Degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold

Abstract

A method for preparing a degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold by subjecting a calcined bovine cancellous bone mineral porous scaffold to a treatment using a ternary system containing a magnesium source, a sulfur source and a phosphorus source, taking out and drying, and subjecting to a high-temperature calcination. The degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold has good three-dimensional interconnected mesh structure, osteoconductivity, degradability, good mechanical strength and biocompatibility, simultaneously. At the same time, calcium sulfate whiskers with larger length-diameter ratio grow in the mesh, thereby increasing the specific surface area of the material and possibly improve the adhesion of cells. The composite biological scaffold may have potential osteoinductivity due to the effective addition of the osteogenic active ionized magnesium and the calcium sulfate which can produce a local high-calcium environment when degraded.

Claims

1. A method for preparing a degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold, comprising the following steps: (a) subjecting a calcined bovine cancellous bone mineral porous scaffold to a treatment using a magnesium source, a sulfur source and a phosphorus source; wherein the step (a) of subjecting the calcined bovine cancellous bone mineral porous scaffold to the treatment using the magnesium source, the sulfur source and the phosphorus source comprises the following step (a-1) or (a-2): (a-1) impregnating the calcined bovine cancellous bone mineral porous scaffold in a magnesium source solution to obtain a magnesium scaffold solution, then taking out a magnesium treated scaffold from the magnesium scaffold solution, and drying the magnesium treated scaffold, and subsequently putting the magnesium treated scaffold into a sulfur source and phosphorus source composite solution to obtain a composite scaffold solution, and performing a hydrothermal reaction on the composite scaffold solution to obtain a treated scaffold solution, or (a-2) subjecting the calcined bovine cancellous bone mineral porous scaffold to a hydrothermal reaction while impregnating the calcined bovine cancellous bone mineral porous scaffold in a magnesium source, sulfur source, and phosphorus source composite solution to obtain a treated scaffold solution; (b) taking out a treated scaffold from the treated scaffold solution and drying the treated scaffold; and (c) subjecting the treated scaffold to a high-temperature calcination to obtain the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold, wherein, in the steps (a-1) and (a-2), the magnesium source comprises at least one magnesium compound selected from the group consisting of magnesium sulfate and magnesium hydrogen phosphate; in the steps (a-1) and (a-2), the sulfur source comprises sulfuric acid and soluble sulfate, and the soluble sulfate comprises at least one sulfate compound selected from the group consisting of sodium sulfate and magnesium sulfate; and in the steps (a-1) and (a-2), the phosphorus source comprises phosphoric acid and soluble phosphate, and the soluble phosphate comprises at least one phosphate compound selected from the group consisting of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, magnesium hydrogen phosphate, a combination of magnesium hydrogen phosphate with diammonium hydrogen phosphate, and a combination of magnesium hydrogen phosphate with ammonium dihydrogen phosphate.

2. The method according to claim 1, wherein the hydrothermal reaction is carried out by a constant temperature hydrothermal method, the temperature is controlled at 70-90 C., and the reaction time is controlled for 8-36 h.

3. The method according to claim 1, wherein, the step (a) is the step (a-1) and in the step (a-1), a solid-liquid ratio of the calcined bovine cancellous bone mineral porous scaffold to the magnesium source solution is 10 g: 50-200 mL, and a solid-liquid ratio of the calcined bovine cancellous bone mineral porous scaffold to the sulfur source and phosphorus source composite solution is 10 g: 50-200 mL.

4. The method according to claim 1, wherein, the step (a) is the step (a-2) and in the step (a-2), a solid-liquid ratio of the calcined bovine cancellous bone mineral porous scaffold to the magnesium source, sulfur source, and phosphorus source composite solution is 10 g: 50-100 mL.

5. The method according to claim 1, wherein the high-temperature calcination is performed at a temperature of 750-900 C. and for a calcining time of 2-9 h.

6. The method according to claim 1, wherein a final concentration of magnesium ions in the magnesium source, the sulfur source and the phosphorus source is 0.05-0.2 mol/L.

7. The method according to claim 1, wherein in the magnesium source, the sulfur source and the phosphorus source, a final concentration of the sulfuric acid is 0.05-0.1 mol/L, and a final concentration of sulfate radicals provided by the soluble sulfate is 0.04-0.6 mol/L.

8. The method according to claim 1, wherein in the magnesium source, the sulfur source and the phosphorus source, a final concentration of the phosphoric acid is 0.85-1.7 wt %, and a final concentration of phosphorus provided by the soluble phosphate is 0.08-0.9 mol/L.

9. The method according to claim 1, wherein the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold comprises a material composition selected from the group consisting of a combination of calcium sulfate and magnesium-containing calcium phosphate, a combination of calcium sulfate, magnesium-containing calcium phosphate and hydroxyapatite, a combination of calcium sulfate, magnesium-containing calcium phosphate, hydroxyapatite and calcium pyrophosphate, a combination of calcium sulfate, magnesium-containing calcium phosphate and calcium pyrophosphate, a combination of calcium sulfate and poly (magnesium-containing calcium hydrogen phosphate), and a combination of calcium sulfate, poly (magnesium-containing calcium hydrogen phosphate) and hydroxyapatite.

10. The method according to claim 1, wherein the calcined bovine cancellous bone mineral porous scaffold has a porosity of 70%-85% and an aperture of 400-1200 m.

11. The method according to claim 1, wherein when the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold is used, the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold is degraded in a gradient fashion; and the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold retains a three-dimensional interconnected mesh structure and a mechanical strength of the calcined bovine cancellous bone mineral porous scaffold, and at the same time, whiskers with a larger length-diameter ratio grow in a mesh, and a length-diameter ratio of the whiskers is 8-25:1, thereby effectively increasing the specific surface area of the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold.

