Photo-thermal controlled release H2S polyurethane reinforced bone cement and preparation method thereof

Abstract

The invention discloses photo-thermal controlled release H2S polyurethane reinforced bone cement which is formed by mixing a solid phase and a liquid phase, the solid phase comprises tetracalcium phosphate, calcium hydrophosphate dihydrate and Allicin-MOF-PB, and the liquid phase is a waterborne polyurethane prepolymer. The invention also discloses a preparation method of the bone cement, which specifically comprises the following steps: uniformly mixing the modified tetracalcium phosphate, calcium hydrophosphate dihydrate and Allicin-MOF-coated PB to obtain a solid phase; preparing a polyurethane prepolymer to obtain a liquid phase; and uniformly stirring the solid phase and the liquid phase, pouring into a mold, and carrying out self-curing. According to the bone cement disclosed by the invention, the polyurethane interpenetrating network is compounded with the surface modified calcium phosphate matrix, so that the bone cement is endowed with high compressive strength, toughness and crack propagation resistance, and the dynamic load requirement of a bone defect part is met; meanwhile, the Allicin-MOF-coated PB releases H2S under the triggering of near-infrared light and cooperates with a photothermal effect, so that bimodal antibiosis penetrating through a biological membrane is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical material preparation, and specifically relates to photothermal controlled-release H2S polyurethane reinforced bone cement, and also relates to a preparation method of photothermal controlled-release H2S polyurethane reinforced bone cement. Background Art

[0002] Infected bone defects are a common complication of severe trauma or surgery. Bone destruction (such as osteomyelitis or osteonecrosis) can rapidly worsen due to inflammatory cytokine storms, bacterial toxin invasion, and local microenvironmental disturbances. Persistent infection not only overactivates osteoclasts but also inhibits bone repair, ultimately leading to bone collapse and loss of mechanical support. Stress imbalance in the defect area accelerates bone resorption and hinders new bone formation, creating a vicious cycle of "infection spread-bone defect expansion-mechanical instability." Abnormal stress simultaneously exacerbates local ischemia and bacterial biofilm formation, weakening the effectiveness of antibiotics, ultimately evolving into a pathological closed loop of mutually reinforcing infection, bone destruction, and mechanical imbalance. Therefore, clinical treatment must simultaneously achieve the dual goals of mechanical support to restore weight-bearing function and effective antimicrobial therapy to control infection.

[0003] Current treatments for infected bone defects primarily include debridement combined with bone cement filling, autologous bone transplantation, or metal fixation. However, traditional polymethyl methacrylate bone cements suffer from limited mechanical properties and lack of bioactivity. Autologous bone transplantation is limited by donor site damage and impaired bone regeneration in diabetic patients. Metal fixation carries risks such as poor mechanical compatibility, metal corrosion, ion release, and secondary surgery. Of particular concern is the need for repair materials to possess both compressive strength and toughness under dynamic stress conditions to withstand cyclical mechanical loading and prevent structural failure due to fatigue fracture. Furthermore, traditional antibiotic therapies struggle to eradicate deep infections due to increasing drug resistance, poor local drug penetration, and biofilm barriers. However, osteonecrosis lesions in infected bone defects are often colonized by multidrug-resistant bacteria. Therefore, repair materials must also possess in situ antimicrobial properties, providing mechanical support while directly intervening in the infection microenvironment and preventing bacterial disruption of bone repair. Calcium phosphate cement (CPC) is considered a potential alternative due to its excellent osteoconductivity and osteoinductivity, biocompatibility, and in situ remodeling capabilities. However, pure CPC itself has low compressive strength, insufficient toughness, and poor fatigue resistance, making it difficult to meet the long-term stability requirements of the mechanical load area. It also lacks antibacterial function and cannot block multidrug-resistant bacterial infection in infected bone defects.

[0004] In recent years, the research and development of CPC (Combine Permeable Copolymer) (CPC) bone repair materials has focused on the dual challenges of synergistically enhancing mechanical properties and antimicrobial function. Regarding mechanical enhancement, while conventional CPC can improve toughness through composite elastic fiber materials, its elastic modulus and compressive strength still fall short of clinical needs. In contrast, organic-inorganic composites demonstrate significant potential for optimizing mechanical properties through a synergistic rigid-flexible strategy. Bio-polyurethane (PU) possesses a high elastic modulus and excellent interfacial bonding, enabling synergistic enhancement with CPC through an interpenetrating network structure while maintaining osteoconductive activity. In the field of anti-infection, photothermal antimicrobial therapy (PTT) has attracted considerable attention due to its antibiotic-independent and physical sterilization mechanism, while gaseous antimicrobial therapy is emerging as an emerging approach due to its low resistance and residue-free properties. Hydrogen sulfide (H2S), an endogenous gaseous signaling molecule, is a promising candidate due to its multi-target bioactivity. It not only exerts selective antimicrobial effects by regulating redox homeostasis but also mediates angiogenesis and tissue repair processes. However, existing H2S controlled-release carriers suffer from technical bottlenecks such as poor stability and low response precision, severely restricting their clinical application. Metal-organic framework (MOF) materials, due to their high specific surface area, tunable pore size, and chemical stability, have become breakthrough carriers for H2S gas delivery systems. Furthermore, MOFs can integrate photosensitive components, achieving a synergistic antibacterial effect through near-infrared light excitation, combining H2S release with localized hyperthermia, significantly enhancing the ability to clear drug-resistant bacterial biofilms. In summary, developing a bone repair material with both excellent mechanical properties and highly effective gas antibacterial properties is key to overcoming the dual bottlenecks of insufficient mechanical support and recurrent infection in the treatment of infected bone defects.

[0005] A Chinese patent application (application number: 202311741926.1, publication number: CN117618659A, publication date: March 1, 2024) discloses a method for preparing an injectable calcium phosphate bone cement modified with a thermosensitive chitosan / sodium β-glycerophosphate hydrogel. α-TCP powder is prepared via a solid-phase reaction, sodium bicarbonate is added to obtain bone cement powder, and then mixed with a curing liquid. While it can form micelles in vivo, improving mechanical properties, it struggles to form a tight bond between the hydrogel and the matrix, resulting in relatively weak interfacial bonding, which, to some extent, limits further improvement in the mechanical properties of the composite bone cement. A Chinese patent application (application number: 202310476149.6, publication number: CN117122733A, publication date: November 28, 2023) discloses a method for preparing a high-strength, fast-curing phosphate bone cement. The method uses a specific calcium salt base material and a conditioning material to prepare a solid phase powder. A binder, such as glycerol, is added to form a liquid phase, which is then blended to form bone cement. Adhesives in the liquid phase solidify rapidly when exposed to tissue fluid, blood, and other materials, and the setting time can be controlled by adjusting the adhesive ratio. Although this method optimizes the mechanical strength of bone cement by selecting a calcium salt substrate and adjusting pH and calcium-phosphorus ratio, it does not create a three-dimensional structure to optimize stress transfer, and the interfacial bonding strength still needs to be further improved.

