Method and device for activating stem cells
Invention embodiments described herein include methods and devices for stimulating mesenchymal stem cells in a stem cell source to differentiate into osteoblasts capable of forming bone. Devices and methods described include exposing a stem cell source, such as bone marrow aspirate, adipose tissue and/or purified allogenic stem cells, to an active agent, in a manner effective to form activated stem cells.
1. A method for preparing an implant composition for promoting bone growth in a mammal, comprising:
(a) contacting stem cells with transforming growth factor beta (TGF-β), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), or a combination thereof for 5 minutes to 24 hours, wherein the TGF-β, FGF, PDGF, or combination thereof osteogenically activates the stem cells thereby forming a population of osteogenic precursor cells having an activated osteogenic potential,
(b) separating the TGF-β, FGF, PDGF, or combination thereof from the osteogenic precursor cells to form a population of osteogenic precursor cells that is substantially free of the TGF-β, FGF, PDGF, or combination thereof, and
(c) mixing the population of osteogenic precursor cells from step (b) with a bone graft substitute to thereby prepare an implant composition for promoting bone growth in a mammal.
2. The method of claim 1 , wherein the stem cells are contacted with the TGF-β, FGF, PDGF, or combination thereof for 5 minutes to 1 hour.
3. The method of claim 1 , wherein the stem cells are contacted with the TGF-β, FGF, PDGF, or combination thereof for 5 minutes to 0.5 hours.
4. The method of claim 1 , wherein the stem cells are from bone marrow, adipose tissue, muscle tissue, umbilical cord blood, embryonic yolk sac, placenta, umbilical cord, periosteum, fetal skin, adolescent skin, or blood.
5. The method of claim 1 , wherein the stem cells are autologous, allogeneic, or xenogeneic.
6. The method of claim 1 , wherein the stem cells are embryonic, post-natal, or adult stem cells.
7. The method of claim 1 , wherein the stem cells comprise mesenchymal stem cells.
8. The method of claim 1 , wherein the stem cells comprise autologous bone marrow aspirate.
9. The method of claim 1 , wherein the method is performed intraoperatively.
10. The method of claim 8 , further comprising, prior to step (a), isolating, concentrating, or isolating and concentrating the stem cells.
11. The method of claim 1 , wherein the stem cells are contacted with TGF-β.
12. The method of claim 1 , wherein the stem cells are contacted with TGF-beta3, PDGF-AB, PDGF-BB, FGF-2, TGF-beta1, FGF-8, or combinations thereof.
13. The method of claim 1 , wherein the stem cells are contacted with FGF.
14. The method of claim 1 , wherein the stem cells are contacted with PDGF.
15. The method of claim 1 , wherein the TGF-β, FGF, PDGF, or combination thereof are provided in a solution.
16. The method of claim 15 , wherein the osteogenic precursor cells are separated from the TGF-β, FGF, PDGF, or combination thereof by a procedure comprising filtration, gel filtration, tangential flow filtration, immunoprecipitation, immuno-absorption, affinity purification column, column chromatography, or a combination thereof.
17. The method of claim 1 , wherein the TGF-β, FGF, PDGF, or combination thereof are attached to a solid support.
18. The method of claim 17 , wherein at least some of the TGF-β, FGF, PDGF, or combination thereof are attached to a solid support via a peptide, an antibody, a chemical cross linker, or a combination thereof.
19. The method of claim 1 , wherein the bone graft substitute comprises a calcium salt.
20. The method of claim 19 , wherein the calcium salt comprises monocalcium phosphate monohydrate, α-tricalcium phosphate, β-tricalcium phosphate, calcium carbonate, or a combination thereof.
21. The method of claim 19 , wherein the bone graft substitute further comprises demineralized bone, a sodium phosphate salt, a polymer, or a combination thereof.
22. The method of claim 21 , wherein the polymer is collagen, gelatin, hyaluronic acid, a hyaluronate salt, hydroxypropylcellulose (HPC), carboxymethylcellulose (CMC), hydroxypropyl methylcellulose (HPMC), hydroxyethylcellulose (HEC), xantham gum, guar gum, alginate, or a combination thereof.
23. The method of claim 1 , further comprising implanting the implant composition into a patient.
24. The method of claim 1 , wherein steps (a) and (b) are performed using a device, wherein the device comprises a solid support to which the TGF-β, FGF, PDGF, or combination thereof are bound, and wherein step (a) is performed by incubating the device with the stem cells and step (b) is performed by separating the device from the osteogenic precursor cells.
25. The method of claim 24 , wherein the TGF-β, FGF, PDGF, or combination thereof are directly bound to the solid support or indirectly bound to the solid support through streptavidin, biotin, a crosslinker, an antibody, or peptide.
26. The method of claim 25 , wherein the antibody is an anti-TGF-β antibody, anti-FGF antibody, anti-PDGF antibody, or combination thereof.