12. The method according to claim 1, wherein the calcined bovine cancellous bone mineral porous scaffold is made by a process comprising: (1) the bovine cancellous bone is cut into bone strips or bone blocks with a thickness of 0.5-1 cm to obtain raw bones; (2) the raw bones are placed in distilled water and cooked in a pressure cooker for 40-60 min, then washed with 40-60 C. drinking water, this step is repeated 4-6 times, then processed raw bones are obtained; and (3) the processed raw bones obtained in the step (2) is dried in a constant temperature drying oven at 80-120 C. for 12-24 h, then placed in a calciner to be calcined at 900-1200 C. for 8-12 h, and cooled to obtain the calcined bovine cancellous bone mineral porous scaffold.

13. A degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold, wherein the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold is obtained by the method according to claim 1.

14. The degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold according to claim 13, wherein the calcined bovine cancellous bone mineral porous scaffold has a porosity of 70%-85% and an aperture of 400-1200 m.

15. The degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold according to claim 13, comprising a material composition selected from the group consisting of a combination of calcium sulfate and magnesium-containing calcium phosphate, a combination of calcium sulfate, magnesium-containing calcium phosphate and hydroxyapatite, a combination of calcium sulfate, magnesium-containing calcium phosphate, hydroxyapatite and calcium pyrophosphate, a combination of calcium sulfate, magnesium-containing calcium phosphate and calcium pyrophosphate, a combination of calcium sulfate and poly (magnesium-containing calcium hydrogen phosphate), and a combination of calcium sulfate, poly (magnesium-containing calcium hydrogen phosphate) and hydroxyapatite.

16. The degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold according to claim 13, wherein when the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold is used, the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold is degraded in a gradient fashion; and the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold retains a three-dimensional interconnected mesh structure and a mechanical strength of the calcined bovine cancellous bone mineral porous scaffold, and at the same time, whiskers with a larger length-diameter ratio grow in a mesh, and a length-diameter ratio of the whiskers is 8-25:1, thereby effectively increasing the specific surface area of the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffold.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a scanning electron micrograph of a product of the present invention.

(2) FIG. 2 is a diagram showing a calcium value of a product of the present invention in an early stage of a dissolution and degradation test in simulated body fluid (n=3, the reference value of human serum calcium ion is 2-2.67 mmol/L).

(3) FIG. 3 is a scanning electron micrograph of a material of a product of the present invention after subjected to a dissolution and degradation test in simulated body fluid.

(4) FIG. 4 is a histological diagram of a product of the present invention in an early stage of a transplant experiment.

(5) FIG. 5 is a histological diagram representation of a product of the present invention in an early stage of another transplant experiment.

(6) FIG. 6 is a histological diagram of a product of the present invention in a later stage of a transplant experiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(7) The technical solutions of the present invention will be further specifically described below with reference to specific embodiments.

(8) In the present invention, the raw materials and equipment used, etc., are commercially available or commonly used in the art unless otherwise specified. The methods in the following embodiments, unless otherwise stated, are all conventional methods in the art.

Example 1 Preparation of Calcined Bovine Cancellous Bone Mineral Porous Scaffold

(9) (1) The bovine cancellous bone (cancellous bone from bovine femoral condyle) is cut into bone strips with a thickness of 0.5 cm to obtain raw bones;

(10) (2) the raw bones are placed in distilled water and cooked in a pressure cooker for 40 min, then washed with 40 C. water, this step is repeated 6 times; and

(11) (3) the processed raw bones obtained in the step (2) are dried in a constant temperature drying oven at 80 C. for 24 h, then placed in a calciner to be calcined at 900 C. (a heating rate is 10 C./min) for 12 h, and cooled with the calciner to obtain the calcined bovine cancellous bone mineral porous scaffold.

Example 2 Preparation of Calcined Bovine Cancellous Bone Mineral Porous Scaffold

(12) (1) The bovine cancellous bone (cancellous bone from bovine femoral condyle) is cut into bone blocks with a thickness of 1 cm to obtain raw bones;

(13) (2) the raw bones are placed in distilled water and cooked in a pressure cooker for 60 min, then washed with water at 60 C., this step is repeated 4 times; and

(14) (3) the processed raw bones obtained in the step (2) are dried in a constant temperature drying oven at 120 C. for 12 h, then placed in a calciner to be calcined at 1200 C. (a heating rate is 10 C./min) for 8 h, and cooled with the calciner to obtain the calcined bovine cancellous bone mineral porous scaffold.

Example 3 Preparation of Calcined Bovine Cancellous Bone Mineral Porous Scaffold

(15) (1) The bovine cancellous bone (cancellous bone from bovine femoral condyle) is cut into bone strips with a thickness of 0.8 cm to obtain raw bones;

(16) (2) the raw bones are placed in distilled water and cooked in a pressure cooker for 50 min, then washed with 50 C. water, this step is repeated 5 times; and

(17) (3) the processed raw bones obtained in the step (2) are dried in a constant temperature drying oven at 100 C. for 18 h, then placed in a calciner to be calcined at 1000 C. (a heating rate is 10 C. imin) for 10 h, and cooled with the calciner to obtain the calcined bovine cancellous bone mineral porous scaffold.

(18) General Implementation Solution 1:

(19) A: The magnesium source, sulfur source, and phosphorus source composite solution is prepared: the phosphorus source is phosphoric acid and soluble phosphate, and the soluble phosphate is magnesium hydrogen phosphate, a combination of magnesium hydrogen phosphate and ammonium dihydrogen phosphate, a combination of magnesium hydrogen phosphate and diammonium hydrogen phosphate; the sulfur source is sulfuric acid and soluble sulfate, and the soluble sulfate is sodium sulfate; and the magnesium source is magnesium hydrogen phosphate.

