KR101309528B1 - Preparing method for bone composite, bone composite prepared thereby, and artificial bone containing the bone composite - Google Patents

Abstract

PURPOSE: A method for preparing bone compositions, bone compositions prepared by the same, and an artificial bone including the same are provided to improve osteoconductivity and quality. CONSTITUTION: A method for preparing bone compositions comprises the following steps: preparing an organic-inorganic composite by mixing one or more carrier materials selected from a calcium aqueous solution, phosphoric acid, gelatin, collagen, chondroitin sulfate, and glycosaminoglycan with one or more bonding regulating materials selected from chitosan, dextrin, polyvinyl acrylate (PVA), polyacrylamide (PAA), and polymethyl methacrylate (PMMA) at pH 6.5-8.5; filtering and drying the organic-inorganic composite under carbon dioxide-free atmosphere. The organic-inorganic composite includes a compound including Ca and P, a carrier material, and a bonding regulating material.

Description

Method for producing a bone composition, bone composition prepared thereby and artificial bone comprising the same {Preparing method for bone composite, bone composite prepared thereby, and artificial bone containing the bone composite}

The present invention relates to a method for preparing a bone composition, a bone composition prepared thereby, and an artificial bone including the same, and more particularly, to provide high mechanical strength and chemical stability when implanted into the body, as well as osteoconductivity. The present invention relates to a method for producing a bone composition having a high and similar porosity similar to that of biological bone tissue and used as an artificial bone, a bone composition prepared thereby, and an artificial bone including the same.

Hydroxyapatite (Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ , hereinafter HAp) has been actively studied as a base material for therapeutic bone substitutes and artificial bones with high biocompatibility and osteoconductivity (WB). BROWN, JP SMITH, JR REHR, AW FRAZIER, Nature 196 (1962) 1048., RAYOUNG, Clinical Orthopedics 113 (1975) 249-60., A. ASCENZI, GH BELL, in Bone as a Mechanical Engineering Problem, The Biochemistry and Physiology of Bone, Vol. 1 (Bone GH, editor.New York: Academic Press, 1972) pp. 311-52.). Bone is an extracellular matrix comprising HAp nanocrystals and collagen fibers as the main component, which HAp nanocrystals have crystal axes aligned with the direction of the collagen fibers (BB DOYLE, Biopolymers 14 (1975;) 937., CF NAWROT , DJ CAMPBELL, J Dent Res 56 (8) (1977) 1017-22.).

A technique for producing HAp-inserted gelatin nanocomposite as an artificial bone substitute by coprecipitation of HAp nanocrystals and water-soluble gelatin matrix by mimicking the osteoblast reaction in vivo has been developed and known in the art (MCCHANG, CC KO, WH DOUGLAS, Biomaterials 24 (17) (2003) 2853-62., MC CHANG, WH DOUGLAS, J. TANAKA, J Mater Sci: Mater Med 17 (2006) 38796.).

However, the above technique is not only difficult to implement a porous size of a suitable size to replace the bone, but also can not achieve a satisfactory mechanical strength.

The unique physical properties of biological bone tissue are due to the organic-inorganic interaction between Ca and P and the specific structure of the protein matrix, such as collagen fibers or glucosamine fibers. Thus, the quality of bone substitutes, including protein matrix, calcium and phosphorus, depends on how well they simulate the physical and molecular structure of bone and how high mechanical strength can be achieved there.

The first problem to be solved by the present invention is not only to provide high mechanical strength and chemical stability when implanted in the body, but also has high osteoconductivity, and when used as an artificial bone because it exhibits a porosity similar to that of biological bone tissue. It is to provide a method for producing a bone composition showing excellent quality.

The second problem to be solved by the present invention is to provide a bone composition which is manufactured according to the manufacturing method and retains the property to be more stabilized after implantation in the body, has a high mechanical strength and promotes bone regeneration. .

The third problem to be solved by the present invention is to provide an artificial bone exhibiting significantly improved utilization and quality in the implantation or bone bonding procedure by including the bone composition.

In order to achieve the first object of the present invention,

In an atmosphere free of carbon dioxide,

Calcium aqueous solution; Phosphoric acid; Carrier material; And it provides a method for producing a bone composition comprising the step of coprecipitating a mixture of;

According to an embodiment of the present invention,

The carbon dioxide-free atmosphere may be a nitrogen atmosphere, an inert gas atmosphere or a vacuum state.

