KR20140007546A - Fabricating method of porous calcium-phosphate bone substitute material and porous calcium-phosphate bone substitute material fabricated thereby - Google Patents

Abstract

The present invention relates to a calcium phosphate based microparticles having a microsized pore structure and a method for manufacturing the same and, more specifically, a method for manufacturing microparticles by manufacturing particles with nanoparticles manufactured by using a polymer as a template and polymer mixed liquid, then manufacturing porous particles which are 800-1200 μm in size by high temperature heating. The size and degrading level of the porous microparticles according to the present invention can be controlled by controlling the concentration of the liquid, reaction time, and the temperature of the heat. Also, since the porous microparticles according to the present invention has an excellent bioactivity, not only as a drug carrier, the porous microparticles induce the formation of apatite, a component similar to human bones, thereby being widely used as a material for a bone filling, a restoration material, and a supporter. [Reference numerals] (AA) Making and mixing water soluble polymer liquid and calcium ion precursor solution; (BB) 0.1N Hydrochloric acid or 0.1N ammonia; (CC) Dropping phosphate ion precursor solution; (DD) Reacting for 24 hours; (EE) Synthesizing hydroxyapatite inorganic particles; (FF) Centrifuging and drying; (GG) Mixture of phosphate ion precursor solution, water soluble polymer, and inorganic particles; (HH) Bridging reacting for 24 hours after dropped into calcium ion precursor solution; (II) Manufacturing porous bone substitute particles

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous calcium phosphate-based bone substitute material and a porous calcium phosphate-based bone substitute material,

The present invention relates to a method for producing a calcium phosphate-based porous bone substitute material and a calcium phosphate-based porous bone substitute material produced thereby. More specifically, the present invention relates to a method for producing a porous calcium phosphate-based bone substitute material, Based porous bone substitute.

When a tissue or an organ is damaged, allografts that use their own body to replace or restore the body, allografts using the tissues of others, and xenotransplantation using animal tissues are performed. Among these, surgical implants Treatment is most ideal, but it has many problems such as immune rejection and delivery of pathogens. Therefore, the demand for various kinds of biomaterials such as artificial joints, bone plates for treatment of fractures, and dental implants is rapidly increasing, and it is required to have high biological stability and effectiveness at the same time because it is a subject of application.

When calcium phosphate-based compounds are embedded in a living body, they do not form a fibrous film around them and make strong chemical bonds by directly contacting the bone. Typically, hydroxyapatite is a major component of teeth and bones, has no toxicity, has excellent biological and chemical properties, and has high biocompatibility. Therefore, when used as an implant in bone or skin, it can be easily incorporated into surrounding tissue.

In addition, tricalcium phosphate is biodegradable as compared with hydroxyapatite, and its physical properties and biocompatibility are similar to hydroxyapatite, so that it is useful as a biomaterial.

When porous bone substitute particles are prepared using such calcium phosphate-based compounds, the surface area of the porous bone substitute particles can be increased to increase the bioabsorption ratio, which is more suitable as a graft material, and thus can be used not only as a bone filling material but also as a drug carrier .

The present invention provides a method for manufacturing a calcium phosphate-based porous bone substitute capable of controlling the size, porosity and pore size of a bone substitute particle, and a calcium phosphate-based porous bone substitute prepared thereby.

One embodiment of the present invention is a method for preparing a polymer solution, comprising: (1) preparing a polymer template solution by dissolving a first water-soluble polymer in distilled water; Providing a first calcium ion precursor solution and a phosphate ion precursor solution, respectively (step 2); Adding the first calcium ion precursor solution and the phosphate ion precursor solution sequentially to the polymer template solution, stirring the mixture, and centrifuging and drying to prepare hydroxyapatite particles (Step 3); Dispersing the hydroxyapatite particles and the tricalcium phosphate particles in a phosphate ion precursor solution in which the second water soluble polymer is dissolved to prepare a dispersion solution (Step 4); Dropping the dispersion solution into a second calcium ion precursor solution to crosslink the water soluble polymer (step 5); And sintering the cross-linked material (step 6).