(20) In the composite solution: a final concentration of phosphoric acid is 0.85-1.7 wt %, a final concentration of phosphorus provided by the phosphate (soluble phosphate and magnesium source) is 0.1-0.9 mol/L, a concentration of sulfuric acid is 0.05-0.1 mol/L, and the soluble sulfate is sodium sulfate, a final concentration of sulfate radicals provided by the sulfate is 0.08-0.6 mol/L; a final concentration of magnesium ion is 0.05-0.2 mol/L.

(21) According to the solid-liquid ratio of the calcined bovine cancellous bone mineral porous scaffolds to the magnesium source, sulfur source, and phosphorus source composite solution of 10 g: 50-100 mL, the calcined bovine cancellous bone mineral porous scaffolds are weighed, and then put into the magnesium source, sulfur source, and phosphorus source composite solution to be subjected to impregnation and hydrothermal reaction. The hydrothermal reaction is a constant temperature hydrothermal reaction, the reaction temperature is controlled at 70-90 C., and the reaction time is controlled for 8-36 h.

(22) B: The porous scaffolds are taken out, and placed in a constant temperature drying oven and dried at 80-90 C. for 20-48 h.

(23) C: The processed calcined bovine cancellous bone mineral porous scaffolds obtained in the step B are placed in a calciner to be calcined at 750-900 C. (a heating rate is 2.5 C. imin) for 2-8 h, and cooled with the calciner to obtain the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffolds.

(24) General Implementation Solution 2:

(25) A: The magnesium source, sulfur source, and phosphorus source composite solution is prepared: the phosphorus source is phosphoric acid and soluble phosphate, and the soluble phosphate is magnesium hydrogen phosphate, or diammonium hydrogen phosphate; the sulfur source is sulfuric acid and soluble sulfate, and the soluble sulfate is magnesium sulfate, or a combination of magnesium sulfate and sodium sulfate; the magnesium source is magnesium sulfate, or a combination of magnesium sulfate and magnesium hydrogen phosphate.

(26) In the composite solution: a final concentration of phosphoric acid is 0.85-1.7 wt %, a final concentration of phosphorus provided by the phosphate is 0.1-0.8 mol/L, a concentration of sulfuric acid is 0.05-0.1 mol/L, and the soluble sulfate is magnesium sulfate, or a combination of magnesium sulfate and sodium sulfate, a final concentration of sulfate radicals provided by the sulfate is 0.08-0.6 mol/L; a final concentration of magnesium ions is 0.05-0.15 mol/L.

(27) B: The magnesium sulfate is first weighed for preparing a magnesium sulfate solution, and the solid-liquid ratio of the calcined bovine cancellous bone mineral porous scaffolds to the magnesium sulfate solution is 10 g: 50-200 mL; subsequently, the calcined bovine cancellous bone mineral porous scaffolds are impregnated into the magnesium sulfate solution for 15-30 min; and then a microwave drying is performed, the microwave output power is 300-500 W, and the drying time is 15-24 min.

(28) C: A sulfur source and phosphorus source composite solution is prepared according to the solid-liquid ratio of the calcined bovine cancellous bone mineral porous scaffolds to the sulfur source and phosphorus source composite solution of 10 g: 50-200 mL; and the processed calcined bovine cancellous bone mineral porous scaffolds obtained in the step B are subjected to impregnation and hydrothermal reaction. The hydrothermal reaction is a constant temperature hydrothermal reaction, the reaction temperature is controlled at 70-90 C., and the reaction time is controlled for 12-36 h.

(29) D: The porous scaffolds are taken out, and placed in a constant temperature drying oven and dried at 80-90 C. for 20-48 h.

(30) E: The processed calcined bovine cancellous bone mineral porous scaffolds obtained in the step D are placed in a calciner to be calcined at 750-900 C. (a heating rate is 2.5 C./min) for 2-9 h, and cooled with the calciner to obtain the degradable magnesium-containing calcium phosphate-calcium sulfate porous composite biological scaffolds.

(31) Each sample is observed in general and subjected to X-ray diffraction (XRD) analysis. Some samples are selected and subjected to microstructure observation under a scanning electron microscopy (SEM), dissolution and degradation tests in simulated body fluid, and animal experiments about bone defect repair. The shape and strength of the materials are observed generally; and some samples are tested for compressive strength using an INSTRON-5566 universal testing machine. Medical sodium chloride injection is used as the simulated body fluid in the dissolution and degradation test in simulated body fluid. The solid-liquid ratio (mass to volume ratio) of the test material to the simulated body fluid is 1 g: 100 ml. The test material and the simulated body fluid are placed in a beaker having a cover, and the dissolution and degradation test in the simulated body fluid is performed under constant temperature condition of 37 C. The dissolution and degradation test duration is 30 days. Calcium ion, phosphorus ion and magnesium ion in the simulated body fluid are detected by AU5800 automatic biochemical analyzer every 4 days. In the first 15 days of the dissolution and degradation, 40% of the simulated body fluid is replaced every 3 days, and the simulated body fluid is not replaced in the later period. After 30 days of the dissolution and degradation test, the mass of the sample is measured by a domestic electronic balance and the degradation rate is calculated. XRD analysis and SEM observation of the materials are performed before and at the end of the dissolution and degradation test. In the animal bone defect repair test, forty-eight of healthy New Zealand white rabbits were selected, and bone defects having diameters of 8 mm were made in the femoral condyles of the rabbits. The rabbits were randomly divided into experimental group (porous composite biomaterials) and control group (imported synthetic calcium-phosphorus materials). The same artificial bone defect was made to the rabbits in the experimental group and the control group, respectively. Then, the rabbits in the experimental group were treated with porous composite biomaterials for repairing the bone defect; and the rabbits in the control group were treated with imported synthetic calcium-phosphorus bone substitute materials for repairing the bone defect. The experimental animals were sacrificed 1, 2, 4 and 8 weeks after the surgery for histological examination of bone defect repair.

