Bionic scaffold material for promoting repair and reconstruction of infectious bone defects as well as preparation method and application of bionic scaffold material

Abstract

The invention relates to the technical field of bionic medical materials, in particular to a bionic scaffold material for promoting repair and reconstruction of infectious bone defects and a preparation method and application of the bionic scaffold material. The preparation method comprises the following steps: wrapping the oxygen vacancy titanium dioxide nanorod in collagen through temperature control, and directionally depositing mineralized crystals in a gap region in the collagen to obtain the porous bionic scaffold with a bone-like structure. The bionic scaffold material disclosed by the invention has a bone-like structure, not only can realize efficient physical antibiosis after ultrasonic irradiation, but also can adjust the intercellular effect of macrophages to promote tissue repair, and the repair and reconstruction effects of the material on infectious bone defects are verified in animal experiments. The successful preparation of the material can realize time-space controllable precise antibiosis, further promote the repair and regeneration of bone tissues, and provide a new method for clinical treatment of bone defects, especially bone defect related diseases accompanied by infection.

Description

Technical Field

[0001] This invention relates to the field of biomimetic medical materials technology, and in particular to a biomimetic scaffold material for promoting the repair and reconstruction of infected bone defects, its preparation method, and its application. Background Technology

[0002] In recent years, the incidence of bone defect-related diseases caused by factors such as trauma, tumors, and congenital malformations has been increasing year by year. Furthermore, factors such as open wounds, tissue spread, and surgical exposure often lead to bacterial invasion of the defect area, causing more complex infectious bone defects. The presence of infection severely impairs the regenerative capacity of local tissues and bone, making the defect difficult to heal, which greatly hinders the treatment and repair of bone defects. Therefore, the treatment of infectious bone defects has become a bottleneck problem that urgently needs to be solved in clinical practice.

[0003] Treatment of infected bone defects involves two main tasks: infection control and bone defect repair and reconstruction. For infection control, the most reliable approach currently is surgical debridement combined with antibiotic therapy. However, antibiotics have drawbacks such as a narrow antibacterial spectrum, disruption of the body's microbiome and immune environment, and long-term, high-dose use easily leads to drug resistance. Bacteria can evade antibiotic attacks through mechanisms such as secreting inactivating enzymes, drug efflux pumps, targeted modification, and penetration barriers. In contrast, physical antibacterial methods rarely induce drug resistance. Sonodynamic therapy, in particular, utilizes the interaction between ultrasound waves and sonosensitive agents to generate large amounts of reactive oxygen species, directly disrupting the integrity of pathogen cell membranes and inducing bacterial death. Compared to traditional antibiotic therapy, sonodynamic therapy not only possesses good broad-spectrum antibacterial activity but also causes less tissue damage and has strong tissue penetration capabilities, showing promising clinical application prospects in the treatment of infectious diseases.

[0004] For bone defect reconstruction, bone grafting is commonly used. Autologous bone grafting is the gold standard in clinical treatment, but it suffers from problems such as insufficient donor bone volume and complications in the donor area; while allogeneic transplantation is limited by potential immune rejection and infection risks. Therefore, the clinical application of natural bone grafts has significant limitations. In recent years, many bone substitute materials have emerged, which can promote bone repair by mimicking the composition and physicochemical properties of natural bone. However, existing bone repair materials generally lack self-antibacterial properties and have poor ability to regulate the immune microenvironment at the injury site, limiting their ability to treat more complex infectious bone defects. Macrophage burial can clear apoptotic cells and cell debris, prevent the continuous release of harmful substances, and maintain immune homeostasis. Studies have shown that restoring impaired macrophage burial can promote the regeneration and repair process of defective tissue. Summary of the Invention

[0005] Given the limitations of traditional clinical treatments and the current state of research in the field of bone defect repair, the purpose of this invention is to provide a biomimetic scaffold material that can achieve highly efficient antibacterial activity under ultrasound irradiation and promote the repair and reconstruction of infected bone defects by regulating macrophage burial. This invention also includes its preparation method and application.