[0006] A Chinese patent application (Application Number: 202411013956.5, Publication Number: CN118903548A, Publication Date: November 8, 2024) discloses a magnetic antibacterial bone cement, its preparation method, and its application. By adding 440°C martensitic steel silver powder to bone cement and utilizing its magnetocaloric effect and antibacterial properties, a bone cement with magnetocaloric heating, long-term stable imaging, and a certain degree of antibacterial properties is prepared. However, the use of silver ions can accelerate the evolution of drug-resistant bacteria and make it difficult to achieve long-term antibacterial effects. A Chinese patent application (Application Number: 202310966230.2, Publication Number: CN116870250A, Publication Date: October 13, 2023) discloses an antibacterial bone cement, its preparation method, and its application. By physically doping antibiotics into non-leaching bone cement, a dual-functional antibacterial bone cement with both non-releasable and releasable antibacterial properties is prepared, providing timely and effective anti-infection and long-term antibacterial capabilities. However, the use of antibiotics can easily lead to the emergence of drug-resistant bacteria. The emergence of drug-resistant bacteria will reduce the efficacy of antibiotics, increase the difficulty and cost of treatment, and may also lead to the persistence and spread of infection. Summary of the Invention

[0007] The purpose of the present invention is to provide a photothermal controlled release H2S polyurethane reinforced bone cement, which solves the problems of poor mechanical properties and low antibacterial properties of existing bone cement.

[0008] Another object of the present invention is to provide a method for preparing photothermal controlled-release H2S polyurethane reinforced bone cement.

[0009] The technical solution employed in this invention is a photothermal controlled-release H2S polyurethane-reinforced bone cement composed of a mixture of a solid phase and a liquid phase. The solid phase includes tetracalcium phosphate, calcium hydrogen phosphate dihydrate, and Allicin-MOF@PB, while the liquid phase is a water-based polyurethane prepolymer. The Allicin-MOF@PB is added in an amount of 10% to 30% of the combined weight of the tetracalcium phosphate and calcium hydrogen phosphate dihydrate powders; the molar ratio of tetracalcium phosphate to calcium hydrogen phosphate dihydrate is 1:1; and the mass ratio of the solid phase to the liquid phase is 2 to 4:1.

[0010] Another technical solution adopted by the present invention is a method for preparing photothermal controlled-release H2S polyurethane reinforced bone cement, which is specifically implemented according to the following steps: Step 1, preparing surface-modified MOF; Step 2, preparation of Allicin-MOF; Step 3: Allicin-MOF is dispersed in deionized water to obtain an Allicin-MOF aqueous solution, and K3[Zn(CN)6] solution and FeCl3 solution are added to the Allicin-MOF aqueous solution, stirred, centrifuged, washed, and vacuum-dried to obtain Allicin-MOF@PB; Step 4, preparing the solid phase of bone cement using tetracalcium phosphate, calcium hydrogen phosphate dihydrate, APTES and Allicin-MOF@PB; Step 5, preparing a liquid phase of bone cement; Step 6: After the solid phase and the liquid phase are evenly stirred, a bone cement slurry is obtained, which is poured into a mold and self-cured to obtain a photothermal controlled-release H2S polyurethane reinforced bone cement.

[0011] The present invention is also characterized in that: In step 1, specifically: Zn(NO3)3·6H2O and 2-MeIM were dissolved in methanol, respectively. The two solutions were mixed, stirred for 20-28 h, centrifuged, washed, and dried in vacuum at 50-70°C for 10-14 h to obtain MOF powder. The MOF powder was dispersed in anhydrous ethanol, 3-(triethoxysilyl)propionic acid was added, stirred at 50-70°C for 4-8 h, centrifuged, washed, and dried in vacuum at 60-80°C for 24-28 h to obtain surface-modified MOF powder. The molar ratio of Zn(NO3)3·6H2O to 2-MeIM was 0.5-1.5:3-5; the mass ratio of MOF powder to 3-(triethoxysilyl)propionic acid was 0.9-1.1:0.2-0.4.

[0012] In step 2, specifically: Allicin was dissolved in PBS buffer in the dark to obtain an Allicin solution; the surface-modified MOF powder prepared in step 1 was added to the Allicin solution, stirred in the dark at 3-5°C for 10-14 hours, centrifuged to remove the supernatant, washed with PBS buffer in the dark, and vacuum dried in the dark at 20-28°C for 10-14 hours to obtain Allicin-MOF powder.

[0013] In step 3, the stirring time is 4 to 8 hours; the vacuum drying temperature is 30 to 35°C, and the vacuum drying time is 10 to 14 hours; the volume ratio of the Allicin-MOF aqueous solution, K3[Zn(CN)6] solution, and FeCl3 solution is 4 to 5:0.9 to 1.1:0.9 to 1.1.

[0014] In step 4, specifically: Tetracalcium phosphate and calcium hydrogen phosphate dihydrate powders were dispersed in anhydrous ethanol, added with APTES and soaked for 1-3 hours, and dried to obtain surface-modified tetracalcium phosphate and calcium hydrogen phosphate dihydrate; then, the powders were evenly mixed with the Allicin-MOF@PB prepared in step 3 to obtain a solid phase of photothermal controlled-release H2S polyurethane-enhanced bone cement.

[0015] The molar ratio of tetracalcium phosphate to calcium hydrogen phosphate dihydrate is 1:1; the addition amount of Allicin-MOF@PB is 10% to 30% of the total weight of tetracalcium phosphate and calcium hydrogen phosphate dihydrate powders; and APTES is 10-15% of the total weight of tetracalcium phosphate and calcium hydrogen phosphate dihydrate powders.

[0016] In step 5, specifically: Under nitrogen protection, the vacuum-dried PCL was heated to 70-80°C, and then LDI and catalyst DBTDL were added dropwise in sequence, stirred and reacted for 32-36 hours. Then, BDO-DMF solution was added dropwise to the reaction solution, and stirred and reacted at 70-80°C for 22-24 hours. The product was then poured into a polytetrafluoroethylene mold, vacuum degassed for 25-30 minutes, and vacuum dried at 45-55°C for 22-26 hours to obtain a liquid phase of photothermally controlled H2S release polyurethane reinforced bone cement. The molar ratio of PCL, LDI, DBTDL and BDO is 0.9~1.1:1.8~2.2:0.0022~0.0024:1.9~2.1.

[0017] In step 6, the mass ratio of the solid phase to the liquid phase is 2 to 4:1, the self-curing temperature is 35° C. to 40° C., and the humidity is 100%.

