Antibacterial drug modified strontium-doped orthopedic implant material as well as preparation method and application thereof

Abstract

The invention discloses an antibacterial drug modified strontium-doped orthopedic implant material and a preparation method and application thereof, and relates to the technical field of bone repair materials, the material comprises a base material, and a strontium-doped functional layer, an antibacterial drug functional layer and a slow-release functional layer which are sequentially formed on the surface of the base material; wherein the strontium-doped functional layer is of a composite structure formed by loading strontium ions in a polypolyphenol or polyphenol amine matrix formed by auto-polymerization of polyphenol or phenol amine compounds. According to the invention, sequential release of functional factors is realized through layered structure design: an antibacterial drug is rapidly released in the early stage of implantation to inhibit bacterial infection, an anti-inflammatory and anti-oxidation effect is continuously exerted in the middle stage, strontium ions are stably and slowly released in the later stage to improve an immune microenvironment and promote osteoblast differentiation and bone matrix deposition, and three-layer functions have a synergistic effect, so that the bone repair effect is improved. The vicious circle of infection-inflammation-oxidative stress-immune imbalance is effectively broken through, and the method can be widely applied to the scenes of orthopedic clinical operations, oral and maxillofacial surgical reconstruction, diabetes-related bone defect repair, infectious bone defect treatment and the like.

Description

Technical Field

[0001] This invention belongs to the field of bone repair materials technology, specifically an antibacterial drug-modified strontium-doped orthopedic implant material, its preparation method, and its application. Background Technology

[0002] Repairing bone defects has always been a major challenge for clinical orthopedics and oral and maxillofacial surgery. Regardless of the cause—whether it's severe trauma, infection, bone tumor resection, or specific pathological conditions such as diabetes accompanied by high oxidative stress and immune dysfunction—the regenerative capacity of bone tissue is significantly weakened, leading to slow repair or even complete failure. Currently, widely used orthopedic implant materials mainly include metallic materials such as titanium and titanium alloys, as well as polymeric materials such as polyetheretherketone (PEEK). While these materials possess good biocompatibility and mechanical properties, they often fail to achieve ideal repair results in complex pathological environments such as infection, inflammation, or immune microenvironment imbalance, thus affecting the long-term stability of the implant.

[0003] In the process of bone defect repair, the homeostasis of the local microenvironment is crucial for osteogenic formation. However, under complex pathological conditions, bacterial infection, high oxidative stress, and immune microenvironment dysregulation often coexist, forming a vicious cycle that severely interferes with the bone repair process. Bacterial infection is one of the most common adverse factors; its secreted toxins and metabolites not only directly destroy newly formed bone tissue but also induce excessive inflammatory responses in the body. Persistent inflammation further promotes the accumulation of reactive oxygen species (ROS), leading to a state of high oxidative stress. Excessive ROS can damage the mitochondrial function of osteoblasts, inhibit the expression of osteogenic-related genes and proteins, induce apoptosis, and simultaneously enhance osteoclast activity, exacerbating bone resorption. Meanwhile, the balance of the immune microenvironment is severely disrupted. In normal bone repair, macrophages can dynamically transform between the pro-inflammatory M1 phenotype and the anti-inflammatory and pro-repair M2 phenotype, thereby coordinating inflammation resolution and tissue regeneration. However, under the combined effects of infection and oxidative stress, the M1 phenotype is overactivated, with pro-inflammatory factors (such as TNF-α and iNOS) remaining at high levels for a prolonged period, while M2 phenotype-related factors (such as IL-10 and CD163) are insufficient. This results in a persistent state of high inflammation and low repair in the local environment. This vicious cycle of "infection-inflammation-oxidative stress-immune imbalance" continuously inhibits osteoblast activity and bone matrix deposition, while bone resorption is overactivated, ultimately leading to insufficient bone mass, a significant decrease in bone integration, and even implant loosening, severely impacting the repair outcome.

[0004] Therefore, how to provide an orthopedic implant material that combines multiple functions such as antibacterial, anti-inflammatory, and osteogenic properties, and can achieve the sequential release of functional factors and avoid mutual interference between components, has become an urgent problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a strontium-doped orthopedic implant material modified with antibacterial drugs, its preparation method and application, in order to solve the problems of existing bone repair materials such as single function, easy interference between drugs and active ions, and insufficient timing regulation, so as to achieve synergistic effects of antibacterial, anti-inflammatory and osteogenic effects, and to be suitable for orthopedic clinical surgery, repair of infected bone defects and other scenarios.

