A biomimetic mineralized dental bone powder and its preparation method

Abstract

This invention provides a biomimetic mineralized dental bone powder and its preparation method, belonging to the field of dental material preparation technology. The biomimetic mineralized dental bone powder of this invention comprises the following raw material components by weight: 80-90 parts tricalcium phosphate and 10-20 parts hydroxyapatite; wherein the hydroxyapatite is coated on the surface of the tricalcium phosphate by a mineralization coating. The mineralization coating is obtained by mineralizing a mixture of tricalcium phosphate and a mineralizing solution. This invention combines the advantages of both hydroxyapatite and tricalcium phosphate to develop a suitable biomimetic mineralized bone powder material with both degradability and bioactivity. The hydroxyapatite coating in this mineralized bone powder material is beneficial for enhancing the adsorption of related proteins by early osteogenic materials, thereby inducing cell adhesion and proliferation; tricalcium phosphate, as a degradable material, provides excellent conditions for later bone ingrowth.

Description

Technical Field

[0001] This invention belongs to the field of dental materials technology, specifically relating to a biomimetic mineralized dental bone powder and its preparation method. Background Technology

[0002] Over the past half-century, dental implant technology has become increasingly mature, and dental implant restoration has gradually become the main method of tooth loss restoration. The success of implantation is closely related to factors such as the volume and density of alveolar bone. The volume and density of alveolar bone will affect the initial stability of the implant. Initial stability is considered to be a key factor in forming good osseointegration and will affect the survival rate of the implant.

[0003] Increasing numbers of animal and human studies have demonstrated that alveolar bone undergoes both horizontal and vertical resorption after tooth extraction. This not only affects the successful placement of implants but also causes aesthetic problems after restoration. Alveolar bone depends on teeth for its existence; its volume and morphology change after tooth loss, and it typically resorbs within 3 to 6 months after extraction.

[0004] Patients often experience bone defects or bone loss after dental surgery, which dentists typically address with bone grafting materials such as bone powder. Currently, bone powder sources are mainly divided into two categories: natural bone derived from animal tissues and synthetic inorganic mineral materials. Natural bone powder derived from animal tissues suffers from drawbacks such as complex processing, high cost, and non-biodegradability in the body. In contrast, synthetic inorganic bone powder can be customized for specific environments and scenarios, and its lower cost makes it easier to use on a large scale in clinical practice.

[0005] With the in-depth research on oral and maxillofacial diseases, hydroxyapatite has been widely used as a bone material in oral surgery, such as in alveolar bone regeneration, periodontal bone defects, and jaw cysts. Hydroxyapatite can provide a favorable microenvironment for cells, promoting bone tissue repair. Its osteoconductivity is beneficial to cell adhesion, proliferation, and differentiation, making it increasingly popular as a site-preserving bone graft material. However, hydroxyapatite degrades relatively slowly, affecting new bone ingrowth in practical applications, thus making it difficult to perfectly meet actual clinical needs.

[0006] On the other hand, tricalcium phosphate materials have good degradation properties and can be naturally degraded in vivo, which is conducive to the ingrowth of new bone, making them a bone replacement material. However, tricalcium phosphate has limited hydrophilicity and its ability to enhance protein adsorption and cell adhesion is relatively small.

[0007] Therefore, existing artificial bone materials or bone powder materials cannot simultaneously solve the drawbacks of the two materials mentioned above, and cannot well integrate the degradation performance and osteoinductive properties of the two materials, resulting in relatively limited performance of the bone powder materials provided.

[0008] For example, patent document CN 112220964 A discloses a composite bioceramic powder, the composite bioceramic artificial bone prepared therefrom, and a preparation method thereof. The composite bioceramic powder comprises calcined bone powder and bioceramic powder, with a mass ratio of calcined bone powder to bioceramic powder of 1:(0.8–3). The bioceramic powder is one or more of β-tricalcium phosphate, calcium carbonate, calcium sulfate, calcium silicate, and bioactive glass. The composite bioceramic powder is used to prepare the composite bioceramic artificial bone via 3D printing. The artificial bone prepared using this composite bioceramic powder not only has good biocompatibility and can effectively promote bone healing, but also has a certain degree of hardness and strength, making it easy to shape. However, the method in this document only utilizes β-tricalcium phosphate and cannot simultaneously leverage the advantages of hydroxyapatite in promoting cell adhesion and bone regeneration.