According to another embodiment of the present invention,

The coprecipitation step may be performed at pH 6.5 to 8.5.

According to another embodiment of the present invention,

The coprecipitation step may be performed at 35 to 50 ° C.

According to another embodiment of the present invention,

The calcium aqueous solution may be one in which calcium is supersaturated.

According to another embodiment of the present invention,

The calcium aqueous solution may be an aqueous solution of calcium oxide.

According to another embodiment of the present invention,

The carrier material is,

It may be one or more substances selected from the group consisting of gelatin, collagen, chondroitin sulfate and glycosaminoglycans.

According to another embodiment of the present invention,

The binding regulator is,

It may be at least one material selected from the group consisting of chitosan, dextrin, polyvinyl acrylate (PVA), polyacrylamide (PAA) and polymethyl methacrylate (PMMA).

According to another embodiment of the present invention,

Filtration or drying of the product obtained from the coprecipitation may be further included.

According to another aspect of the present invention,

Compounds comprising Ca and P; Carrier material; And binding modulators;

Provided is a bone composition characterized in that when the body is implanted by the body fluid is carbonated.

According to an embodiment of the present invention,

The compound containing Ca and P,

β-tricalcium phosphate, anhydrous dicalcium phosphate (CaHPO ₄ , DCPA), tetracalcium dihydrogen phosphate (Ca ₄ H ₂ P ₆ O ₂₀ , TTCP), hydroxyapatite (HAp) and dicalcium phosphate dihydrate (CaHPO ₄ 2H ₂ O, DCPD) may be one or more substances selected from the group consisting of.

According to another embodiment of the present invention,

The carrier material is,

It may be one or more substances selected from the group consisting of gelatin, collagen, chondroitin sulfate and glycosaminoglycans.

According to another embodiment of the present invention,

The binding regulator is,

It may be at least one material selected from the group consisting of chitosan, dextrin, polyvinyl acrylate (PVA), polyacrylamide (PAA) and polymethyl methacrylate (PMMA).

According to another embodiment of the present invention,

The content of the binding regulator may be 1 to 25% by weight.

In order to achieve the third object,

It provides an artificial bone comprising the bone composition.

As described above, the present invention provides high mechanical strength and chemical stability when implanted in the body, has high osteoconductivity, exhibits a porous similarity to biological bone tissue, and has excellent quality when applied to artificial bones. In addition to being able to make and use the bone compositions shown, artificial bones comprising them exhibit significantly improved utility and quality in implantation or bone bonding procedures.

1 is a phase equilibrium graph of materials that change depending on a pH environment and a calcium concentration environment when the aqueous calcium solution and phosphoric acid are reacted.
2 is a schematic diagram of a manufacturing method according to an embodiment of the present invention.
3 is an exemplary image of substrates that can be used to prepare a bone composition in accordance with the present invention.
4 is a graph illustrating the results of thermal analysis of inventive examples and comparative examples.
5 is a transmission electron microscope (TEM) image of an embodiment of the present invention.
6 is an enlarged transmission electron microscope (TEM) image of an embodiment of the present invention.
7 is a graph of the FTIR measurement of Examples and Comparative Examples of the present invention.
8 is a graph of the FTIR measurement of Examples and Comparative Examples of the present invention.
9 is a graph of the FTIR measurement of Examples and Comparative Examples of the present invention.
10 is a graph of PO4-FTIR measurement in Examples and Comparative Examples of the present invention.
11 is a graph of the FTIR measurement of Examples and Comparative Examples of the present invention.
12 is an XRD measurement graph of the Examples and Comparative Examples of the present invention.
13 is a graph of the XRD pattern that changes when an embodiment of the present invention is dried in a carbon dioxide environment.

Hereinafter, the present invention will be described in detail.

The present invention first provides a method for preparing a bone composition which elicits a specific organic-inorganic interaction between the carrier substance matrix-calcium-phosphate by means of a binding modulator. Due to the organic-inorganic interaction and mineralization (mineralization), the bone composition prepared according to the manufacturing method of the present invention not only very similar to bone but also has a significantly high strength properties.