[0006] To address the aforementioned technical problems, this application provides the following technical solution:

[0007] A method for preparing a biomimetic scaffold material that promotes the repair and reconstruction of infected bone defects involves: encapsulating oxygen-vacancy titanium dioxide nanorods within collagen under temperature control, and then directionally depositing mineralized crystals within the interstitial regions of the collagen to obtain a porous biomimetic scaffold with a bone-like structure. This method improves the mechanical and osteoconductive properties of the scaffold material while endowing it with multi-dimensional and multifunctional characteristics to better meet clinical treatment needs.

[0008] Among them, the oxygen-vacancy titanium dioxide nanorods (TiO2) 2-x The preparation method of the titanium precursor solution is as follows: titanium tetrachloride and oleic acid are used as raw materials to prepare a titanium precursor solution, which is then subjected to vacuum heating, cooling, rapid heating, washing and centrifugation to finally obtain oxygen vacancy titanium dioxide nanorods.

[0009] The titanium precursor solution is prepared by dissolving titanium tetrachloride and oleic acid in 1-octadecene to obtain a titanium precursor solution containing 0.2 M titanium tetrachloride and 1.0 M titanium tetrachloride.

[0010] In the preparation method of the oxygen vacancy titanium dioxide nanorods, 1-octadecene, oleylamine and oleic acid are added to a reactor and heated under vacuum at 90°C, then cooled to 60°C under N2; then a titanium precursor solution is injected into the system, and then rapidly heated to 290°C and held at this temperature for a period of time. The remaining titanium precursor solution is added at a certain rate. After cooling to room temperature, the titanium dioxide nanorods are collected, washed with isopropanol, and centrifuged at 8000 rpm to obtain oxygen vacancy titanium dioxide nanorods.

[0011] Furthermore, the type I rat tail collagen solution was concentrated to 8-10 mg / mL, and the prepared oxygen vacancy titanium dioxide nanorods were thoroughly mixed with the type I rat tail collagen solution and stirred at a constant temperature in the dark. Then, the mixture was slowly injected into a dialysis bag, and the dialysis bag was transferred to a mineralization solution that could provide mineralization-related substances such as calcium and phosphorus. The mixture was assembled in a constant temperature shaker for 7-10 days, and the mineralization solution was replaced with fresh solution every other day. After freeze-drying, cross-linking and washing steps, a three-dimensional porous biomimetic scaffold material was obtained.

[0012] The mineralization solution is prepared by weighing 8g NaCl, 3g Na2HPO4, 0.2g KCl, and 0.35g KH2PO4, dissolving them in 1L of deionized water for later use; before each use, take 100mL of the above solution, add 47.9mg K2HPO4, 66.2mg CaCl2•2H2O, and 10mg polyaspartic acid, and dissolve them thoroughly.

[0013] The freeze-drying process involves pre-freezing at -20°C for 24 hours before freeze-drying, followed by a freeze-drying time of 12-14 hours. The cross-linking agent used is an 80% anhydrous ethanol solution containing 1-ethyl(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC), and the cross-linking time is 4-5 hours.

[0014] The temperature of the light-proof, constant-temperature stirring is 25±0.5℃; the temperature of the constant-temperature shaking table is 37±0.5℃.

[0015] This invention utilizes temperature control to directionally assemble oxygen-vacancy titanium dioxide nanorods and mineralized crystals within collagen fibers. This creates a biomimetic scaffold material with ultrasonic response, macrophage regulation, and a structure and composition similar to natural bone, without altering the original topology and physicochemical properties of the collagen. The biomimetic scaffold material prepared by this invention can generate reactive oxygen species through acoustic dynamics under ultrasonic irradiation, exerting a highly efficient physical antibacterial effect. (Ultrasound: 1MHz, 50% vacancy ratio, 1.5 W / cm²) 2 Irradiation for 15 minutes can achieve an antibacterial rate of over 95%. It can also regulate the cytotoxicity of macrophages and further promote tissue repair.

