Composition with developing effect and bone inductive ability and its preparation method and application

Abstract

The application discloses a composition with developing effect and bone inductive capacity, and a preparation method and application thereof. The composition comprises tetracalcium phosphate, L-serine phosphorylation product, bone inductive component, other basic calcium phosphate salt and liquid phase component. After the solid phase component and the liquid phase component are mixed, a reaction occurs, and a paste-like material is obtained, which is completely solidified after 20-30 minutes of reaction. The reaction temperature is lower than 40 DEG C, and the developing CT value is greater than 450 HU. The composition can be used as a filling material, filled into the position between an intervertebral fusion cage and adjacent vertebrae in intervertebral fusion, and used for providing immediate stability for the intervertebral fusion cage and meeting the anti-pressing requirement after operation. The problems of displacement and falling of the fusion cage and poor developing effect of the fusion cage in the existing intervertebral fusion are solved, and bone tissue growth can be effectively induced after operation, so that the success rate and treatment effect of the intervertebral fusion are improved.

Description

Technical Field

[0001] This invention relates to the field of medical devices, specifically to a composition having imaging effect and bone induction ability, its preparation method, and its application. Background Technology

[0002] Interbody fusion is a crucial treatment for spinal diseases and is widely used in clinical practice. Its core steps involve removing the diseased tissue, inserting an interbody fusion cage for bone grafting, and then using a pedicle screw system to fix adjacent vertebrae with pedicle screws and connecting rods to achieve internal fixation and stability. Postoperatively, the body waits for new bone tissue to fill the fusion cage, completing the fusion process. However, the pedicle screw system has limitations. Firstly, it may lead to complications such as screw loosening and adjacent segment degeneration (ASD), and also carries risks of significant trauma, pseudoarthrosis, and bone loss. Secondly, traditional bioactive bone materials typically have a CT value below 300 HU on X-ray and CT images, resulting in poor imaging and difficulty in intraoperative localization. Approximately 8-12% of cases experience uneven material filling or spinal canal leakage. Furthermore, the lack of postoperative monitoring makes it difficult for surgeons to accurately assess the distribution and filling of bone repair material during surgery. This can lead to improper placement of the interbody fusion cage and insufficient or uneven distribution of bone repair material, affecting the overall effectiveness of interbody fusion.

[0003] PEEK material, due to its good biocompatibility, is often used to fabricate interbody fusion cages. Some methods propose modifying the surface of PEEK material interbody fusion cages with hydroxyapatite. Hydroxyapatite is a major inorganic component of human bone tissue; after implantation, calcium and phosphorus are released from the material surface and absorbed by body tissues, leading to the growth of new tissue and inducing bone growth, thus accelerating the fusion of bone tissue and the interbody fusion cage. Simultaneously, the surface of the interbody fusion cage can be designed to increase the friction between the cage and the vertebrae through microstructure, aiming to achieve single-cage fixation without the introduction of a rod-and-screw system. However, due to insufficient immediate postoperative stability, cage subsidence or displacement may occur in complex cases.

[0004] Therefore, developing a composition with good imaging effect and bone induction ability, and capable of low-temperature curing to improve the immediate stability of the interbody fusion device to ensure that the position is not lost and that it is eventually fused, has important clinical significance and application value. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes a composition with imaging effect and bone induction ability, its preparation method, and its application. It synergistically optimizes imaging effect, bone induction activity, and biocompatibility, solving the problems of limited bone induction ability and poor immediate stability of PEEK-type interbody fusion devices in current interbody fusion surgeries, as well as insufficient imaging clarity of the filling material, mismatch between degradation and bone regeneration rates, and poor biocompatibility.

[0006] In a first aspect, the present invention discloses a composition having imaging effect and bone-inducing ability, the composition being used to prepare a filling material for intervertebral fusion, comprising, by weight percentage, the following components:

[0007] Tetracalcium phosphate 35%~60%.

[0008] L-serine phosphorylation products: 35-45%.

[0009] Bone-inducing components: 1%~10%.

[0010] Other alkaline calcium phosphate salts should be added to bring the total to 100%.

[0011] Preferably, the other basic calcium phosphate salts have a mass percentage of 10-25% and are selected from one or more of hydroxyapatite, β-tricalcium phosphate, and α-tricalcium phosphate.

[0012] Preferably, the bone-inducing component is selected from one or more combinations of bone morphogenetic proteins (BMP-2, BMP-7), osteogenic growth peptides, bone repair materials, or malleable bone repair materials.

[0013] Preferably, the bone-inducing component has a mass percentage of 5%.