In one embodiment, the first water-soluble polymer includes at least one member selected from the group consisting of beta-cyclodextrin, alginate, polyvinylpyrrolidone, polyvinyl alcohol, hyaluronic acid, laminarin, pullulan, fucoidan and gelatin .

In one embodiment, the calcium ion precursor may include at least one selected from the group consisting of calcium nitrate, calcium chloride, calcium sulfate, and calcium hydroxide.

In one embodiment, the phosphate ion precursor is selected from the group consisting of ammonium phosphate, sodium phosphate monobasic, sodium phosphate dibasic, sodium phosphate dibasic, potassium monophosphate, potassium dibasic and potassium dibasic potassium phosphate. Or more species.

In one embodiment, the second water soluble polymer may include at least one member selected from the group consisting of alginate, hyaluronic acid, polyacetic acid, polygamma glutamate, and gelatin.

In one embodiment, the ratio of the weight of the hydroxyapatite particles to the weight of the tricalcium phosphate particles in step 4 may be (50 to 100%) (0 to 50%).

In one embodiment, the sintering may be performed at 1,000 to 1,300 ° C.

Another embodiment of the present invention is a calcium phosphate-based porous bone substitute prepared in accordance with the above method, wherein the particles have an average diameter of 300 to 1,200 μm, the particles have open pores, the average diameter of the open pores may be a calcium phosphate-based porous bone substitute of 0.5 to 2 탆.

In one embodiment, the particles may include 50 to 100% by weight of hydroxyapatite and 0 to 50% by weight of tricalcium phosphate.

In one embodiment, the hydroxyapatite may have a ratio of calcium to phosphoric acid of 1.67: 1.

In one embodiment, the hydroxyapatite may have an average diameter of 20-50 nm.

According to the present invention, the size, porosity and pore size of the bone substitute particles can be controlled by controlling the concentration, reaction time, and temperature of the solution.

The calcium phosphate-based porous bone substitute according to the present invention is more suitable as a graft material because of its high surface area and high bioabsorption rate, and thus can be used not only as a bone filling material but also as a drug carrier

In addition, since it exhibits excellent bioactivity, it can be widely used not only as a drug carrier but also as a bone filler, a restorative material, a support, and the like by inducing the formation of apatite, a living bone-like component.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a manufacturing process of a calcium phosphate-based porous bone substitute according to an embodiment of the present invention. FIG.
2A to 2C are photomicrographs of a surface of a calcium phosphate-based porous bone substitute particle according to an embodiment of the present invention.
FIGS. 3A and 3B are photomicrographs of surfaces of hydroxyapatite particles according to an embodiment of the present invention. FIG.
FIG. 4 is a result of X-ray diffraction analysis of calcium phosphate-based porous bone substitute particles prepared by different ratios of hydroxyapatite particles and tricalcium phosphate according to an embodiment of the present invention.
FIG. 5 is a FT-IR spectrum measurement result of calcium phosphate-based porous bone substitute particles prepared by varying the ratio of hydroxyapatite particles to tricalcium phosphate according to an embodiment of the present invention.
6A to 6B are photographs showing the growth behavior of osteoblasts on the surfaces of the calcium phosphate-based porous bone substitute particles according to one embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention may be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below.

Furthermore, embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art.

Accordingly, the shapes and sizes of the elements in the drawings may be exaggerated for clarity of description, and the elements denoted by the same reference numerals in the drawings are the same elements.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a manufacturing process of a calcium phosphate-based porous bone substitute according to an embodiment of the present invention. FIG.