[0016] The biomimetic scaffold material of this invention exhibits excellent biocompatibility and generates a large amount of reactive oxygen species under ultrasound, achieving highly efficient physical antibacterial effects and reducing the occurrence of infection. Furthermore, this scaffold material can modulate macrophage burial, promoting bone defect repair and reconstruction by reshaping the local immune microenvironment while exerting bone-guiding properties. Its efficacy has been preliminarily verified in an animal model of infectious bone defects. Implantation of this material at the defect site combined with ultrasound therapy yields excellent anti-infection and bone defect repair effects.

[0017] Compared with the prior art, the biomimetic scaffold material for promoting the repair and reconstruction of infected bone defects of the present invention, its preparation method and application have at least the following beneficial effects:

[0018] (1) The biomimetic scaffold material prepared by the method of this invention generates a sonodynamic effect under ultrasonic irradiation, exhibiting highly efficient physical antibacterial properties. Through temperature control, oxygen-vacant titanium dioxide nanorods are assembled into the collagen fibers, enhancing the antibacterial and anti-infection effects of the material without altering the original topological structure and physicochemical properties of the collagen. Simultaneously, the material degrades slowly, maintaining the spatial structure of the bone defect area and regulating the burial function of macrophages, which is beneficial for the repair and reconstruction of bone defects. This material has significant clinical implications for the precise treatment of bone defect-related diseases, especially complex bone defects accompanied by infection.

[0019] (2) The therapeutic effect of the bionic scaffold material of the present invention has been preliminarily verified in an animal model of infectious bone defects. Implanting the material at the defect site and combining it with ultrasound treatment can achieve excellent anti-infection and bone defect repair effects.

[0020] (3) The successful preparation of the material of this invention can be used in the clinical treatment of refractory infectious bone defects, achieving precise antibacterial control in time and space, and further promoting the repair and regeneration of bone tissue, providing a new method for the clinical treatment of bone defects, especially bone defect-related diseases accompanied by infection. This material has the dual advantages of infection control and defect reconstruction, providing more options for the clinical treatment of infectious bone defects, reducing the overall treatment cost for patients, alleviating patient suffering and treatment side effects, and promoting the development of biomedicine.

[0021] The following description, in conjunction with the accompanying drawings, further illustrates the biomimetic scaffold material for promoting the repair and reconstruction of infected bone defects of the present invention, its preparation method, and its application. Attached Figure Description

[0022] Figure 1 The solution absorption spectrum of the mixture of oxygen vacancy titanium dioxide nanorods and 1,3-diphenylisobenzofuran solution (DPBF) in Example 1 at different time points under ultrasonic irradiation is used to reflect the acoustic-dynamic properties of the material.

[0023] Figures 2-3 These are the morphology and energy dispersive spectroscopy (EDS) images of the oxygen vacancy titanium dioxide-biomimetic mineralization scaffold material in Example 1 under transmission electron microscopy and scanning electron microscopy. Figure 2 The image on the left is a transmission electron microscope image, and the image on the right is its energy dispersive spectroscopy (EDS) spectrum. Figure 3 It is a scanning electron microscope image.

[0024] Figure 4 This shows the cell proliferation of bone marrow mesenchymal stem cells co-cultured with biomimetic mineralized scaffold material containing titanium dioxide nanorods with different concentrations of oxygen vacancies for 1 day, 3 days, and 5 days in Example 2.

[0025] Figure 5In Example 3, the oxygen-vacancy titanium dioxide-biomimetic mineralized scaffold material was co-cultured with Staphylococcus aureus or Escherichia coli, using 1MHz, 50% empty fraction, and 1.5 W / cm². 2 The survival status of bacteria after 15 minutes of ultrasound irradiation.

[0026] Figures 6-7 The results are from flow cytometry analysis of the strength of cell burial activity after co-culturing the oxygen vacancy titanium dioxide-biomimetic mineralized scaffold material with Raw264.7 cells for 24 hours in Example 4.

