Collagen device and method of preparing the same

Abstract

A laminated, bioimplantable dural graft product is configured for use as both an onlay graft and a suturable graft. The dural graft product is sufficiently pliable so as to sufficiently conform to a curvature of a tissue surface to which it is applied, such as the curved surface of a meningeal membrane. The use of the graft product can have improved properties, including suture retention strength and fluid impermeability. To use the dural graft product as an implant to replace, reinforce or strengthen bodily tissue, or to act as an adhesion barrier, the dural graft is placed in contact with bodily tissue and conforms to the curvature of the bodily tissue. Sutures can be used to maintain the contact between the dural graft and the bodily tissue.

1 . A bioimplantable dural graft substitute comprising: 
 a collagen layer having substantially planar opposed surfaces; and    at least one reinforcement layer disposed on at least one planar surface of the collagen layer, the reinforcement layer having a suture retention strength greater than a suture retention strength of the collagen layer and being configured to substantially conform to a curvature of a tissue.    
     
     
         2 . The bioimplantable dural graft substitute of  claim 1  wherein the reinforcement layer and the collagen layer have a suture retention strength substantially in the range of about 2 pounds force to 4 pounds force.  
     
     
         3 . The bioimplantable dural graft substitute of  claim 1  wherein the collagen layer comprises a cross-linked collagen layer defining a plurality of pores, at least a portion of the plurality of pores defining a diameter of less than about 10 micrometers.  
     
     
         4 . The bioimplantable dural graft substitute of  claim 1  wherein the reinforcement layer comprises a substantially fluid impermeable material.  
     
     
         5 . The bioimplantable dural graft substitute of  claim 1  wherein the reinforcement layer is formed from a bioabsorbable polymer.  
     
     
         6 . The bioimplantable dural graft substitute of  claim 5  wherein the bioabsorbable polymer is selected from the group consisting of polylactic acid, polyglycolic acid, polycaprolactone, polydioxanone, trimethylene carbonate, copolymers or blends thereof.  
     
     
         7 . The bioimplantable dural graft substitute of  claim 1  wherein the reinforcement layer couples to at least one planar surface of the collagen layer.  
     
     
         8 . The bioimplantable dural graft substitute of  claim 7  wherein the reinforcement layer physically couples to the at least one planar surface of the collagen layer, the physical coupling selected from the group consisting of a suture, a heat press adhesion, heating in the presence of a vacuum, heating in the absence of a vacuum, exposure to a heating element, exposure to heated air, or a spot weld adhesion.  
     
     
         9 . The bioimplantable dural graft substitute of  claim 1  wherein the at least one reinforcement layer comprises a first reinforcement layer and a second reinforcement layer, each of the first reinforcement layer and the second reinforcement layer disposed on one of the opposite planar surfaces of the collagen layer.  
     
     
         10 . The bioimplantable dural graft substitute of  claim 1  wherein the collagen layer comprises a first collagen layer and a second collagen layer, the at least one reinforcement layer disposed between the first collagen layer and the second collagen layer.  
     
     
         11 . The bioimplantable dural graft substitute of  claim 1  wherein the collagen layer comprises a thickness in the range of about 0.02 inches to 0.20 inches.  
     
     
         12 . The bioimplantable dural graft substitute of  claim 1  wherein the at least one reinforcement layer comprises a thickness in the range of about 0.001 inches to 0.016 inches.  
     
     
         13 . The bioimplantable dural graft substitute of  claim 1  wherein the at least one reinforcement layer comprises a biological agent selected from the group consisting of an antibiotic, a growth factor, a hemostasis factor, an anti-adhesion agent, or an anti-cancer agent.  
     
     
         14 . A dural graft material comprising: 
 at least one collagen layer defining a plurality of pores, wherein a majority of the plurality of pores defining a diameter of less than about 10 micrometers; and    at least one reinforcement layer joined to the collagen layer, the reinforcement layer being substantially fluid impermeable.    
     
     
         15 . The dural graft material of  claim 14  wherein the at least one reinforcement layer comprises a suture retention strength greater than a suture retention strength of the collagen layer.  
     
     
         16 . The dural graft material of  claim 15  wherein the reinforcement layer and the collagen layer have a suture retention strength substantially in the range of about 2 pounds force to 4 pounds force.  
     
     
         17 . The dural graft material of  claim 14  wherein the at least one reinforcement layer is configured to substantially conform to a curvature of a tissue.  
     
     
         18 . The dural graft material of  claim 14  wherein the reinforcement layer is formed from a bioabsorbable polymer.  
     
     
         19 . The dural graft material of  claim 18  wherein the bioabsorbable polymer is selected from the group consisting of polylactic acid, polyglycolic acid, polycaprolactone, polydioxanone, trimethylene carbonate, copolymers or blends thereof.  
     
     
         20 . The dural graft material of  claim 14  wherein the reinforcement layer physically couples to the at least one planar surface of the collagen layer, the physical coupling selected from the group consisting of a suture, a heat press adhesion, heating in the presence of a vacuum, heating in the absence of a vacuum, exposure to a heating element, exposure to heated air, or a spot weld adhesion.  
     
     
         21 . The dural graft material of  claim 14  wherein the at least one reinforcement layer comprises a first reinforcement layer and a second reinforcement layer, each of the first reinforcement layer and the second reinforcement layer joined on one of the opposite planar surfaces of the collagen layer.  
     
     
         22 . The dural graft material of  claim 14  wherein the collagen layer comprises a first collagen layer and a second collagen layer, the reinforcement layer joined between the first collagen layer and the second collagen layer.  
     
     
         23 . The dural graft material of  claim 14  wherein the collagen layer comprises a thickness in the range of about 0.02 inches to 0.20 inches and the at least one reinforcement layer comprises a thickness in the range of about 0.001 inches to 0.016 inches.  
     
     
         24 . The dural graft material of  claim 14  wherein the at least one reinforcement layer comprises a biological agent selected from the group consisting of an antibiotic, a growth factor, a hemostasis factor, an anti-adhesion agent, or an anti-cancer agent.  
     
     
         25 . A method for repairing a damaged dura comprising: 
 implanting at a site of dura damage a dural graft comprising a collagen layer having substantially planar opposed surfaces and a reinforcement layer joined to one of the opposed planar surfaces, the reinforcement layer being substantially fluid impermeable.    
     
     
         26 . The method of  claim 25  comprising securing the dural graft to the site of dura damage with a suture.  
     
     
         27 . The method of  claim 26  comprising wherein securing comprises securing the dural graft to the site of dura damage with the suture, the dural graft having a suture retention strength in the range of about 2 pounds force to 4 pounds force.  
     
     
         28 . The method of  claim 26  comprising inserting the suture through the collagen layer and the reinforcement layer to join the collagen layer and the reinforcement layer.  
     
     
         29 . The method of  claim 25  comprising substantially conforming the dural graft to a curvature of the site of dura damage.