[0006] The objective of this invention is achieved through the following technical solution: Technical Solution 1: An antimicrobial drug-modified strontium-doped orthopedic implant material includes a matrix material and a strontium-doped functional layer, an antimicrobial drug functional layer, and a sustained-release functional layer sequentially formed on the surface of the matrix material. The strontium-doped functional layer is a composite structure in which strontium ions are loaded in a polyphenol or polyphenol amine matrix formed by the self-polymerization of polyphenols or phenolamines.

[0007] This invention proposes a time-regulated bone repair material with strontium-doped surface functionalization modified with antibacterial drugs. By constructing a phenol (amine) functionalized interface with good interlayer compatibility and introducing a sustained-release layer on the surface, the release kinetics of antibacterial drugs and metal ions are regulated, thus forming a sequential response in the time dimension of "early antibacterial—mid-term anti-inflammatory and antioxidant—late-term osteogenic". Specifically, in the early stage of implantation, the controllable and rapid release of antibacterial drugs not only inhibits bacterial infection but also reduces inflammation and oxidative stress, thereby solving the technical bottleneck that strontium-doped materials alone cannot effectively exert osteogenic effects in complex pathological environments such as infection, inflammation, or immune microenvironment imbalance. In the mid-to-late stage of repair, the continuous release of strontium ions induces macrophages to transform into the M2 anti-inflammatory phenotype, restores immune homeostasis, and further promotes osteoblast differentiation and matrix deposition. It is noteworthy that the trilayer structure exhibits a significant synergistic effect after integration: the early antibacterial, antioxidant, and immunomodulatory effects of the antimicrobial drug create a favorable repair microenvironment for the subsequent effects of strontium ions, while the immunomodulatory effect of strontium ions further synergizes with the anti-inflammatory effect of the drug. This mode of action far exceeds the effects achievable by monolayer modification or simple superposition, forming a closed positive regulatory cycle.

[0008] Therefore, this invention can still achieve stable and reliable bone repair under complex environments of infection, high oxidative stress, and immune imbalance. It is widely applicable to complex scenarios such as orthopedic clinical surgery, oral and maxillofacial reconstruction, repair of diabetes-related bone defects, and treatment of infected bone defects, and has significant application prospects and transformation value.

[0009] Technical Solution Two: A method for preparing an antibacterial drug-modified strontium-doped orthopedic implant material includes the following steps: S1. Preparation of Strontium-doped functional layer: The matrix material is immersed in an alkaline solution of polyphenols or phenolamines, reacted, and then washed and dried; then it is immersed in a strontium ion solution to load strontium ions, reacted, and then washed; finally, it is immersed in an alkaline solution of polyphenols or phenolamines again, undergoes a second self-polymerization reaction, and is then washed and dried to obtain a matrix material containing a strontium-doped functional layer; S2. Preparation of antibacterial drug functional layer: Antibacterial drug solution is dropped onto the surface of the matrix material containing strontium-doped functional layer, reacted fully under dark conditions, and then washed and dried to obtain matrix material containing strontium-doped antibacterial drug composite functional layer; S3. Preparation of sustained-release functional layer: A sustained-release material solution is dropped onto the surface of the matrix material containing the strontium-doped antibacterial drug composite functional layer. After sufficient reaction, the material is washed and dried to obtain the strontium-doped antibacterial drug-sustained-release composite functional layer, i.e., strontium-doped orthopedic implant material modified with antibacterial drug.

[0010] As some possible implementations of this application, the matrix material is selected from metallic orthopedic implant materials, polymeric orthopedic implant materials, and inorganic non-metallic orthopedic implant materials; The metallic orthopedic implant materials are selected from titanium, titanium alloys, stainless steel, cobalt alloys, zinc alloys, and magnesium alloys; The polymeric orthopedic implant material is selected from polyetheretherketone, supramolecular polyethylene, polyurethane, polylactic acid-glycolic acid copolymer, polylactic acid, polyhydroxyalkanoate, and polyacrylate; The inorganic non-metallic orthopedic implant materials are selected from alumina ceramics, zirconium oxide ceramics, hydroxyapatite, bioactive glass, and tricalcium phosphate.