More specifically, the method for producing a bone composition according to the present invention, in a carbon dioxide-free atmosphere, calcium aqueous solution; Phosphoric acid; Carrier material; And co-precipitating a mixture of the binding modulators. Specific organic-inorganic interaction between the carrier material matrix-calcium-phosphate occurs in the coprecipitation, and thus the structure and the molecular specific aspect embodied therein (as will be described later in the examples) According to the mineralization (mineralization) will be referred to as a bone composition according to the present invention is to exhibit significantly superior strength characteristics and bone similarity such as porosity compared to the prior art.

In addition, the carbon dioxide-free atmosphere may refer to an atmosphere in which carbon dioxide does not react or contact in a reaction process, that is, a nitrogen atmosphere, an inert gas atmosphere, or a vacuum state as in the art. According to the present invention, the carbon composition is not included, contacted or reacted during the manufacturing process, so that the bone composition having the characteristics of the conventional non-implementation, which is carbonated and stabilized in the body only after implantation in the body, can be prepared. Therefore, the carbon dioxide-free atmosphere may be referred to as an indispensable condition for implementing one feature of the present invention. However, the carbon dioxide-free atmosphere may be implemented by a nitrogen atmosphere, an inert gas atmosphere or a vacuum state as well as other methods, and the present invention is not limited by the above-described atmospheric conditions.

In the coprecipitation step, Ca-P compounds are also produced due to the interaction of calcium and phosphoric acid. Such compounds include β-tricalcium phosphate, anhydrous dicalcium phosphate (CaHPO ₄ , DCPA), tetracalcium dihydrogen phosphate (Ca ₄ H ₂ P ₆ O ₂₀ , TTCP), hydroxyapatite (HAp) or dicalcium phosphate di Hydrate (CaHPO ₄ 2H ₂ O, DCPD), which can be used to achieve desirable porosity and high mechanical strength by eliciting desirable organic-inorganic interactions and mineralization of Ca-P compounds, carrier materials, and binding regulators. Among the Ca-P compounds, hydroxyapatite (hereinafter referred to as HAp) is the most efficient component, and the present inventors suggest that the process of preparing a bone composition according to the present invention is preferably performed at pH 6.5 to 8.5. .

Figure 1 shows the main obtainable material of the Ca-P compound, depending on pH conditions, when supersaturated calcium and phosphoric acid interact to form a Ca-P compound. As shown, when Ca-P compound is synthesized by reacting calcium supersaturated aqueous solution with phosphoric acid, HAp is obtained as a main product in the case of pH 6.5-8.5, β-TCP in the range of pH 4.2-4.8, A mixed phase of HAp, octacalcium phosphate (OCP), αtricalcium phosphate (α-TCP) and tetracalcium phosphate (TTCP) forms, and below pH 4.2, dicalcium phosphate dihydrate (CaHPO ₄ 2H ₂ O, DCPD) The largest amount is formed as the most stable phase. That is, in carrying out the production method according to the present invention, the pH is most preferably 6.5 ~ 8.5. In addition, the present invention is not limited thereto, but the aqueous calcium solution may be prepared by dissolving prepared calcium oxide (CaO).

Method for producing a bone composition according to the invention comprises the step of synthesizing the Ca-P compound. That is, the step of the interaction of calcium and phosphoric acid to synthesize a Ca-P compound; And the step of co-precipitating the bone composition on the complex by the interaction of the Ca-P compound, the carrier material, and the binding regulator, each of which may occur simultaneously or sequentially, as described above in the 'calcium aqueous solution; Phosphoric acid; Carrier material; And the step of co-precipitating a mixture of a binding modulator; should be understood as a concept including all of them.

The carrier material is preferably a protein capable of forming a fibrous matrix, more preferably gelatin, collagen, chondroitin sulfate or glycosaminoglycan, and the binding regulator is preferably an anionic polymer (macromolecule), More preferably, it may be chitosan, dextrin, polyvinyl acrylate (PVA), polyacrylamide (PAA) or polymethyl methacrylate (PMMA). However, the selection of these materials is only an example, and the present invention does not limit the molecular structure and the physical structure similar to the biological bone by the organic-inorganic interaction during the coprecipitation reaction.