[0014] Preferably, the particle size of the tetracalcium phosphate and other calcium phosphate salts is less than 50 μm.

[0015] Preferably, the L-serine phosphorylation product is selected from one or more combinations of O-phosphorylated polypeptides, cyclic phospholipid analogs, 3-phosphoserine, and O-phospho-L-serine.

[0016] Preferably, the composition further includes a liquid phase component. The liquid phase component is one or more of physiological saline, purified water, phosphate buffered saline solution, platelet-rich plasma (PRP), and sodium citrate solution.

[0017] Preferably, the liquid phase component is a sodium citrate solution with a concentration of 5% to 30%.

[0018] Preferably, the mass ratio of the solid phase to the liquid phase in the composition is 1:(0.2-0.4).

[0019] In a second aspect, the present invention discloses a method for preparing a composition with imaging effect and bone induction ability. First, solid components are weighed and mixed according to mass percentage. Then, a liquid phase composition is added to the mixed solid components according to mass ratio. After reaction, a paste-like composition with imaging effect is obtained. The reaction temperature is below 40°C, and the imaging CT value is greater than 450 HU. The mixture completely solidifies after 20-30 minutes of reaction.

[0020] In a third aspect, the present invention discloses the application of a composition with radiopaque properties and bone-inducing capabilities, used to prepare a filling and fixation material for interbody fusion surgery. This material is used to fill the space between the interbody fusion cage and adjacent vertebrae during interbody fusion surgery. The composition has radiopaque properties before curing, allowing for assessment of the material's filling and distribution. After curing, it can fix the position of the interbody fusion cage, providing immediate stability and compressive strength.

[0021] In a fourth aspect, the present invention discloses an immediately stable interbody fusion device for individual placement in the intervertebral space during interbody fusion surgery. The immediately stable interbody fusion device comprises an interbody fusion device body and a bioactive coating disposed on the surface of the body. The bioactive coating is the aforementioned composition having radiopaque effect and bone-inducing ability.

[0022] The present invention has the following beneficial effects:

[0023] 1. Excellent imaging effect: The composition of this invention contains components with excellent imaging properties, with a CT value ≥300HU, enabling clear imaging in X-ray, CT, and other imaging examinations. When used as a filler in intervertebral fusion surgery, it helps doctors clearly see the distribution of the composition in the intervertebral space, allowing for timely adjustments to the surgical procedure and avoiding surgical errors caused by unclear imaging.

[0024] 2. Strong osteoinductive ability and good biocompatibility: The composition contains multiple components with osteoinductive activity, which can stimulate the proliferation and differentiation of osteocytes and promote the growth and fusion of bone tissue. Compared with traditional filler materials, it can significantly shorten the bone fusion time and improve the quality of bone fusion. It has good biocompatibility and no obvious irritation or toxicity to human tissues. It can integrate well with surrounding tissues in vivo, reducing the occurrence of postoperative complications.

[0025] 3. Low curing temperature and suitable curing time: By compounding other acidic phosphates into tetracalcium phosphate to lower the solid phase pH and simultaneously optimizing the liquid phase pH, the overall curing temperature of the material is controlled below 40℃ through the synergistic regulation of the solid-liquid two-phase system, effectively avoiding cell damage caused by excessively high curing temperatures. Simultaneously, the suitable curing time allows sufficient time for filling and shaping the composition during clinical surgery without excessively long curing times that could affect surgical efficiency. With a compressive strength exceeding 20 MPa, it can immediately provide stable support for the interbody fusion device. Attached Figure Description

[0026] Figure 1 Postoperative X-ray image of the composition injected into the intervertebral fusion cage and the space between adjacent vertebrae in Example 11.

[0027] Figure 2 This is a postoperative X-ray image of the intervertebral fusion device being placed separately into the intervertebral space in Example 11. Detailed Implementation

[0028] The present invention will be further explained and described below with reference to the accompanying drawings. It should be noted that the following embodiments are illustrative of the present invention and not intended to limit the invention. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0029] Unless otherwise specified, the experimental methods described in the embodiments are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0030] Example 1

[0031] This embodiment prepares a composition with imaging effect and bone induction ability, and the specific method is as follows:

[0032] Step 1: Weigh the solid components according to the mass percentage, specifically 50% tetracalcium phosphate with a purity of 99.5% and a particle size of 25 μm, 35% O-phospho-L-serine, 5% BMP-2 and 10% α-tricalcium phosphate with a particle size <30 μm.

[0033] Step 2: Mix the solid components in a planetary ball mill for 2 hours at a speed of 300 rpm to obtain a uniform solid powder composition.

