Nano-catalyst-loaded Zn-based composite material as well as preparation method and application thereof

Abstract

The invention discloses a Zn-based composite material loaded with a nano-catalyst as well as a preparation method and application of the Zn-based composite material. The Zn-based composite material loaded with the nano-catalyst is composed of a Zn substrate, the nano-catalyst and a hydroxyapatite coating, wherein holes are densely distributed in the surface layer of the Zn substrate, the nano-catalyst is embedded into the holes, and the hydroxyapatite coating is arranged on the Zn substrate; the nano-catalyst is an M / NC composite material, wherein M is selected from Fe and / or Se. According to the Zn-based composite material loaded with the nano-catalyst, the nano-catalyst is embedded into the holes in the surface layer of the Zn substrate, and then the nano-catalyst is ingeniously packaged in the holes through the hydroxyapatite coating, so that slow and continuous release is achieved, and the antibacterial and anticancer effects are achieved; and due to introduction of the hydroxyapatite coating, explosion release of zinc ions is inhibited, the corrosion resistance of the zinc alloy is enhanced, good biocompatibility is shown, cell viability is remarkably improved, and adhesion is good.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of biomaterials, and particularly relates to a Zn-based composite material loaded with a nano-catalyst, a preparation method therefor and applications thereof. BACKGROUND

[0002] Degradable zinc alloys have shown great potential in cardiovascular stents, orthopedic implants and bone defect repair in recent years as a new type of biomedical material. Their advantages include good biocompatibility, moderate degradation rate (between the excessively fast degradation of magnesium alloys and the excessively slow degradation of iron alloys), and no hydrogen generation. However, this field is still in the development stage and there are many challenges. Among them, the mechanical properties of zinc alloys are inherently insufficient, which restricts their application in clinical practice. Most zinc alloys cannot meet the requirements of vascular stents (yield strength > 200 MPa, tensile strength > 300 MPa, elongation 15%-18%). At the same time, zinc alloys are prone to dynamic recrystallization (DRX) during deformation at room temperature, leading to work-softening, which affects the stability of stent compression and the uniformity of expansion. The plasticity of some alloys (such as Zn-Mg) decreases significantly (elongation decreases by 50% within 1 month) after storage at room temperature, resulting in unstable mechanical properties and exhibiting natural aging phenomenon. In addition, the degradation behavior of zinc alloys is difficult to control, for example, some alloys have a tendency to localized corrosion, and the degradation uniformity is insufficient. In order to improve the mechanical properties of the alloy, some alloying elements such as Fe, Mg, rare earth elements, etc. are usually added to the alloy, which may form stable intermetallic compounds that are difficult to be absorbed, affecting the biocompatibility; and may also cause inflammatory reactions during the degradation process.

[0003] Surface treatment of biodegradable zinc alloys can regulate degradation behavior, improve biocompatibility, and endow functional properties. To address the problem of uniform corrosion turning into local pitting in zinc alloys in body fluids, active elements (such as lithium to induce a dense Li2CO3 layer to delay pitting for 30 days) are added, alloy composition is optimized (0.4% iron to improve uniformity, and excessive iron to accelerate corrosion), and corrosion product layers (Zn(OH)2 / ZnO / ZnCO3) are used to slow down the degradation rate. Surface modification techniques mainly include chemical conversion coatings (such as phosphate), organic coatings (such as polylactic acid to control ion release), and emerging metal-organic framework (MOF) biofunctional coatings, which can enhance bioactivity and antibacterial properties. In terms of biocompatibility, zinc ion release can be regulated by coatings to reduce cytotoxicity, and the addition of elements such as magnesium, copper, and silver can improve cell compatibility, promote vascularization, and endow antibacterial properties, respectively. Functional design such as drug-loaded coatings (anti-restenosis) and bioactive coatings (bone integration promotion) further expands application scenarios. The current challenge is that traditional treatments may exacerbate ion release, while the addition of alloy elements may increase the inherent brittleness of zinc alloys. Therefore, developing surface modification techniques for zinc alloys to precisely regulate degradation-mechanical-biofunctional properties is crucial for promoting the clinical application of zinc alloys. SUMMARY

[0004] In view of the deficiencies in the prior art, a first object of the present application is to provide a Zn-based composite material loaded with a nano-catalyst.

[0005] A second object of the present application is to provide a method for preparing a Zn-based composite material loaded with a nano-catalyst.

[0006] A third object of the present application is to provide an application of a Zn-based composite material loaded with a nano-catalyst.

[0007] To achieve the above objects, the present application adopts the following technical solutions:

[0008] The Zn-based composite material loaded with a nano-catalyst comprises a Zn substrate with densely arranged holes on the surface layer, a nano-catalyst embedded in the holes, and a hydroxyapatite coating layer arranged on the surface of the Zn substrate; the nano-catalyst is an M / NC composite material, wherein M is selected from Fe and / or Se.

[0009] The Zn-based composite material loaded with a nano-catalyst provided by the present application embeds the nano-catalyst in the holes on the surface layer of the Zn substrate, and then cleverly encapsulates the nano-catalyst in the holes through the hydroxyapatite coating layer, achieving slow and continuous release and exerting antibacterial and anticancer effects. In addition, the introduction of the hydroxyapatite coating layer also inhibits the explosive release of zinc ions, enhances the corrosion resistance of zinc alloys, and exhibits good biocompatibility, significantly improving cell viability and good adhesion.

[0010] In a preferred embodiment, the nanocatalyst possesses an SOD topological framework structure. This framework structure has numerous defects and a high specific surface area, providing a large number of active sites for metal elements to bind, and significantly enhancing catalytic performance.

[0011] In a preferred embodiment, the particle size of the nanocatalyst is 10 nm to 200 nm. Experiments have shown that controlling the particle size of the nanocatalyst within this range results in optimal performance.