The binding regulator is incorporated into the carrier matrix and serves to introduce an anionic moiety thereto. In the mineralization process in which the Ca-P compound and the carrier material are cured while forming an porous structure by organic-inorganic interaction, the anionic moiety introduced into the carrier material serves to further promote the mineralization. In this way, the bone composition according to the present invention, which is rapidly cured, is cured before the density of the particles during coprecipitation becomes higher than necessary to have desirable porosity and high strength properties. Regarding this mineralization process, the temperature for reproducing or embodying the present invention is preferably 35 to 50 ° C, since the temperature is also a factor that affects the crystallization of the bone composition formed according to the mineralization process. At temperatures exceeding 50 ° C., crystallinity is too high to obtain satisfactory porosity. On the other hand, at temperatures below 35 ° C., crystallinity is too low and the spacing between particles is too short, which is also satisfactory porosity. Cannot be obtained.

The mixture in the coprecipitation step of the present invention exhibits an aspect of slurry or suspension, and it is also possible to use the bone compositions according to the invention on powders or solids by filtration or drying of the obtained products in which they have all subsided to form a supernatant. Since it is a well known fact, the description of the drying or filtration process will be omitted.

The bone composition according to the present invention, prepared by the above method, comprises a compound comprising Ca and P according to the above-mentioned characteristics (ie, Ca-P compound); Carrier material; And a binding regulator; characterized in that carbonated by the body fluid when implanted in the body.

In the case of using nonstoichimetric apatite as a material for artificial bone, if carbon dioxide (CO ₂ ) is present during the synthesis, it will enter into the apatite crystal structure with CO ₃ ^2- group during apatite formation and bonding reaction with organics. While increasing the strength of the apatite complex, stabilization significantly reduces osteolysis. That is, after the bone compound is fused into the human bone (after the transplantation is performed), this reaction is preferable in terms of physical properties, but it is better not to react with carbon dioxide until it is fused with the human bone. In consideration of this, in consideration of this, by providing a non-CO ₂ atmosphere in the manufacturing process, the artificial bone manufacturing system is not developed in which the CO ₃ ^2- group is not fused in the artificial bone.

Depending on the nature of the coprecipitation process in which the chemical composition in the manufacturing process remains the same, the details of these components will be replaced with those described above. However, a person who intends to reproduce or implement the present invention, a compound containing Ca and P (that is, Ca-P compound); Carrier material; And binding modulators; Although the composition ratio can be arbitrarily set, it should be noted that if the content of the binding regulator is too high, it may cause an inflammatory response when implanted in vivo, so that the content is preferably performed within 1 to 25% by weight. good.

The bone composition according to the present invention, 1) is carbonated and chemically stabilized in contact with carbonic acid in body fluids when implanted in the body, 2) provides very high mechanical strength by unique interactions between the comprising molecules, 3) By providing porosity similar to living bone, it is characterized in that it provides very efficient and high osteoconductivity in specific applications such as transplantation procedures. Therefore, when the bone composition according to the present invention is particularly included in artificial bone, the artificial bone can be used as a novel material significantly improved in the treatment of bone diseases such as fracture or bone growth disorder.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. However, these examples are only examples, and it will be apparent to those skilled in the art that the present invention is not limited thereto.

Preparation Example: Preparation of calcium oxide (CaO), calcium aqueous solution and phosphoric acid

CaCO ₃ was calcined at 1050 ° C. for 2 hours or more in air to obtain CaO powder. This was slowly cooled to 300 ° C. and transferred to a three-necked flask without a carbon dioxide atmosphere, followed by kneading using a stir bar and a stir chamber. Second distilled water was slowly added thereto. The internal temperature of the reactor was changed according to the time course of the vigorous exothermic reaction occurring, the amount and rate of distilled water added. Two hours prior to the execution of the example, this quicklime decomposition reaction was performed to prepare an aqueous solution in which a sufficient amount of Ca ²⁺ free ions and OH ⁻ free ions were dissolved.

The carbon dioxide free atmosphere of the three necked flask consisted of purging N ₂ gas and injecting decarbonized air through KOH. That is, CaO was transferred to a three-necked flask, and the rubber stopper was immediately closed, followed by purging with nitrogen gas three times or more using a hose connected to the stopper and a Schlenk line, followed by supplying air passed through a KOH flask.

Another three-necked flask vessel was charged with an appropriate amount of H ₃ PO ₄ solution and filled with ultrapure distilled water, and the connected air hose was purged with nitrogen as before, and then connected with a hose supplied with air passed through a KOH flask.

Reference Example 1:

Figure 2 is a schematic diagram of a manufacturing process according to a reference example or an embodiment of the present invention, Figure 3 is an image of the substrates used in this manufacturing process.