[0011] As some possible implementations of this application, in step S1, the polyphenolic compound is selected from tannic acid, gallic acid, epigallocatechin, and gallic acid ester; the phenolic amine compound is selected from dopamine, dopamine hydrochloride, norepinephrine, levodopa, and 6-nitrodopamine.

[0012] As some possible implementations of this application, in step S1, the concentration of the alkaline solution of the polyphenol or phenolamine compound is 0.1-5 mg / mL, and the reaction time is 2-24 h. As some possible implementations of this application, in step S1, the strontium ions are selected from strontium chloride, strontium nitrate, strontium chlorate, strontium perchlorate, and other strontium salts that are soluble in water and release strontium ions.

[0013] As some possible implementations of this application, in step S2, the antibacterial drug in the antibacterial drug functional layer is selected from tetracyclines (such as minocycline, minocycline hydrochloride, minocycline sulfate, doxycycline, etc.), macrolides, aminoglycosides, fluoroquinolones, penicillins, cephalosporins, non-antibiotic antibacterial agents (such as chlorhexidine, benzalkonium bromide, etc.) or their pharmaceutically acceptable salts and combinations thereof.

[0014] As some possible implementations of this application, in step S2, the concentration of the antibacterial drug solution is 0.1-1 mg / mL, and the reaction time is 2-24 h.

[0015] As some possible implementations of this application, in step S3, the sustained-release material is selected from chitosan and its derivatives (such as carboxymethyl chitosan, hydroxypropyl chitosan, quaternized chitosan, etc.), cellulose and its derivatives (such as sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose, etc.), natural polymers (such as gelatin, sodium alginate, hyaluronic acid, silk fibroin, etc.) or mixtures thereof.

[0016] As some possible implementations of this application, in step S3, the concentration of the sustained-release material solution is 1-10 mg / mL, and the reaction time is 2-24 h.

[0017] Technical Solution 3: Application of antimicrobial drug-modified strontium-doped orthopedic implant materials in the preparation of therapeutic bone repair products.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. A multifunctional but non-conflicting temporal regulation mechanism: Through the top sustained-release layer and the inner double-layer phenol (amine) functionalized interface, the spatial / chemical structure design of "preferential release of antibacterial drugs in the outer layer + sustained release of strontium ions in the inner layer" is realized. Without increasing the complexity of the system, the time allocation and sequence of different biological effects are optimized, avoiding mutual interference or early ineffective consumption caused by traditional multi-drug release.

[0019] 2. Synergistic Enhancement of Various Functions: This three-layer system is not a "linear superposition of single-layer functions," but rather exhibits a time-dependent synergistic effect of mutual prerequisites. Specifically, the early release of antibacterial drugs significantly reduces local bacterial load and peak levels of pro-inflammatory factors, thereby reducing ROS levels and inflammation-mediated osteogenic inhibition. This early microenvironmental modification provides a more favorable cellular environment for subsequent osteogenic signals from strontium ions (e.g., maintaining osteoblast mitochondrial function and avoiding inhibition of the Runx2 pathway by pro-inflammatory signals), amplifying the osteogenic and immunomodulatory effects of strontium ions. The top sustained-release layer and the phenolic (amine) functionalized interfaces between the layers further amplify their temporal complementarity and stability by controlling the diffusion gradient and the time of action. Therefore, the composite layer shown in this invention can produce comprehensive improvements in multiple dimensions, including antibacterial, anti-inflammatory, antioxidant, immune remodeling, and osteogenic promotion, exceeding the comprehensive improvements achievable by any single layer or simple mixture.

[0020] 3. Enhanced adaptability to complex pathological environments such as diabetes: In the context of high oxidative stress and immune disorders, such as in diabetes, this invention simultaneously covers the entire chain of "antibacterial—anti-inflammatory / antioxidant—immune remodeling—bone-promoting / anti-osteoclastic" processes, thereby disrupting the amplification chain of "infection—inflammation—oxidative stress—immune imbalance," reducing the risk of postoperative infection and the resulting probability of bone integration failure. Compared to single strontium doping or single drug-loaded materials, it is easier to achieve stable and repeatable bone integration effects in high-risk scenarios.

