Demineralized bone fibers and preparation thereof
The present invention provides demineralized bone fibers exhibiting optimal handling properties (e.g., high moldability and low elastic modulus) and biological activities (e.g., osteoinductivity) as well as non-demineralized bone fibers useful for preparing the demineralized bone fibers. A well-controlled demineralization process for preparing the demineralized bone of fibers is also provided. Products comprising the demineralized bone fibers and uses thereof are further provided.
1. A method for preparing a demineralized bone graft, wherein the demineralized bone graft has a residual calcium content of less than 6 wt % based on the dry weight of the demineralized bone graft, comprising subjecting a non-demineralized bone graft to a single incubation in an acid solution for no more than 300 seconds, wherein the acid solution has a pH of 0-4.
2. The method of claim 1 , wherein the non-demineralized bone graft comprises bone fibers, bone particles, bone sheets, bone cubes, bone shafts, or a combination thereof.
3. The method of claim 1 , wherein the non-demineralized bone graft comprises non-demineralized bone fibers, and wherein the demineralized bone graft comprises demineralized bone fibers.
4. The method of claim 3 , wherein the demineralized bone fibers are osteoinductive.
5. The method of claim 3 , wherein the non-demineralized bone fibers have an average shortest dimension of less than 200 μm.
6. The method of claim 3 , wherein the demineralized bone fibers have an elastic modulus of less than 100 kPa.
7. The method of claim 3 , further comprising adding an effective amount of a buffer to the acid solution after the single incubation.
8. The method of claim 3 , further comprising storing the demineralized bone fibers at room temperature.
9. The method of claim 3 , further comprising drying the demineralized bone fibers.
10. The method of claim 3 , further comprising releasing at least 75 wt % of calcium in the non-demineralized bone fibers.
11. The method of claim 3 , further comprising retaining at least 1 ng of a bone morphogenetic protein (BMP) per gram of the non-demineralized bone fibers, based on the dry weight of the non-demineralized bone fibers, wherein the BMP is selected from the group consisting of BMP-2, BMP-3, BMP-4, BMP-5, BMP-6, BMP-7, BMP-8, BMP-9, BMP-10, BMP-11, BMP-12, BMP-13, BMP-14, BMP-15 and a mixture thereof.
12. The method of claim 3 , wherein the non-demineralized bone fibers are generated by a Computer Numerical Control (CNC) machine using a chip load of 0.004″-0.011″.
13. A composition comprising the demineralized bone fibers produced by the method of claim 3 .
14. A composition comprising demineralized bone fibers having a residual calcium content of between 0.5-6 wt % based on the dry weight of the demineralized bone fibers, wherein the demineralized bone fibers are osteoinductive, wherein the demineralized bone fibers have a specific area 185-5,550 cm 2 /g, and wherein the demineralized bone fibers are combined with and stored in glycerol.
15. The composition of claim 14 , wherein the demineralized bone fibers have an average shortest dimension of less than 200 μm.
16. The composition of claim 14 , wherein the demineralized bone fibers have a specific surface area of at least 200 cm 2 /g.
17. The composition of claim 14 , wherein the demineralized bone fibers have an elastic modulus of less than 100 kPa.
18. An implant comprising the composition of claim 14 .
19. The implant of claim 18 , further comprising a synthetic material.
20. The implant of claim 18 , further comprising a bone particle or particulate.
21. A method for treating a tissue or organ defect in a subject, comprising applying to a site of the defect an effective amount of the composition of claim 14 .
22. A method for preparing a demineralized bone graft, wherein the demineralized bone graft has a residual calcium content of less than 6 wt % based on the dry weight of the demineralized bone graft, comprising subjecting a non-demineralized bone graft to a single incubation in an acid solution for no more than 300 seconds, wherein the acid solution has a pH of 0-4 and the demineralized bone graft is combined with and stored in glycerol.
23. The method of claim 22 , wherein the non-demineralized bone graft comprises bone fibers, bone particles, bone sheets, bone cubes, bone shafts, or a combination thereof.
24. The method of claim 22 , wherein the non-demineralized bone graft comprises non-demineralized bone fibers, and wherein the demineralized bone graft comprises demineralized bone fibers.
25. The method of claim 24 , wherein the demineralized bone fibers are osteoinductive.
26. The method of claim 24 , wherein the non-demineralized bone fibers have an average shortest dimension of less than 200 μm.
27. The method of claim 24 , wherein the demineralized bone fibers have an elastic modulus of less than 100 kPa.
28. The method of claim 24 , further comprising adding an effective amount of a buffer to the acid solution after the single incubation.
29. The method of claim 28 , wherein the pH of the resulting solution is adjusted to 2.5-7 within 90 seconds after the addition of the buffer.
30. The method of claim 24 , further comprising storing the demineralized bone fibers at room temperature.
31. The method of claim 24 , further comprising drying the demineralized bone fibers.
32. The method of claim 24 , further comprising releasing at least 75 wt % of calcium in the non-demineralized bone fibers.
33. The method of claim 24 , further comprising retaining at least 1 ng of a bone morphogenetic protein (BMP) per gram of the non-demineralized bone fibers, based on the dry weight of the non-demineralized bone fibers, wherein the BMP is selected from the group consisting of BMP-2, BMP-3, BMP-4, BMP-5, BMP-6, BMP-7, BMP-8, BMP-9, BMP-10, BMP-11, BMP-12, BMP-13, BMP-14, BMP-15 and a mixture thereof.
34. The method of claim 24 , wherein the non-demineralized bone fibers are generated by a Computer Numerical Control (CNC) machine using a chip load of 0.004″-0.011″.
35. A composition comprising the demineralized bone fibers produced by the method of claim 24 .