As shown, after the purge of nitrogen, the main reaction vessel filled with CO ₂ -free air after nitrogen purging is connected to a vessel containing aqueous calcium solution and a vessel containing phosphoric acid (concentrations and capacity of aqueous calcium solution and phosphoric acid are generated). HAp was calculated to be about 10 g), and these solutions were mixed in the main reaction vessel using a Masterflex pump and a silicone tube. The precipitation reaction proceeds while maintaining the pH of these mixed phases at 7.5 and the temperature at about 37 ° C. When the fine nano-precipitate was formed by the precipitation reaction, and the calcium aqueous solution or phosphoric acid was used up, the temperature of the main reaction vessel was maintained at 37 ° C. but left for about 24 hours to separate the precipitate and the supernatant. Next, the precipitate was filtered and dried at 25 ° C. and carbon dioxide-free atmosphere for about 6 hours to form a precipitate on a cake, and then ground to prepare a bone composition.

Reference Example 2:

A bone composition was prepared in the same manner as in Reference Example 1 except for flowing general air instead of CO ₂ -free air in the main reaction vessel and performing the same under a general air atmosphere during drying.

Example 1: Preparation of Bone Composition

A bone composition was prepared in the same manner as in Reference Example 1, except that 2 g of gelatin powder and 1 g of chitosan powder were dissolved in the phosphoric acid solution mixed in the main reaction container in Reference Example 1.

Example 2

Example 2 was prepared in the same manner as in Example 1, except that 3 g of gelatin powder and 0.1 g of chitosan powder were used in the phosphoric acid solution.

Example 3

Example 3 was prepared in the same manner as in Example 1, except that 3 g of gelatin powder and 0.3 g of chitosan powder were used in the phosphoric acid solution.

Example 4

Example 4 was prepared in the same manner as in Example 1, except that 3 g of gelatin powder and 0.5 g of chitosan powder were used in the phosphoric acid solution.

Example 5

Example 5 was prepared in the same manner as in Example 1, except that 3 g of gelatin powder and 0.5 g of chondroitin sulfate powder were used instead of chitosan in the phosphoric acid solution.

Comparative Example 1

Comparative Example 1 was prepared in the same manner as in Example 1, except that 2 g of gelatin powder was added to the phosphoric acid solution, but no chitosan powder was added.

Comparative Example 2

Comparative Example 1 was prepared in the same manner as in Reference Example 2, except that 2 g of gelatin powder was added to the phosphoric acid solution, but no chitosan powder was added.

Comparative Example 3

Comparative Example 3 was prepared in the same manner as in Reference Example 2, except that 3 g of gelatin powder and 0.1 g of chitosan powder were used in the phosphoric acid solution.

Comparative Example 4

Comparative Example 4 was prepared in the same manner as in Reference Example 2, except that 3 g of gelatin powder and 0.5 g of chitosan powder were used in the phosphoric acid solution.

Comparative Example 5

Comparative Example 5 was prepared in the same manner as in Reference Example 2, except that 3 g of gelatin powder and 0.5 g of chondroitin sulfate powder were used instead of chitosan in the phosphoric acid solution.

Test Example 1: Thermal Analysis

Thermal analysis (TG-DTA TG8120, USA) for Example 1 and Comparative Example 1 was performed. The thermal analysis was elevated at a rate of 10 ° C./min at temperatures between 25 and 1100 ° C., on atmospheric conditions and on platinum plates.

Figure 4 shows the TG-TGA pattern of Example 1 and Comparative Example 1. After the exothermic peak, an endothermic peak was observed at a temperature of about 80 ° C. At 300 to 550 ° C., the organic components of Example 1 and Comparative Example 1 were separated with increasing temperature. Above 790 ° C, carbon dioxide was released from the carbonate of HAp. As shown, in the case of Example 1, in which chitosan was added, compared to Comparative Example 1, in which mass change due to thermal decomposition was remarkably shown at 320 ° C and 351 ° C, the temperatures were 347 ° C and 362 ° C, which is compared with Example 1. It suggests that it included additional binding force compared to Example 1. This can be further discussed through TEM, SEM images and FTIR analysis.

Test Example 2: Micro Image

The bone composition of Example 1 was taken with an electron microscope (JEOL, Japan).