[0018] The beneficial effects of this invention are as follows: through the composite design of a polyurethane interpenetrating network (PU) and a surface-modified calcium phosphate matrix, the bone cement material is endowed with high compressive strength and crack propagation resistance, combined with elastic cushioning properties, adapting to the dynamic load requirements of bone defects. Simultaneously, the near-infrared photothermal response of Allicin-MOF@PB triggers the precise release of H₂S from Allicin, which, combined with the photothermal bactericidal effect of PB, achieves dual-modal synergistic antibacterial properties, effectively penetrating the deep biofilm of infected bone defects and inhibiting infection by drug-resistant bacteria. Furthermore, the strong interfacial bonding between PU and the inorganic phase ensures the material's long-term service stability, while the MOF carrier, coated with PB and loaded with H₂S donors, prevents sudden drug release and prolongs the release period. Finally, the excellent biocompatibility of the waterborne polyurethane prepolymer and the calcium phosphate matrix allows for a near-infrared light-controlled release strategy that achieves targeted therapy without complex manipulation, adapting to minimally invasive clinical needs. This composite bone cement, through its dual-functional "mechanical-antibacterial" synergistic system, overcomes the core challenges of insufficient mechanical support and recurrent infection in the treatment of infected bone defects. DETAILED DESCRIPTION

[0019] The present invention is described in detail below with reference to specific embodiments.

[0020] The photothermal controlled-release H2S polyurethane reinforced bone cement of the present invention is composed of a mixture of a solid phase and a liquid phase, wherein the solid phase includes tetracalcium phosphate, calcium hydrogen phosphate dihydrate and Allicin-MOF@PB, and the liquid phase is an aqueous polyurethane prepolymer; The addition amount of Allicin-MOF@PB is 10% to 30% of the total weight of tetracalcium phosphate and calcium hydrogen phosphate dihydrate powders; the molar ratio of tetracalcium phosphate to calcium hydrogen phosphate dihydrate is 1:1; and the mass ratio of the solid phase to the liquid phase is 2 to 4:1.

[0021] The preparation method of the photothermal controlled-release H2S polyurethane reinforced bone cement of the present invention is specifically implemented according to the following steps: Step 1, preparation of surface-modified metal organic framework (MOF); Zinc nitrate (Zn(NO3)3·6H2O) and 2-methylimidazole (2-MeIM) were dissolved in methanol, respectively. The two solutions were quickly mixed and magnetically stirred at room temperature for 20-28 hours. The mixture was centrifuged, washed, and vacuum-dried at 50-70°C for 10-14 hours to obtain MOF powder. The MOF powder was dispersed in anhydrous ethanol, and 3-(triethoxysilyl) propionic acid (TESPA) was added. The mixture was stirred at 50-70°C for 4-8 hours. The mixture was centrifuged, washed, and vacuum-dried at 60-80°C for 24-28 hours to obtain surface-modified MOF powder. The molar ratio of Zn(NO3)3·6H2O and 2-MeIM is 0.5~1.5:3~5; The mass ratio of MOF powder to 3-(triethoxysilyl) propionic acid is 0.9-1.1:0.2-0.4; Step 2, preparation of Allicin-loaded MOF (Allicin-MOF); Allicin was dissolved in PBS buffer in the dark to obtain an Allicin solution; the surface-modified MOF powder prepared in step 1 was added to the Allicin solution, stirred in the dark at 3-5°C for 10-14 hours, centrifuged to remove the supernatant, washed three times with PBS buffer in the dark, and dried in a vacuum at 20-28°C in the dark for 10-14 hours to obtain Allicin-MOF powder; The pH of PBS buffer is 7.4; The concentration of allicin solution is 1-5 mg / mL; The molar ratio of surface-modified MOF powder and Allicin was 1:0.518~2.597.

[0022] Step 3: Preparation of Prussian blue-coated Allicin-MOF (Allicin-MOF@PB): The Allicin-MOF powder prepared in step 2 was dispersed in deionized water to obtain an Allicin-MOF aqueous solution. Potassium ferrocyanide (K3[Zn(CN)6]) solution and FeCl3 solution were then added to the Allicin-MOF aqueous solution. The mixture was stirred at room temperature for 4-8 hours, centrifuged, washed, and dried under vacuum at 30-35°C for 10-14 hours to obtain Allicin-MOF@PB. The concentrations of K3[Zn(CN)6] aqueous solution and FeCl3 aqueous solution were both 0.01 M; The concentration of Allicin-MOF aqueous solution is 0.8~1.2mg / ml.

[0023] The volume ratio of Allicin-MOF aqueous solution, K3[Zn(CN)6] solution, and FeCl3 solution is 4~5:0.9~1.1:0.9~1.1; Step 4, preparing a solid phase of photothermal controlled release H2S polyurethane reinforced bone cement; Tetracalcium phosphate and calcium hydrogen phosphate dihydrate powders were dispersed in anhydrous ethanol, and APTES (γ-aminopropyltriethoxysilane) was added and soaked for 1-3 hours. The mixture was dried to obtain surface-modified tetracalcium phosphate and calcium hydrogen phosphate dihydrate. The surface-modified tetracalcium phosphate and calcium hydrogen phosphate dihydrate were then mixed with the Allicin-MOF@PB prepared in step 3 to obtain a solid phase of photothermal controlled release H2S polyurethane-enhanced bone cement. The molar ratio of tetracalcium phosphate to calcium hydrogen phosphate dihydrate is 1:1; The addition amount of Allicin-MOF@PB is 10% to 30% of the total weight of tetracalcium phosphate and calcium hydrogen phosphate dihydrate powders; APTES is 10-15% of the total mass of tetracalcium phosphate and dibasic calcium phosphate dihydrate powders.

[0024] Step 5, preparing the liquid phase of photothermal controlled release H2S polyurethane enhanced bone cement: Under nitrogen protection, the vacuum-dried PCL was heated to 70-80°C, and then LDI (L-lysine diisocyanate) and catalyst DBTDL (dibutyltin dilaurate) were added dropwise in sequence. The reaction was stirred for 32-36 hours. Then, BDO-DMF solution was added dropwise to the reaction solution, and the stirring reaction was continued for 22-24 hours at a temperature of 70-80°C. The product was then poured into a polytetrafluoroethylene mold, vacuum-degassed for 25-30 minutes, and vacuum-dried at 45-55°C for 22-26 hours to obtain a liquid phase of photothermally controlled H2S release polyurethane-reinforced bone cement. The vacuum drying temperature of PCL (polycaprolactone diol) is 80°C and the vacuum drying time is 12h; BDO-DMF solution is made by mixing BDO (1,4-butanediol) and DMF; The molar ratio of PCL, LDI, DBTDL, and BDO is 0.9~1.1:1.8~2.2:0.0022~0.0024:1.9~2.1; Step 6, preparation of photothermal controlled release H2S polyurethane reinforced bone cement: The solid phase of the photothermal controlled-release H2S polyurethane enhanced bone cement prepared in step 4 and the liquid phase of the photothermal controlled-release H2S polyurethane enhanced bone cement prepared in step 5 are uniformly stirred to obtain a bone cement slurry, which is poured into a mold and self-cured to obtain a photothermal controlled-release H2S polyurethane enhanced bone cement; The mass ratio of the solid phase to the liquid phase is 2 to 4:1, the self-curing temperature is 35° C. to 40° C., and the humidity is 100%.