[0021] 4. Improved interfacial hydrophilicity and cell adhesion: The surface sustained-release functional layer can mimic the biomimetic structure of the mucus secreted by marine corals, which can effectively improve wettability and protein adsorption conformation, which is conducive to the adhesion and spread of osteoblast-related cells, and enhances the efficiency of early cell response and subsequent tissue integration.

[0022] 5. Mild preparation conditions, simple operation, good versatility and scalability: Phenol (amine) self-polymerization and wet loading are both carried out under mild aqueous phase conditions, which can be adapted to various orthopedic matrices such as metals, ceramics, and polymers. It has strong adhesion and has almost no impact on the mechanical properties of the matrix, which is convenient for large-scale production and integration with existing implant production lines. The manufacturing cost and quality consistency are controllable. Attached Figure Description

[0023] Figure 1 Surface morphology images of three groups of materials: PEEK group, PEEK-Sr group, and PEEK-Sr-Mino group; Figure 2 Surface composition analysis diagrams of three groups of materials: PEEK group, PEEK-Sr group, and PEEK-Sr-Mino group; Figure 3 Water contact angle measurements of the surfaces of three material groups: PEEK group, PEEK-Sr group, and PEEK-Sr-Mino group.

[0024] Figure 4 : Detection diagram of strontium ion and minocycline release behavior in the PEEK-Sr-Mino group; Figure 5 Antibacterial zone experiments of three groups of materials: PEEK group, PEEK-Sr group, and PEEK-Sr-Mino group; Figure 6 Colony plate counting experiments of three groups of materials: PEEK group, PEEK-Sr group, and PEEK-Sr-Mino group; Figure 7 The total antioxidant capacity of the three groups of materials: PEEK, PEEK-Sr, and PEEK-Sr-Mino. Figure 8 The absorbance values ​​of the reaction solutions of the three materials (PEEK group, PEEK-Sr group, and PEEK-Sr-Mino group) at 515 nm in the DPPH free radical scavenging experiment; Figure 9 Expression of inflammation-related genes in three groups of materials: PEEK group, PEEK-Sr group, and PEEK-Sr-Mino group; Figure 10 The secretion of inflammation-related factors in the three groups of materials: PEEK group, PEEK-Sr group, and PEEK-Sr-Mino group; Figure 11 This refers to the proliferation of mouse MC3T3-E1 pre-osteoblasts after culture on the surfaces of three groups of materials: PEEK group, PEEK-Sr group, and PEEK-Sr-Mino group, as detected by CCK-8 assay. Figure 12 Expression of osteogenic-related genes in mouse MC3T3-E1 preosteoblasts after 7 and 14 days of culture on the surfaces of three groups of materials: PEEK group, PEEK-Sr group, and PEEK-Sr-Mino group. Figure 13 Results of alkaline phosphatase activity of mouse MC3T3-E1 pre-osteoblasts after 7 and 14 days of culture on the surfaces of three groups of materials: PEEK group, PEEK-Sr group, and PEEK-Sr-Mino group. Detailed Implementation

[0025] Example 1: Preparation of strontium-doped orthopedic implant material modified with antibacterial drugs.

[0026] S1. Preparation of strontium-doped functional layer: The matrix material (medical polyetheretherketone, PEEK) was successively polished with 1000, 2000, and 3000 grit sandpaper, then ultrasonically cleaned for 20 minutes each in acetone, anhydrous ethanol, and deionized water, and vacuum dried at 37 °C. It was then placed in a 2 mg / mL dopamine hydrochloride solution (pH=8.5 Tris-HCl buffer) and reacted at room temperature in the dark for 24 h. After ultrasonic cleaning and drying, an intermediate product with surface-deposited polydopamine (PDA) was obtained. This intermediate product was then immersed in a 10 mg / mL strontium chloride solution and allowed to react at room temperature for 12 h, allowing strontium ions to be loaded onto the PDA surface through coordination chelation. The material was then immersed again in a 2 mg / mL dopamine hydrochloride solution (pH=8.5 Tris-HCl buffer) and reacted at room temperature in the dark for 3 h. After ultrasonic cleaning and drying, a matrix material containing a strontium-doped functional layer (PEEK-Sr) was obtained.