5 and 6 show a TEM image of an embodiment. As shown, in FIG. 5 a micro-unit composite network between the Example 1 components was observed. In FIG. 6, which is an enlarged image of FIG. 5, the network is formed as a needle-shaped HAp crystal phase, and the crystal phase has a width of about 3 nanometers and a length of about 20 nanometers. The composite network structure of such nano-unit crystal phases suggests higher strength of the examples.

Test Example 3: Dispersion Reflectance FTIR

Organic-inorganic interactions between HAp, gelatin and chitosan in the examples were further analyzed by FTIR. In addition, organic-organic interactions between gelatin and chitosan were analyzed by FTIR based on GRAMS AI (7.0). First, the dispersion reflectance FTIR (Magna 750R, Nicolet, U.S.A) method was performed in the Examples.

As a reference, the chitosan molecule alone FTIR case 7 with a 3450-3100 cm ¹ broad OH stretch of the absorption band, and aliphatic CH stretching absorption band in 2990 ~ 2850 cm ^-1 appears as shown in Fig. As can be seen in the side-by-side line of OH stretching bands and aliphatic CH stretching bands, this is a broad spectrum ranging from 3450-2850 cm ^-1 . Another major absorption band, 1220-1020 cm ^-1, represents a free primary amino group (-NH ₂ ) at the glucosamine C2 position, which is the main functional group of chitosan. The peak at the 1647 cm ⁻¹ position represents the acetylated amino group of chitin, suggesting that the chitosan sample was not fully deacetylated. The peak at the 1384 cm ⁻¹ position represents the CO stretching of the primary alcohol group (—CH ₂ —OH).

8 shows FTIR spectra relatively similar to Comparative Example 1. FIG. However, as observed locally and in detail, the organic-inorganic interaction between HAp, gelatin and chitosan can be explained.

As shown in FIG. 9 (extended spectrum of FIG. 8), amide I, II, III bands are found in Examples and Comparative Example 1. FIG. The 1335 cm ^-1 band of Comparative Example 1 is a spectral pattern suggesting resonance of the Ca-COO- complex. This is due to the longitudinal vibrations that are expressed while the proline side chains form covalent bonds with HAp. The inclusion of gelatin also reveals a common band at 1339 cm ⁻¹ , which suggests a red-shift phenomenon of the HAp-gelatin composition. The low chemical shift at gelatin 1339 cm ⁻¹ is due to very small HAp crystals bound to the gelatin molecules, which in turn suggests a low energy wagging of the proline side chains.

The band peaks of the examples are shown as 1339.4 cm −1 as shown in FIG. 9, which indicates a strong organic-organic interaction between the chitosan and the gelatin matrix. That is, these observations confirm that HAp / gelatin-chitosan nanocomposite was prepared as a polymer composite matrix by gelatin and chitosan.

In the case of the examples, the inclusion of chitosan results in a greater amount of carbonyl groups interacting with Ca ²⁺ during the coprecipitation reaction. This makes the amide I and II spectra bands of the examples more pronounced than in Comparative Example 1. The amide II band spectra of the examples appeared at 1547 and 1512 cm ⁻¹ , suggesting an organic-organic interaction between gelatin-chitosan as a more complex and delicate aspect.

This may also be described as the PO4 spectra of FIG. 10. PO4 v3 and v1 spectra are associated with bands due to HAp or HAp phosphate. The gentle spectra pattern represented by PO4 v3 in the examples suggests a greater amount of tissue response compared to HAp alone samples or Comparative Example 1.

Even in Example 2, where 0.1 g of chitosan was added to 3 g of gelatin matrix, the organic-organic interaction between gelatin and chitosan was quite strong. Chitosans contained within the gelatin molecules and their binding resulted in very high levels of organized HAp samples.

Although not shown, the soft spectra of the examples are very similar to the samples using 5 g of gelatin except for chitosan. The appearance of the slurry during the obtaining process was very sticky and, when dried, showed very good strength properties. As can be seen in the bands of CO3 v3 and v1 shown in FIG. 9, the example was much less carbonateized than Comparative Example 1, which showed high activity interaction between HAp and gelatin-chitosan matrix during coprecipitation. Suggests lower carbonates.

That is, the organic-inorganic interaction is very active during the coprecipitation process, which is thought to be further strengthened due to the organic-organic interaction between the gelatin-chitosan. The organic-organic interaction between gelatin-chitosan has a more positive effect on the formation of HAp by chemically interacting with Ca ²⁺ and phosphoric acid.