[0027] Figures 8-9 This is from Example 5, which describes the use of oxygen-vacancy titanium dioxide-biomimetic mineralized scaffold material combined with ultrasound treatment for infectious skull defects in rats. Two weeks post-surgery, HE staining and Gram staining images of the defect area are shown. Figure 7 These are HE staining images of tissues from each group; the arrows indicate the infiltration of inflammatory cells. Figure 8 This is a Gram staining diagram; the arrows indicate the distribution of Gram-positive Staphylococcus aureus.

[0028] Figure 10 In Example 5, the treatment of infectious skull defects in rats using oxygen-vacancy titanium dioxide-biomimetic mineralized scaffold material combined with ultrasound was performed. At 8 and 12 weeks post-surgery, the bone defect repair status of each group was shown by Micro-CT (left image), and the new bone volume and BV / TV value of each group were also shown (right image). Detailed Implementation

[0029] Example 1: Preparation and Morphology Characterization of Oxygen Vacancy Titanium Dioxide-Bionic Mineralized Scaffold Material

[0030] (1) Synthesis of oxygen-vacancy titanium dioxide nanorods (TiO2) 2-x ): Titanium tetrachloride (2.19 mL) and oleic acid (31.59 mL) were dissolved in 1-octadecene (66.25 mL) to prepare a titanium precursor solution containing 0.2 M titanium tetrachloride and 1.0 M titanium tetrachloride, and stored in a glove box filled with N2. In a four-necked reactor, 1-octadecene (10 mL), oleylamine (10 mL), and oleic acid (0.48 mL) were heated at 90 °C under vacuum for 1 h to remove dissolved water and oxygen, and then cooled to 60 °C under N2. 1.5 mL of the titanium precursor solution was injected into the system, and then rapidly heated to 290 °C and held at this temperature for 10 min. 8 mL of additional titanium precursor solution was added at a rate of 0.3 mL•min⁻¹. After cooling to room temperature, oxygen-vacancy titanium dioxide nanorods were collected, washed with isopropanol, and centrifuged at 8000 rpm for 8 min.

[0031] (2) Ultrasonic response performance of oxygen-vacancy titanium dioxide nanorods: 1,3-diphenylisobenzofuran solution (DPBF) was mixed with oxygen-vacancy titanium dioxide nanorod suspension (final concentration 0.5 mg / mL), and ultrasonicated (1 MHz, 50% vacancy ratio, 1.5 W / cm²). 2 Irradiate the mixture for 10 minutes, record the absorption spectrum of the solution every 2 minutes, and plot the corresponding curve. Figure 1 The results showed that the characteristic absorption peak of the solution at 410-420 nm gradually increased with time, indicating that the prepared oxygen-vacancy titanium dioxide nanorods could generate active oxygen under ultrasonic irradiation, and the active oxygen production was positively correlated with the irradiation time.

[0032] (3) Oxygen vacancy titanium dioxide-biomimetic mineralized scaffold material (IMC / TiO) 2-x Preparation of the titanium dioxide nanorods: Type I rat tail collagen solution was concentrated to a concentration of 8-10 mg / mL. The prepared titanium dioxide nanorods were thoroughly mixed with the type I rat tail collagen solution and stirred at a constant temperature (25±0.5℃) for 30 minutes in the dark. The mixture was then slowly injected into a dialysis bag, which was then transferred to a mineralization solution providing calcium, phosphorus, and other mineralization-related substances. The mixture was assembled in a constant-temperature shaker for 7-10 days at 37±0.5℃, with the mineralization solution replaced every other day. The suspension obtained from the dialysis bag was gently removed and poured into a mold. After pre-freezing at -20℃ for 24 hours, it was freeze-dried for 12-14 hours. The material was removed from the mold and cross-linked with an 80% anhydrous ethanol solution containing 1-ethyl(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) for 4-5 hours to obtain the oxygen-vacancy titanium dioxide-biomimetic mineralization scaffold material. The cross-linked scaffold material was then washed alternately with a 1% glycine solution and deionized water.

