Fluorapatite glass-ceramics
The present invention provides a highly-sintered fluorapatite glass-ceramic comprising a high Ca/Al or Sr/Al mole-ratio, that possesses a microstructure that induces apatite/bone deposition.
1. A fluorapatite glass-ceramic body prepared by a process comprising:
(a) providing powdered glass by heating a SiO 2 —Al 2 O 3 —P 2 O 5 —MgO—Na 2 O—K 2 O—CaO—CaF 2 mixture having a CaO:Al 2 O 3 mole-ratio of about 2.5-30:1;
(b) compacting the powdered glass into a solid form; and
(c) heating the solid form to about 650-1050° C. for a time sufficient to yield a sintered fluorapatite glass-ceramic body.
2. A fluorapatite glass-ceramic body prepared by a process comprising:
(a) producing powdered glass by heating a mixture of SiO 2 —Al 2 O 3 —P 2 O 5 —MgO—Na 2 O—K 2 O—CaF 2 , comprising SrO or a combination of CaO and SrO having a mole ratio of SrO to Al 2 O 3 of about 2.5-30:1;
(b) compacting the powdered glass into a solid firm; and
(c) heating the solid form to about 650° C.-1050° C. for a time sufficient to yield a sintered fluorapatite glass-ceramic body.
3. The body of claim 1 wherein SrO is absent.
4. The body of claim 2 wherein both SrO and CaO are present.
5. The body of claim 2 wherein CaO is absent and SrO is present.
6. The body of claim 1 or 2 wherein step (c) is carried out at about 700° C.-900° C.
7. The body of claim 1 or 2 wherein the degree of sintering in step (c) is about 90-99.5%.
8. The body of claim 1 wherein the CaO:Al 2 O 3 mole-ratio is about 3-25:1.
9. The body of claim 2 wherein the SrO:CaO mole ratio is about 3-1:1.
10. The body of claim 3 wherein the solid form is sintered at about 750-800° C.
11. The body of claim 10 wherein the heating is carried out for about 0.25-5.0 hrs.
12. The body of claim 1 or 2 wherein the glass comprises niobium.
13. The body of claim 1 that comprises flower-shaped fluorapatite crystals substantially as shown in FIG. 4 , Panels C or D.
14. The body of claim 1 wherein the fluorapatite glass of step (a) is prepared by melting a mixture of the composition:
Ingredient
wt-%
SiO 2
28-38
MgO
12-18
Nb 2 O 5
1-5
CaO
20-30
Na 2 O
1-3
K 2 O
5-8
Al 2 O 3
0.5-7.5
CaF 2
4-6
P 2 O 5
10-14.
15. The body of claim 14 further comprising SrO.
16. The body of claim 1 wherein the fluorapatite glass of step (a) is prepared by melting a composition of the formulas C-D:
Composition (mole-%)
C
D
SiO 2
32.3
31.5
MgO
21.8
21.2
Nb 2 O 5
0.2
0.2
CaO
19.0
23.9
Na 2 O
2.4
2.3
K 2 O
3.9
3.8
Al 2 O 3
3.9
0.9
CaF 2
11.5
11.2
P 2 O 5
5.1
5.0.
17. The body of claim 16 wherein the solid form prepared from composition C is heated at about 700° C.-900° C. or the solid form prepared from composition D is heated at about 775° C.-950° C.
18. The body of claim 2 wherein the fluorapatite glass of step (a) is prepared by melting a composition of the formulas E-G:
Composition (mole-%)
E
F
G
SiO 2
31.5
31.5
31.5
MgO
21.2
21.2
21.2
Nb 2 O 5
0.2
0.2
0.2
CaO
11.9
6.0
0.0
SrO
11.9
17.9
23.9
Na 2 O
2.3
2.3
2.3
K 2 O
3.8
3.8
3.8
Al 2 O 3
0.9
0.9
0.9
CaF 2
11.2
11.2
11.2
P 2 O 5
5.0
5.0
5.0.
100
100
100
19. The body of claim 1 or 2 further comprising stem cells cultured thereupon.
20. The body of claim 19 wherein the stem cells are hMSCs.
21. A therapeutic method comprising implanting a shaped body of claim 1 or 2 in vivo in an amount effective to stimulate bone growth in a mammal.
22. The method of claim 21 wherein the mammal is a human.
23. The glass of step (a) of claim 1 or 2 .
24. A bone filler, bone replacement material or bone graft material formed from the fluorapatite glass-ceramic body of claim 1 or 2 .
25. A glass-ceramic scaffold formed from the fluorapatite glass-ceramic body of claim 1 or 2 .