Referring to FIG. 1, an embodiment of the present invention includes a step (step 1) of preparing a polymer template solution by dissolving a first water-soluble polymer in distilled water; Providing a first calcium ion precursor solution and a phosphate ion precursor solution, respectively (step 2); Adding the first calcium ion precursor solution and the phosphate ion precursor solution to the polymer template solution, stirring the mixture, and centrifuging and drying to prepare hydroxyapatite particles (Step 3); Dispersing the hydroxyapatite particles and the tricalcium phosphate particles in a phosphate ion precursor solution in which the second water soluble polymer is dissolved to prepare a dispersion solution (Step 4); Dropping the dispersion solution into a second calcium ion precursor solution to crosslink the water soluble polymer (step 5); And sintering the cross-linked material (step 6).

First, a polymer template solution can be prepared by dissolving a first water-soluble polymer in distilled water (Step 1).

The first water-soluble polymer may include at least one member selected from the group consisting of beta-cyclodextrin, alginate, polyvinylpyrrolidone, polyvinyl alcohol, hyaluronic acid, laminarin, pullulan, fucoidan and gelatin.

Next, the first calcium ion precursor solution and the phosphate ion precursor solution can be respectively provided (Step 2).

The first calcium ion precursor may be at least one selected from the group consisting of calcium nitrate, calcium chloride, calcium sulfate and calcium hydroxide, although it is not particularly limited as long as it is a substance capable of providing calcium ions.

The phosphate ion precursor is not particularly limited as long as it is a substance capable of providing a phosphate ion, but specifically includes ammonium phosphate dibasic, sodium phosphate dibasic, sodium phosphate dibasic, sodium monophosphate, potassium monophosphate, And potassium tertiary phosphate.

Next, the first calcium ion precursor solution and the phosphate ion precursor solution are added to the polymer template solution, stirred, centrifuged and dried to prepare hydroxyapatite particles (Step 3).

The hydroxyapatite particles are in a state of mixing a polymer, a calcium ion precursor, and a phosphate ion precursor, and may have a uniform and spherical shape. As will be described later, the polymer may be pyrolyzed and volatilized during the sintering process and pores may be formed in the space where the polymer is present.

Next, the hydroxyapatite particles and the tricalcium phosphate particles can be dispersed in a phosphate ion precursor solution in which the second water-soluble polymer is dissolved (Step 4).

The second water-soluble polymer may include at least one member selected from the group consisting of alginate, hyaluronic acid, polyacetic acid, polygamma glutamate and gelatin. Particularly, a polymer having a large amount of a hydroxyl group and a carboxylic acid group is suitable.

In step 4, the ratio of the weight of the hydroxyapatite particles to the weight of the tricalcium phosphate particles may be (50% to 100%) (0% to 50%). When the weight percentage of the hydroxyapatite particles is less than 50%, the strength may be lowered and the pore size may be increased too much.

Next, the water-soluble polymer may be crosslinked by dropping the dispersion solution into the second calcium ion precursor solution (step 5).

It is preferable to maintain the crosslinking reaction sufficiently, but it is preferable to maintain the crosslinking reaction for at least about 24 hours.

The second calcium ion precursor may include calcium nitrate, calcium chloride, calcium sulfate, and calcium hydroxide. The separation of the calcium ion precursor solution into the first and second components is intended to indicate that the solution is a separately prepared solution. The first and second calcium ion precursor solutions may have the same solvent, solute, and concentration.

Next, the crosslinked material can be sintered (step 6).

The polymer material in the crosslinked material may be pyrolyzed and volatilized while sintering, and the polymer material may remain as an empty space to form an open pore, whereby the porous material having a constant pore size Calcium phosphate-based bone substitute can be obtained.

Sintering can be performed at 1,000 to 1,300 ° C. If the sintering temperature is lower than 1,000 ° C., the polymer material may not sufficiently volatilize and may act as a foreign substance. If the sintering temperature is higher than 1,300 ° C., undersize may occur and the pore may be reduced.

Another embodiment of the present invention is a calcium phosphate-based porous bone substitute prepared in accordance with the above embodiment, wherein the calcium phosphate-based porous bone substitute particles have an average diameter of 300 to 1,200 탆 and the particles have open pores The average diameter of the open pores may be 0.5 to 2 占 퐉.