[0027] S2. Preparation of the antibacterial drug functional layer: A 0.5 mg / mL minocycline hydrochloride solution was dropped onto the surface of the strontium-doped functional layer of PEEK-Sr. The mixture was allowed to stand in the dark for 12 h. After washing and drying, a matrix material containing a strontium-doped antibacterial drug composite functional layer was obtained. S3. Preparation of the sustained-release functional layer: A carboxymethyl chitosan solution with a concentration of 5 mg / mL was added to the surface of the above composite functional layer, and the reaction was carried out for 12 h. After rinsing with deionized water and drying, the antibacterial drug-modified strontium-doped orthopedic implant material (PEEK-Sr-Mino) was obtained.

[0028] Experimental Example This experiment sets up three parallel experimental samples, as follows: Blank control group (PEEK group): medical pure PEEK tablets, without any surface functionalization modification; Single functional layer group (PEEK-Sr group): that is, the matrix material containing strontium-doped functional layer prepared in step S1 of Example 1; Composite functional layer group (PEEK-Sr-Mino group): that is, the complete composite functional layer material prepared in step S3 of Example 1).

[0029] Using the three groups of experimentally modified samples mentioned above as the research objects, the following experiments were conducted: 1. Material characterization and experimental methods and results.

[0030] (1) Material surface morphology inspection (e.g.) Figure 1 ): The surface morphology of the materials in each experimental group was observed using a scanning electron microscope (SEM).

[0031] like Figure 1 As shown, the PEEK group ( Figure 1 a) The surface shows obvious sandpaper polishing marks, PEEK-Sr group ( Figure 1 The polishing marks in b) are still visible, indicating that the strontium-doped functional layer is uniformly distributed and relatively thin, in the PEEK-Sr-Mino group ( Figure 1 c) The relatively smooth surface indicates that the minocycline functional layer is relatively thick, partially concealing the polishing marks on the material surface.

[0032] Material surface composition analysis (e.g.) Figure 2 X-ray photoelectron spectroscopy (XPS) was used to detect characteristic elements such as strontium and nitrogen on the material surface and to analyze the atomic percentage of each element on the material surface.

[0033] like Figure 2 As shown in figure a, the PEEK group exhibits characteristic C1s and O1s peaks on its surface. After modification with a strontium-doped functional layer, a distinct Sr3d peak appears. After modification with a minocycline functional layer, a Na1s peak is observed.

[0034] Figure 2 b represents the atomic percentage of the sample surface in each group analyzed by XPS. As shown in the figure, strontium appeared on the sample surface after the formation of the strontium-doped functional layer, and the nitrogen content increased. After the formation of the strontium / minocycline composite functional layer, the strontium content on the material surface decreased, indicating that the strontium-doped functional layer was partially covered by the minocycline layer.

[0035] (2) Detection of hydrophilicity of material surface: The hydrophilicity of the material surface was tested using a static water contact angle tester. 4 μL of deionized water was vertically suspended and dropped onto the sample surface using a syringe. The droplet was photographed using the instrument's built-in imaging system, and the contact angle was analyzed.

[0036] like Figure 3 As shown, the water contact angle of the PEEK group was 80.8°; after the formation of the strontium-doped functional layer, the water contact angle of the PEEK-Sr group was 57.2°; and after the formation of the strontium / minocycline composite functional layer on the surface, the water contact angle of the PEEK-Sr-Mino group was 72.6°. Although the hydrophilicity of the PEEK-Sr-Mino group was slightly weaker than that of the PEEK-Sr group, it was still a significant improvement compared to the PEEK group. This improved hydrophilicity will facilitate osteoblast adhesion and proliferation, contributing to better subsequent bone repair.

[0037] (3) Detection of strontium ion and minocycline release behavior (e.g.) Figure 4PEEK-Sr-Mino samples were immersed in 5 mL of PBS solution (37 °C). The PBS solution was collected periodically and an equal amount of fresh PBS was added. The concentrations of strontium ions and minocycline in the collected PBS were determined by inductively coupled plasma mass spectrometry (ICP-MS) and ultraviolet spectrophotometry, respectively. Figure 4 a and Figure 4 In diagram b, the horizontal axis represents the number of days of release, and the vertical axis represents the cumulative concentrations of strontium ions and minocycline, respectively. Figure 4 After the initial burst release, strontium ions in the display material can be stably and continuously released for at least 42 days. Figure 4 b shows that the release of minocycline from the material increases rapidly in the first 12 hours of immersion, followed by a gradual decrease in the release rate, which continues until day 14. The different release behaviors of strontium ions and minocycline indicate that the PEEK-Sr-Mino sample can achieve early release of minocycline for antibacterial and antioxidant effects, while the sustained release of strontium ions in the later stages exerts anti-inflammatory and osteogenic functions.