[0025] In this invention, after the polyurethane prepolymer is composited with a calcium phosphate matrix, the -NCO group reacts with the surface-modified bone cement to form a preliminary cross-linked network, imparting initial elasticity to the material. As the hydration reaction proceeds, the resulting hydroxyapatite (HA) crystals interpenetrate within the polyurethane network, providing rigid support. When the dual networks are fully interwoven, a three-dimensional interpenetrating skeleton forms at the interface. This structure disperses stress through chemical bonds and physical entanglement, effectively inhibiting crack propagation and significantly improving the material's fatigue resistance. Furthermore, Prussian blue (PB) is used as a photothermal material to coat allicin loaded on a surface-modified metal-organic framework (MOF) to create a near-infrared light-responsive composite material. Under near-infrared light irradiation, PB converts light energy into heat, triggering the thermosensitive decomposition of allicin to release H2S for sterilization. Simultaneously, the photothermal effect of PB directly kills pathogens, creating a "chemical-physical" dual-modal antimicrobial synergy. By combining rigidity and flexibility with mechanical reinforcement and photothermal controlled-release antimicrobial properties, this composite bone cement overcomes the core challenges of mechanical failure and recurrent infection in the treatment of infected bone defects.

[0026] Example 1 The preparation method of the photothermal controlled-release H2S polyurethane reinforced bone cement of the present invention is specifically implemented according to the following steps: Step 1: Preparation of surface-modified metal organic framework (MOF): 1 g Zn(NO3)3·6H2O and 0.756 g 2-MeIM were dissolved in 25 ml methanol respectively. The two solutions were quickly mixed, magnetically stirred at room temperature for 20 h, centrifuged, washed, and vacuum dried at 50°C for 14 h to obtain MOF powder. 1 g MOF powder was dispersed in anhydrous ethanol, 0.3 g TESPA was added, stirred at 50°C for 8 h, centrifuged, washed, and vacuum dried at 60°C for 28 h to obtain surface-modified MOF powder.

[0027] Step 2: Preparation of Allicin-loaded MOF (Allicin-MOF): In the dark, prepare a 3 mg / mL Allicin solution in PBS at pH 7.4. Add 100 mg of the surface-modified MOF powder prepared in step 1 to 10 mL of the Allicin solution. Stir in the dark at 4°C for 12 h. Centrifuge to remove the supernatant, wash three times with cold PBS in the dark, and dry in a vacuum at 25°C in the dark for 12 h to obtain Allicin-MOF.

[0028] Step 3: Preparation of Prussian blue-coated Allicin-MOF (Allicin-MOF@PB): Disperse 50 mg of Allicin-MOF prepared in step 2 in 50 ml of deionized water, add 10 mL of 0.1 M K3[Zn(CN)6] solution and FeCl3 solution, stir at room temperature for 4 h, centrifuge, wash, and dry in vacuum at 30 °C for 10 h to obtain Allicin-MOF@PB.

[0029] Step 4: Preparation of the solid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 3.66 g of tetracalcium phosphate and 1.72 g of calcium hydrogen phosphate dihydrate powder were dispersed in 20 ml of anhydrous ethanol, 0.538 g of APTES was added and soaked for 1 hour, and dried to obtain surface-modified tetracalcium phosphate and calcium hydrogen phosphate dihydrate, which were then mixed evenly with 1.076 g of Allicin-MOF@PB prepared in step 3 to obtain a photothermal controlled release H2S polyurethane reinforced bone cement solid phase.

[0030] Step 5: Preparation of liquid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 4.5 g of PCL was vacuum dried at 80°C for 12 h, added to a three-necked flask, protected by nitrogen, and heated to 70°C. 1 g of LDI and 6.48 mg of DBTDL were added dropwise, and the mixture was stirred and reacted for 32 h under a nitrogen atmosphere. 0.482 g of BDO was dissolved in 20 ml of DMF and added dropwise to the system. The mixture was stirred and reacted at 70°C for 22 h. The product was poured into a polytetrafluoroethylene mold, vacuum degassed for 25 min, and vacuum dried at 45°C for 22 h to obtain a liquid phase of photothermally controlled H2S release polyurethane reinforced bone cement.

[0031] Step 6: Preparation of photothermal controlled release H2S polyurethane reinforced bone cement: The solid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 4 and the liquid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 5 are mixed evenly in a mass ratio of 2:1 to obtain a bone cement slurry, which is poured into a mold and self-cured at a temperature of 37°C and a humidity of 100% to obtain a photothermal controlled release H2S polyurethane enhanced bone cement.

[0032] Example 2 The preparation method of the photothermal controlled-release H2S polyurethane reinforced bone cement of the present invention is specifically implemented according to the following steps: Step 1: Preparation of surface-modified metal organic framework (MOF): 1 g Zn(NO3)3·6H2O and 0.756 g 2-MeIM were dissolved in 25 ml methanol respectively. The two solutions were quickly mixed, magnetically stirred at room temperature for 28 h, centrifuged, washed, and vacuum dried at 70°C for 10 h to obtain MOF powder. 1 g MOF powder was dispersed in anhydrous ethanol, 0.3 g TESPA was added, stirred at 70°C for 4 h, centrifuged, washed, and vacuum dried at 80°C for 24 h to obtain surface-modified MOF powder.

[0033] Step 2: Preparation of Allicin-loaded MOF (Allicin-MOF): Prepare a 3 mg / mL Allicin solution in PBS at pH 7.4 in the dark. Add 100 mg of the surface-modified MOF powder prepared in step 1 to 10 mL of the Allicin solution, stir at 4°C in the dark for 12 h, remove the supernatant by centrifugation, wash three times with cold PBS in the dark, and dry in a vacuum at 25°C in the dark for 12 h to obtain Allicin-MOF.

[0034] Step 3: Preparation of Prussian blue-coated Allicin-MOF (Allicin-MOF@PB): 50 mg of Allicin-MOF prepared in step 2 was dispersed in 50 ml of deionized water, and 11.25 mL of 0.1 M K3[Zn(CN)6] solution and FeCl3 solution were added. The mixture was stirred at room temperature for 8 h, centrifuged, washed, and dried in vacuum at 35 °C for 14 h to obtain Allicin-MOF@PB.