As indicated in the examples, gelatin powder and chitosan powder were dissolved in an aqueous solution of H ₃ PO ₄ at 37 ° C. prior to coprecipitation. During the dissolution, the gelatin and chitosan molecules were phosphorylated to form a molecular network between them. Phosphorylated and complexed molecules become a matrix for mineralization by HAp addition.

During the coprecipitation reaction of HAp, Ca-P ionic clusters of HAp complex with chemically bound gelatin-chitosan molecules. This produces a HAp / gelatin-chitosan nanocomposite.

In FIG. 10, it can be seen that the strength of HPO ₄ ^2- band spectra is relatively strong in HAp, moderate in Comparative Example 1 and very weak in Example 1, which is HPO ₄ ^2- and gelatin-chitosan matrix. It suggests that an active chemical reaction has taken place.

During the dissolution of H ₃ PO ₄ in distilled water, 3-protic phosphoric acid is formed dynamically (monobasic (H ₂ PO ^4- ), bibasic (HPO ₄ ^2- ) or tribasic (PO ₄ ^3- ) phosphate ). These basic ions interact with the side chains of the amides in the gelatinous polymer.

Chitosan includes carboxyl groups in the sulfate chain. Thus interactions for Ca ²⁺ -COO ^- bond formation can occur. It is read in the 1339.4 cm ⁻¹ band, resulting in Ca-COO binding. The 1339.4 cm ^-1 band of Example 1 is very strong compared to Comparative Example 1.

HPO ₄ ^2- bands typically at 903 cm ⁻¹ suggest the presence of OCP (octacalcium phosphate) during the mineralization process. Comparative Example 1 Samples show HPO ₄ ^2- band spectra and OCP images by FTIR and TEM observations. In contrast, in Example 1, no OCP was observed. This means that the molecular structure of the gelatin is controlled by organic interactions triggered by chitosan, and very ionic Ca ²⁺ in distilled water is consumed very quickly by interaction with COO- sites derived from gelatin and chitosan molecules. This is because, HAp is formed by reaction with PO ₄ ^3- and not reactively produced HPO ₄ ² -as Ca-P. This is another evidence of organic-organic interactions between activated gelatin and chitosan molecules in phosphate solutions.

11 is another FTIR spectra of Example 1 and Comparative Example 1. FIG. This is noted by the fact that the PO4 spectra pattern has changed greatly by the introduction of chitosan. That is, it can be observed that 1 g of chitosan chemically incorporated and linked 2 g of gelatin matrix molecules, whereby the PO4 pattern formed a very well-organized nanocomposite. That is, the HAp / gelatin-chitosan matrix elicited a smooth FTIR pattern as evidence of well organized Ca-P.

Test Example 4: X-ray Diffraction Pattern Analysis

As shown in FIG. 12, the XRD pattern of HAp / gelatin nanocompositions (Examples 1 to 4) controlled by chitosan is similar to Comparative Example 1. The examples are a hybrid composition of HAp and gelatin-chitosan matrix, wherein the shift of the (002) peak in the pattern appears to be due to HAp mineralization of gelatin and chitosan polymers. The X-ray powder diffraction pattern of standard HA (Tucker et al 1996, Fig 5b) is described by File No. of Joint Committee on Powder Diffraction Standards (JCPDS). Recorded at 9-432.

Diffraction peaks that are well analyzed and show sharp patterns exhibit some patterns unique to apatite, suggesting the high crystallinity of the present invention. These peaks were indexed based on the hexagonal system. In addition, the unit parameter was calculated using the d-spaced of the indexed peaks.

Test Example 5: Reaction with Carbon Dioxide

The examples according to the invention are all prepared in a carbon dioxide free environment and do not contain CO ₃ ^2- . Due to these chemical properties, the bone composition according to the present invention is carbonated by carbonate ions of body fluid only when implanted into the body, and as described above, the bone composition according to the present invention containing apatite is stabilized at the same time as carbonation and has higher strength. Characteristics are given.

To prove the above mechanism, the bone composition according to Example 1 was left in a common atmosphere containing carbon dioxide and further dried (heated or unheated). Figure 13 shows the XRD pattern graph of the result.