[0033] The specific preparation method of the mineralization solution is as follows: Weigh 8g NaCl, 3g Na2HPO4, 0.2g KCl, and 0.35g KH2PO4, and dissolve them in 1L of deionized water for later use; Before each use, take 100mL of the above solution, add 47.9mg K2HPO4, 66.2mg CaCl2•2H2O, and 10mg polyaspartic acid, and dissolve them thoroughly.

[0034] (4) Observation using transmission electron microscopy ( Figure 2 Oxygen-vacant titanium dioxide and type I collagen were co-assembled for 48 h as described above. The resulting composite material was placed on a nickel grid, negatively stained with 1-2% sodium phosphotungstenate solution, and thoroughly rinsed with deionized water. After drying, the morphology of the material was observed by transmission electron microscopy, and EDS energy dispersive spectroscopy analysis was performed to understand the distribution of C, N, O, Ti, Ca, and P in the material.

[0035] (5) Observation using a scanning electron microscope ( Figure 3 ): Take an appropriate amount of the prepared oxygen vacancy titanium dioxide-biomimetic mineralized scaffold material and perform gold sputtering treatment. Observe the surface morphology of the material using a scanning electron microscope.

[0036] Example 2: Biocompatibility determination of oxygen vacancy titanium dioxide-biomimetic mineralized scaffold material

[0037] (1) According to the preparation method in steps (1)-(3) of Example 1, mineralized collagen (IMC) and biomimetic mineralized scaffold materials (IMC / TiO) containing titanium dioxide with different concentrations of oxygen vacancies were prepared. 2-x (0.1 mg / mL, 0.25 mg / mL, 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL), for subsequent cell experiments.

[0038] (2) Co-culture of bone marrow mesenchymal stem cells (BMSCs) with materials: BMSCs were passaged in α-MEM medium (containing 15% fetal bovine serum), and then cultured at 6×10⁻⁶ ppm. 3 Cells were seeded at a density of 1 cell / well in 48-well plates. After cell attachment, different scaffold materials prepared in step (1) were placed in the plates. After culturing for 1, 3, and 5 days, the medium was replaced with medium containing 10% CCK-8, and the plates were incubated at 37°C for 90 minutes. The absorbance of the solution at 450 nm was measured using a spectrophotometer. Figure 4 The results showed that when the assembly concentration of titanium dioxide nanorods reached 1.5 mg / mL, the material had no significant effect on cell viability, indicating that this oxygen vacancy titanium dioxide-biomimetic mineralized scaffold material (IMC / TiO2) was effective. 2-x It has good biocompatibility.

[0039] Example 3: Testing of the antibacterial properties of oxygen-vacancy titanium dioxide-biomimetic mineralized scaffold material

[0040] (1) According to the preparation method in steps (1)-(3) of Example 1, mineralized collagen (IMC) and oxygen vacancy titanium dioxide-biomimetic mineralized scaffold material (IMC / TiO) were synthesized. 2-x ).

[0041] (2) The culture of Staphylococcus aureus or Escherichia coli in the logarithmic growth phase (OD) 600 =1.0-1.5) Dilute to 1×10 7 CFU / mL was added to EP tubes containing mineralized collagen or oxygen-vacancy titanium dioxide-biomimetic mineralized scaffold material, and equilibrated in the dark for 30 minutes. The experimental group was then sonicated (1MHz, 50% empty fraction, 1.5 W / cm²). 2Irradiate for 15 min. Dilute the bacterial suspensions after different treatments appropriately, and take 50 μL of each suspension to spread onto LB agar plates using a spiral inoculator. Incubate at 37°C for 24 h. Colony count results show ( Figure 5 The number of colonies was significantly reduced in the group using oxygen-vacancy titanium dioxide-biomimetic mineralized scaffold material combined with ultrasonic treatment, and the antibacterial rate reached over 95%.

[0042] Example 4: Investigation into the regulatory ability of oxygen vacancy titanium dioxide-biomimetic mineralized scaffold material on macrophage burial.