[0012] In a preferred embodiment, the diameter of the pores is between 10 and 50 μm. It has been found that controlling the pore diameter to 10 μm or more allows for better embedding of the nanocatalyst within the pores, while controlling it to below 50 μm provides better adhesion to the hydroxyapatite coating.

[0013] In a preferred embodiment, the nanocatalyst is an Fe-Se / NC composite material. Dual-Atom Catalysts (DACs) are a class of atomically dispersed catalysts formed by two adjacent metal atoms (homonuclear or heteronuclear) linked by coordination bonds or metal-metal bonds. Their active sites are typically anchored on porous materials such as carbon-based supports (e.g., graphene, nitrogen-doped carbon) or molecular sieves. Compared to traditional single-atom catalysts (SACs) and nanoparticle catalysts, DACs possess the unique advantages of high atom utilization (approaching 100%) and dual-site synergistic effects. Adjacent metal atoms can regulate the adsorption behavior of intermediate products through electronic coupling and spatial synergy, thereby significantly enhancing catalytic activity and selectivity. Therefore, the highly efficient catalytic properties and precise control capabilities of DACs demonstrate potential application value in the biomedical field. First, their excellent redox activity can be used for biomolecular detection and sensing. Second, the enzyme-mimicking properties of DACs (e.g., peroxidase-like activity) can be applied to catalytic therapy in tumor treatment. Studies have shown that diatomic sites can synergistically activate hydrogen peroxide (H2O2) to generate highly toxic hydroxyl radicals (·OH), which specifically kill cancer cells while reducing damage to normal tissues. Fe / NC has the best anti-cancer effect known to date among single-atom catalysts. Experiments have found that by introducing the non-metallic element Se, the d-band center of Fe is changed, which can further improve the catalytic performance.

[0014] This invention also provides a method for preparing a Zn-based composite material supported on nanocatalysts. Magnesium powder particles are coated onto the surface of a Zn plate, which is then rolled to obtain a Zn plate with embedded magnesium powder particles. The magnesium powder particles are etched to obtain a Zn plate with densely arranged pores on the surface. The M / NC composite material is then dispersed in a solvent to obtain a dispersion. The dispersion is filled into the pores, and after drying, a Zn plate with M / NC composite material dispersed in the pores is obtained. This plate is then placed in a hydroxyapatite precursor solution and subjected to hydrothermal treatment to obtain the Zn-based composite material supported on nanocatalysts.

[0015] The preparation method of this invention involves rolling magnesium powder particles into a pure Zn plate, then etching away the Mg powder particles embedded in the surface of the Zn plate to leave uniformly distributed densely packed pores on the surface. After dissolving M / NC in a solution and ultrasonically dispersing it, the M / NC is dispersed into the pores on the Zn surface, allowing the M / NC to be stably loaded onto the Zn plate surface. Finally, a hydroxyapatite coating is prepared on the surface of the Zn plate fully loaded with M / NC. The hydroxyapatite coating cleverly encapsulates the nano-catalyst in the pores, thus obtaining a Zn-based composite metal loaded with M / NC.

[0016] In a preferred embodiment, the magnesium powder particles have a particle size of 1~20μm. By controlling the particle size of the magnesium powder particles within the above range, and after rolling and etching, pores of 10~50μm are finally obtained.

[0017] In a preferred embodiment, magnesium powder particles are ultrasonically dispersed in acetone and then uniformly coated onto the surface of a Zn plate. After the acetone is removed, the Zn plate coated with magnesium powder particles is wrapped with Zn foil and then rolled. After rolling is completed, the Zn foil is removed.

[0018] In a preferred embodiment, the reduction during rolling is controlled to be 15-30%. Experiments have shown that controlling the reduction within the range of this invention allows for the achievement of the required hole diameter and sufficient depth after corrosion. If the reduction is too small, the magnesium powder cannot be completely rolled into the zinc alloy, while if the reduction is too large, the magnesium powder is rolled into the zinc alloy to an excessive depth, preventing the deep magnesium powder from being corroded during subsequent corrosion processes.

[0019] In a preferred embodiment, magnesium powder particles are etched using a nitric acid solution, wherein the nitric acid in the nitric acid solution has a mass fraction of 20% to 40%.

[0020] In a preferred embodiment, when M is selected from Fe, the M / NC composite material is obtained as follows: Iron acetylacetone is added to a methanol solution of zinc nitrate hexahydrate and ultrasonically dispersed to obtain a dispersed liquid. The dispersed liquid is then added to a methanol solution containing dimethylimidazole under continuous stirring. The mixture is reacted for 6-12 hours under stirring to obtain a turbid solution. After standing, precipitation is performed, and solid-liquid separation is carried out. The obtained solid phase is washed with methanol solution and dried to obtain Fe-ZIF-8 powder, which is then pyrolyzed to obtain the final product.

[0021] In a further preferred embodiment, in Scheme 1, the molar concentration of dimethylimidazole in the methanol solution containing dimethylimidazole is 2.0~3.0M; and the molar concentration of zinc nitrate in the methanol solution of zinc nitrate hexahydrate is 0.20~0.40M.

[0022] In a further preferred embodiment, in Scheme 1, the molar ratio of Fe to Zn in the turbid solution is 0.1~0.2:1.

[0023] In a further preferred embodiment, in Scheme 1, the pyrolysis temperature is 950℃~1000℃ and the pyrolysis time is 1~4h.

[0024] In a preferred embodiment, when M is selected from Se, the M / NC composite material is obtained as follows: A methanol solution of zinc nitrate hexahydrate is added to a methanol solution containing dimethylimidazole, and the mixture is reacted with stirring for 6-12 hours to obtain a turbid solution. The solution is then allowed to stand, and precipitation is performed. Solid-liquid separation is carried out, and the resulting solid phase is washed with methanol solution and dried to obtain ZIF-8 powder. NC powder is obtained through pyrolysis. The NC powder is then mixed with Se powder to obtain a mixed powder, which is then heat-treated to obtain the final product.