The calcium phosphate-based porous bone substitute material may contain 50 to 100% by weight of hydroxyapatite and 0 to 50% by weight of tricalcium phosphate, and hydroxyapatite may contain phosphoric acid and calcium in a molar ratio (Ca / P) of 1.68: As shown in FIG. The hydroxyapatite may be in the form of particles, and the average diameter of the particles may be from 20 to 50 nm.

Even if hydroxyapatite and tricalcium phosphate are produced in different weight ratios, the calcium phosphate-based porous bone substitute material may have a chemical structure similar to that of commercially available hydroxyapatite and a crystal form.

When a bone substitute has a porous structure as a particle having a diameter as described above, it can have a large surface area, and when the surface area is wide, it is more suitable as a graft material because of its high bio-absorbability and can be used as a drug carrier as well as a bone filling material.

Since it exhibits excellent bioactivity, it can induce the formation of apatite, which is a bone-like component, and can be widely used as a material for bone filling materials, restorative materials and supports. Biological activity can be confirmed by looking at the growth behavior of osteoblasts.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

1. Synthesis of hydroxyapatite particles

The water-soluble beta-cyclodextrin, 0.01 to 1.0 w / v%, is dissolved in distilled water, and a solution of calcium nitrate, which is a calcium ion precursor, is added thereto. The concentration of the solution is adjusted to 0.01 to 0.1 M, and then 0.1 N hydrochloric acid solution or ammonia water The pH of the solution was adjusted to 10.

Subsequently, the ammonium phosphate solution, which is a phosphate ion precursor, was added in small amounts while stirring at room temperature so that the phosphate ion precursor had a Ca / P ratio of 1.67, and the reaction was continued for 24 hours after completion of the addition to prepare hydroxyapatite particles. Here, Ca / P represents the molar ratio of calcium (Ca) to phosphorus (P).

The prepared hydroxyapatite particles were dried for 24 hours or more using a vacuum drying method after centrifugation.

The results of the diameter and shape of the hydroxyapatite particles are shown in Table 1.

Polymer concentration
(w / v%) Solution pH Reaction temperature Ca / P mole ratio Particle shape Particle diameter
(Nm) Example 1 0.1 10 45 ° C 1.68 Spherical shape 40 Comparative Example 1 0.05 10 45 ° C 1.72 Spherical shape 60 Comparative Example 2 0.02 10 45 ° C 1.72 Spherical shape 60 Comparative Example 3 0.01 10 45 ° C 1.74 Spherical shape 80 Comparative Example 4 0.1 9 45 ° C 1.53 Rod / plate mixture 100-1,200 Comparative Example 5 0.1 8 45 ° C 1.54 Rod / plate mixture 100-1,200 Comparative Example 6 0.1 7 45 ° C 1.50 Rod / plate mixture 100-1,200

Referring to Table 1, in Example 1, the ratio of calcium to phosphoric acid (Ca / P molar ratio) was 1.68, and the diameter of the particles was formed to be 40 nm. On the other hand, in the case of Comparative Examples 1 to 6 in which the ratio of calcium to phosphoric acid is not 1.68, it can be confirmed that the diameter of the particles is greatly increased to 60 nm or more.

The results of Table 1 confirm that the ratio of calcium to phosphoric acid is a major factor in controlling the diameter of hydroxyapatite particles and that hydroxyapatite particles having a diameter of 40 nm can be obtained when the ratio is 1.68 Able to know.

2. Synthesis of calcium phosphate-based porous bone substitute particles

The hydroxyapatite particles prepared above were mixed with the tricalcium phosphate particles to prepare a phosphate ion precursor, ammonium phosphate To prepare a dispersion solution.

50 to 100% of hydroxyapatite and 0 to 50% of tricalcium phosphate were mixed in a weight ratio.

Alginate was used as the water-soluble polymer, and the polymer was dissolved in an ammonium phosphate solution of 0.01 to 0.1 M phosphate ion precursor in an amount of 2 to 10 w / v%, and 2 to 15 w / v% of hydroxyapatite / Calcium phosphate mixed inorganic particles were dispersed to prepare a dispersion solution.

