Selective uptake of materials by bone implants

Abstract

This invention provides a novel unitary bone implant having at least one rigid, mineralized bone segment, which may be machined to include threads, grooves, a driver head, perforations, a recess or a symmetric or asymmetric shape, and a flexible, demineralized segment, which may also be machined to any desired shape prior to demineralization, or after demineralization. The implant of this invention has wide orthopedic applicability, including but not limited to repair or replacement of ligaments, tendons and joints and for inducing vertebral fusions and fractured bone repair. In a particular embodiment of this invention, selective uptake of biologically active or inactive materials into the segmentally demineralized portion of the implant is disclosed.

What is claimed is:  
     
         1 . A segmentally demineralized bone implant designed for implantation in a patient, said implant comprising at least one mineralized segment, and at least one demineralized segment, wherein said demineralized segment is modified by selective uptake of a cell, or biologically active or inert molecule.  
     
     
         2 . The implant according to    claim 1    wherein said demineralized segment is modified by selective uptake of cells, blood components, growth factors, nucleic acids, proteins, peptides, antibiotics, antineoplastics, anti-inflammatory compounds, and combinations thereof.  
     
     
         3 . The implant of    claim 1   , wherein said implant is derived from cortical, corticocancellous, cancellous bone, or combinations thereof.  
     
     
         4 . The implant of    claim 2    wherein said cells are mesenchymal stem cells (MSC's).  
     
     
         5 . The implant of    claim 2    wherein said growth factors are bone morphogenetic proteins, (BMPs), fibroblast growth factors (FGFs), platelet derived growth factor (PDGF), cartilage derived morphogenetic proteins (CDMPs), tissue derived growth factors (TGFs), and combinations thereof.  
     
     
         6 . The implant according to    claim 2    wherein said biologically active compound is selected from the group consisting of nucleic acids, proteins, peptides, antibiotics, antineoplastics, anti-inflammatory compounds, and combinations thereof.  
     
     
         7 . A method of repairing damaged tissue in a patient, human or non-human, in need thereof which comprises implanting in said patient an implant comprising a segmentally demineralized bone implant designed for implantation in a patient, said implant comprising at least one mineralized segment, and at least one demineralized segment, wherein said demineralized segment is modified by selective uptake of a cell, or biologically active or inert molecule.  
     
     
         8 . A method of making a biological implant which comprises segmentally demineralizing a portion of bone, either before or after machining said bone into any desirable shape for implantation into a patient, human or animal, in need thereof, contacting said segmentally demineralized implant with a composition containing a substance the infusion of which into said demineralized portion of said bone implant is desired, and implanting the thus-treated implant into said patient in need thereof.  
     
     
         9 . An implant made by the process of    claim 8   .  
     
     
         10 . A method of treating a disease condition which comprises removal of diseased or damaged tissue and implanting in place thereof a segmentally demineralized bone implant designed for implantation in a patient, said implant comprising at least one mineralized segment, and at least one demineralized segment, wherein said demineralized segment is modified by selective uptake of a cell, or biologically active or inert molecule, or combinations thereof.  
     
     
         11 . The method according to    claim 10    wherein said biologically active molecule is an antibiotic, an antineoplastics, an anti-inflammatory, an antiviral, an antifungal, or a combination of such molecules.