[0025] In a further preferred embodiment, in Scheme 2, the molar concentration of dimethylimidazole in the methanol solution containing dimethylimidazole is 2.0~3.0M; and the molar concentration of zinc nitrate in the methanol solution of zinc nitrate hexahydrate is 0.20~0.40M.

[0026] In a further preferred embodiment, in Scheme 2, the volume ratio of the methanol solution of zinc nitrate hexahydrate to the methanol solution of dimethylimidazolium is 0.8 to 1.2.

[0027] In a further preferred embodiment, in Scheme 2, the pyrolysis temperature is 950℃~1000℃ and the pyrolysis time is 1~4h.

[0028] In a further preferred embodiment, in Scheme 2, the mass ratio of Se powder to Fe / NC powder in the mixed powder is 0.1~0.2 by mass.

[0029] In a further preferred embodiment, in Scheme 2, the heat treatment process involves heating the temperature to 1000℃~1100℃ at a heating rate of 5~10℃ / min under a protective atmosphere and holding the temperature for 1~2 hours.

[0030] In a preferred embodiment, when M is selected from Fe and Se, the M / NC composite material is obtained as follows: Iron acetylacetone is added to a methanol solution of zinc nitrate hexahydrate and ultrasonically dispersed to obtain a dispersed liquid. The dispersed liquid is then added to a methanol solution containing dimethylimidazole under continuous stirring. The mixture is reacted for 6-12 hours under stirring to obtain a turbid solution. After standing, precipitation is performed, and solid-liquid separation is carried out. The resulting solid phase is washed with methanol solution and dried to obtain Fe-ZIF-8 powder. Fe-NC powder is obtained through pyrolysis. The Fe-NC powder is then mixed with Se powder to obtain a mixed powder. The mixed powder is then heat-treated to obtain the final product.

[0031] In a further preferred embodiment, in Scheme 3, the molar concentration of dimethylimidazole in the methanol solution containing dimethylimidazole is 2.0~3.0M; and the molar concentration of zinc nitrate in the methanol solution of zinc nitrate hexahydrate is 0.20~0.40M.

[0032] In a further preferred embodiment, in Scheme 3, the molar ratio of Fe to Zn in the turbid solution is 0.1~0.2:1.

[0033] In a further preferred embodiment, in Scheme 3, the pyrolysis temperature is 950℃~1000℃ and the pyrolysis time is 1~4h.

[0034] In a further preferred embodiment, in Scheme 3, the mass ratio of Se powder to Fe / NC powder in the mixed powder is 0.1~0.2. Controlling the amount of Se powder added within this range results in the optimal catalytic performance of the final catalyst.

[0035] In a further preferred embodiment, in Scheme 3, the heat treatment process involves heating the temperature to 1000℃~1100℃ at a heating rate of 5~10℃ / min under a protective atmosphere, and holding the temperature for 1~2 hours.

[0036] In the above three schemes, during actual operation, the mixture is allowed to stand until a thin layer of powder precipitates at the bottom of the beaker. After solid-liquid separation, the lower precipitate is washed three times with methanol solution and centrifuged. Finally, it is vacuum dried overnight at 60°C to obtain ZIF-8 powder or Fe-ZIF-8 powder.

[0037] This invention synthesizes Fe-ZIF-8 powder by coordinating an iron source with an alcoholic solution containing a zinc source and dimethylimidazole using a spatial confinement method. The Fe-ZIF-8 powder is then pyrolyzed, and the resulting pyrolysis product, NC, retains the porous structure of ZIF-8. Furthermore, due to the evaporation of Zn atoms and other impurity atoms, numerous active sites remain. At a high temperature of 1000℃, Se powder evaporates into Se vapor, which enters the structure of NC, is reduced and anchored at specific sites, thereby forming a Fe-Se / NC composite material. This method significantly improves the success rate of Fe-Se / NC powder synthesis, with a clear and simplified process, and can increase the mass percentage of Fe and Se to 1%.

[0038] In a preferred embodiment, the M / NC composite material is dispersed in methanol to obtain a dispersion.

[0039] The preferred method involves filling the pores with the dispersion by coating the dispersion onto the surface of a Zn plate with densely arranged pores and then using ultrasound until the dispersion fills the pores.

[0040] In actual operation, the methanol is completely evaporated through drying, leaving the dried nano-catalyst in the pores.

[0041] In a preferred embodiment, the hydroxyapatite precursor solution is obtained by adding calcium nitrate and disodium hydrogen phosphate to water and adjusting the pH value to 3.0-4.0 with nitric acid, wherein the concentration of calcium nitrate is 0.15-2.0 mol / L and the concentration of disodium hydrogen phosphate is 0.08-1.2 mol / L.

[0042] In a preferred embodiment, the hydrothermal treatment temperature is 110~130 ℃ and the hydrothermal treatment time is 12~16.

[0043] In the actual operation of this invention, all reagents are of analytical purity.

[0044] Beneficial effects

[0045] The Zn-based composite material supported on nanocatalysts provided by this invention achieves slow and continuous release by embedding the nanocatalysts into the pores of the Zn substrate surface and then cleverly encapsulating the nanocatalysts in the pores through a hydroxyapatite coating. This results in antibacterial and anticancer effects. In addition, the introduction of the hydroxyapatite coating also inhibits the explosive release of zinc ions, enhances the corrosion resistance of the zinc alloy, exhibits good biocompatibility, significantly improves cell viability, and shows good adhesion.

