Graft scaffold for cartilage repair and process for making same
The present invention relates to a method of providing a graft scaffold for cartilage repair, particularly in a human patient. The method of the invention comprising the steps of providing particles and/or fibres; providing an aqueous solution of a gelling polysaccharide; providing mammalian cells; mixing said particles and/or fibres, said aqueous solution of a gelling polysaccharide and said mammalian cells to obtain a printing mix; and depositing said printing mix in a three-dimensional form. The invention further relates to graft scaffolds and grafts obtained by the method of the invention.
1. A method of providing a graft scaffold for cartilage repair in a human patient, comprising the steps of:
providing an aqueous solution of a gelling polysaccharide selected from the group consisting of gellan gum, acylated and sulfated gellan gum;
providing at least one of:
particles selected from the group consisting of ECM, cartilage, hydroxyapatite (HA), polymer, biocompatible conductive material and calcium phosphate and/or fibres selected from the consisting of silk, elastin, and resilin; and
mammalian cells;
mixing said aqueous solution of a gelling polysaccharide, said particles and/or fibres, and/or said mammalian cells to obtain a printing mix;
depositing said printing mix in a three-dimensional form,
wherein said solution has a concentration of 3% to 3.5% of said gelling polysaccharide, and wherein said solution of a gelling polysaccharide further comprises alginate.
2. The method of claim 1 , wherein said gelling polysaccharide is acylated gellan gum.
3. The method of claim 1 , wherein said aqueous solution of a gelling polysaccharide further comprises between 10 and 150 mmol/l of divalent ions.
4. The method of claim 1 , wherein both mammalian cells and at least one of particles and fibres are provided for obtaining said printing mix.
5. The method of claim 1 , wherein said solution of a gelling polysaccharide further comprises a monosaccharide sugar or disaccharide sugar at physiologic osmolarity.
6. The method of claim 1 , wherein a growth factor and/or a mitogenic factor is provided within the printing mix.
7. The method of claim 6 , wherein the growth factor or mitogenic factor is selected from the group consisting of BMP-2, BMP-7, TGF-β1, TGF-β2, TGF-β3, FGF-2, and IGF-1.
8. The method of claim 6 , wherein the concentration of growth factors is 0.1-5 ng/ml, 5-50 ng/ml or 50-500 ng/ml.
9. The method of claim 1 , wherein said mammalian cells are cartilage cells, cartilage stem cells or cartilage precursor cells.
10. The method of claim 1 , wherein said mammalian cells are present at concentrations of 3×10 6 cells/ml-50×10 6 cells/ml.
11. The method of claim 1 , wherein said printing mix comprises 10 ng/ml TGF beta 3.
12. The method of claim 1 , wherein depositing said printing mix in a three-dimensional form is performed by deposition of lines of said printing mix, wherein each line has a width of 700 to 1100 μm and said lines overlap by 20% to 60%.
13. The method of claim 1 , wherein said depositing is performed by 3-D-printing methods.
14. The method of claim 1 , wherein said depositing is performed by additive manufacturing methods.
15. The method of claim 14 , wherein the additive manufacturing method is ink jet printing, bioprinting, extrusion printing or layer-by-layer method.
16. The method of claim 13 , wherein the three-dimensional form is generated based on a computer model of a contralateral organ of said human patient.
17. The method of claim 1 , wherein the alginate concentration is 2.5% or 3.0%.