[0038] 2. Antibacterial ability assessment and experimental methods and results.

[0039] (1) Inhibition zone test (e.g.) Figure 5 Staphylococcus aureus and Escherichia coli were used as experimental strains. 100 μL of bacterial suspension (10...) was added to each strain. 7 A drop of CFU / mL was applied to the surface of a solid agar plate and spread evenly. The sample was then placed on the plate with the active side facing down. After incubation at 37 °C for 16–18 h, the radius of the inhibition zone was measured. Figure 5 a and Figure 5 As shown in Figure c, neither the PEEK nor PEEK-Sr groups exhibited inhibition zones against Staphylococcus aureus or Escherichia coli, indicating a lack of antibacterial activity. In contrast, the PEEK-Sr-Mino group showed distinct inhibition zones against both bacteria. For Staphylococcus aureus and Escherichia coli, the inhibition zone radii of PEEK-Sr-Mino were 13 mm and 9 mm, respectively. Figure 5 b and Figure 5 d).

[0040] (2) Colony plate counting experiment (e.g.) Figure 6 Staphylococcus aureus and Escherichia coli were used as experimental strains. 100 μL of a 10- solution was added to the surface of each sample. 7A bacterial suspension of CFU / mL was prepared and incubated at 37 °C for 3 h. After bacterial adhesion, 1 mL of culture medium was added, and the culture was continued for 24 h. The culture medium was then removed, and 1 mL of PBS was added to the surface of the substrate to obtain a bacterial suspension. The bacterial suspension was then diluted 10-fold, and 100 μL was spread onto agar plates. After incubation at 37 °C for 16–18 h, colony counts were performed, and the antibacterial rate was calculated. Figure 6 a and Figure 6 As shown in b, the antibacterial rates of the PEEK and PEEK-Sr groups against Staphylococcus aureus and Escherichia coli were both 0%. In contrast, the antibacterial rates of the PEEK-Sr-Mino group against Staphylococcus aureus and Escherichia coli were close to 100%. This further demonstrates that the PEEK-Sr-Mino group has strong antibacterial ability against both Gram-positive and Gram-negative bacteria, including Staphylococcus aureus and Escherichia coli, and can effectively prevent early infection after implantation.

[0041] 3. Antioxidant capacity assessment and experimental methods and results.

[0042] (1) Total antioxidant capacity assay: The total antioxidant capacity was assessed using the FRAP Total Antioxidant Capacity Assay Kit. 200 μL of FRAP working solution was added to the surface of each sample and incubated at 37 °C for 5 minutes. After incubation, the absorbance of the reaction solution at 593 nm was measured using a microplate reader. A standard curve was obtained using FeSO4 standards, and the total antioxidant activity of each sample was calculated accordingly. Figure 7 As shown, the PEEK group exhibited almost no total antioxidant capacity. In contrast, both the PEEK-Sr and PEEK-Sr-Mino groups demonstrated strong total antioxidant capacity, with the PEEK-Sr-Mino group showing a further improvement in total antioxidant capacity compared to the PEEK-Sr group.

[0043] (2) DPPH radical scavenging experiment: The DPPH radical scavenging kit was used for evaluation. 500 μL of working solution was added to the surface of each sample and incubated at 37 °C for 30 minutes. After incubation, the absorbance of the reaction solution at 515 nm was measured using a microplate reader. The strength of the radical scavenging activity of each group of materials was determined based on the absorbance value. The lower the absorbance value at 515 nm, the stronger the DPPH radical scavenging ability of the material. Figure 8 As shown, the absorbance value of the PEEK group was around 0.5, while the absorbance values ​​of the PEEK-Sr and PEEK-Sr-Mino groups were 0.3 and 0.085, respectively. This further demonstrates that the PEEK-Sr-Mino group has a strong antioxidant capacity, which can effectively remove reactive oxygen species generated around the implant, thereby reducing the inflammatory response of cells.