[0046] The preparation method of this invention involves rolling magnesium powder particles into a pure Zn plate, then etching away the Mg powder particles embedded in the surface of the Zn plate to leave uniformly distributed densely packed pores on the surface. After dissolving M / NC in a solution and ultrasonically dispersing it, the M / NC is dispersed into the pores on the Zn surface, allowing the M / NC to be stably loaded onto the Zn plate surface. Finally, a hydroxyapatite coating is prepared on the surface of the Zn plate fully loaded with M / NC. The hydroxyapatite coating cleverly encapsulates the nano-catalyst in the pores, thus obtaining a Zn-based composite metal loaded with M / NC.

[0047] The preparation process of this invention is simple, the nanocatalyst is evenly distributed on the substrate surface and has strong binding force, exhibiting good biocompatibility and anti-cancer and antibacterial effects. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0049] Figure 1 The process flow diagram of Embodiment 1 of the present invention.

[0050] Figure 2 The image shows the SEM-EDS image of the Fe-Se / NC composite material prepared in Example 1.

[0051] Figure 3 SEM images of Fe-ZIF-8, Fe / NC, and Fe-Se / NC prepared in Example 1.

[0052] Figure 4 The image shows the morphology of the surface pores of the Zn plate in Example 1.

[0053] Figure 5 The image shows the morphology of the Zn-based composite material obtained by coating with hydroxyapatite in Example 1. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0055] Example 1:

[0056] (1) Synthesis of Fe-ZIF-8: Prepare 100 mL each of 0.3 M zinc nitrate hexahydrate methanol solution and 2.4 M dimethylimidazole methanol solution. Add 3.1785 g of acetylacetone iron (Fe / Zn molar ratio of 0.2) to the zinc nitrate hexahydrate methanol solution and disperse ultrasonically. Slowly add the zinc nitrate hexahydrate methanol solution to the dimethylimidazole solution while stirring continuously for 12 h. After stopping stirring, let the turbid solution stand for 24 h to precipitate. Take the lower precipitate in the solvent, wash it three times with methanol solution and centrifuge. Finally, vacuum dry it overnight at 60 °C to obtain Fe-ZIF-8 crystal powder with an average grain size of 350~400 nm.

[0057] (2) Preparation of Fe-Se / NC: 0.5g of Fe-ZIF-8 powder was thoroughly ground in a mortar and then transferred to a tube furnace for pyrolysis. Argon atmosphere was introduced during pyrolysis, and the temperature was raised to 950℃ at a rate of 5℃ / min, held for 3 hours, and then cooled with the furnace. The cooled Fe / NC was then mixed and ground with Se powder in a 10:1 mass ratio in an agate mortar, and then transferred to a tube furnace for Se atom anchoring. This process required raising the temperature to 1000℃ at a rate of 5℃ / min under an argon atmosphere, holding for 1 hour, and then cooling with the furnace.

[0058] (3) Surface pretreatment of pure Zn plates: Mg powder particles with a diameter of 1 μm were ultrasonically dispersed in acetone solution and then uniformly coated onto the surface of the Zn plate. After the acetone evaporated, the surface coated with Mg powder was wrapped with Zn foil and rolled at a rolling mill with a 20% reduction in pressure. The outer Zn foil of the rolled Zn plate was removed, and the Mg powder on the surface of the Zn plate was etched off with 30% dilute nitric acid, leaving dense pores on the Zn surface. Fe-Se / NC was ultrasonically dispersed in methanol solution and then uniformly dispersed into each pore on the Zn surface. After filling the pores, the methanol solution was completely evaporated. The sample was then treated using a hydrothermal method. A 50 ml polytetrafluoroethylene-lined reactor was used as the hydrothermal reaction chamber. The hydrothermal solution used was calcium nitrate tetrahydrate (Ca(NO3)2·4H2O) and anhydrous disodium hydrogen phosphate (NaH2PO4) to generate an apatite coating. A zinc alloy sample was then placed in a reactor containing 20 ml of the hydrothermal solution, which consisted of 0.17 mol / L calcium nitrate and 0.1 mol / L sodium dihydrogen phosphate, with the pH adjusted to 3.5 using diluted nitric acid. The reactor was placed in a drying oven and reacted at 115 °C for 16 h. This yielded a Fe-Se / NC-loaded Zn-based composite metal.

[0059] (4) Figure 2The image shows the SEM-EDS image of the Fe-Se / NC composite material prepared in Example 1. It can be seen from the image that Fe and Se elements were successfully doped into the NC framework. Figure 3 Electron microscopy images show that Fe / NC and Fe-Se / NC still retain the original ZIF-8 framework structure, namely the SOD topological framework structure, with the prepared Fe-Se / NC powder having a particle size of 180~200 nm.

[0060] Figure 4 The image shows the morphology of the pores on the surface of the Zn plate in Example 1. The pores are densely packed on the surface of the Zn plate and have a diameter of 10~50μm.

[0061] Figure 5 The morphology after the hydroxyapatite coating is applied shows that the hydroxyapatite coating forms a complete coverage.

[0062] (5) Effect of the sample on cell viability was tested using MC3T3 cells. The culture medium after sample soaking was diluted to different concentrations and cultured with MC3T3 cells for 3 days. Cell viability in the culture dishes was then detected. The results showed that when the cell soaking medium was diluted to 25% and 12.5%, compared with the negative control group, the viability of MC3T3 cells did not show a statistically significant decrease after 24 hours of treatment (p > 0.05), indicating that the sample had no significant cytotoxicity within this concentration range. In mouse ischemic platelet plasma (PPP) containing bone cancer cells, the Zn-based alloy loaded with Fe-Se / NC inactivated bone cancer cells with a viability rate of 1.2%. This indicates that the sample has a certain bone cancer inactivation rate, meets the requirements of clinical medical biomaterials, and possesses excellent biomedical value.