[0034] Step 3: Add purified water to the solid powder at a solid-liquid mass ratio of 1:0.25, and stir rapidly for 30 seconds using a stirring rod to obtain a paste-like composition.

[0035] Example 2

[0036] This embodiment prepares a composition with imaging effect and bone induction ability. Based on Example 1, the mass percentage of tetracalcium phosphate in the solid phase component is adjusted to 60%, and the mass percentage of α-tricalcium phosphate is adjusted to 0%.

[0037] Example 3

[0038] This embodiment prepares a composition with imaging effect and bone induction ability. Based on Example 1, the mass percentage of tetracalcium phosphate in the solid phase component is adjusted to 35%, and the mass percentage of α-tricalcium phosphate is adjusted to 25%.

[0039] Example 4

[0040] This embodiment prepares a composition with imaging effect and bone induction ability. Based on Example 1, the mass percentage of tetracalcium phosphate in the solid phase component is adjusted to 10%, and the mass percentage of α-tricalcium phosphate is adjusted to 50%.

[0041] Example 5

[0042] This embodiment prepares a composition with imaging effect and bone induction ability. Based on Example 1, the mass percentage of tetracalcium phosphate in the solid phase component is adjusted to 55%, and O-phospho-L-serine is adjusted to 30%.

[0043] Example 6

[0044] This embodiment prepares a composition with imaging effect and bone induction ability. Based on Example 1, the mass percentage of tetracalcium phosphate in the solid phase component is adjusted to 40%, and O-phospho-L-serine is adjusted to 45%.

[0045] Example 7

[0046] This embodiment prepares a composition with imaging effect and bone induction ability. Based on Example 1, the mass percentage of tetracalcium phosphate in the solid phase component is adjusted to 60%, and O-phospho-L-serine is adjusted to 25%.

[0047] Example 8

[0048] This embodiment prepares a composition with imaging effect and bone induction ability. Based on Example 1, the mass percentage of tetracalcium phosphate in the solid phase component is adjusted to 54%, and BMP-2 is adjusted to 1%.

[0049] Example 9

[0050] This embodiment prepares a composition with imaging effect and bone induction ability. Based on Example 1, the mass percentage of tetracalcium phosphate in the solid phase component is adjusted to 45%, and BMP-2 is adjusted to 10%.

[0051] Example 10

[0052] This embodiment prepares a composition with imaging effect and bone induction ability. Based on Example 1, purified water is replaced with a 25% sodium citrate solution.

[0053] Comparative Example 1

[0054] This embodiment prepares a composition without bone-inducing components. Based on Example 1, the mass percentage of tetracalcium phosphate in the solid phase component is adjusted to 55%, and BMP-2 is adjusted to 0%.

[0055] Test Example 1 tested the developability and mechanical properties of the compositions prepared in Examples 1-10 and Comparative Example 1, and measured the curing time and curing problems.

[0056] (1) Development performance test

[0057] Following clinical CT scanning conditions (120 kVp, 250 mAs, slice thickness 1.25 mm), the compositions obtained in each example and comparative example were injected into a polytetrafluoroethylene mold with an inner diameter of 10 mm and cured for 24 hours to prepare five cylindrical samples with a diameter of 10 mm and a height of 10 mm. Three consecutive slices were selected from the center of the sample on the axial CT image, with a circular region of interest of 5 mm in diameter set in each slice. CT values ​​were measured and the average value was recorded.

[0058] (2) Mechanical property testing

[0059] After soaking the samples in SBF solution at 37℃ for 7 days, they were tested according to the standards YY 0459-2025 (compression), GB / T 1040.1-2018 (tensile), and GB / T 7124-2008 (shear).

[0060] (3) Curing time test

[0061] According to the YY 0459-2025 standard, the Gilmore needle method was used, with 113.4 g needles for initial coagulation and 453.6 g needles for final coagulation. Under the conditions of temperature (23±1)℃ and relative humidity (50±10)%, the time from the start of liquid-solid mixing to the point where no complete circular indentation was left on the needle tip was recorded.

[0062] (4) Curing temperature test

[0063] According to YY 0459-2025 for the highest temperature test, before the experiment begins, the mixing equipment, testing device and composition are kept at (23±1)℃ and (50±10)% relative humidity for at least 2 hours. Then, a T-type thermocouple is inserted into the center of the composition, and the highest temperature of the curing process is monitored in a constant temperature environment of 23℃.