[0043] (1) According to the preparation method in steps (1)-(3) of Example 1, mineralized collagen (IMC) and oxygen vacancy titanium dioxide-biomimetic mineralized scaffold material (IMC / TiO) were prepared. 2-x ).

[0044] (2) Co-culture of Raw264.7 cells with materials: Raw264.7 cells were passaged in DMEM high glucose medium (containing 10% fetal bovine serum), and then cultured at 5×10⁻⁶ cells / year. 5 Cells were seeded at a density of 1 cell per well in 12-well plates. After the cells adhered, the biomimetic scaffold material prepared in step (1) was placed in (or not placed in) the plates, and the plates were cultured for 24 hours.

[0045] (3) Flow cytometry detection of cell burial: 1 μM STS was added to the jurkat cell suspension to induce apoptosis. After 4 h, the cells were centrifuged and the apoptotic jurkat cells were stained according to the PKH26 staining kit instructions. Apoptotic cells were added to wells of Raw264.7 cells at a ratio of 5:1. After 45 min, the Raw264.7 cells were washed three times with PBS, blown off the cells, and FITC-F4 / 80 staining was performed. The proportion of macrophages burial (i.e., the proportion of PKH26+FITC+ cells) was analyzed by flow cytometry. The results showed ( Figures 6-7 The proportion of double-positive cells in Raw264.7 cells co-cultured with oxygen-vacancy titanium dioxide-bionic mineralized scaffold material significantly increased, suggesting that this biomimetic scaffold material can enhance the cytotoxicity of macrophages.

[0046] Example 5: Therapeutic effect of oxygen-vacancy titanium dioxide-biomimetic mineralized scaffold material on infectious skull defects in rats.

[0047] (1) According to the preparation method in steps (1)-(3) of Example 1, mineralized collagen (IMC) and oxygen vacancy titanium dioxide-biomimetic mineralized scaffold material (IMC / TiO) were prepared. 2-x ).

[0048] (2) Establishment of a rat model of infectious skull defects: 6-8 week old SD rats were randomly divided into control group, IMC+US group, and IMC / TiO group. 2-x Group and IMC / TiO 2-x +US group. A rat model of infectious skull defect was established under general anesthesia: the skull was exposed by full-thickness incision, and a 5mm diameter circular defect was created bilaterally along the midline using an implantation machine. 100μL of Staphylococcus aureus bacterial suspension in the logarithmic growth phase was then applied (10... 7 (CFU / mL), after filling with the appropriate material, suture in layers for alignment. For the IMC+US group and IMC / TiO2 group... 2-x The +US group received ultrasound irradiation treatment on local tissues 1 and 3 days after surgery.

[0049] (3) Evaluation of anti-infective and osteogenic effects in the treatment of infected bone defects: Some rats were sacrificed after 2 weeks for HE (hematoxylin and eosin) treatment. Figure 8 ) and Gram staining ( Figure 9 The results showed that IMC / TiO 2-x The +US group showed the least amount of inflammatory cell infiltration and residual bacteria at the defect site, indicating that the oxygen-vacancy titanium dioxide-biomimetic mineralized scaffold material combined with ultrasound therapy has excellent anti-infective properties. Rats were sacrificed at 8 and 12 weeks for Micro-CT (micro-CT scan). Figure 10 The bone formation rate and BV / TV values ​​of each group were measured and analyzed. Results showed IMC / TiO₂ 2-x The +US group showed the highest amount of new bone formation at the defect site, demonstrating excellent bone defect repair. In conclusion, this oxygen-vacancy titanium dioxide-biomimetic mineralized scaffold material exhibits excellent therapeutic effects on infected bone defects.