[0035] Step 4: Preparation of the solid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 3.66 g of tetracalcium phosphate and 1.72 g of calcium hydrogen phosphate dihydrate powder were dispersed in 20 ml of anhydrous ethanol, 0.6752 g of APTES was added and soaked for 2 h, and dried to obtain surface-modified tetracalcium phosphate and calcium hydrogen phosphate dihydrate, which were then mixed evenly with 0.538 g of Allicin-MOF@PB prepared in step 3 to obtain a photothermal controlled release of H2S polyurethane reinforced bone cement solid phase.

[0036] Step 5: Preparation of liquid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 5.5 g of PCL was vacuum dried at 80°C for 12 h, added to a three-necked flask, protected by nitrogen, and heated to 75°C. 1 g of LDI and 6.48 mg of DBTDL were added dropwise, and the mixture was stirred and reacted for 34 h under a nitrogen atmosphere. 0.473 g of BDO was dissolved in 20 ml of DMF and added dropwise to the system. The mixture was stirred and reacted at 75°C for 23 h. The product was poured into a polytetrafluoroethylene mold, vacuum degassed for 28 min, and vacuum dried at 48°C for 24 h to obtain a liquid phase of photothermally controlled H2S release polyurethane reinforced bone cement.

[0037] Step 6: Preparation of photothermal controlled release H2S polyurethane reinforced bone cement: The solid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 4 and the liquid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 5 are mixed evenly in a mass ratio of 3:1 to obtain a bone cement slurry, which is poured into a mold and self-cured at a temperature of 37°C and a humidity of 100% to obtain a photothermal controlled release H2S polyurethane enhanced bone cement.

[0038] Example 3 The preparation method of the photothermal controlled-release H2S polyurethane reinforced bone cement of the present invention is specifically implemented according to the following steps: Step 1: Preparation of surface-modified metal organic framework (MOF): 1 g Zn(NO3)3·6H2O and 0.378 g 2-MeIM were dissolved in 25 ml methanol respectively. The two solutions were quickly mixed, magnetically stirred at room temperature for 24 h, centrifuged, washed, and vacuum dried at 60°C for 12 h to obtain MOF powder. 1.1 g MOF powder was dispersed in anhydrous ethanol, 0.3 g TESPA was added, stirred at 60°C for 6 h, centrifuged, washed, and vacuum dried at 70°C for 26 h to obtain surface-modified MOF powder.

[0039] Step 2: Preparation of Allicin-loaded MOF (Allicin-MOF): Prepare an Allicin solution with a concentration of 1 mg / mL in PBS at pH 7.4 in the dark. Add 100 mg of the surface-modified MOF powder prepared in step 1 to 10 mL of the Allicin solution, stir at 3°C in the dark for 14 h, centrifuge to remove the supernatant, wash three times with cold PBS in the dark, and dry in a vacuum at 20°C in the dark for 14 h to obtain Allicin-MOF.

[0040] Step 3: Preparation of Prussian blue-coated Allicin-MOF (Allicin-MOF@PB): 40 mg of Allicin-MOF prepared in step 2 was dispersed in 50 ml of deionized water, and 12.5 mL of 0.1 M K3[Zn(CN)6] solution and FeCl3 solution were added. The mixture was stirred at room temperature for 6 h, centrifuged, washed, and dried in vacuum at 30°C for 14 h to obtain Allicin-MOF@PB.

[0041] Step 4: Preparation of the solid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 3.66 g of tetracalcium phosphate and 1.72 g of calcium hydrogen phosphate dihydrate powder were dispersed in 20 ml of anhydrous ethanol, 0.807 g of APTES was added and soaked for 3 h, and dried to obtain surface-modified tetracalcium phosphate and calcium hydrogen phosphate dihydrate, which were then mixed evenly with 1.076 g of Allicin-MOF@PB prepared in step 3 to obtain a photothermal controlled release H2S polyurethane reinforced bone cement solid phase.

[0042] Step 5: Preparation of liquid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 5.5 g of PCL was vacuum dried at 80°C for 12 h, added to a three-necked flask, protected by nitrogen, and heated to 80°C. 1 g of LDI and 7.46 mg of DBTDL were added dropwise, and the mixture was stirred and reacted for 36 h under a nitrogen atmosphere. 0.473 g of BDO was dissolved in 20 ml of DMF and added dropwise to the system. The mixture was stirred and reacted at 80°C for 24 h. The product was poured into a polytetrafluoroethylene mold, vacuum degassed for 30 min, and vacuum dried at 50°C for 26 h to obtain a liquid phase of photothermally controlled H2S release polyurethane reinforced bone cement.

[0043] Step 6: Preparation of photothermal controlled release H2S polyurethane reinforced bone cement: The solid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 4 and the liquid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 5 are mixed evenly in a mass ratio of 3:1 to obtain a bone cement slurry, which is poured into a mold and self-cured at a temperature of 37°C and a humidity of 100% to obtain a photothermal controlled release H2S polyurethane enhanced bone cement.

[0044] Example 4 The preparation method of the photothermal controlled-release H2S polyurethane reinforced bone cement of the present invention is specifically implemented according to the following steps: Step 1: Preparation of surface-modified metal organic framework (MOF): 1 g Zn(NO3)3·6H2O and 1.777 g 2-MeIM were dissolved in 25 ml methanol respectively. The two solutions were quickly mixed, magnetically stirred at room temperature for 24 h, centrifuged, washed, and vacuum dried at 60°C for 12 h to obtain MOF powder. 1 g MOF powder was dispersed in anhydrous ethanol, 0.4 g TESPA was added, stirred at 60°C for 6 h, centrifuged, washed, and vacuum dried at 70°C for 26 h to obtain surface-modified MOF powder.

[0045] Step 2: Preparation of Allicin-loaded MOF (Allicin-MOF): Prepare a 3 mg / mL Allicin solution in PBS at pH 7.4 in the dark. Add 100 mg of the surface-modified MOF powder prepared in step 1 to 10 mL of the Allicin solution, stir at 5°C in the dark for 10 h, remove the supernatant by centrifugation, wash three times with cold PBS in the dark, and dry in a vacuum at 28°C in the dark for 10 h to obtain Allicin-MOF.

[0046] Step 3: Preparation of Prussian blue-coated Allicin-MOF (Allicin-MOF@PB): 40 mg of Allicin-MOF prepared in step 2 was dispersed in 50 ml of deionized water, and 13.5 mL of 0.1 M K3[Zn(CN)6] solution and FeCl3 solution were added. The mixture was stirred at room temperature for 6 h, centrifuged, washed, and dried in vacuum at 35 °C for 10 h to obtain Allicin-MOF@PB.