[0064] The test results are shown in Table 1:

[0065] Table 1

[0066]

[0067] Clinically, a CT value above 300 HU is generally considered sufficient for clear imaging. However, in this method, the CT values ​​of all samples obtained were above 410 HU. In particular, when the mass percentage of tetracalcium phosphate was above 35%, the CT value exceeded 488 HU, far exceeding the clinically satisfactory imaging threshold. Therefore, the composition of this invention meets the imaging requirements during and after surgery. The compressive strength of the composition is 22.8~40.2 MPa, which generally meets the requirements for cancellous bone repair. The tensile strength is 0.5~1.5 MPa, and the shear strength is 0.4~1.3 MPa. In Examples 2~4, the mass percentage of α-tricalcium phosphate gradually increased, and the compressive strength of the resulting composition also gradually increased, indicating a positive correlation between the content of other basic calcium phosphate salts in the composition and the compressive strength, suggesting that basic calcium phosphate salts can contribute to rigidity. In Examples 5-7, the mass percentage of O-phospho-L-serine gradually increased, and the tensile strength and shear strength of the resulting compositions also showed an increasing trend. This indicates a positive correlation between the content of L-serine phosphorylation products in the compositions and the toughness index, suggesting that L-serine phosphorylation products may enhance interfacial bonding through molecular chain entanglement. Example 10 showed a significant increase in both tensile strength and shear strength compared to Example 1, suggesting that sodium citrate solution may optimize the interfacial transition zone through chelation.

[0068] The content of the osteoinductive component can simultaneously affect the mechanical properties, reaction temperature, and imaging performance of the composition. In Example 8, the osteoinductive component content of 1% resulted in the best overall mechanical properties. In Example 9, the osteoinductive component content of 10% led to a decrease in mechanical strength, but also a prolonged coagulation time and a lower temperature. In Example 1, the highest CT value was achieved when the osteoinductive component content was 5%. The content of the osteoinductive component can be adjusted according to the requirements for the mechanical properties, reaction temperature, and imaging performance of the composition.

[0069] The highest curing temperatures of the compositions in the examples ranged from 35.8 to 44.1°C, all below the biosafety threshold of 50°C, effectively preventing thermal damage. Comparison of different examples revealed that the content of other basic calcium phosphate salts was negatively correlated with temperature, indicating that high levels of basic calcium phosphate salts reduced the exothermic reaction through physical dilution. However, the content of tetracalcium phosphate and L-serine phosphorylation products was positively correlated with temperature, suggesting that these components may participate in the exothermic reaction, with increased content leading to a rise in system temperature. Example 10 used a 25% sodium citrate solution instead of purified water, which reduced the highest temperature by 1.9°C compared to Example 1, while simultaneously increasing the tensile strength by 66.7%, indicating that the sodium citrate solution may reduce the exothermic peak by slowing the reaction rate.

[0070] Test Example 2

[0071] Cytotoxicity, acute systemic toxicity, intradermal irritation, and muscle implantation tests were conducted in accordance with the ISO 10993 series of standards.

[0072] (1) Cytotoxicity test

[0073] The testing standard was ISO 10993-5, the experimental model used was L929 mouse fibroblasts, the experimental method was CCK-8 assay, and cell viability was used as the evaluation index. The results after 72 hours of culture are shown in Table 2.

[0074] Table 2

[0075]

[0076] According to the experimental results, except for Example 4, which has the highest content of other alkaline calcium phosphate salts and shows slight toxicity, the other compositions are non-toxic, and Example 4 still meets the ISO safety threshold of cell survival rate greater than 80%.

[0077] (2) Acute systemic toxicity test

[0078] The testing standard was ISO 10993-11. ICR mice were injected via the tail vein at a dose of 50 mL / kg. 14-day survival rate, weight change, and organ pathology were used as evaluation indicators. The results are shown in Table 3.

[0079] Table 3

[0080]

[0081] All tested samples had an LD50 greater than 5000 mg / kg, which meets the practically non-toxic standard in GB / T 15193.3-2014.

[0082] (3) Intradermal stimulation test

[0083] The testing standard was ISO 10993-10. New Zealand rabbits were injected intradermally with 0.2 mL at a time. After 72 hours of observation, erythema and edema were scored from 0 to 8. The results are shown in Table 4.

[0084] Table 4

[0085]

[0086] The total stimulation index of all experimental groups was less than 2.0, which met the criteria for no stimulation / mild stimulation.

[0087] (4) Muscle implantation experiment

[0088] The testing standard was ISO 10993-6. The implant was placed in the dorsal muscles of SD rats, and the inflammatory response grade and fibrous capsule thickness were observed after 8 weeks. The results are shown in Table 5.