The solution was dropped by one drop into a calcium nitrate solution using a syringe, and crosslinked for 24 hours or more, and sintered at 1,000 to 1,300 ° C for 2 hours to prepare calcium phosphate-based porous bone substitute particles.

FIGS. 3A and 3B are photomicrographs of surfaces of hydroxyapatite particles according to an embodiment of the present invention. FIG. FIG. 3A is a photograph enlarged to 10,000 times, and FIG. 3B is a photograph enlarged to 50,000 times.

Referring to FIGS. 3A and 3B, it can be seen that spherical hydroxyapatite particles of uniform size are formed.

Properties of the calcium phosphate-based porous bone substitute particles prepared as described above are shown in Table 2.

Polymer concentration
(w / v%) Inorganic Particle Concentration (w / v%) HA / TCP
ratio Reaction time Reaction temperature (캜) Particle size
(탆) pore
size
(탆) Particle strength Solubility (%) Example 2 2 4 10: 0 24h 45 800 0.5 hard
(7.0 MPa) 24.7 Example 3 4 4 10: 0 24h 45 800 One hard
(6.8 MPa) 24.3 Example 4 4 8 10: 0 24h 45 1000 One hard
(7.1 MPa) 16.7 Example 5 4 8 6: 4 24h 45 1000 One hard
(6.2 MPa) 34.9 Comparative Example 7 4 8 4: 6 24h 45 1000 2 Ripen
(3.0 MPa) 51.8 Comparative Example 8 4 8 10: 0 12h 45 1200 One Ripen
(2.8 MPa) 62.4 Comparative Example 9 4 8 10: 0 24h 20 800 0.5 Ripen
(2.7 MPa) 78.2

In Table 2, the particle strength was measured by a tensile compression tester. When the measured value was 6 MPa or more, it was judged to be hard, and when the measured value was less than 3 MPa, it was judged to be insufficient.

Referring to Table 2, Comparative Example 7 shows a case where the ratio of TCP to HA is 4: 6, the diameter of the pores is 2 탆, which is a large value, and the particle strength is insufficient. In Comparative Example 8, the reaction time was set to 12 hours, but the particle strength was insufficient. In Comparative Example 9, the reaction temperature was 20 占 폚, but the particle strength was insufficient. In Examples 2 to 5, the ratio of TCP to HA is (4 to 10): (0 to 4), the pore size is 0.5 to 1 탆, and the particle strength is hard.

From the above results, it can be seen that the pore size and particle strength can be controlled by controlling the ratio of HA to TCP (HA / TCP), reaction time and reaction temperature.

Further, referring to Table 2, it can be seen that Examples 2 to 5 have a low solubility and Comparative Examples 7 to 9 have a high solubility. The bone substitute material according to the present invention has a long life span in the living body and is stable, so that it can exert excellent performance as a bone replacement material.

The solubility was calculated by using 0.1 g of particles in distilled water and dissolving at 37 ℃ for 5 days in a shaking incubator. After the particles were washed with distilled water and dried, the difference between the particle weight and the remaining particle weight was calculated.

2A to 2C are photomicrographs of surfaces of calcium phosphate-based porous bone substitute particles according to an embodiment of the present invention. 2A is a photograph enlarged to 50 times, FIG. 2B to 5,000 times, and FIG. 2C to 10,000 times.

2A to 2C, it can be confirmed that the porous calcium phosphate-based bone substitute particles have pores of a certain size.

FIG. 4 is a result of X-ray diffraction analysis of calcium phosphate-based porous bone substitute particles prepared by different ratios of hydroxyapatite particles and tricalcium phosphate according to an embodiment of the present invention, and FIG. The results of FT-IR spectroscopy of calcium phosphate-based porous bone substitute particles prepared by varying the ratio of hydroxyapatite particles to tricalcium phosphate according to the morphology.