[0047] Step 4: Preparation of the solid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 3.66 g of tetracalcium phosphate and 1.72 g of calcium hydrogen phosphate dihydrate powder were dispersed in 20 ml of anhydrous ethanol, 0.807 g of APTES was added and soaked for 1 hour, and dried to obtain surface-modified tetracalcium phosphate and calcium hydrogen phosphate dihydrate, which were then mixed evenly with 1.076 g of Allicin-MOF@PB prepared in step 3 to obtain a photothermal controlled release H2S polyurethane reinforced bone cement solid phase.

[0048] Step 5: Preparation of liquid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 3.68 g of PCL was vacuum dried at 80°C for 12 h, added to a three-necked flask, protected by nitrogen, and heated to 70°C. 1 g of LDI and 6.11 mg of DBTDL were added dropwise, and the mixture was stirred and reacted for 36 h under a nitrogen atmosphere. 0.351 g of BDO was dissolved in 20 ml of DMF and added dropwise to the system. The mixture was stirred and reacted at 70°C for 24 h. The product was poured into a polytetrafluoroethylene mold, vacuum degassed for 25 min, and vacuum dried at 50°C for 22 h to obtain a liquid phase of photothermally controlled H2S release polyurethane reinforced bone cement.

[0049] Step 6: Preparation of photothermal controlled release H2S polyurethane reinforced bone cement: The solid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 4 and the liquid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 5 are mixed evenly in a mass ratio of 3:1 to obtain a bone cement slurry, which is poured into a mold and self-cured at a temperature of 37°C and a humidity of 100% to obtain a photothermal controlled release H2S polyurethane enhanced bone cement.

[0050] Example 5 The preparation method of the photothermal controlled-release H2S polyurethane reinforced bone cement of the present invention is specifically implemented according to the following steps: Step 1: Preparation of surface-modified metal organic framework (MOF): 1 g Zn(NO3)3·6H2O and 1.302 g 2-MeIM were dissolved in 25 ml methanol respectively. The two solutions were quickly mixed, magnetically stirred at room temperature for 24 h, centrifuged, washed, and vacuum dried at 60°C for 12 h to obtain MOF powder. 1 g MOF powder was dispersed in anhydrous ethanol, 0.3 g TESPA was added, stirred at 60°C for 6 h, centrifuged, washed, and vacuum dried at 70°C for 26 h to obtain surface-modified MOF powder.

[0051] Step 2: Preparation of Allicin-loaded MOF (Allicin-MOF): Prepare a 5 mg / mL Allicin solution in PBS at pH 7.4 in the dark. Add 100 mg of the surface-modified MOF powder prepared in step 1 to 10 mL of the Allicin solution, stir at 3°C in the dark for 10 h, centrifuge to remove the supernatant, wash three times with cold PBS in the dark, and dry in a vacuum at 20°C in the dark for 10 h to obtain Allicin-MOF.

[0052] Step 3: Preparation of Prussian blue-coated Allicin-MOF (Allicin-MOF@PB): 60 mg of Allicin-MOF prepared in step 2 was dispersed in 50 ml of deionized water, and 9 mL of 0.1 M K3[Zn(CN)6] solution and FeCl3 solution were added. The mixture was stirred at room temperature for 6 h, centrifuged, washed, and dried in vacuum at 35 °C for 12 h to obtain Allicin-MOF@PB.

[0053] Step 4: Preparation of the solid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 3.66 g of tetracalcium phosphate and 1.72 g of calcium hydrogen phosphate dihydrate powder were dispersed in 20 ml of anhydrous ethanol, 0.538 g of APTES was added and soaked for 3 h, and dried to obtain surface-modified tetracalcium phosphate and calcium hydrogen phosphate dihydrate, which were then mixed evenly with 1.076 g of Allicin-MOF@PB prepared in step 3 to obtain a photothermal controlled release H2S polyurethane reinforced bone cement solid phase.

[0054] Step 5: Preparation of liquid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 4.5 g of PCL was vacuum dried at 80°C for 12 h, added to a three-necked flask, protected by nitrogen, and heated to 80°C. 1 g of LDI and 6.45 mg of DBTDL were added dropwise, and the mixture was stirred and reacted for 32 h under a nitrogen atmosphere. 0.406 g of BDO was dissolved in 20 ml of DMF and added dropwise to the system. The mixture was stirred and reacted at 80°C for 22 h. The product was poured into a polytetrafluoroethylene mold, vacuum degassed for 30 min, and vacuum dried at 45°C for 26 h to obtain a liquid phase of photothermally controlled H2S release polyurethane reinforced bone cement.

[0055] Step 6: Preparation of photothermal controlled release H2S polyurethane reinforced bone cement: The solid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 4 and the liquid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 5 are mixed evenly in a mass ratio of 3:1 to obtain a bone cement slurry, which is poured into a mold and self-cured at a temperature of 37°C and a humidity of 100% to obtain a photothermal controlled release H2S polyurethane enhanced bone cement.

[0056] Example 6 The preparation method of the photothermal controlled-release H2S polyurethane reinforced bone cement of the present invention is specifically implemented according to the following steps: Step 1: Preparation of surface-modified metal organic framework (MOF): 1 g Zn(NO3)3·6H2O and 1.302 g 2-MeIM were dissolved in 25 ml methanol respectively. The two solutions were quickly mixed, magnetically stirred at room temperature for 24 h, centrifuged, washed, and vacuum dried at 60°C for 12 h to obtain MOF powder. 0.9 g MOF powder was dispersed in anhydrous ethanol, 0.4 g TESPA was added, stirred at 60°C for 6 h, centrifuged, washed, and vacuum dried at 70°C for 26 h to obtain surface-modified MOF powder.

[0057] Step 2: Preparation of Allicin-loaded MOF (Allicin-MOF): Prepare a 3 mg / mL Allicin solution in PBS at pH 7.4 in the dark. Add 100 mg of the surface-modified MOF powder prepared in step 1 to 10 mL of the Allicin solution, stir at 5°C in the dark for 14 h, remove the supernatant by centrifugation, wash three times with cold PBS in the dark, and dry in a vacuum at 28°C in the dark for 14 h to obtain Allicin-MOF.

[0058] Step 3: Preparation of Prussian blue-coated Allicin-MOF (Allicin-MOF@PB): 60 mg of Allicin-MOF prepared in step 2 was dispersed in 50 ml of deionized water, and 11 mL of 0.1 M K3[Zn(CN)6] solution and FeCl3 solution were added. The mixture was stirred at room temperature for 6 h, centrifuged, washed, and dried in vacuum at 35 °C for 12 h to obtain Allicin-MOF@PB.

[0059] Step 4: Preparation of the solid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 3.66 g of tetracalcium phosphate and 1.72 g of calcium hydrogen phosphate dihydrate powder were dispersed in 20 ml of anhydrous ethanol, 0.6725 g of APTES was added and soaked for 2 h, and dried to obtain surface-modified tetracalcium phosphate and calcium hydrogen phosphate dihydrate, which were then mixed evenly with 1.614 g of Allicin-MOF@PB prepared in step 3 to obtain a photothermal controlled release H2S polyurethane reinforced bone cement solid phase.