[0050] The results of Examples 1-5 show that the oxygen-vacancy titanium dioxide-biomimetic mineralized scaffold material proposed in this invention can generate a large amount of reactive oxygen species under ultrasonic conditions to achieve highly efficient physical antibacterial activity. This biomimetic scaffold material exhibits good biocompatibility and osteoconductivity, and can regulate the burial activity of macrophages, promoting the regeneration and repair of damaged tissues by reshaping the local immune microenvironment. In an animal model of infectious bone defects, the use of this biomimetic scaffold material combined with ultrasound therapy achieved excellent anti-infection and defect repair effects. Therefore, the oxygen-vacancy titanium dioxide-biomimetic mineralized scaffold material proposed in this invention has significant advantages in addressing refractory infectious bone defects.

[0051] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a biomimetic scaffold material that promotes the repair and reconstruction of infected bone defects, characterized in that: By controlling the temperature, oxygen-vacancy titanium dioxide nanorods are encapsulated inside collagen, and mineralized crystals are oriented to deposit in the interstitial region inside the collagen, resulting in a porous biomimetic scaffold with a bone-like structure.

2. The method for preparing the biomimetic scaffold material according to claim 1, characterized in that: The oxygen-vacancy titanium dioxide nanorods are prepared by using titanium tetrachloride and oleic acid as raw materials to prepare a titanium precursor solution, followed by vacuum heating, cooling, rapid heating, washing and centrifugation to finally obtain oxygen-vacancy titanium dioxide nanorods.

3. The method for preparing the biomimetic scaffold material according to claim 2, characterized in that: The titanium precursor solution is prepared by dissolving titanium tetrachloride and oleic acid in 1-octadecene to obtain a titanium precursor solution containing 0.2 M titanium tetrachloride and 1.0 M titanium tetrachloride.

4. The method for preparing the biomimetic scaffold material according to claim 3, characterized in that: In the preparation method of oxygen vacancy titanium dioxide nanorods, 1-octadecene, oleylamine and oleic acid are added to a reactor and heated under vacuum at 90°C, then cooled to 60°C under N2; then a titanium precursor solution is injected into the system, and then rapidly heated to 290°C and held at this temperature for a period of time. The remaining titanium precursor solution is added at a certain rate. After cooling to room temperature, the titanium dioxide nanorods are collected, washed with isopropanol, and centrifuged at 8000 rpm to obtain oxygen vacancy titanium dioxide nanorods.

5. The method for preparing the biomimetic scaffold material according to claim 1, characterized in that: Type I rat tail collagen solution was concentrated to 8-10 mg / mL. The prepared oxygen vacancy titanium dioxide nanorods were thoroughly mixed with the type I rat tail collagen solution and stirred at a constant temperature in the dark. The mixture was then slowly injected into a dialysis bag, which was then transferred to a mineralization solution and assembled in a constant temperature shaker for 7-10 days. Fresh mineralization solution was replaced every other day. After freeze-drying, cross-linking, and washing, a three-dimensional porous biomimetic scaffold material was obtained.

6. The method for preparing the biomimetic scaffold material according to claim 5, characterized in that: The mineralization solution is prepared by weighing 8g NaCl, 3g Na2HPO4, 0.2g KCl, and 0.35g KH2PO4, dissolving them in 1L of deionized water for later use; before each use, take 100mL of the above solution, add 47.9 mg K2HPO4, 66.2 mg CaCl2•2H2O, and 10 mg polyaspartic acid, and dissolve them thoroughly.

7. The method for preparing the biomimetic scaffold material according to claim 6, characterized in that: Before freeze-drying, the sample was pre-frozen at -20℃ for 24 hours, and the freeze-drying time was 12-14 hours. The crosslinking agent used was an 80% anhydrous ethanol solution containing 1-ethyl(3-dimethylaminopropyl)carbodiimide hydrochloride, and the crosslinking time was 4-5 hours.

8. The method for preparing the biomimetic scaffold material according to claim 7, characterized in that: The temperature of the light-proof, constant-temperature stirring is 25±0.5℃; the temperature of the constant-temperature shaking table is 37±0.5℃.

9. The biomimetic scaffold material prepared by the preparation method according to any one of claims 1-8.

10. The application of the biomimetic scaffold material of claim 9 in the preparation of anti-infection and bone defect repair materials.

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