[0009] For example, patent document CN 107596440 A discloses a bone repair material comprising a composition of α-calcium sulfate hemihydrate and autologous bone powder, wherein the autologous bone powder accounts for 20-60% of the weight percentage of the bone repair material, the α-calcium sulfate hemihydrate accounts for 40-80% of the weight percentage of the bone repair material, and the particle size range of the bone repair material is 50-1000 μm. The method for manufacturing the bone repair material includes the following steps: converting calcium sulfate dihydrate to α-calcium sulfate hemihydrate by microwave heating, grinding autologous bone to obtain autologous bone powder, and mixing the α-calcium sulfate hemihydrate with the autologous bone powder to form the bone repair material. This patent document utilizes a combination of α-calcium sulfate hemihydrate and autologous bone powder; however, the processing cost of autologous bone powder is relatively high.

[0010] Therefore, how to fully combine the advantages of hydroxyapatite and tricalcium phosphate to develop a suitable bone repair material that combines degradation properties and bioactivity has become an urgent technical problem to be solved. Summary of the Invention

[0011] The present invention aims to solve the aforementioned technical problems by providing a biomimetic mineralized dental bone powder and its preparation method. The technical objective of this invention is to provide a combination of hydroxyapatite and tricalcium phosphate to obtain a dental bone powder material with both good degradation properties and excellent bioactivity, thereby overcoming the functional shortcomings of existing bone powder materials.

[0012] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0013] This invention first provides a biomimetic mineralized dental bone powder, which, by weight, comprises the following raw material components:

[0014] Tricalcium phosphate 80-90 parts, hydroxyapatite 10-20 parts;

[0015] The hydroxyapatite is coated onto the surface of tricalcium phosphate through a mineralization coating.

[0016] The advantages of the two bone meal raw materials selected in this invention are as follows:

[0017] Tricalcium phosphate, as a biodegradable ceramic, possesses good biological activity, biocompatibility, and osteoconductive properties. Its tissue composition is similar to the inorganic components of bone tissue, thus rarely causing rejection after implantation. It also promotes bone formation and does not elicit significant inflammatory responses. After implantation, tricalcium phosphate is gradually degraded, promoting osteoblast proliferation and inducing osteogenesis, after which it is replaced by newly formed bone tissue. However, the degradation rate of tricalcium phosphate exceeds the rate of osteogenesis, which can affect bone repair outcomes.

[0018] Hydroxyapatite is a typical bioactive ceramic used in the repair of human hard tissues, exhibiting excellent bioactivity and biocompatibility. In the human physiological environment, it can chemically bond with tissues, forming a tight biochemical bond between the implant and the body tissue. This promotes the repair of bone defects and accelerates their healing, providing a scaffold for new bone formation and inducing its growth, making it a relatively ideal alternative material for human bone repair. However, hydroxyapatite also has some drawbacks, such as high brittleness and poor toughness. It degrades very slowly at the implantation site. While it provides certain mechanical properties, it cannot provide sufficient space for new bone ingrowth. Current methods mostly involve modifying it to better meet clinical needs.

[0019] This invention selects tricalcium phosphate, which has good degradation properties, as the base component of the bone powder material. It fully utilizes its excellent biological properties and osteoconductive properties. Through biomimetic mineralization, hydroxyapatite is used to modify the surface of tricalcium phosphate, effectively solving the problem of the mismatch between the rapid degradation of tricalcium phosphate in vivo and new bone growth. Simultaneously, the biomimetic mineralized hydroxyapatite coating can effectively improve the bioactivity of the material. Compared with tricalcium phosphate, hydroxyapatite effectively improves the adsorption of osteogenic proteins, which is beneficial to cell adhesion and enhances the osteoinductive properties of the material. The slow degradation of the coating allows the overall material to better match the ingrowth of new bone, effectively improving the osteogenic performance of the material.

[0020] Experiments show that the bone powder material of the present invention has good biocompatibility after implantation, with no obvious inflammatory response. In particular, its osteoinductive properties are extremely excellent, which is beneficial to accelerating the bone repair process.

[0021] Furthermore, by weight, its raw material composition is: 88 parts tricalcium phosphate and 12 parts hydroxyapatite.

[0022] Furthermore, the tricalcium phosphate includes β-tricalcium phosphate and / or α-tricalcium phosphate.

[0023] Furthermore, the mineralized coating is obtained by mineralizing a mixture of mineralizing solution and tricalcium phosphate.

[0024] Furthermore, the mineralizing solution comprises a mixed solution of sodium chloride, dipotassium hydrogen phosphate, magnesium chloride, 4-hydroxyethylpiperazine ethanesulfonic acid, calcium chloride, and sodium bicarbonate in a weight ratio of 20:0.6:0.6:12:1.1:1.5.

[0025] Furthermore, the pH of the mineralization solution is 6.4-7.2.