[0060] Step 5: Preparation of liquid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 4.5 g of PCL was vacuum dried at 80°C for 12 h, added to a three-necked flask, protected by nitrogen, and heated to 75°C. 1 g of LDI and 2.8 mg of DBTDL were added dropwise, and the mixture was stirred and reacted for 34 h under a nitrogen atmosphere. 0.39 g of BDO was dissolved in 20 ml of DMF and added dropwise to the system. The mixture was stirred and reacted at 75°C for 23 h. The product was poured into a polytetrafluoroethylene mold, vacuum degassed for 28 min, and vacuum dried at 48°C for 24 h to obtain a liquid phase of photothermally controlled H2S release polyurethane reinforced bone cement.

[0061] Step 6: Preparation of photothermal controlled release H2S polyurethane reinforced bone cement: The solid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 4 and the liquid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 5 are mixed evenly in a mass ratio of 3:1 to obtain a bone cement slurry, which is poured into a mold and self-cured at a temperature of 37°C and a humidity of 100% to obtain a photothermal controlled release H2S polyurethane enhanced bone cement.

[0062] Example 7 The preparation method of the photothermal controlled-release H2S polyurethane reinforced bone cement of the present invention is specifically implemented according to the following steps: Step 1: Preparation of surface-modified metal organic framework (MOF): 1 g Zn(NO3)3·6H2O and 1.302 g 2-MeIM were dissolved in 25 ml methanol respectively. The two solutions were quickly mixed, magnetically stirred at room temperature for 24 h, centrifuged, washed, and vacuum dried at 60°C for 12 h to obtain MOF powder. 1.1 g MOF powder was dispersed in anhydrous ethanol, 0.2 g TESPA was added, stirred at 60°C for 6 h, centrifuged, washed, and vacuum dried at 70°C for 26 h to obtain surface-modified MOF powder.

[0063] Step 2: Preparation of Allicin-loaded MOF (Allicin-MOF): Prepare a 3 mg / mL Allicin solution in PBS at pH 7.4 in the dark. Add 100 mg of the surface-modified MOF powder prepared in step 1 to 10 mL of the Allicin solution, stir at 4°C in the dark for 12 h, remove the supernatant by centrifugation, wash three times with cold PBS in the dark, and dry in a vacuum at 25°C in the dark for 12 h to obtain Allicin-MOF.

[0064] Step 3: Preparation of Prussian blue-coated Allicin-MOF (Allicin-MOF@PB): Disperse 50 mg of Allicin-MOF prepared in step 2 in 50 ml of deionized water, add 11.1 mL of 0.1 M K3[Zn(CN)6] solution and FeCl3 solution, stir at room temperature for 6 h, centrifuge, wash, and dry in vacuum at 35 °C for 12 h to obtain Allicin-MOF@PB.

[0065] Step 4: Preparation of the solid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 3.66 g of tetracalcium phosphate and 1.72 g of calcium hydrogen phosphate dihydrate powder were dispersed in 20 ml of anhydrous ethanol, 0.6725 g of APTES was added and soaked for 2 h, and dried to obtain surface-modified tetracalcium phosphate and calcium hydrogen phosphate dihydrate, which were then mixed evenly with 1.076 g of Allicin-MOF@PB prepared in step 3 to obtain a photothermal controlled release H2S polyurethane reinforced bone cement solid phase.

[0066] Step 5: Preparation of liquid phase of photothermal controlled release H2S polyurethane reinforced bone cement: 4.5 g of PCL was vacuum dried at 80°C for 12 h, added to a three-necked flask, protected by nitrogen, and heated to 75°C. 1 g of LDI and 2.52 mg of DBTDL were added dropwise, and the mixture was stirred and reacted for 34 h under a nitrogen atmosphere. 0.473 g of BDO was dissolved in 20 ml of DMF and added dropwise to the system. The mixture was stirred and reacted at 75°C for 23 h. The product was poured into a polytetrafluoroethylene mold, vacuum degassed for 28 min, and vacuum dried at 48°C for 24 h to obtain a liquid phase of photothermally controlled H2S release polyurethane reinforced bone cement.

[0067] Step 6: Preparation of photothermal controlled release H2S polyurethane reinforced bone cement: The solid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 4 and the liquid phase of the photothermal controlled release H2S polyurethane enhanced bone cement prepared in step 5 were mixed evenly in a mass ratio of 4:1 to obtain a bone cement slurry, which was poured into a mold and self-cured at a temperature of 37°C and a humidity of 100% to obtain a photothermal controlled release H2S polyurethane enhanced bone cement.

[0068] While traditional hydrogel or adhesive modifications can enhance the mechanical strength of materials, their inherent brittleness makes them difficult to meet dynamic load-bearing requirements. Existing antibiotic or silver ion antibacterial strategies, due to their large molecular weight, cannot penetrate deep biomembranes and face problems such as uncontrolled release and accelerated evolution of drug-resistant bacteria. To address these limitations, a synergistic antibacterial system based on PU interpenetrating network and H2S gas has achieved a breakthrough through the dynamic integration of "mechanical strengthening and antibacterial penetration": PU prepolymer liquid covalently bonds with the modified CPC matrix to form an elastic network, while hydrated HA crystals are embedded in the rigid and flexible interpenetrating framework. This synergistic chemical bond-physical entanglement disperses stress and suppresses microcracks, significantly improving fatigue resistance and overcoming the brittleness of traditional materials. Meanwhile, H2S gas molecules, thanks to their low molecular weight, freely penetrate deep into the biomembrane. Combined with a near-infrared light-controlled release system, this system achieves precise sterilization in both time and space, avoiding the risk of explosive silver ion release while leveraging the rapid diffusion properties of the gas to enhance broad-spectrum antibacterial activity while reducing the probability of drug resistance induction. The synergistic mechanism between the two is reflected in the three-level integration of "structure-function-timing": the PU network significantly improves the CPC's crack resistance through elastic modulus matching and interfacial chemical bonding, providing stable mechanical support for the defect site. Its interfacial fusion ability can also support the load of the photothermal material, establishing a mechanical framework for controlled H2S release. In terms of functional timing, the PU-CPC complex prioritizes the load-bearing requirements of bone defect repair, and then the photothermal response system releases H2S on demand to clear deep infection foci, forming a progressive treatment logic of "mechanical support first, then antibacterial intervention." This strategy directly addresses the pain points of infected bone defect treatment. Through the synergistic paradigm of "mechanical support as the foundation and gas antibacterial as the blade," it provides an innovative treatment path for infected bone defects that combines mechanical property adaptability, antibacterial penetration, and drug resistance avoidance.