[0063] Example 2:

[0064] (1) Synthesis of ZIF-8: Prepare 100 mL each of 0.3 M zinc nitrate hexahydrate methanol solution and 2.4 M dimethylimidazole methanol solution. The zinc nitrate hexahydrate methanol solution was slowly added to the dimethylimidazole solution under continuous stirring for 12 h. After stopping stirring, the turbid solution was allowed to stand for 24 h to precipitate. The lower precipitate in the solvent was washed three times with methanol solution and centrifuged. Finally, it was vacuum dried overnight at 60 °C to obtain ZIF-8 crystal powder with an average grain size of 100 nm.

[0065] (2) Preparation of Se / NC: 0.5g of ZIF-8 powder was thoroughly ground in a mortar and then transferred to a tube furnace for pyrolysis. Argon atmosphere was introduced during pyrolysis, and the temperature was raised to 950℃ at a rate of 5℃ / min, held for 3 hours, and then cooled with the furnace. The cooled NC was then mixed and ground with Se powder in a 10:1 mass ratio in an agate mortar, and then transferred to a tube furnace for Se atom anchoring. This process required raising the temperature to 1000℃ at a rate of 5℃ / min under an argon atmosphere, holding for 1 hour, and then cooling with the furnace.

[0066] (3) Surface pretreatment of pure Zn plates: Mg powder particles with a diameter of 1 μm were ultrasonically dispersed in acetone solution and then uniformly coated onto the surface of the Zn plate. After the acetone evaporated, the surface coated with Mg powder was wrapped with Zn foil and rolled at a rolling mill with a 20% reduction in pressure. The outer Zn foil of the rolled Zn plate was removed, and the Mg powder on the surface of the Zn plate was etched off with 30% dilute nitric acid, leaving dense pores on the Zn surface. Se / NC was ultrasonically dispersed in methanol solution and then uniformly dispersed into each pore on the Zn surface. After filling the pores, the methanol solution was completely evaporated. The sample was then treated using a hydrothermal method. A 50 ml polytetrafluoroethylene-lined reactor was used as the hydrothermal reaction chamber. The hydrothermal solution used was calcium nitrate tetrahydrate (Ca(NO3)2·4H2O) and anhydrous disodium hydrogen phosphate (NaH2PO4) to generate an apatite coating. A zinc alloy sample was then placed in a reactor containing 20 ml of the hydrothermal solution, which consisted of 0.17 mol / L calcium nitrate and 0.1 mol / L sodium dihydrogen phosphate, with the pH adjusted to 3.5 using diluted nitric acid. The reactor was placed in a drying oven and reacted at 115 °C for 16 h. This yielded a Se / NC-loaded Zn-based composite metal.

[0067] (4) Effect of the sample on cell viability was tested using MC3T3 cells. The culture medium after sample soaking was diluted to different concentrations and cultured with MC3T3 cells for 3 days. Cell viability in the culture dishes was then detected. The results showed that when the cell soaking medium was diluted to 25% and 12.5%, compared with the negative control group, the viability of MC3T3 cells did not show a statistically significant decrease after 24 hours of treatment (p > 0.05), indicating that the sample had no significant cytotoxicity within this concentration range. In mouse platelet-ischemic plasma (PPP) containing bone cancer cells, the Zn-based alloy loaded with Fe-Se / NC inactivated bone cancer cells with a viability rate of 2.2%. This indicates that the sample has a certain bone cancer inactivation rate, meets the requirements of clinical medical biomaterials, and possesses excellent biomedical value.

[0068] Example 3:

[0069] (1) Synthesis of Fe-ZIF-8: Prepare 100 mL each of 0.3 M zinc nitrate hexahydrate methanol solution and 2.4 M dimethylimidazole methanol solution. Add 3.1785 g of acetylacetone iron (Fe / Zn molar ratio of 0.2) to the zinc nitrate hexahydrate methanol solution and disperse ultrasonically. Slowly add the zinc nitrate hexahydrate methanol solution to the dimethylimidazole solution while stirring continuously for 12 h. After stopping stirring, let the turbid solution stand for 24 h to precipitate. Take the lower precipitate in the solvent, wash it three times with methanol solution and centrifuge. Finally, vacuum dry it overnight at 60 °C to obtain Fe-ZIF-8 crystal powder with an average grain size of 400 nm.

[0070] (2) Preparation of Fe / NC: Take 0.5g of ZIF-8 powder and grind it thoroughly in a mortar, then transfer it to a tube furnace for pyrolysis. Argon atmosphere is required during pyrolysis. The temperature is raised to 950℃ at a rate of 5℃ / min, held for 3h, and then cooled with the furnace.

[0071] (3) Surface pretreatment of pure Zn plates: Mg powder particles with a diameter of 1 μm were ultrasonically dispersed in acetone solution and then uniformly coated onto the surface of the Zn plate. After the acetone evaporated, the surface coated with Mg powder was wrapped with Zn foil and rolled at a rolling mill with a 20% reduction in pressure. The outer Zn foil of the rolled Zn plate was removed, and the Mg powder on the surface of the Zn plate was etched off with 30% dilute nitric acid, leaving dense pores on the Zn surface. Fe / NC was ultrasonically dispersed in methanol solution and then uniformly dispersed into each pore on the Zn surface. After filling the pores, the methanol solution was completely evaporated. The sample was then treated using a hydrothermal method. A 50 ml polytetrafluoroethylene-lined reactor was used as the hydrothermal reaction chamber. The hydrothermal solution used was calcium nitrate tetrahydrate (Ca(NO3)2·4H2O) and anhydrous disodium hydrogen phosphate (NaH2PO4) to generate an apatite coating. A zinc alloy sample was then placed in a reactor containing 20 ml of the hydrothermal solution, which consisted of 0.17 mol / L calcium nitrate and 0.1 mol / L sodium dihydrogen phosphate, with the pH adjusted to 3.5 using diluted nitric acid. The reactor was placed in a drying oven and reacted at 115 °C for 16 h. This yielded a Fe / NC-loaded Zn-based composite metal.

