim 1 , wherein one or more of the yarns is a braid, textured yarn, twisted yarn, cabled yarn, or combinations thereof. 
     
     
         19 . The fabric of  claim 18 , wherein the sericin-extracted fibroin fibers are twisted or cabled about each other at 0 to 11.8 twists per cm. 
     
     
         20 . The fabric of  claim 1 , wherein one or more of the yarns has a single-level hierarchical organization comprising one or more groups of parallel or intertwined fibers to form the yarn(s). 
     
     
         21 . The fabric of  claim 20 , wherein the fibers are intertwined by twisting or weaving to form the group(s). 
     
     
         22 . The fabric of  claim 1 , wherein one or more of the yarns has a two-level hierarchical organization comprising one or more bundles of intertwined groups, wherein a group comprises parallel or intertwined fibers. 
     
     
         23 . The fabric of  claim 22 , wherein the groups are intertwined by twisting or weaving to form the bundle(s). 
     
     
         24 . The fabric of  claim 1 , wherein one or more of the yarns has a three-level hierarchical organization comprising one or more strands of intertwined bundles, wherein a bundle comprises intertwined groups, wherein a group comprises parallel or intertwined fibers. 
     
     
         25 . The fabric of  claim 24 , wherein the bundles are intertwined by twisting or weaving to form the strand(s). 
     
     
         26 . The fabric of  claim 1 , wherein one or more of the yarns has a four-level hierarchical organization comprising one or more cords of intertwined strands, wherein a strand comprises intertwined bundles, wherein a bundle comprises intertwined groups, wherein a group comprises parallel or intertwined fibers. 
     
     
         27 . The fabric of  claim 26 , wherein the strands are intertwined by twisting or weaving to form the cord(s). 
     
     
         28 . The fabric of  claim 1 , wherein one or more of the yarns is twisted at or below 30 twists per inch. 
     
     
         29 . The fabric of  claim 1 , wherein one or more of the yarns comprise a composite of the sericin-extracted fibroin fibers and one or more degradable polymers selected from group consisting of collagens, polylactic acid or its copolymers, polyglycolic acid or its copolymers, polyanhydrides, elastin, glycosamino glycans, and polysaccharides. 
     
     
         30 . The fabric of  claim 1 , that is coated, dobby, laminated, or combinations thereof. 
     
     
         31 . The fabric of  claim 1 , further comprising a drug. 
     
     
         32 . The fabric of  claim 1 , further comprising a cell-attachment factor. 
     
     
         33 . The fabric of  claim 32 , wherein the cell-attachment factor is RGD. 
     
     
         34 . The fabric of  claim 1 , wherein one or more of the yarns is treated with gas plasma. 
     
     
         35 . The fabric of  claim 1 , further comprising biological cells seeded therein. 
     
     
         36 . A method for generating connective tissue in an individual comprising implanting a fabric having one or more biomechanical properties of the connective tissue, into the individual at an anatomical location that provides the appropriate physiologic environment for the development of the connective tissue from the implanted fabric, wherein the fabric is comprised of one or more individual yarns comprised of sericin-extracted native fibroin fibers. 
     
     
         37 . The method of  claim 36 , wherein the yarns are intertwined to form a 2-dimensional mesh. 
     
     
         38 . The method of  claim 36 , wherein the one or more biomechanical properties is selected from the group consisting of ultimate tensile strength, linear stiffness, yield point, percent elongation at break, and combinations thereof. 
     
     
         39 . The method of  claim 36 , wherein one or more of the individual yarns has a single-level hierarchical organization comprising a group of parallel or intertwined fibers to form the yarn(s). 
     
     
         40 . The method of  claim 36 , wherein one or more of the individual yarns has a two-level hierarchical organization comprising a bundle of intertwined groups, wherein a group comprises parallel or intertwined fibers. 
     
     
         41 . The method of  claim 36 , wherein one or more of the individual yarns has a three-level hierarchical organization comprising a strand of intertwined bundles, wherein a bundle comprises intertwined groups, wherein a group comprises parallel or intertwined fibers. 
     
     
         42 . The method of  claim 36 , wherein one or more of the individual yarns has a four-level hierarchical organization comprising a cord of intertwined strands, wherein a strand comprises intertwined bundles, wherein a bundle comprises intertwined groups, wherein a group comprises parallel or intertwined fibers. 
     
     
         43 . The method of  claim 36 , wherein the fabric is implanted intramuscularly. 
     
     
         44 . The method of  claim 36 , wherein the fabric is implanted into the individual to replace or repair damaged tissue. 
     
     
         45 . The method of  claim 36 , wherein the connective tissue is ligament or tendon. 
     
     
         46 . The method of  claim 36 , wherein the fabric has one or more biomechanical properties of a body wall connective tissue and is implanted into the individual at the site of the body wall. 
     
     
         47 . The method of  claim 36 , wherein the fabric has one or more biomechanical properties of chest wall connective tissue and is implanted into the individual at the site of the chest wall. 
     
     
         48 . The method of  claim 36 , wherein the fabric has one or more biomechanical properties of organ supporting connective tissue and is implanted in the individual to position or support an organ. 
     
     
         49 . The method of  claim 46 , wherein the fabric is implanted subcutaneously or intramuscularly. 
     
     
         50 . The method of  claim 46 , wherein the fabric is implanted into the individual to replace or repair damaged tissue. 
     
     
         51 . The method of  claim 46 , wherein the fabric has one or more biomechanical properties of a ligament or tendon. 
     
     
         52 . A method for supporting a tissue in an individual, comprising implanting a the fabric of  claim 1  in contact with the tissue, to thereby support the tissue within the individual. 
     
     
         53 . The method of  claim 52 , wherein the fabric is implanted into the individual at the location of a body wall. 
     
     
         54 . The method of  claim 52 , wherein the fabric is implanted in the thorax of the individual. 
     
     
         55 . The method of  claim 52 , wherein the fabric is implanted to immobilize an organ of the individual. 
     
     
         56 . The method of  claim 52 , wherein the fabric is implanted in the individual following surgery. 
     
     
         57 . The method of  claim 52 , wherein implanting is selected from the group consisting of sewing, stapling, gluing, and laying in place without tensioning. 
     
     
         58 . A method for filling a cavity in the body of an individual, comprising implanting the fabric of  claim 1  in the cavity. 
     
     
         59 . The method of  claim 58 , wherein the fabric is implanted in the individual following surgery. 
     
     
         60 . The method of  claim 58 , wherein implanting is selected from the group consisting of sewing, stapling, gluing, and laying in place without tensioning. 
     
     
         61 . A method for strengthening an injured area of a subject following surgery comprising implanting a fabric of  claim 1  in contact with the injured area. 
     
     
         62 . The method of  claim 61 , wherein the injured area comprises an organ. 
     
     
         63 . The method of  claim 61 , wherein implanting is selected from the group consisting of sewing, stapling, gluing, and laying in place without tensioning. 
     
     
         64 . A method for generating soft-tissue in the body of an individual, comprising implanting a fabric having one or more biomechanical properties of soft tissue into the body of the individual, wherein the fabric comprises one or more individual yarns comprised of sericin-extracted native fibroin fibers. 
     
     
         65 . A fabric for repair or support of the chest, comprising one or more individual yarns comprised of biocompatible, biodegradable, sericin-extracted native fibroin fibers, wherein the yarn(s) are intertwined to form a 2-dimensional mesh.