Embodiment 1

(32) 10 ml of 1 mol/L sulfuric acid, 4.26 g sodium sulfate, 1.74 g magnesium hydrogen phosphate, and 2 ml of 85 wt % phosphoric acid stock solution are taken, and added into deionized water to prepare 100 ml of composite solution containing 0.1 mol/L sulfuric acid, 0.3 mol/L sodium sulfate, 0.1 mol/L magnesium hydrogen phosphate and 1.7 wt % phosphoric acid; and the pH of the composite solution is about 2.5. 10 g of calcined bovine cancellous bone mineral porous scaffold is impregnated in the composite solution and subjected to impregnation and hydrothermal reaction for 20 h at a constant temperature of 70 C., and is covered by an inversely beaker. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 80 C. for 24 h, then calcined in a calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C. imin and maintained at 750 C. for 6 h, and cooled with the calciner to room temperature to obtain 511035E.

(33) 511035E

(34) TABLE-US-00001 CaSO.sub.4 33.33% Ca.sub.2.89Mg.sub.0.11(PO.sub.4).sub.2 33.16% Ca.sub.9.74(PO.sub.4).sub.6(OH).sub.2.08 33.51%.

Embodiment 2

(35) 511036

(36) 10 ml of 1 mol/L sulfuric acid, 4.26 g sodium sulfate, 3.46 g magnesium hydrogen phosphate, and 2 ml of 85 wt % phosphoric acid are taken, and added into deionized water to prepare 100 ml of composite solution containing 0.1 mol/L sulfuric acid, 0.3 mol/L sodium sulfate, 0.2 mol/L magnesium hydrogen phosphate and 1.7 wt % phosphoric acid, a pH of the composite solution is about 3.0. 10 g of calcined bovine cancellous bone mineral porous scaffold is impregnated in the composite solution and subjected to impregnation and hydrothermal reaction for 20 h at a constant temperature of 70 C., and is covered by an inversely beaker. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 80 C. for 24 h, then calcined in a calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 6 h, and cooled with the calciner to room temperature to obtain 511036E.

(37) 511036E

(38) TABLE-US-00002 CaSO.sub.4 26.23% Ca.sub.18Mg.sub.2H.sub.2(PO.sub.4).sub.14 59.97% Ca.sub.5(PO.sub.4)OH 13.80%.

Embodiment 3

(39) 511135

(40) 5 ml of 1 mol/L sulfuric acid, 1.12 g sodium sulfate, 1.70 g magnesium hydrogen phosphate, and 1 ml of 85 wt %/o phosphoric acid are taken, and added into deionized water to prepare 100 ml of composite solution containing 0.05 mol/L sulfuric acid, 0.08 mol/L sodium sulfate, 0.1 mol/L magnesium hydrogen phosphate and 0.85 wt % phosphoric acid, a pH of the composite solution is about 3-3.5. 10 g of calcined bovine cancellous bone mineral porous scaffold is impregnated in the composite solution and subjected to impregnation and hydrothermal reaction for 8 h at a constant temperature of 90 C., and is covered by an inversely beaker. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 80 C. for 24 h, a weight of the calcined bovine cancellous bone mineral porous scaffold after drying is 11.93 g, then calcined in a calciner where the temperature is raised to 900 C. at a heating rate of 2.5 C./min and maintained at 900 C. for 8 h, and cooled with the calciner to room temperature to obtain 511135M.

(41) 511135M

(42) TABLE-US-00003 CaSO.sub.4 20.01% Ca.sub.2.71Mg.sub.0.29H.sub.2(PO.sub.4).sub.2 45.57% Ca.sub.2.89Mg.sub.0.11(PO.sub.4).sub.2 34.42%.

Embodiment 4

(43) 601052

(44) 2.5 ml of 1 mol/L sulfuric acid, 4.26 g sodium sulfate, 1 ml of 85 wt % phosphoric acid, 5.28 g diammonium hydrogen phosphate, and 0.86 g magnesium hydrogen phosphate are taken, and added into deionized water to prepare 50 ml of composite solution containing 0.05 mol/L sulfuric acid, 0.3 mol/L sodium sulfate, 0.85 wt % phosphoric acid, 0.8 mol/L diammonium hydrogen phosphate and 0.1 mol/L magnesium hydrogen phosphate. 10 g of calcined bovine cancellous bone mineral porous scaffold is impregnated in the composite solution and subjected to impregnation and hydrothermal reaction for 24 h at a constant temperature of 90 C., and is covered by an inversely beaker. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 100 C. for 24 h, then calcined in a calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 2 h, and cooled with the calciner to room temperature to obtain 601052A; and the calcined bovine cancellous bone mineral porous scaffold after being subjected to drying is calcined in the calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 5 h, and cooled with the calciner to room temperature to obtain 601052E.

(45) 601052A

(46) TABLE-US-00004 CaSO.sub.4 20.46% (Ca.sub.2.589Mg.sub.0.411)(PO.sub.4).sub.2 19.17% Ca.sub.2(P.sub.2O.sub.7) 37.88% Ca.sub.10.042(PO.sub.4).sub.5.952(OH).sub.2.292 22.50%.
601052E

(47) TABLE-US-00005 CaSO.sub.4 29.36% (Ca.sub.2.589Mg.sub.0.411)(PO.sub.4).sub.2 19.64% Ca.sub.2(P.sub.2O.sub.7) 28.05% Ca.sub.10.042(PO.sub.4).sub.5.952(OH).sub.2.292 22.94%.