[0072] (4) Effect of the sample on cell viability was tested using MC3T3 cells. The culture medium after sample soaking was diluted to different concentrations and cultured with MC3T3 cells for 3 days. Cell viability in the culture dishes was then detected. The results showed that when the cell soaking medium was diluted to 25% and 12.5%, compared with the negative control group, the viability of MC3T3 cells did not show a statistically significant decrease after 24 hours of treatment (p > 0.05), indicating that the sample had no significant cytotoxicity within this concentration range. In mouse ischemic platelet plasma (PPP) containing bone cancer cells, the Zn-based alloy loaded with Fe-Se / NC inactivated bone cancer cells with a viability rate of 6.8%. This indicates that the sample has a certain bone cancer inactivation rate, meets the requirements of clinical medical biomaterials, and possesses excellent biomedical value.

[0073] Comparative Example 1:

[0074] (1) Synthesis of ZIF-8: Prepare 100 mL each of 0.3 M zinc nitrate hexahydrate methanol solution and 2.4 M dimethylimidazole methanol solution. The zinc nitrate hexahydrate methanol solution was slowly added to the dimethylimidazole solution under continuous stirring for 12 h. After stopping stirring, the turbid solution was allowed to stand for 24 h to precipitate. The lower precipitate in the solvent was washed three times with methanol solution and centrifuged. Finally, it was vacuum dried overnight at 60 °C to obtain ZIF-8 crystal powder with an average grain size of 100 nm.

[0075] (2) Surface pretreatment of pure Zn plates: Mg powder particles with a diameter of 1 μm were ultrasonically dispersed in acetone solution and then uniformly coated onto the surface of the Zn plate. After the acetone evaporated, the surface coated with Mg powder was wrapped with Zn foil and rolled at a rolling mill with a 20% reduction in pressure. The outer Zn foil of the rolled Zn plate was removed, and the Mg powder on the surface of the Zn plate was etched off with 30% dilute nitric acid, leaving dense pores on the Zn surface. ZIF-8 was ultrasonically dispersed in methanol solution and then uniformly dispersed into each pore on the Zn surface. After filling the pores, the methanol solution was completely evaporated. The sample was then treated using a hydrothermal method. A 50 ml polytetrafluoroethylene-lined reactor was used as the hydrothermal reaction chamber. The hydrothermal solution consisted of calcium nitrate tetrahydrate (Ca(NO3)2·4H2O) and anhydrous disodium hydrogen phosphate (NaH2PO4) to generate an apatite coating. A zinc alloy sample was then placed in a reactor containing 20 ml of the hydrothermal solution, which consisted of 0.17 mol / L calcium nitrate and 0.1 mol / L sodium dihydrogen phosphate, with the pH adjusted to 3.5 using diluted nitric acid. The reactor was placed in a drying oven and reacted at 115 °C for 16 h. This yielded a Zn-based composite metal loaded with ZIF-8.

[0076] (3) Effect of the sample on cell viability was tested using MC3T3 cells. The culture medium after soaking the sample was diluted to different concentrations and cultured with MC3T3 cells for 3 days. Cell viability in the culture dishes was then detected. The results showed that when the cell soaking medium was diluted to 25% and 12.5%, compared with the negative control group, the viability of MC3T3 cells did not show a statistically significant decrease after 24 hours of treatment (p > 0.05), indicating that the sample had no significant cytotoxicity within this concentration range. In mouse ischemic platelet plasma (PPP) containing bone cancer cells, the Zn-based alloy loaded with Fe-Se / NC inactivated bone cancer cells with a viability rate of 88.5%. This indicates that the sample does not have a high bone cancer inactivation rate, does not meet the requirements for clinical medical biomaterials, and has no biomedical value.

[0077] Comparative Example 2:

[0078] (1) Synthesis of Fe-ZIF-8: Prepare 100 mL each of 0.3 M zinc nitrate hexahydrate methanol solution and 2.4 M dimethylimidazole methanol solution. Add 3.1785 g of acetylacetone iron (Fe / Zn molar ratio of 0.2) to the zinc nitrate hexahydrate methanol solution and disperse ultrasonically. Slowly add the zinc nitrate hexahydrate methanol solution to the dimethylimidazole solution while stirring continuously for 12 h. After stopping stirring, let the turbid solution stand for 24 h to precipitate. Take the lower precipitate in the solvent, wash it three times with methanol solution and centrifuge. Finally, vacuum dry it overnight at 60 °C to obtain Fe-ZIF-8 crystal powder with an average grain size of 400 nm.

[0079] (2) Preparation of Fe-Se / NC: 0.5g of Fe-ZIF-8 powder was thoroughly ground in a mortar and then transferred to a tube furnace for pyrolysis. Argon atmosphere was introduced during pyrolysis, and the temperature was raised to 950℃ at a rate of 5℃ / min, held for 3 hours, and then cooled with the furnace. The cooled Fe / NC was then mixed and ground with Se powder in a 10:1 mass ratio in an agate mortar, and then transferred to a tube furnace for Se atom anchoring. This process required raising the temperature to 1000℃ at a rate of 5℃ / min under an argon atmosphere, holding for 1 hour, and then cooling with the furnace.

[0080] (3) Surface pretreatment of pure Zn plates: Mg powder particles with a diameter of 1 μm were ultrasonically dispersed in acetone solution and then uniformly coated onto the surface of the Zn plate. After the acetone evaporated, the surface coated with Mg powder was wrapped with Zn foil and rolled at a rolling mill with a 20% reduction in pressure. The outer Zn foil of the rolled Zn plate was removed, and the Mg powder on the surface of the Zn plate was etched off with 30% dilute nitric acid, leaving dense pores on the Zn surface. Fe-Se / NC was ultrasonically dispersed in methanol solution and then uniformly dispersed into each pore on the Zn surface. After filling the pores, the methanol solution was completely evaporated.