4 and 5, calcium phosphate-based porous bone particles prepared by varying the weight ratio of hydroxyapatite and tricalcium phosphate to 6: 4, 8: 2, and 10: 0 according to an embodiment of the present invention It can be confirmed that the substitute material has a chemical structure and crystal form similar to that of commercially available hydroxyapatite (HA).

6A to 6B are photographs showing the growth behavior of osteoblasts on the surfaces of the calcium phosphate-based porous bone substitute particles according to one embodiment of the present invention. 6A is a photograph after one day, and FIG. 6B is a photograph after three days.

6A and 6B, it can be confirmed that the calcium phosphate-based porous bone substitute according to the present invention has excellent bioactivity through the growth behavior of osteoblasts.

According to the above results, it can be confirmed that the strength of the bone substitute particles can be controlled by controlling the ratio of the calcium phosphate compound of hydroxyapatite and tricalcium phosphate.

It is also confirmed that porosity can be imparted to the bone substitute particles by volatilizing the polymer substance through the heat treatment, and the porosity of the particles can be controlled by adjusting the concentration of the polymer as a prerequisite.

Also, it can be confirmed that the pore size, particle size and degree of decomposition (solubility) can be controlled by adjusting the concentration of the solution used, the reaction time, and the temperature of the applied heat.

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited only by the appended claims. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. something to do.

Claims (11)

Preparing a polymer template solution by dissolving the first water-soluble polymer in distilled water (step 1);
Providing a first calcium ion precursor solution and a phosphate ion precursor solution, respectively (step 2);
Adding the first calcium ion precursor solution and the phosphate ion precursor solution sequentially to the polymer template solution, stirring the mixture, and centrifuging and drying to prepare hydroxyapatite particles (Step 3);
Dispersing the hydroxyapatite particles and the tricalcium phosphate particles in a phosphate ion precursor solution in which the second water soluble polymer is dissolved to prepare a dispersion solution (Step 4);
Dropping the dispersion solution into a second calcium ion precursor solution to crosslink the water soluble polymer (step 5); And
Sintering the crosslinked material (step 6). The method of claim 1,
The first water-soluble polymer is calcium phosphate-based porous bone containing at least one selected from the group consisting of beta-cyclodextrin, alginate, polyvinylpyrrolidone, polyvinyl alcohol, hyaluronic acid, laminarin, pullulan, fucoidan and gelatin Method of making substitutes. The method of claim 1,
Wherein the calcium ion precursor comprises at least one selected from the group consisting of calcium nitrate, calcium chloride, calcium sulfate, and calcium hydroxide. The method of claim 1,
Wherein the phosphate ion precursor comprises at least one member selected from the group consisting of ammonium diphosphate, sodium phosphate dibasic, sodium phosphate dibasic, sodium phosphate dibasic, potassium monophosphate, potassium dibasic and potassium dibasic. A method for manufacturing a calcium phosphate-based porous bone substitute material. The method of claim 1,
Wherein the second water-soluble polymer comprises at least one member selected from the group consisting of alginate, hyaluronic acid, polyacetic acid, polygamma glutamate, and gelatin. The method of claim 1,
The ratio of the weight of the hydroxyapatite particles to the weight of the tricalcium phosphate particles in the step 4 is (50 ~ 100%): (0 ~ 50%). The method of claim 1,
Wherein the sintering is performed at 1,000 to 1,300 ° C. A calcium phosphate-based porous bone substitute prepared in accordance with the method of claim 1, wherein the particles have an average diameter of from 300 to 1,200 μm, the particles have open pores and the open pores Calcium phosphate-based porous bone substitute having an average diameter of 0.5 to 2 탆. The method of claim 8,
Wherein the particles comprise 50 to 100% by weight of hydroxyapatite and 0 to 50% by weight of tricalcium phosphate. The method of claim 9,
The hydroxyapatite is a porous calcium phosphate bone substitute having a ratio of calcium to phosphate of 1.68: 1. 10. The method of claim 9,
The hydroxyapatite is a calcium phosphate-based porous bone substitute having a particle size of 40 nm in average diameter.

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