Embodiment 5

(48) 601053

(49) 5 ml of 1 mol/L sulfuric acid, 2.84 g sodium sulfate, 1 ml of 85 wt % phosphoric acid solution, 2.64 g diammonium hydrogen phosphate, and 1.72 g magnesium hydrogen phosphate are taken, and added into deionized water to prepare 50 ml of composite solution containing 0.1 mol/L sulfuric acid, 0.2 mol/L sodium sulfate, 0.85 wt % phosphoric acid, 0.4 mol/L diammonium hydrogen phosphate and 0.2 mol/L magnesium hydrogen phosphate. 6 g of calcined bovine cancellous bone mineral porous scaffold is impregnated in the composite solution and subjected to impregnation and hydrothermal reaction for 36 h at a constant temperature of 90 C. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 100 C. for 24 h, then calcined in a calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C. imin and maintained at 750 C. for 2 h, and cooled with the calciner to room temperature to obtain 601053A; and the calcined bovine cancellous bone mineral porous scaffold after being subjected to drying is calcined in the calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 5 h, and cooled with the calciner to room temperature to obtain 601053E.

(50) 601053A

(51) TABLE-US-00006 CaSO.sub.4 18.25% (Ca.sub.2.589Mg.sub.0.411)(PO.sub.4).sub.2 13.45% Ca.sub.2(P.sub.2O.sub.7) 19.38% Ca.sub.10.042(PO.sub.4).sub.5.952(OH).sub.2.292 48.92%.

(52) TABLE-US-00007 CaSO.sub.4 21.03% (Ca.sub.2.589Mg.sub.0.411)(PO.sub.4).sub.2 28.22% Ca.sub.2(P.sub.2O.sub.7) 27.63% Ca.sub.10.042(PO.sub.4).sub.5.952(OH).sub.2.292 24.15%.

Embodiment 6

(53) 511033

(54) 10 ml of 1 mol/L sulfuric acid, 4.26 g sodium sulfate, 0.86 g magnesium hydrogen phosphate, 5.78 g ammonium dihydrogen phosphate, and 2 ml of 85 wt % phosphoric acid are taken, and added into deionized water to prepare 100 ml of composite solution containing 0.1 mol/L sulfuric acid, 0.3 mol/L sodium sulfate, 0.05 mol/L magnesium hydrogen phosphate, 1.7 wt % phosphoric acid and 0.5 mol/L ammonium dihydrogen phosphate. 10 g of calcined bovine cancellous bone mineral porous scaffold is impregnated in the composite solution and subjected to impregnation and hydrothermal reaction for 20 h at a constant temperature of 70 C., and is covered by an inversely beaker. Then, the calcined bovine cancellous bone mineral porous scaffold with a pH of about 2.5 is taken out, and dried at 80 C. for 24 h, then calcined in a calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 6 h, and cooled with the calciner to room temperature to obtain 511033E.

(55) 511033E

(56) TABLE-US-00008 CaSO.sub.4 37.97% Ca.sub.2.86Mg.sub.0.14(PO.sub.4) 28.90% Ca.sub.2(P.sub.2O.sub.7) 53.13%.

Embodiment 7

(57) 511034

(58) 5 ml of 1 mol/L sulfuric acid, 1.43 g sodium sulfate, 0.87 g magnesium hydrogen phosphate, 5.78 g ammonium dihydrogen phosphate, and 2 ml of 85 wt % phosphoric acid stock solution are taken, and added into deionized water to prepare 100 ml of composite solution containing 0.05 mol/L sulfuric acid, 0.1 mol/L sodium sulfate, 0.1 mol/L magnesium hydrogen phosphate, 0.5 mol/L ammonium dihydrogen phosphate, and 1.7 wt % phosphoric acid; and the pH of the composite solution is about 2.5. 10 g of calcined bovine cancellous bone mineral porous scaffold is impregnated in the composite solution and subjected to impregnation and hydrothermal reaction for 20 h at a constant temperature of 70 C., and is covered by an inversely beaker. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 80 C. for 24 h, then calcined in a calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C. imin and maintained at 750 C. for 6 h, and cooled with the calciner to room temperature to obtain 511034E.

(59) 511034E

(60) TABLE-US-00009 CaSO.sub.4 7.2% Ca.sub.2.89Mg.sub.0.11(PO.sub.4).sub.2 27.03% Ca.sub.2(P.sub.2O.sub.7) 64.17%.

Embodiment 8

(61) 602124

(62) According to the amount of solution required for hydrothermal reaction, 0.1 mol/L magnesium sulfate hexahydrate, and a composite solution containing 1.7 wt % phosphoric acid, 0.1 mol/L sulfuric acid and 0.4 mol/L diammonium hydrogen phosphate are prepared, for this purpose, 1.2 g of magnesium sulfate hexahydrate, 1 ml of phosphoric acid, 5 ml of sulfuric acid and 2.64 g of diammonium hydrogen phosphate are taken. First, 50 ml of magnesium-containing solution is prepared with 1.2 g magnesium sulfate; and 5 g of calcined bovine cancellous bone mineral porous scaffold is impregnated in the magnesium-containing solution, then dried with microwave, and taken out. 5 ml of 1 mol/L sulfuric acid, 1 ml of 85 w % phosphoric acid, and 2.64 g diammonium hydrogen phosphate are taken, and added into deionized water to prepare 50 ml of the composite solution; then the calcined bovine cancellous bone mineral porous scaffold after being subjected to impregnating in the magnesium-containing solution is impregnated in the composite solution and reacted at 70 C. for 36 h. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 70 C. for 30 h, a weight of the calcined bovine cancellous bone mineral porous scaffold after drying is 5.89 g, then calcined in a calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C. imin and maintained at 750 C. for 6 h, and cooled with the calciner to room temperature to obtain 602124E; and the calcined bovine cancellous bone mineral porous scaffold after being subjected to drying is calcined in the calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 9 h, and cooled with the calciner to room temperature to obtain 602124K. The permeability, strength and appearance are good.

(63) 602124E

(64) TABLE-US-00010 CaSO.sub.4 36.4% (Ca.sub.2.589Mg.sub.0.411)(PO.sub.4).sub.2 10.5% Ca.sub.10.042(PO.sub.4).sub.5.952(OH).sub.2.292 53.1%.
602124K

(65) TABLE-US-00011 CaSO.sub.4 54.8% (Ca.sub.2.589Mg.sub.0.411)(PO.sub.4).sub.2 11.4% Ca.sub.10.042(PO.sub.4).sub.5.952(OH).sub.2.292 33.8%.