[0081] (4) Effect of the sample on cell viability was tested using MC3T3 cells. The culture medium after soaking the sample was diluted to different concentrations and cultured with MC3T3 cells for 3 days. Cell viability in the culture dishes was then detected. The results showed that when the cell soaking medium was diluted to 25% and 12.5%, compared with the negative control group, the viability of MC3T3 cells decreased significantly after 24 hours of treatment (p > 0.05), indicating that the sample had significant cytotoxicity within this concentration range. In mouse platelet-ischemic plasma (PPP) containing bone cancer cells, the Zn-based alloy loaded with Fe-Se / NC inactivated bone cancer cells with a viability rate of 89.8%. This indicates that the sample does not have a high bone cancer inactivation rate, does not meet the requirements for clinical medical biomaterials, and has no biomedical value.

[0082] Comparative Example 3:

[0083] (1) Synthesis of Fe-ZIF-8: Prepare 100 mL each of 0.3 M zinc nitrate hexahydrate methanol solution and 2.4 M dimethylimidazole methanol solution. Add 3.1785 g of acetylacetone iron (Fe / Zn molar ratio of 0.2) to the zinc nitrate hexahydrate methanol solution and disperse ultrasonically. Slowly add the zinc nitrate hexahydrate methanol solution to the dimethylimidazole solution while stirring continuously for 12 h. After stopping stirring, let the turbid solution stand for 24 h to precipitate. Take the lower precipitate in the solvent, wash it three times with methanol solution and centrifuge. Finally, vacuum dry it overnight at 60 °C to obtain Fe-ZIF-8 crystal powder with an average grain size of 400 nm.

[0084] (2) Preparation of Fe-Se / NC: 0.5g of Fe-ZIF-8 powder was thoroughly ground in a mortar and then transferred to a tube furnace for pyrolysis. Argon atmosphere was introduced during pyrolysis, and the temperature was raised to 950℃ at a rate of 5℃ / min, held for 3 hours, and then cooled with the furnace. The cooled Fe / NC was then mixed and ground with Se powder in a 10:1 mass ratio in an agate mortar, and then transferred to a tube furnace for Se atom anchoring. This process required raising the temperature to 1000℃ at a rate of 5℃ / min under an argon atmosphere, holding for 1 hour, and then cooling with the furnace.

[0085] (3) Surface pretreatment of pure Zn plates: Fe-Se / NC was ultrasonically dispersed in methanol solution and then uniformly dispersed onto the surface of Zn plates. After the methanol solution had completely evaporated, the sample was treated by hydrothermal method. A PTFE-lined reactor (50 ml) was used as the hydrothermal reaction chamber. The hydrothermal solution used was calcium nitrate tetrahydrate (Ca(NO3)2·4H2O) and anhydrous disodium hydrogen phosphate (NaH2PO4) to generate an apatite coating. The zinc alloy sample was then placed in a reactor containing 20 ml of hydrothermal solution. The hydrothermal solution was formulated as follows: 0.17 mol / L calcium nitrate and 0.1 mol / L sodium dihydrogen phosphate. The pH was adjusted to 3.5 with diluted nitric acid. The reactor was placed in a drying oven and reacted at 115 ℃ for 16 h. Zn-based composite metal loaded with Fe-Se / NC was obtained.

[0086] (4) Effect of the sample on cell viability was tested using MC3T3 cells. The culture medium after sample soaking was diluted to different concentrations and cultured with MC3T3 cells for 3 days. Cell viability in the culture dishes was then detected. The results showed that when the cell soaking medium was diluted to 25% and 12.5%, compared with the negative control group, the viability of MC3T3 cells did not show a statistically significant decrease after 24 hours of treatment (p > 0.05), indicating that the sample had no significant cytotoxicity within this concentration range. In mouse ischemic platelet plasma (PPP) containing bone cancer cells, the Zn-based alloy loaded with Fe-Se / NC achieved a bone cancer cell inactivation survival rate of 65.2%. This indicates that the sample had a poor bone cancer inactivation rate, did not meet the requirements for clinical medical biomaterials, and lacked biomedical value.

Claims

1. A Zn-based composite material loaded with nanocatalysts, characterized in that: The Zn-based composite material loaded with the nano-catalyst is composed of a Zn substrate with densely arranged holes on the surface layer, the nano-catalyst embedded in the holes, and a hydroxyapatite coating arranged on the surface of the Zn substrate; the nano-catalyst is an M / NC composite material, wherein M is selected from Fe and / or Se.

2. The Zn-based composite material loaded with nanocatalysts according to claim 1, characterized in that: The particle size of the nano-catalyst is 10 nm-200 nm; The diameter of the holes is 10-50 μm; The nano-catalyst has an SOD topological skeleton structure.

3. The Zn-based composite material loaded with nanocatalysts according to claim 1 or 2, characterized in that: The nano-catalyst is an Fe-Se / NC composite material.

4. The method for preparing a Zn-based composite material loaded with nanocatalysts according to any one of claims 1-3, characterized in that: The magnesium powder particles are coated on the surface of the Zn plate, and then the Zn plate inlaid with the magnesium powder particles is obtained by rolling. The magnesium powder particles are etched to obtain the Zn plate with densely arranged holes on the surface layer. The M / NC composite material is dispersed in a solvent to obtain a dispersion liquid. The dispersion liquid is filled into the holes. After drying, the Zn plate with the M / NC composite material dispersed in the holes is obtained. The Zn plate is placed in a hydroxyapatite precursor solution, and hydrothermal treatment is performed, thereby obtaining the Zn-based composite material loaded with the nano-catalyst.