As shown, when compared with Example 1, which is not in contact with carbon dioxide, the 26-degree band intensity increases proportionally with drying when contacted with and dried. This suggests that the bone composition according to the present invention rapidly absorbs when it comes into contact with CO ₂ to form a (CO ₃ ^2- ) apatite phase containing carbonic acid and to stabilize and strengthen.

Due to the above mechanism, even when the bone composition according to the present invention is stored before use, contact with carbon dioxide should be avoided, and contact and reaction with carbon dioxide are preferably performed in the body after the implantation procedure.

In order to introduce micro-sized pores into the bone composition for artificial bone, organic-organic interactions and organic-inorganic interactions between the contained components must be properly controlled. Organic-inorganic interactions affect the control of strength and density in the nanocomposites, and organic-organic interactions affect the viscosity of the matrix organisms and the degree of porosity formed. While controlling these according to the invention, one can use bone compositions that exhibit better strength and porosity by implementing compositions free of carbonic acid. In other words, the nanostructures according to the present invention exhibit remarkably excellent strength characteristics when used as artificial bones, while exhibiting molecules and physical structures similar to living bones due to properly controlled organic-organic interactions and organic-inorganic interactions.

Test Example 6: Compressive Strength

The bone compositions of Reference Examples 1 and 2, Examples 2, 4 and 5, and Comparative Examples 1 to 5 were prepared as a paste, and rod-shaped specimens were made using a syringe, and after drying naturally, specimens having a diameter of 1.9 cm and a height of 3.3 cm. The compressive strength was measured with a universal testing machine [Dasan ENG, DS-UTM-1000] Instron 10ton and the results are shown in Table 1.

division atmosphere gelatin Chitosan Chondroitin Compressive strength (MPa) Reference Example 1 CO2 free Free Free Free 0.4 ± 0.2 Reference Example 2 General air Free Free Free 0.2 ± 0.2 Example 2 CO2 free contain contain Free 5.6 ± 0.2 Example 4 CO2 free contain contain Free 7.8 ± 0.2 Example 5 CO2 free contain Free contain 2.1 ± 0.2 Comparative Example 1 CO2 free contain Free Free 1.6 ± 0.2 Comparative Example 2 General air contain Free Free 1.0 ± 0.2 Comparative Example 3 General air contain contain Free 2.5 ± 0.2 Comparative Example 4 General air contain contain Free 4.5 ± 0.2 Comparative Example 5 General air contain Free contain 1.9 ± 0.2

Claims (15)

In a carbon dioxide-free atmosphere, an aqueous calcium solution; Phosphoric acid; At least one carrier material selected from the group consisting of gelatin, collagen, chondroitin sulfate and glycosaminoglycan; And a mixture of chitosan, dextrin, polyvinyl acrylate (PVA), polyacrylamide (PAA) and polymethyl methacrylate (PMMA), at least one binding modulator selected from the group consisting of: Preparing an organic-inorganic complex; And
And filtering or drying the organic-inorganic complex produced from the co-precipitation in a carbon dioxide-free atmosphere.
The organic-inorganic complex is composed of a compound containing a Ca and P, a carrier material and a binding regulator,
Compounds containing Ca and P include hydroxyapatite (HAp), and together with the hydroxyapatite (HAp) β-tricalcium phosphate, anhydrous dicalcium phosphate (CaHPO ₄ , DCPA), tetracalcium dihydrogen A mixture comprising at least one substance selected from the group consisting of phosphate (Ca ₄ H ₂ P ₆ O ₂₀ , TTCP) and dicalcium phosphate dihydrate (CaHPO ₄ 2H ₂ O, DCPD),
A method for producing a bone composition comprising an organic-inorganic complex that is carbonated by body fluid when implanted in the body. The method of claim 1,
The carbon dioxide-free atmosphere is a method for producing a bone composition, characterized in that the inert gas atmosphere or vacuum. delete The method of claim 1,
The coprecipitation step is a method for producing a bone composition, characterized in that carried out at 35 to 50 ℃. The method of claim 1,
The calcium aqueous solution is a method for producing a bone composition, characterized in that supersaturated calcium. The method of claim 1,
The calcium aqueous solution is a method for producing a bone composition, characterized in that the aqueous solution of calcium oxide. delete delete delete delete delete delete delete delete Claims 1, 2 and 4 to 6 artificial bones, characterized in that it comprises a bone composition prepared by the method of any one of claims.

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