Embodiment 9

(66) 602123

(67) According to the amount of solution required for hydrothermal reaction, 0.1 mol/L magnesium sulfate hexahydrate, and a composite solution containing 1.7 wt % phosphoric acid, 0.1 mol/L sulfuric acid and 0.2 mol/L diammonium hydrogen phosphate are prepared, for this purpose, 1.2 g of magnesium sulfate hexahydrate, 1 ml of phosphoric acid, 5 ml of sulfuric acid and 1.32 g of diammonium hydrogen phosphate are taken. First, 50 ml of magnesium-containing solution is prepared with 1.2 g magnesium sulfate; and 5 g of calcined bovine cancellous bone mineral porous scaffold is impregnated in the magnesium-containing solution, then dried with microwave, and taken out. 5 ml of 1 mol/L sulfuric acid, 1 ml of 85 w % phosphoric acid, and 1.32 g diammonium hydrogen phosphate are taken, and added into deionized water to prepare 50 ml of the composite solution; then the calcined bovine cancellous bone mineral porous scaffold after being subjected to impregnating in the magnesium-containing solution is impregnated in the composite solution and reacted at 70 C. for 36 h. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 70 C. for 30 h, a weight of the calcined bovine cancellous bone mineral porous scaffold after drying is 5.68 g, then calcined in a calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 3 h, and cooled with the calciner to room temperature to obtain 602123A; the calcined bovine cancellous bone mineral porous scaffold after being subjected to drying is calcined in the calciner, where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 6 h, and cooled with the calciner to room temperature to obtain 602123E; and the calcined bovine cancellous bone mineral porous scaffold after being subjected to drying is calcined in the calciner, where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 9 h, and cooled with the calciner to room temperature to obtain 602123K.

(68) 602123A

(69) TABLE-US-00012 CaSO.sub.4 39.79% (Ca.sub.2.589Mg.sub.0.411)(PO.sub.4).sub.2 9.82% Ca.sub.9.74(PO.sub.4).sub.6(OH).sub.2.08 50.39%.
602123E

(70) TABLE-US-00013 CaSO.sub.4 37.7% Ca.sub.2.71Mg.sub.0.29(PO.sub.4).sub.2 11.3% Ca.sub.9.74(PO.sub.4).sub.6(OH).sub.2.08 51.0%.
602123K

(71) TABLE-US-00014 CaSO.sub.4 65.2% (Ca.sub.2.589Mg.sub.0.411)(PO.sub.4).sub.2 9.5% Ca.sub.10.042(PO.sub.4).sub.5.952(OH).sub.2.292 25.3%.

Embodiment 10

(72) 602122

(73) According to the amount of solution required for hydrothermal reaction, 0.15 mol/L magnesium sulfate hexahydrate, and a composite solution containing 1.7 wt % phosphoric acid, 0.1 mol/L sulfuric acid, 0.375 mol/L sodium sulfate and 0.2 mol/L diammonium hydrogen phosphate are prepared, for this purpose, 1.8 g of magnesium sulfate hexahydrate, 1 ml of 85 wt % phosphoric acid, 5 ml of sulfuric acid, 2.13 g of sodium sulfate and 1.32 g of diammonium hydrogen phosphate are taken. First, 50 ml of magnesium-containing solution is prepared with 1.8 g magnesium sulfate; and 5 g of calcined bovine cancellous bone mineral porous scaffold is impregnated in the magnesium-containing solution, dried with microwave, and taken out. 5 ml of 1 mol/L sulfuric acid, 2.13 g sodium sulfate, 1 ml of 85 w % phosphoric acid, and 1.32 g diammonium hydrogen phosphate are taken, and added into deionized water to prepare 50 ml of the composite solution of sulfuric acid, sodium sulfate, phosphoric acid and diammonium hydrogen phosphate; then, the calcined bovine cancellous bone mineral porous scaffold after being subjected to impregnating in the magnesium-containing solution is impregnated in the composite solution to be subjected to impregnation and hydrothermal reaction at 70 C. for 36 h. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 70 C. for 30 h, a weight of the calcined bovine cancellous bone mineral porous scaffold after being subjected to drying is 6.12 g, then calcined in a calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 6 h, and cooled with the calciner to room temperature to obtain 602122E; and the calcined bovine cancellous bone mineral porous scaffold after being subjected to drying is calcined in the calciner, where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 9 h, and cooled with the calciner to room temperature to obtain 602122K.

(74) 602122E

(75) TABLE-US-00015 CaSO.sub.4 53.5% (Ca.sub.2.589Mg.sub.0.411)(PO.sub.4).sub.2 14.8% Ca.sub.10.042(PO.sub.4).sub.5.952(OH).sub.2.292 31.7%.
602122K

(76) TABLE-US-00016 CaSO.sub.4 44.5% (Ca.sub.2.589Mg.sub.0.411)(PO.sub.4).sub.2 16.3% Ca.sub.9.74(PO.sub.4).sub.6(OH).sub.2.08 39.2%.