5. The preparation method of the Zn-based composite material loaded with the nano-catalyst according to claim 4, characterized in that: The particle size of the magnesium powder particles is 1-20 μm; The magnesium powder particles are uniformly coated on the surface of the Zn plate after ultrasonic dispersion in acetone. After the acetone is volatilized, the surface of the Zn plate coated with the magnesium powder particles is wrapped with a Zn foil, and then rolling is performed. After the rolling is completed, the Zn foil is removed. During the rolling, the reduction is controlled to be 15-30%.

6. The method for preparing a Zn-based composite material supported on a nanocatalyst according to claim 4, characterized in that: The magnesium powder particles are etched by using a nitric acid solution. In the nitric acid solution, the mass fraction of nitric acid is 20%-40%.

7. The preparation method of the Zn-based composite material loaded with the nano-catalyst according to claim 4, characterized in that: When M is selected from Fe, the M / NC composite material is obtained by scheme one: acetylacetone iron is added into a methanol solution of zinc nitrate hexahydrate to obtain a dispersion liquid. The dispersion liquid is added into a methanol solution containing dimethylimidazole under continuous stirring. The turbid solution is obtained after stirring for 6-12 h. The solution is left to stand, and then precipitation is performed. The solid phase is obtained by solid-liquid separation, washed with a methanol solution, and dried to obtain Fe-ZIF-8 powder. Pyrolysis is performed, and the M / NC composite material is obtained. In scheme one, the molar concentration of dimethylimidazole in the methanol solution containing dimethylimidazole is 2.0-3.0 M; and the molar concentration of zinc nitrate in the methanol solution of zinc nitrate hexahydrate is 0.20-0.40 M. In scheme one, the molar ratio of Fe to Zn in the turbid solution is 0.1-0.2:

1. In scheme one, the pyrolysis temperature is 950°C-1000°C, and the pyrolysis time is 3 h-4 h. When M is selected from Se, the M / NC composite material is obtained by scheme two: a methanol solution of zinc nitrate hexahydrate is added to a methanol solution containing dimethylimidazole, and the mixture is stirred for 6-12 h to obtain a turbid solution, which is then left to stand, precipitated, and solid-liquid separated, and the obtained solid phase is washed with a methanol solution and dried to obtain ZIF-8 powder, pyrolyzed to obtain NC powder, and then mixed with Se powder to obtain a mixed powder, which is then heat-treated to obtain the M / NC composite material; In scheme two, the molar concentration of dimethylimidazole in the methanol solution containing dimethylimidazole is 2.0-3.0 M; and the molar concentration of zinc nitrate in the methanol solution of zinc nitrate hexahydrate is 0.20-0.40 M. In scheme two, the volume ratio of the methanol solution of zinc nitrate hexahydrate to the methanol solution of dimethylimidazole is 0.8-1.

2. In scheme two, the pyrolysis temperature is 950-1000℃, and the pyrolysis time is 3-4 h. In scheme two, in the mixed powder, the mass ratio of Se powder to Fe / NC powder is 0.1-0.

2. In scheme two, the heat treatment process is as follows: under a protective atmosphere, the temperature is raised to 1000-1100℃ at a temperature raising rate of 5-10℃ / min, and the temperature is kept for 1-2 h. When M is selected from Fe and Se, the M / NC composite material is obtained by scheme three: iron acetylacetonate is added to a methanol solution of zinc nitrate hexahydrate to obtain a dispersed solution, which is then added to a methanol solution containing dimethylimidazole under continuous stirring, and the mixture is stirred for 6-12 h to obtain a turbid solution, which is then left to stand, precipitated, and solid-liquid separated, and the obtained solid phase is washed with a methanol solution and dried to obtain Fe-ZIF-8 powder, pyrolyzed to obtain Fe-NC powder, and then mixed with Se powder to obtain a mixed powder, which is then heat-treated to obtain the M / NC composite material. In scheme three, the molar concentration of dimethylimidazole in the methanol solution containing dimethylimidazole is 2.0-3.0 M; and the molar concentration of zinc nitrate in the methanol solution of zinc nitrate hexahydrate is 0.20-0.40 M. In scheme three, in the turbid solution, the molar ratio of Fe to Zn is 0.1-0.2:

1. In scheme three, the pyrolysis temperature is 950-1000℃, and the pyrolysis time is 3-4 h. In scheme three, in the mixed powder, the mass ratio of Se powder to Fe / NC powder is 0.1-0.

2. In scheme three, the heat treatment process is as follows: under a protective atmosphere, the temperature is raised to 1000-1100℃ at a temperature raising rate of 5-10℃ / min, and the temperature is kept for 1-2 h.

8. The method according to claim 4, wherein: the M / NC composite material is dispersed in methanol to obtain a dispersion solution; and the dispersion solution is filled into the holes by coating the dispersion solution on the surface of the Zn plate with densely arranged holes on the surface layer and then performing ultrasonic treatment until the holes are filled with the dispersion solution. ​ ​ 9. The method of claim 4, wherein the Zn-based composite material loaded with nanocatalysts is prepared by the following steps: preparing a hydroxyapatite precursor solution by adding calcium nitrate and disodium hydrogen phosphate into water and adjusting the pH value to 3.0-4.0 by nitric acid, wherein the concentration of calcium nitrate is 0.15-2.0 mol / L and the concentration of sodium dihydrogen phosphate is 0.08-1.2 mol / L; and hydrothermally treating the hydroxyapatite precursor solution at a temperature of 110-130 ℃ for 12-16 h. The temperature of the hydrothermal treatment is 110-130 ℃, and the time of the hydrothermal treatment is 12-16 h.

10. The method for preparing a Zn-based composite material supported on a nanocatalyst according to claim 4, characterized in that: ​

Images