[0069] The mechanical properties, H2S release concentration under near-infrared stimulation and antibacterial period of the photothermal controlled-release H2S polyurethane reinforced bone cement prepared in the embodiment are compared with those of the existing CPC material, as shown in Tables 1 and 2 below: Table 1 Comparison of mechanical properties of bone cement in the embodiment and existing CPC materials

[0070] Table 2 Comparison of H2S release concentration and antibacterial period between bone cement and CPC material in the examples

[0071] As shown in the table above, the mechanically reinforced and photothermal antibacterial dual-functional polyurethane composite calcium phosphate bone cement material of the present invention modifies the mechanical and antibacterial properties of the bone cement by varying the solid-to-liquid mass ratio of the polyurethane composite calcium phosphate bone cement, the adsorption capacity of Allicin, and the doping level of Allicin-MOF@PB, thereby addressing the issues of insufficient mechanical support and recurrent infection in the treatment of infected bone defects. Therefore, the photothermal controlled-release H2S polyurethane reinforced bone cement prepared in this invention has promising application prospects.

Claims

1. Photothermal controlled release H2S polyurethane reinforced bone cement, characterized in that: It is composed of a mixture of a solid phase and a liquid phase, wherein the solid phase includes tetracalcium phosphate, calcium hydrogen phosphate dihydrate and Allicin-MOF@PB, and the liquid phase is a waterborne polyurethane prepolymer.

2. The photothermal controlled release H2S polyurethane reinforced bone cement according to claim 1, characterized in that: The added amount of the Allicin-MOF@PB is 10% to 30% of the total weight of tetracalcium phosphate and calcium hydrogen phosphate dihydrate powders; the molar ratio of the tetracalcium phosphate to calcium hydrogen phosphate dihydrate is 1:1; and the mass ratio of the solid phase to the liquid phase is 2 to 4:

1.

3. A method for preparing photothermal controlled release H2S polyurethane reinforced bone cement, characterized in that: Please follow the steps below to implement: Step 1, preparing surface-modified MOF; Step 2, preparation of Allicin-MOF; Step 3: Allicin-MOF is dispersed in deionized water to obtain an Allicin-MOF aqueous solution, and K3[Zn(CN)6] solution and FeCl3 solution are added to the Allicin-MOF aqueous solution, stirred, centrifuged, washed, and vacuum-dried to obtain Allicin-MOF@PB; Step 4, preparing the solid phase of bone cement using tetracalcium phosphate, calcium hydrogen phosphate dihydrate, APTES and Allicin-MOF@PB; Step 5, preparing a liquid phase of bone cement; Step 6: After the solid phase and the liquid phase are evenly stirred, a bone cement slurry is obtained, which is poured into a mold and self-cured to obtain a photothermal controlled-release H2S polyurethane reinforced bone cement.

4. The method for preparing photothermal controlled release H2S polyurethane reinforced bone cement according to claim 3, characterized in that: In the step 1, specifically: Zn(NO3)3·6H2O and 2-MeIM were dissolved in methanol, respectively. The two solutions were mixed, stirred for 20-28 h, centrifuged, washed, and dried in vacuum at 50-70°C for 10-14 h to obtain MOF powder. The MOF powder was dispersed in anhydrous ethanol, 3-(triethoxysilyl)propionic acid was added, stirred at 50-70°C for 4-8 h, centrifuged, washed, and dried in vacuum at 60-80°C for 24-28 h to obtain surface-modified MOF powder. The molar ratio of Zn(NO3)3·6H2O to 2-MeIM was 0.5-1.5:3-5; the mass ratio of MOF powder to 3-(triethoxysilyl)propionic acid was 0.9-1.1:0.2-0.

4.

5. The method for preparing photothermal controlled release H2S polyurethane reinforced bone cement according to claim 3, characterized in that: In the step 2, specifically: Allicin was dissolved in PBS buffer in the dark to obtain an Allicin solution; the surface-modified MOF powder prepared in step 1 was added to the Allicin solution, stirred in the dark at 3-5°C for 10-14 hours, centrifuged to remove the supernatant, washed with PBS buffer in the dark, and vacuum dried in the dark at 20-28°C for 10-14 hours to obtain Allicin-MOF powder.

6. The method for preparing photothermal controlled release H2S polyurethane reinforced bone cement according to claim 3, characterized in that: In step 3, the stirring time is 4 to 8 hours; the vacuum drying temperature is 30 to 35° C., and the vacuum drying time is 10 to 14 hours; the volume ratio of the Allicin-MOF aqueous solution, the K3[Zn(CN)6] solution, and the FeCl3 solution is 4 to 5:0.9 to 1.1:0.9 to 1.

1.

7. The method for preparing photothermal controlled release H2S polyurethane reinforced bone cement according to claim 3, characterized in that: In the step 4, specifically: Tetracalcium phosphate and calcium hydrogen phosphate dihydrate powders were dispersed in anhydrous ethanol, added with APTES and soaked for 1-3 hours, and dried to obtain surface-modified tetracalcium phosphate and calcium hydrogen phosphate dihydrate; then, the powders were evenly mixed with the Allicin-MOF@PB prepared in step 3 to obtain a solid phase of photothermal controlled-release H2S polyurethane-enhanced bone cement.

8. The method for preparing photothermal controlled release H2S polyurethane reinforced bone cement according to claim 7, characterized in that: The molar ratio of tetracalcium phosphate to calcium hydrogen phosphate dihydrate is 1:1; the addition amount of Allicin-MOF@PB is 10% to 30% of the total weight of tetracalcium phosphate and calcium hydrogen phosphate dihydrate powders; and APTES is 10-15% of the total weight of tetracalcium phosphate and calcium hydrogen phosphate dihydrate powders.

9. The method for preparing photothermal controlled release H2S polyurethane reinforced bone cement according to claim 3, characterized in that: In the step 5, specifically: Under nitrogen protection, the vacuum-dried PCL was heated to 70-80°C, and then LDI and catalyst DBTDL were added dropwise in sequence, stirred and reacted for 32-36 hours. Then, BDO-DMF solution was added dropwise to the reaction solution, and stirred and reacted at 70-80°C for 22-24 hours. The product was then poured into a polytetrafluoroethylene mold, vacuum degassed for 25-30 minutes, and vacuum dried at 45-55°C for 22-26 hours to obtain a liquid phase of photothermally controlled H2S release polyurethane reinforced bone cement. The molar ratio of PCL, LDI, DBTDL and BDO is 0.9~1.1:1.8~2.2:0.0022~0.0024:1.9~2.

1.

10. The method for preparing photothermal controlled release H2S polyurethane reinforced bone cement according to claim 3, characterized in that: In step 6, the mass ratio of the solid phase to the liquid phase is 2 to 4:1, the self-curing temperature is 35° C. to 40° C., and the humidity is 100%.

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