Embodiment 11

(77) 602121

(78) According to the amount of solution required for hydrothermal reaction, 0.1 mol/L magnesium sulfate hexahydrate, and a composite solution containing 1.7 wt % phosphoric acid, 0.1 mol/L sulfuric acid, 0.5 mol/L sodium sulfate and 0.4 mol/L diammonium hydrogen phosphate are prepared, for this purpose, 1.2 g of magnesium sulfate hexahydrate, 1 ml of 85 wt % phosphoric acid, 5 ml of sulfuric acid, 2.84 g of sodium sulfate and 1.32 g of diammonium hydrogen phosphate are taken. First, 1.2 g of magnesium sulfate hexahydrate is taken and added into deionized water to prepare 50 ml of magnesium sulfate solution; and 5 g of calcined bovine cancellous bone mineral porous scaffold with a porosity of about 85% is impregnated in the magnesium sulfate solution for 30 min, dried with microwave, and taken out. 5 ml of 1 mol/L sulfuric acid, 2.84 g sodium sulfate, 1 ml of 85 wt % phosphoric acid, and 2.64 g diammonium hydrogen phosphate are taken to prepare 50 ml of the composite solution containing sulfuric acid, 0.1 mol/L sodium sulfate, 1.7 wt % phosphoric acid and diammonium hydrogen phosphate; then, the calcined bovine cancellous bone mineral porous scaffold after being subjected to impregnating in the magnesium sulfate solution is impregnated in the composite solution to be subjected to impregnation and hydrothermal reaction for 36 h at a constant temperature of 90 C., and is covered by an inversely beaker. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 70 C. for 30 h, a weight of the calcined bovine cancellous bone mineral porous scaffold after being subjected to drying is 6.18 g, and the calcined bovine cancellous bone mineral porous scaffold after being subjected to drying has good permeability, good strength, good appearance and appears to have whisker formation. The calcined bovine cancellous bone mineral porous scaffold after being subjected to drying is calcined in a calciner where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 6 h, and cooled with the calciner to room temperature to obtain 602121E; and the calcined bovine cancellous bone mineral porous scaffold after being subjected to drying is calcined in the calciner, where the temperature is raised to 750 C. at a heating rate of 2.5 C./min and maintained at 750 C. for 9 h, and cooled with the calciner to room temperature to obtain 602121K.

(79) 602121E

(80) TABLE-US-00017 CaSO.sub.4 29.6% (Ca.sub.2.589Mg.sub.0.411)(PO.sub.4).sub.2 23.8% Ca.sub.10.042(PO.sub.4).sub.5.952(OH).sub.2.292 46.6%.
602121K

(81) TABLE-US-00018 CaSO.sub.4 39.0% Ca.sub.18Mg.sub.2H.sub.2(PO.sub.4).sub.14 22.2% Ca.sub.9.74(PO.sub.4).sub.6(OH).sub.2.08 38.8%.

Embodiment 12

(82) 603292

(83) According to the amount of solution required for hydrothermal reaction, 0.05 mol/L magnesium sulfate hexahydrate, and a composite solution containing 1.7 wt % phosphoric acid, 0.1 mol/L sulfuric acid, 0.2 mol/L sodium sulfate and 0.1 mol/L magnesium hydrogen phosphate are prepared, for this purpose, 0.6 g of magnesium sulfate hexahydrate, 2 ml of 85 wt % phosphoric acid, 5 ml of sulfuric acid, 2.23 g of sodium sulfate and 1.74 g of magnesium hydrogen phosphate are taken. First, 0.6 g of magnesium sulfate hexahydrate is taken to prepare 100 ml of magnesium sulfate solution; and 5 g of calcined bovine cancellous bone mineral porous scaffold with a porosity of about 85% is put into the magnesium sulfate solution for impregnation for 30 min, dried at 500 W microwave for 103 min, and taken out. 5 ml of 1 mol/L sulfuric acid, 2.23 g sodium sulfate, 1.74 g magnesium hydrogen phosphate, and 2 ml of 85 w % phosphoric acid are used to prepare 100 ml of the composite solution containing sulfuric acid, sodium sulfate, magnesium hydrogen phosphate and phosphoric acid with a pH of 3.5; the calcined bovine cancellous bone mineral porous scaffold after being subjected to impregnating in the magnesium sulfate solution is impregnated in the composite solution to be subjected to impregnation and hydrothermal reaction for 12 h at a constant temperature of 90 C., and is covered by an inversely beaker. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 90 C. for 24 h, and then calcined in a calciner where the temperature is raised to 900 C. at a heating rate of 2.5 C. imin and maintained at 900 C. for 8 h, and cooled with the calciner to room temperature to obtain 603292E.

(84) 603292E

(85) TABLE-US-00019 CaSO.sub.4 51.1% (Ca.sub.2.89Mg.sub.0.11)(PO.sub.4).sub.2 48.9%

Embodiment 13

(86) 603294

(87) 0.6 g of magnesium sulfate hexahydrate is taken and added into deionized water to prepare 60 ml of magnesium sulfate solution; and 5 g of calcined bovine cancellous bone mineral porous scaffold with a porosity of about 85% is put into the magnesium sulfate solution for impregnation for 30 min, dried at 500 W microwave for 83 min, and taken out. 5 ml of 1 mol/L sulfuric acid, 1 ml of 85 w % phosphoric acid, and 0.86 g magnesium hydrogen phosphate are taken, and added into deionized water to prepare 60 ml of composite solution; the calcined bovine cancellous bone mineral porous scaffold after being subjected to impregnating in the magnesium sulfate solution is impregnated in the composite solution and to be subjected to impregnation and hydrothermal reaction for 24 h at a constant temperature of 70 C. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 90 C. for 24 h, and then calcined in a calciner where the temperature is raised to 900 C. at a heating rate of 2.5 C./min and maintained at 900 C. for 6 h, and cooled with the calciner to room temperature to obtain 603294E.

(88) 603294E

(89) TABLE-US-00020 CaSO.sub.4 72.5% (Ca.sub.2.89Mg.sub.0.11)(PO.sub.4).sub.2 27.5%.