[0044] 4. Assessment of immune regulation capacity and experimental methods and results.

[0045] (1) Expression of inflammation-related genes (e.g.) Figure 9 ): Mouse RAW264.7 macrophages were seeded and cultured on the surface of each group of treated samples. After 3 days of culture, the expression levels of M1 and M2 phenotypic marker genes in RAW264.7 cells were detected by real-time quantitative PCR. Figure 9 The horizontal axis represents the name of the M1 phenotypic marker gene in RAW264.7 cells, and the vertical axis represents the expression of each marker gene. Figure 9 The horizontal axis represents the names of the M2 phenotypic marker genes in RAW264.7 cells, and the vertical axis represents the expression levels of each marker gene. As shown in the figure, compared to the PEEK and PEEK-Sr groups, the PEEK-Sr-Mino group exhibited the lowest expression levels of most M1 phenotypic marker genes. Figure 9 a), and the highest expression of the M2 phenotypic marker gene ( Figure 9 b). This indicates that the PEEK-Sr-Mino sample prepared in this invention has the function of clearing inflammation in the early post-implantation stage, inhibiting the transformation of macrophages to the pro-inflammatory M1 phenotype, and promoting their transformation to the anti-inflammatory M2 phenotype.

[0046] (2) The secretion status of inflammation-related factors (e.g.) Figure 10 Mouse RAW264.7 macrophages were seeded and cultured on the surface of each treated sample for 3 days. The concentrations of the inflammatory cytokine TNF-α and the anti-inflammatory cytokine TGF-β1 in the cell culture supernatant were detected using an ELISA kit to evaluate the material's effect in reducing inflammation. Figure 10 a and Figure 10 To date, cells cultured on the surface of the PEEK-Sr-Mino group samples release the least amount of TNF-α (b). Figure 10 a), while simultaneously secreting the most TGF-β1 ( Figure 10 b). This further demonstrates that the PEEK-Sr-Mino sample has the ability to regulate the polarization of RAW264.7 macrophages towards the M2 phenotype.

[0047] 5. Osteogenic capacity assessment and experimental methods and results.

[0048] (1) Evaluation of osteoblast proliferation capacity: Mouse MC3T3-E1 osteoblasts were seeded and cultured on the surface of samples in each group. Cell proliferation was measured using a CCK-8 assay kit at 1, 3, and 5 days of culture. Figure 11As shown, the horizontal axis represents the number of days the cells were cultured on the material surface, and the vertical axis represents the absorbance value of the reaction solution at 450 nm. The results show that the absorbance values ​​of the reaction solution in the PEEK-Sr-Mino group were the highest on days 3 and 5 of culture, indicating that this group had the largest number of cells and the best cell proliferation activity.

[0049] (2) Expression of osteogenic-related genes (e.g.) Figure 12 Mouse MC3T3-E1 osteoblasts were seeded and cultured on the surface of each treated sample group for 7 and 14 days. Real-time quantitative PCR was then used to detect the expression levels of osteogenic-related genes in the mouse MC3T3-E1 osteoblasts. Figure 12 a and Figure 12 As shown in Figure b, the horizontal axis represents the names of osteogenic-related genes, and the vertical axis represents the expression levels of each osteogenic-related gene. The results show that most osteogenic-related genes were expressed at the highest levels in the PEEK-Sr-Mino group.

[0050] (3) Evaluation of alkaline phosphatase (ALP) activity: Mouse MC3T3-E1 osteoblasts were seeded and cultured on the surface of each group of treated samples for 7 and 14 days. The ALP secretion level in mouse MC3T3-E1 osteoblasts was detected using an ALP quantitative detection kit, and normalized using the total intracellular protein content. Figure 13 As shown, the horizontal axis represents the number of days the cells were cultured on the material surface, and the vertical axis represents the ALP activity after normalization using the total intracellular protein content. The results show that the ALP activity of cells on the PEEK-Sr-Mino group was highest on both day 7 and day 14 of culture, further demonstrating that PEEK-Sr-Mino can significantly promote osteogenic formation.