[0026] The second objective of this invention is to provide a method for preparing the biomimetic mineralized dental bone powder as described above, comprising the following steps:

[0027] (1) Preparation of mineralizing solution:

[0028] Sodium chloride, dipotassium hydrogen phosphate, magnesium chloride, 4-hydroxyethylpiperazine ethanesulfonic acid, calcium chloride, and sodium bicarbonate were mixed in a weight ratio of 20:0.6:0.6:12:1.1:1.5 to prepare a mixed solution; the pH of the mixed solution was adjusted to 6.4-7.2 and stirred until clear;

[0029] (2) Mineralization reaction:

[0030] Tricalcium phosphate and mineralizing solution were mixed at a weight ratio of 1.5-12:800 and subjected to constant temperature shaking at 37℃ and 100rpm for 16-48h for mineralization reaction.

[0031] (3) Mineral drying: After mineralization is completed, the minerals are washed and dried to obtain the product.

[0032] Furthermore, in step (1), the pH value is adjusted to 6.4-7.2 using a 2 mol / L sodium hydroxide solution or hydrochloric acid solution.

[0033] Furthermore, the mineralizing solution is replaced every 24 hours in step (2).

[0034] Furthermore, the drying in step (3) is performed at 60°C for 24 hours.

[0035] The beneficial effects of this invention are as follows:

[0036] (1) This invention combines the advantages of hydroxyapatite and tricalcium phosphate to develop a suitable biomimetic mineralized bone meal material with both degradability and bioactivity. This invention uses a biomimetic mineralization method, selecting tricalcium phosphate as the substrate and modifying its surface with a hydroxyapatite coating. Through washing, filtration, and drying, mineralized bone meal is obtained. The hydroxyapatite coating enhances the adsorption of related proteins by early osteogenic materials, thereby inducing cell adhesion and proliferation. Tricalcium phosphate, as a biodegradable material, provides excellent conditions for later bone ingrowth.

[0037] (2) This invention utilizes biomimetic mineralization to modify the surface of tricalcium phosphate using hydroxyapatite. This addresses the mismatch between the rapid degradation of tricalcium phosphate in vivo and new bone growth. Furthermore, the biomimetic mineralized hydroxyapatite coating effectively enhances the bioactivity of the material. Compared to tricalcium phosphate, hydroxyapatite significantly improves the adsorption of osteogenic proteins, facilitating cell adhesion and enhancing the material's osteoinductive properties. The slow degradation of the coating allows the overall material to better match the ingrowth of new bone, effectively improving the material's osteogenic performance. Attached Figure Description

[0038] Figure 1 The present invention relates to mineralized bone powder adsorbed with fluorescently labeled bovine serum albumin;

[0039] Figure 2 The adsorption experiments of bovine serum albumin on different samples are shown in the figure. The bars in the figure, from left to right, represent the adsorption amounts of bovine serum albumin on mineralized bone powder (GBR), tricalcium phosphate, and Gell-Hill bone powder of the present invention.

[0040] Figure 3 This is a SEM image of tricalcium phosphate after mineralization;

[0041] Figure 4 This is the XRD pattern of the mineralized bone meal. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described in detail below with reference to embodiments. It should be noted that the following embodiments are for explanation and illustration only and are not intended to limit the invention. Non-essential improvements and adjustments made by those skilled in the art based on the above description are still within the scope of protection of this invention.

[0043] Example 1

[0044] A biomimetic mineralized bone powder material is composed of the following raw material components: 80 parts of β-tricalcium phosphate and 20 parts of hydroxyapatite.

[0045] The preparation method of this biomimetic mineralized bone meal material includes the following process steps:

[0046] (I) Preparation of mineralizing solution

[0047] Sodium chloride, dipotassium hydrogen phosphate, magnesium chloride, 4-hydroxyethylpiperazine ethanesulfonic acid, calcium chloride, and sodium bicarbonate were weighed in a weight ratio of 20:0.6:0.6:12:1.1:1.5. The weighing results are as follows:

[0048] (1) Sodium chloride weighing (g): purified water: sodium chloride = 1000: 20.5709;

[0049] (2) Weighing of dipotassium hydrogen phosphate trihydrate (g): purified water: dipotassium hydrogen phosphate trihydrate = 1000: 0.6847;

[0050] (3) Weighing of magnesium chloride (g): Purified water: magnesium chloride = 1000: 0.6099;

[0051] (4) Weighing of 4-hydroxyethylpiperazine ethanesulfonic acid (g): purified water: 4-hydroxyethylpiperazine ethanesulfonic acid = 1000: 12;

[0052] (5) Weighing of calcium chloride (g): Purified water: Calcium chloride = 1000: 1.1761;

[0053] (6) Weighing of sodium bicarbonate (g): Purified water: Sodium bicarbonate = 1000: 1.5122;

[0054] (7) Dissolve the above 6 components in sequence, and use a stirrer to adjust to 1500 rpm to stir the solution evenly;

[0055] (8) Use a 2 mol / L sodium hydroxide solution or hydrochloric acid solution to adjust the pH of the solution to 6.4, and continue stirring the solution until it becomes clear.