Embodiment 14

(90) 603295

(91) 0.6 g of magnesium sulfate hexahydrate is taken and added into deionized water to prepare 60 ml of magnesium sulfate solution; and 5 g of calcined bovine cancellous bone mineral porous scaffold with a porosity of about 85% is put into the magnesium sulfate solution for impregnation for 30 min, dried at a microwave output power of 500 W for 83 min, and taken out. 5 ml of 1 mol/L sulfuric acid, 1 ml of 85 w % phosphoric acid, 1.72 g magnesium hydrogen phosphate are taken to prepare 60 ml of composite solution; then the calcined bovine cancellous bone mineral porous scaffold is put in the composite solution and subjected impregnation and hydrothermal reaction for 24 h at a constant temperature of 70 C. Then, the calcined bovine cancellous bone mineral porous scaffold is taken out, and dried at 70 C. for 30 h, the calcined bovine cancellous bone mineral porous scaffold after being subjected to drying has general strength and general permeability. The calcined bovine cancellous bone mineral porous scaffold after being subjected to drying is calcined in the calciner where the temperature is raised to 900 C. at a heating rate of 2.5 C./min and maintained at 900 C. for 6 h, and cooled with the calciner to room temperature to obtain 603295E.

(92) 603295E

(93) TABLE-US-00021 CaSO.sub.4 70.2% (Ca.sub.2.89Mg.sub.0.11)(PO.sub.4).sub.2 29.8%.
1. Testing Results:

(94) The general observation, strength measurement, XRD component analysis and SEM observation of the materials show that the prefabricated form of the bovine cancellous bone is well retained in all kinds of products, without fragmentation, collapse or powdering, and the products have good mechanical strength. The compressive strengths of the cancellous bones from specimens Nos. 1-5 having a size of 101010 mm were tested using the INSTRON-5566 universal testing machine and the results are shown in Tab. 1. The X-ray diffraction (XRD) test confirms that the calcined bovine cancellous bone mineral scaffold, impregnated with magnesium sulfate, subjected to hydrothermal reaction in a sulfur source and phosphorus source composite solution, and after drying and calcination, can be converted into degradable magnesium-doped calcium phosphate-calcium sulfate porous composite biological scaffold materials, such as the compounds of calcium sulfate/magnesium-containing calcium phosphate, calcium sulfate/magnesium-containing calcium phosphate/hydroxyapatite, calcium sulfate/magnesium-containing calcium phosphate/hydroxyapatite/calcium pyrophosphate, calcium sulfate/magnesium-containing calcium phosphate/calcium pyrophosphate, calcium sulfuric/poly (magnesium-containing calcium hydrogen phosphate), etc. Magnesium-containing calcium phosphate is magnesium-containing tricalcium phosphate or poly (magnesium-containing calcium hydrogen phosphate) with good degradation characteristics. The molar percentage of the content of magnesium ions to the content of total cations is 0.5%-10%, the magnesium-containing component such as magnesium-containing tricalcium phosphate or poly (magnesium-containing calcium hydrogen phosphate) accounts for 9.6%-72.5% of the total mass of the material, and calcium sulfate accounts for 8%-72.5% of the total mass of the material.

(95) The scanning electron microscopy (referring to FIG. 1) shows that the products have retained the main structure of the three-dimensional interconnected mesh microstructure of the natural bone mineral of the bovine cancellous bone, and at the same time, calcium sulfate whiskers with larger length-diameter ratio grow in the mesh, which can increase the specific surface area of the materials and possibly improve the adhesion of cells.

(96) TABLE-US-00022 TABLE 1 Compressive strength No. compressive strength (MPa) 1 8.40 2 6.35 3 13.79 4 11.46
2. In-Vitro Dissolution and Degradation Test of Materials

(97) Medical sodium chloride injection is used as the simulated body fluid in the dissolution and degradation test in simulated body fluid. The solid-liquid ratio (mass to volume ratio) of the test material to the simulated body fluid is 1-2 g: 100 ml. The test material and the simulated body fluid were placed in a beaker having a cover, and the dissolution test in the simulated body fluid was performed under constant temperature condition of 37 C. The dissolution test duration was 4 weeks. Calcium ions, phosphorus ions and magnesium ions in the simulated body fluid were detected by AU5800 automatic biochemical analyzer. The mass of material at 4.sup.th week was measured by a domestic electronic balance and the degradation rate was calculated. XRD analysis and SEM observation of the materials were performed before and at the end of the dissolution test. The test shows that the material has a good degradation rate (as shown in Tab. 2); in the early stage (within half a month) of the simulated body fluid test, most samples had higher concentrations of calcium ions in the simulated body fluids, which were maintained between 1-5 times of the median of normal reference values of human serum (as shown in FIG. 2); and active ionized magnesium were released. XRD analysis of the materials of the simulated body fluid test shows that the compositions and mass ratio of the material change over time, calcium sulfate and magnesium-containing calcium phosphate gradually decrease or disappear, and the scaffold material gradually changes to hydroxyapatite. The dissolution of materials and the redeposition of mineral components can be observed by scanning electron microscope (as shown in FIG. 3).

(98) TABLE-US-00023 TABLE 2 Degradation rate of materials impregnated in simulated body fluids for 4 weeks Groups degradation rate hydroxyapatite 1.56% product A of the present invention 33.11% product B of the present invention 21.6% product C of the present invention 43.2% product D of the present invention 38.23%
3. Animal Bone Defect Repair Test

(99) In the early stage (1 week) of transplantation of the product of the present invention, cells and blood vessels can be seen to enter the whole space of the scaffold, and proliferation and differentiation of bone repair cells, and secretion of bone matrix by the bone repair cells can be seen (as shown in FIG. 4). Bone trabecula is formed within two weeks, and the new bone tissue is perfectly combined with the scaffold (as shown in FIG. 5). No immunological rejection or obvious inflammation was observed during the observation. The materials have good biocompatibility. During the observation, it was found that the new bone trabecula was gradually embedded in the wall of the scaffold material, indicating that the material could be gradually degraded (as shown in FIG. 6).

(100) The above-mentioned embodiments are merely preferred embodiments of the present invention, which are not intended to limit the present invention in any form, and other variations and modifications of the present invention are possible without departing from the technical solutions as recited in the appended claims.