[0089] Table 5

[0090]

[0091] The inflammatory response grade of the compositions obtained in all examples was ≤1, which meets the safety requirements of ISO 10993-6. The thickness of the fibrous capsule was <50μm, indicating that the material has good compatibility with muscle tissue and no obvious foreign body reaction.

[0092] Example 11

[0093] The composition obtained in Example 10 was used to prepare a filling and fixation material for interbody fusion surgery. The composition was injected into the space between the interbody fusion device and the adjacent vertebrae using a syringe. Figure 1 Postoperative X-ray images of the composition injected into the intervertebral fusion cage and adjacent vertebral space during animal experiments for interbody fusion surgery. Figure 2 Postoperative X-ray images of intervertebral fusion cages placed separately in the intervertebral space are used as a control.

[0094] from Figure 1 As can be seen, the composition is uniformly distributed within the intervertebral space, clearly visualized, and well-integrated with the fusion cage and vertebral interface. This demonstrates that the composition proposed in this invention exhibits excellent imaging performance in intervertebral fusion surgery. Surgeons can clearly observe the filling of the material around the fusion cage using X-rays or CT scans, ensuring adequate filling and improving the success rate of the surgery. Furthermore, data from Test Example 2 shows that the composition proposed in this invention meets biocompatibility requirements and is suitable for use in patients with low immune function and those requiring long-term implantation. Simultaneously, data from Test Example 1 shows that the composition proposed in this invention has a reaction temperature below the biosafety threshold and an appropriate curing time, providing immediate postoperative stability; therefore, it can be used as a filling and fixation material in intervertebral fusion surgery.

Claims

1. A composition having imaging effect and bone-inducing ability, characterized in that: The composition is used to prepare a filling material for use in interbody fusion surgery, filling the space between the interbody fusion cage and adjacent vertebrae; the composition comprises the following components by weight percentage: Tetracalcium phosphate 35%~60%; L-serine phosphorylation products: 35-45%; Bone-inducing components: 1%~10%; And the remainder of other alkaline calcium phosphate salts, wherein the mass percentage of the other alkaline calcium phosphate salts is 10% to 25%.

2. The composition with imaging effect and bone induction ability as described in claim 1, characterized in that: The other basic calcium phosphate salts have a mass percentage of 10-25% and are selected from one or more of hydroxyapatite, β-tricalcium phosphate, and α-tricalcium phosphate.

3. The composition with imaging effect and bone induction ability as described in claim 2, characterized in that: The particle size of the tetracalcium phosphate and other calcium phosphate salts is less than 50 μm.

4. The composition with imaging effect and bone induction ability as described in claim 1, characterized in that: The bone-inducing component has a mass percentage of 5% and is selected from one or more combinations of bone morphogenetic proteins, osteogenic growth peptides, bone repair materials, or malleable bone repair materials.

5. The composition with imaging effect and bone induction ability as described in claim 1, characterized in that: The L-serine phosphorylation product is selected from one or more combinations of O-phosphorylated polypeptides, cyclic phospholipid analogs, 3-phosphoserine, and O-phospho-L-serine.

6. The composition with imaging effect and bone induction ability as described in claim 1, characterized in that: The composition further includes a liquid phase component; the liquid phase component is one or more of physiological saline, purified water, phosphate buffer solution, platelet-rich plasma (PRP), and sodium citrate solution.

7. The composition with imaging effect and bone induction ability as described in claim 6, characterized in that: The liquid phase component is a sodium citrate solution with a concentration of 5% to 30%.

8. A method for preparing a composition having imaging effect and bone-inducing ability as described in any one of claims 1 to 7, characterized in that: First, weigh and mix the solid components according to the mass percentage. Then, add the liquid components to the mixed solid components according to the mass ratio. After the reaction, a paste-like composition with developing effect is obtained. The reaction temperature is below 40℃, and the developing CT value is greater than 450 HU. The mixture is completely cured after 20~30 minutes of reaction.

9. The use of a composition with radiopaque effect and bone-inducing ability as described in any one of claims 1 to 7 in a medicament for intervertebral fusion disease; preferably, the use includes the steps of: using the composition to prepare a filling and fixation material for intervertebral fusion surgery, which is filled in the position between the intervertebral fusion device and the adjacent vertebrae during intervertebral fusion surgery, the composition having radiopaque effect before curing, and being able to fix the position of the intervertebral fusion device after curing, providing immediate stability and compressive strength.

10. An immediately stable interbody fusion device, characterized in that: It includes a body of an intervertebral fusion device and a bioactive coating disposed on the surface of the body; the bioactive coating is a composition with imaging effect and bone induction ability as described in any one of claims 1 to 7.

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