[0056] (II) Mineralization

[0057] (1) Turn on the thermostatic oscillator and set the temperature to 37℃;

[0058] (2) Weigh the mineralizing solution and β-tricalcium phosphate in a weight ratio of 800:1.5;

[0059] (3) Set the oscillation rate to 100 rpm and mineralize for 16 hours;

[0060] (4) After mineralization, transfer the minerals to a new sterile container, add 1000g of purified water, set the shaking speed to 100rpm, wash for 5min, and repeat the washing three times.

[0061] (5) The mineralized material is placed in an oven for drying (60℃, 24h).

[0062] Example 2

[0063] A biomimetic mineralized bone powder material is composed of the following raw material components: 90 parts of β-tricalcium phosphate and 10 parts of hydroxyapatite.

[0064] The preparation method of this biomimetic mineralized bone meal material includes the following process steps:

[0065] (I) Preparation of mineralizing solution

[0066] (1) Weighing sodium chloride: purified water: sodium chloride = 1000: 20.5709;

[0067] (2) Weighing of dipotassium hydrogen phosphate trihydrate: purified water: dipotassium hydrogen phosphate trihydrate = 1000: 0.6847;

[0068] (3) Weighing magnesium chloride: purified water: magnesium chloride = 1000: 0.6099;

[0069] (4) Weighing of 4-hydroxyethylpiperazine ethanesulfonic acid: purified water: 4-hydroxyethylpiperazine ethanesulfonic acid = 1000: 12;

[0070] (5) Weighing calcium chloride: Purified water: Calcium chloride = 1000: 1.1761;

[0071] (6) Weighing sodium bicarbonate: purified water: sodium bicarbonate = 1000: 1.5122;

[0072] (7) Dissolve each of the above components in sequence, and use a stirrer to adjust to 1500 rpm to stir the solution evenly;

[0073] (8) Use a 2 mol / L sodium hydroxide solution to adjust the pH of the solution to 7.2, and continue stirring the solution until it becomes clear.

[0074] (II) Mineralization

[0075] (1) Turn on the thermostatic oscillator and set the temperature to 37℃;

[0076] (2) Weigh the mineralizing solution and β-tricalcium phosphate in a weight ratio of 800:12;

[0077] (3) Set the oscillation rate to 100 rpm, replace the mineralizing solution every 24 hours, and mineralize for 48 hours;

[0078] (4) After mineralization, transfer the minerals to a new sterile container, add 1000g of purified water, set the shaking speed to 100rpm, wash for 5min, and repeat the washing three times.

[0079] (5) The mineralized material is placed in an oven for drying (60℃, 24h).

[0080] Example 3

[0081] A biomimetic mineralized bone powder material is composed of the following raw material components: 88 parts of tricalcium phosphate and 12 parts of hydroxyapatite.

[0082] The preparation method of this biomimetic mineralized bone meal material includes the following process steps:

[0083] (I) Preparation of mineralizing solution

[0084] (1) Weighing sodium chloride: purified water: sodium chloride = 1000: 20.5709;

[0085] (2) Weighing of dipotassium hydrogen phosphate trihydrate: purified water: dipotassium hydrogen phosphate trihydrate = 1000: 0.6847;

[0086] (3) Weighing magnesium chloride: purified water: magnesium chloride = 1000: 0.6099;

[0087] (4) Weighing of 4-hydroxyethylpiperazine ethanesulfonic acid: purified water: 4-hydroxyethylpiperazine ethanesulfonic acid = 1000: 12;

[0088] (5) Weighing calcium chloride: Purified water: Calcium chloride = 1000: 1.1761;

[0089] (6) Weighing sodium bicarbonate: purified water: sodium bicarbonate = 1000: 1.5122;

[0090] (7) Dissolve each of the above components in sequence, and use a stirrer to adjust to 1500 rpm to stir the solution evenly;

[0091] (8) Use a 2 mol / L sodium hydroxide solution or hydrochloric acid solution to adjust the pH of the solution to 6.8, and continue stirring the solution until it becomes clear.

