Cancellous bone treated with collagenase and essentially free of blood cells

Abstract

A bone implant comprising cancellous bone that is essentially free of blood cells, and which has been treated with at least one loosening agent, such as collagenase or a digestive enzyme, for a time and at a concentration to loosen the osteogenic cells in the cancellous bone matrix. The osteogenic cells in the matrix are viable cells. The treatment of the cancellous bone with at least one loosening agent enables the osteogenic cells to be more available for carrying out their osteogenic function and to provide for an increased rate of bone formation. Such implant also may include demineralized bone, such as demineralized cortical bone, which enhances the bone regenerative capacity of the cancellous bone.

1 . A bone implant, comprising:
 cancellous bone, said cancellous bone being essentially free of blood cells and having been treated with at least one loosening agent for a time and at a concentration to loosen osteogenic cells in the cancellous bone matrix, said osteogenic cells in the cancellous bone matrix being viable cells.   
     
     
         2 . The implant of  claim 1  wherein said at least one loosening agent is selected from the group consisting of collagenase and digestive enzymes. 
     
     
         3 . The implant of  claim 2  wherein said at least one loosening agent is collagenase. 
     
     
         4 . The implant of  claim 3  wherein said bone is treated with said collagenase at a concentration of from about 0.1 mg/ml to about 3 mg/ml. 
     
     
         5 . The implant of  claim 4  wherein said bone is treated with said collagenase at a concentration of from about 1.0 mg/ml to about 3 mg/ml. 
     
     
         6 . The implant of  claim 3  wherein said bone is treated with said collagenase for a period of time from about 5 min. to about 3 hrs. 
     
     
         7 . The implant of  claim 6  wherein said bone is treated with said collagenase for a period of time from about 5 min. to about 30 min. 
     
     
         8 . The implant of  claim 3  wherein said bone is treated with said coliagenase at a concentration of about 1.0 mg/ml for a period of time from about 10 minutes. 
     
     
         9 . A bone implant comprising:
 (i) cancellous bone, said cancellous bone including cancellous bone which is essentially free of blood cells and having been treated with at least one loosening agent for a time and at a concentration to loosen osteogenic cells in the cancellous bone matrix, said osteogenic cells in the cancellous bone matrix being viable cells; and   (ii) cortical bone which has been treated with at least one demineralization agent for a time and at a concentration to expose osteoinductive proteins present in the cortical bone matrix.   
     
     
         10 . The implant of  claim 9  wherein said at least one demineralization agent is hydrochloric acid. 
     
     
         11 . The implant of  claim 10  wherein said cortical bone is treated with said hydrochloric acid at a concentration of from about 0.1N to about 12N. 
     
     
         12 . The implant of  claim 11  wherein said cortical bone is treated with said hydrochloric acid at a concentration of about 0.5N. 
     
     
         13 . The implant of  claim 9  wherein said cortical bone is treated with said at least one demineralization agent for a period of time of from about 1 minute to about 72 hours. 
     
     
         14 . The implant of  claim 13  wherein said cortical bone is treated with said at least one demineralization agent for a period of time of from about 50 minutes to about 70 minutes. 
     
     
         15 . The implant of  claim 9  wherein said cortical bone comprises particles having a D 90  of less than about 1,500 microns. 
     
     
         16 . The implant of  claim 15  wherein said particles have a D 90  from about 125 microns to about 1,500 microns. 
     
     
         17 . The implant of  claim 16  wherein said particles have a D 90  from about 780 microns to about 1,500 microns. 
     
     
         18 . The implant of  claim 16  wherein said particles have a D 90  from about 125 microns to about 780 microns. 
     
     
         19 . The implant of  claim 15  wherein said cortical bone comprises a first portion comprising particles having a D 90  of from about 780 microns to about 1,500 microns and a second portion comprising particles having a D 90  of from about 125 microns to about 780 microns. 
     
     
         20 . The bone implant of  claim 19  wherein said bone implant includes at least 50 vol. % of said cancellous bone, from about 5 vol. % to about 40 vol. % of said cortical bone particles having a D 90  of from about 780 microns to about 1,500 microns, and from about 5 vol. % to about 20 vol. % of said cortical bone particles having a D 90  of from about 125 microns to about 780 microns. 
     
     
         21 . The implant of  claim 20  wherein said cancellous bone is present in said implant in an amount of from about 55 vol. % to about 85 vol. %. 
     
     
         22 . The implant of  claim 21  wherein said cancellous bone is present in said implant in an amount of from about 55 vol. % to about 65 vol. %. 
     
     
         23 . The implant of  claim 20  wherein said cortical bone particles having a D 90  of from about 780 microns to about 1,500 microns are present in an amount of from about 5 vol. % to about 30 vol. %. 
     
     
         24 . The implant of  claim 23  wherein said cortical bone particles having a D 90  from about 780 microns to about 1,500 microns are present in an amount of from about 24 vol. % to about 28 vol. %. 
     
     
         25 . The implant of  claim 20  wherein said cortical bone particles having a D 90  from about 125 microns to about 780 microns are present in an amount of from about 8 vol. % to about 18 vol. %. 
     
     
         26 . The implant of  claim 25  wherein said cortical bone particles having a D 90  from about 125 microns to about 780 microns are present in an amount of about 18 vol %.