Tissue-engineered ligament

Abstract

An apparatus and method for the reconstruction of a previously torn ligament using a tissue-engineered ligament. The tissue-engineered ligament includes a scaffold of biocompatible material having at least one layer and forming a sheet. The scaffold is placed in a cultured medium for seeding with fibrocyte forming cells. The seeded scaffold is then placed in an incubator to increase the number of cells. The seeded scaffold is then formed into a slender structure suitable for implantation. The method of making a tissue-engineered ligament includes forming a scaffold of biocompatible material having at least one layer forming a sheet. Next, the scaffold sheet is seeded with fibrocyte forming cells. The method further includes increasing the number of cells on the seeded scaffold and forming a slender structure suitable for implantation from the scaffold.

1 . An apparatus for reconstruction of a previously torn ligament, said apparatus comprising: 
 a scaffold of biocompatible material, the scaffold having at least one layer forming a scaffold sheet;    means for seeding the scaffold sheet with fibrocyte forming cells to form a seeded scaffold;    means for increasing the number of the fibrocyte forming cells seeded on the scaffold to create a tissue-engineered scaffold; and    means for forming a slender structure from the tissue-engineered scaffold, the slender structure being a tissue-engineered ligament suitable for implantation into a patient for reconstruction of a ligament.    
     
     
         2 - 10 . (Canceled)  
     
     
         11 . The apparatus of  claim 45  wherein the means for attaching is an interference screw for fixation of the end of each ligament at the implantation site.  
     
     
         12 - 17 . (Canceled)  
     
     
         18 . The apparatus of  claim 1  wherein the fibrocyte forming cells are fibroblast cells.  
     
     
         19 - 23 . (Canceled)  
     
     
         24 . A method of making a tissue-engineered ligament, said method comprising: 
 forming a scaffold sheet of biocompatible material having at least one layer;    seeding the scaffold sheet with fibrocyte forming cells to form a seeded scaffold of at least one sheet;    increasing the number of the fibrocyte forming cells on the seeded scaffold to create a tissue-engineered scaffold; and    forming a slender structure from the tissue-engineered scaffold, the slender structure being a tissue-engineered ligament suitable for implantation into a patient for reconstruction of a ligament.    
     
     
         25 . The method of  claim 24  further comprising attaching each end of the tissue-engineered ligament to implantation sites within a patient.  
     
     
         26 . The method of  claim 24  wherein the scaffold is a single sheet.  
     
     
         27 . The method of  claim 24  wherein the scaffold is slit at least once, the slit is made in the direction of a first end of the scaffold to a second end of the scaffold, and the slit terminates prior to the first end and the second end.  
     
     
         28 . The method of  claim 24  wherein seeding the scaffold with fibrocyte forming cells includes placing the scaffold into a cultured medium containing the fibrocyte forming cells.  
     
     
         29 . The method of  claim 24  wherein increasing the number of fibrocyte cells includes incubating the scaffold sheet after seeding.  
     
     
         30 . The method of  claim 25  wherein increasing the number of fibrocyte cells further includes incubating the tissue-engineered ligament after forming the slender structure.  
     
     
         31 . The method of  claim 24  wherein increasing the number of fibrocyte cells includes incubating the tissue-engineered ligament after forming the slender structure.  
     
     
         32 . The method of  claim 24  wherein forming a slender structure includes rolling the scaffold sheet to form a rolled tubular structure.  
     
     
         33 . The method of  claim 24  wherein forming a slender structure includes folding the scaffold sheet to form an accordion structure.  
     
     
         34 . The method of  claim 24  wherein forming a slender structure includes cutting a series of strips from the scaffold sheet and stacking the series of strips on top of one another to form the slender structure.  
     
     
         35 . The method of  claim 25  wherein attaching each end of the ligament to implantation sites within a patient involves using an interference screw for fixation.  
     
     
         36 . The method of  claim 24  further comprising molding threads into each end of the tissue-engineered ligament for implantation.  
     
     
         37 . The method of  claim 24  further comprising providing interlocking surfaces on the scaffold sheet for locking the scaffold sheet into the tissue-engineered ligament when the method step of forming a slender structure is accomplished.  
     
     
         38 . The method of  claim 24  further comprising applying cyclic tensile loading of the seeded scaffold prior to implantation to increase the strength of the scaffold.  
     
     
         39 . The method of  claim 24  further comprising applying cyclic tensile loading of the slender structure prior to implantation to strengthen the tissue-engineered scaffold.  
     
     
         40 . The method of  claim 24  further comprising forming spaces within the slender structure to allow the fibrocyte forming cells to grow therein.  
     
     
         41 . The method of  claim 24  wherein increasing the number of fibrocyte forming cells further comprises implanting the seeded scaffold in a penultimate section of a patient's body prior to implantation in a functional location.  
     
     
         42 . The method of  claim 24  wherein increasing the number of fibrocyte forming cells further comprises implanting the slender structure in a penultimate location of a patient's body prior to implantation in a functional location.  
     
     
         43 . The method of  claim 24  further comprising coating the scaffold sheet with a material to promote adhesion of the fibrocyte forming cells.  
     
     
         44 . The method of  claim 24  further comprising genetically altering fibrocyte forming cells to increase production of fibrocyte cells.  
     
     
         45 . The apparatus of  claim 1  wherein the apparatus further comprises: 
 means for attaching each end of the tissue-engineered ligament to implantation sites within a patient.  
 
     
     
         46 . (Canceled)  
     
     
         47 . The method of  claim 24  further comprising forming microchannels in the scaffold sheet.  
     
     
         48 . A tissue engineering ligament formed by forming a scaffold sheet, seeding the scaffold sheet with cells, increasing the number of cells, and forming a slender structure suitable for use as a ligament.