[0092] (II) Mineralization

[0093] (1) Turn on the thermostatic oscillator and set the temperature to 37℃;

[0094] (2) Weigh the mineralizing solution and β-tricalcium phosphate in a weight ratio of 800:6;

[0095] (3) Set the oscillation rate to 100 rpm, replace the mineralizing solution after 24 hours, and mineralize for 32 hours.

[0096] (4) After mineralization, transfer the minerals to a new sterile container, add 1000g of purified water, set the shaking speed to 100rpm, wash for 5min, and repeat the washing three times.

[0097] (5) The mineralized material is placed in an oven for drying (60℃, 24h).

[0098] Experimental Example 1

[0099] The biomimetic mineralized bone powder prepared in the embodiments of the present invention was characterized in terms of performance. Taking Example 1 as an example, the characterization results are as follows: Figure 1-4 As shown. The biomimetic mineralized bone powder prepared in other embodiments has similar properties.

[0100] The specific characterization methods are as follows:

[0101] Take 100 mg of bovine serum albumin and dilute to 100 mL with PBS buffer. Group the samples according to Table 1, weigh the corresponding samples into 1.5 mL centrifuge tubes, add 1 mL of bovine serum albumin solution to each tube, and perform three replicates for each group. Seal the centrifuge tubes with sealing film and place them in an air bath constant temperature shaking incubator, setting the shaking speed to 100 RPM and the temperature to 37 °C.

[0102] Table 1

[0103]

[0104] According to the grouping, supernatant was collected from each sample at the corresponding time, and the protein content in the supernatant was detected using a BCA kit. Figure 2 The amount of protein adsorbed in the sample was calculated based on the protein content in the supernatant. After sampling, an equal volume of PBS solution was added, and the sample was shaken for 24 hours. The protein-adsorbed sample was then washed three times with PBS buffer. Subsequently, the protein adsorption was observed under a fluorescence microscope. Figure 1 After mineralizing tricalcium phosphate in SBF solution for 48 hours, the sample was washed, dried, and its surface morphology was observed by scanning electron microscopy (SEM). Figure 3 Similarly, an appropriate amount of mineralized sample was taken and its diffraction pattern was determined by X-ray diffraction (XRD) within a scanning range of 5°-80°. Figure 4 ).

Claims

1. A biomimetic mineralized dental bone powder, characterized in that, The raw material components include, by weight parts: tricalcium phosphate 80-90 parts, hydroxyapatite 10-20 parts; The hydroxyapatite is coated on the surface of the tricalcium phosphate by a mineralization coating; the mineralization coating is obtained by mixing a mineralization solution with the tricalcium phosphate and then mineralizing; the mineralization solution includes a mixed solution of sodium chloride, dipotassium hydrogen phosphate, magnesium chloride, 4-hydroxyethyl piperazine ethanesulfonic acid, calcium chloride, and sodium bicarbonate in a weight ratio of 20:0.6:0.6:12:1.1:1.5; the pH of the mineralization solution is 6.4-7.

2.

2. The biomimetically mineralized dental bone powder according to claim 1, characterized in that, The raw material components include, by weight parts: tricalcium phosphate 88 parts, hydroxyapatite 12 parts.

3. The biomimetically mineralized dental bone powder according to claim 1, wherein, The tricalcium phosphate includes β-tricalcium phosphate and / or α-tricalcium phosphate.

4. The method of producing a biomimetic mineralized dental bone powder according to any one of claims 1 to 3, wherein The method includes the following steps: (1) Preparation of the mineralization solution: Sodium chloride, dipotassium hydrogen phosphate, magnesium chloride, 4-hydroxyethyl piperazine ethanesulfonic acid, calcium chloride, and sodium bicarbonate are mixed in a weight ratio of 20:0.6:0.6:12:1.1:1.5 to prepare a mixed solution; the pH of the mixed solution is adjusted to 6.4-7.2, and the solution is stirred until it is clear; (2) Mineralization reaction: Tricalcium phosphate and the mineralization solution are mixed in a weight ratio of 1.5-12:800, and the mixture is subjected to constant temperature oscillation at 37°C and 100 rpm for 16-48 h to perform the mineralization reaction; (3) Drying of the mineralization product: after the mineralization is completed, the mineralization product is washed and dried.

5. The preparation method according to claim 4, characterized in that, In step (1), a 2 mol / L sodium hydroxide solution or a hydrochloric acid solution is used to adjust the pH to 6.4-7.

2.

6. The preparation method according to claim 4, characterized in that, In step (2), the mineralization solution is replaced every 24 h.

7. The preparation method according to claim 4, characterized in that, In step (3), the drying is performed at 60°C for 24 h.

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