Claims

1. A strontium-doped orthopedic implant material modified with an antibacterial drug, characterized in that, It includes a matrix material, and a strontium-doped functional layer, an antibacterial drug functional layer, and a sustained-release functional layer sequentially formed on the surface of the matrix material; The strontium-doped functional layer is a composite structure in which strontium ions are loaded in a polyphenol or polyphenol amine matrix formed by the self-polymerization of polyphenols or phenolamines.

2. The method for preparing an antibacterial drug-modified strontium-doped orthopedic implant material according to claim 1, characterized in that, Includes the following steps: S1. Preparation of Strontium-doped functional layer: The matrix material is immersed in an alkaline solution of polyphenols or phenolamines, reacted, and then washed and dried; then it is immersed in a strontium ion solution to load strontium ions, reacted, and then washed; finally, it is immersed in an alkaline solution of polyphenols or phenolamines again, undergoes a second self-polymerization reaction, and is then washed and dried to obtain a matrix material containing a strontium-doped functional layer; S2. Preparation of antibacterial drug functional layer: Antibacterial drug solution is dropped onto the surface of the matrix material containing strontium-doped functional layer, reacted fully under dark conditions, and then washed and dried to obtain matrix material containing strontium-doped antibacterial drug composite functional layer; S3. Preparation of sustained-release functional layer: A sustained-release material solution is dropped onto the surface of the matrix material containing the strontium-doped antibacterial drug composite functional layer. After sufficient reaction, the material is washed and dried to obtain the strontium-doped antibacterial drug-sustained-release composite functional layer, i.e., strontium-doped orthopedic implant material modified with antibacterial drug.

3. The method for preparing an antibacterial drug-modified strontium-doped orthopedic implant material according to claim 2, characterized in that, In step S1, the matrix material is selected from metallic orthopedic implant materials, polymeric orthopedic implant materials, and inorganic non-metallic orthopedic implant materials; The metallic orthopedic implant materials are selected from titanium, titanium alloys, stainless steel, cobalt alloys, zinc alloys, and magnesium alloys; The polymeric orthopedic implant material is selected from polyetheretherketone, supramolecular polyethylene, polyurethane, polylactic acid-glycolic acid copolymer, polylactic acid, polyhydroxyalkanoate, and polyacrylate; The inorganic non-metallic orthopedic implant materials are selected from alumina ceramics, zirconium oxide ceramics, hydroxyapatite, bioactive glass, and tricalcium phosphate.

4. The method for preparing an antibacterial drug-modified strontium-doped orthopedic implant material according to claim 2, characterized in that, In step S1, the polyphenolic compounds are selected from tannic acid, gallic acid, epigallocatechin, and gallic acid esters; the phenolic amine compounds are selected from dopamine, dopamine hydrochloride, norepinephrine, levodopa, and 6-nitrodopamine.

5. The method for preparing an antibacterial drug-modified strontium-doped orthopedic implant material according to claim 2, characterized in that, In step S1, the concentration of the alkaline solution of the polyphenol or phenolamine compound is 0.1-5 mg / mL.

6. The method for preparing an antibacterial drug-modified strontium-doped orthopedic implant material according to claim 2, characterized in that, In step S1, the strontium ions are selected from strontium chloride, strontium nitrate, strontium chlorate, strontium perchlorate, and other strontium salts that are soluble in water and release strontium ions.

7. The method for preparing an antibacterial drug-modified strontium-doped orthopedic implant material according to claim 2, characterized in that, In step S2, the antibacterial drug is selected from tetracyclines, macrolides, aminoglycosides, fluoroquinolones, penicillins, cephalosporins, non-antibiotic antibacterial agents, or pharmaceutically acceptable salts thereof and combinations thereof.

8. The method for preparing an antibacterial drug-modified strontium-doped orthopedic implant material according to claim 2, characterized in that, In step S2, the concentration of the antibacterial drug solution is 0.1-1 mg / mL, and the reaction time is 2-24 h.

9. The method for preparing an antibacterial drug-modified strontium-doped orthopedic implant material according to claim 2, characterized in that, In step S3, the sustained-release material is selected from chitosan and its derivatives, cellulose and its derivatives, natural polymers or mixtures thereof.

10. The use of the antimicrobial drug-modified strontium-doped orthopedic implant material according to any one of claims 1-9 in the preparation of therapeutic bone repair products.

Images