Novel metal-polyphenol microspheres as well as preparation method and application thereof

Abstract

The invention relates to the technical field of drug-loaded microspheres, and discloses novel metal-polyphenol microspheres and a preparation method and application thereof.The preparation method comprises the following steps that firstly, catechin, F127 and NaCl are dispersed in a mixture composed of distilled water and ethyl alcohol, and a mixed solution A is obtained; step 2, adding toluene and formaldehyde into the mixed solution A, and stirring the emulsion at a rotating speed of 500rpm for 30 minutes to obtain a mixed solution B; step 3, slowly dropwise adding NH3.H2O into the mixed solution B, carrying out centrifugal treatment and washing treatment after reaction to obtain a product, and carrying out vibration washing on the product to obtain a mesoporous catechin microsphere solution; and step 4, adding a saturated zinc acetate solution into the mesoporous catechin microsphere solution to obtain the mesoporous catechin / Zn microspheres containing the zinc ions. According to the method, natural polyphenol catechin is used as a substrate, mesoporous microspheres with the diameter of about 200nm are prepared, and the mesoporous microspheres are free of biotoxicity, degradable and capable of loading metal ions to endow the mesoporous microspheres with better antibacterial / anti-inflammatory / vascularization functions and the like.

Description

Technical Field

[0001] This invention relates to the field of drug-loaded microsphere technology, specifically to a novel metal-polyphenol microsphere, its preparation method, and its application. Background Technology

[0002] Metal-polyphenol microspheres, as a novel type of functional carrier material, demonstrate irreplaceable value in the field of drug delivery. The core requirements of drug delivery systems are targeted drug release, reduced toxicity, and improved bioavailability. Metal-polyphenol microspheres, with their inherent biocompatibility of polyphenols, the adjustable functionality of metal ions, and the advantages of their microsphere structure in terms of drug-carrying space, have become ideal drug carriers. Specifically, the catechol / pyrogallol structure of polyphenol molecules can stably load metal ions through coordination, endowing the microspheres with biological functions such as antibacterial, anti-inflammatory, and tissue repair promotion. The mesoporous structure of the microspheres can efficiently encapsulate small molecule drugs, proteins, and other active ingredients, achieving controlled drug release. In scenarios such as tumor treatment, wound repair, and intervention for inflammatory diseases, metal-polyphenol microspheres can protect drugs from biodegradation and enhance drug efficacy through the synergistic effect of metal ions and polyphenols. Therefore, optimizing their performance is of great significance for promoting the clinical translation of drug delivery systems.

[0003] Existing technologies for improving the performance of metal-polyphenol microspheres mainly focus on three directions: First, optimizing raw material selection by using natural polyphenols (such as tannic acid and gallic acid) to replace synthetic polymers, thereby improving biocompatibility and reducing in vivo toxicity; second, regulating the microsphere structure by adjusting the preparation process (such as reverse emulsion method and solvent evaporation method) to control the microsphere size (from micrometer to nanometer scale) and pore structure (such as mesopore size and distribution), thereby improving drug loading and release controllability; and third, expanding functional modification by introducing different metal ions (such as Fe). 3+ Cu 2+ Zn 2+The biological activity of metal ions is used to endow microspheres with antibacterial, antioxidant or cell proliferation-promoting functions. Some studies have achieved targeted intervention of microspheres for single diseases (such as skin infections). However, existing metal-polyphenol microspheres still have the following defects: (1) Insufficient biodegradability. Although some microspheres use natural polyphenols, the strong coordination between metal ions and polyphenols leads to a slow degradation rate. Long-term retention in the body can easily cause foreign body reactions; (2) Single function. Most microspheres are only loaded with a single metal ion, which is difficult to meet multiple treatment needs such as antibacterial, anti-inflammatory and tissue regeneration promotion at the same time. The effect is limited, especially in complex pathological environments (such as chronic wounds); (3) Poor drug loading stability. The mesoporous structure of some microspheres is prone to collapse in the physiological environment, resulting in drug burst release or premature leakage. The competitive binding of metal ions and drugs may reduce drug loading efficiency; (4) Some preparation processes rely on organic solvents or chemical cross-linking agents. Residual components will increase the risk of biotoxicity and there is a gap with the safety requirements of clinical application. Summary of the Invention

[0004] The present invention aims to provide a novel metal-polyphenol microsphere, its preparation method and application, in order to solve the technical problem that most existing mesoporous microspheres are difficult to degrade in vivo.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a method for preparing novel metal-polyphenol microspheres, comprising the following steps: Step 1: Disperse catechins, F127 and NaCl in a mixture of distilled water and ethanol to obtain mixture A; Step 2: Add toluene and formaldehyde to mixture A, and stir the emulsion at 500-1500 rpm for 30-90 minutes to obtain mixture B; Step 3: Slowly add NH3·H2O dropwise to the above mixture B. After the reaction, centrifuge and wash to obtain the product. After shaking and washing, the product can be used to obtain a mesoporous catechin microsphere solution. Step 4: Add the saturated zinc acetate solution to the mesoporous catechin microsphere solution to obtain mesoporous catechin / Zn microspheres containing zinc ions.

[0006] Preferably, as an improvement, in step one, the mass ratio of catechin, F127 and NaCl in the mixture A is 150~900:100~300:1000~3000; the volume ratio of distilled water and ethanol in the mixture A is 6:4; and the concentration of catechin in the mixture A is 150~900 mg / ml.

[0007] Preferably, as an improvement, in step two, the amount of toluene added to mixture B is 10-30% of the volume of the mixture of distilled water and ethanol; the amount of formaldehyde added to mixture B is 1.5-4.0% of the volume of the mixture of distilled water and ethanol.

[0008] Preferably, as an improvement, in step three, the amount of NH3·H2O added is such that the pH of the mixture B is 9~11.5.

[0009] Preferably, as an improvement, in step three, the reaction is carried out at room temperature for 4 to 10 hours; the centrifugation process involves centrifuging the solution at 12,000 to 14,000 rpm and collecting the precipitate; the washing process involves washing the precipitate 2 to 3 times with a mixture of water and ethanol in a ratio of 1:1 to 1:2.

[0010] Preferably, as an improvement, in step three, the shaking wash is performed by adding a 50% ethanol solution to the product and then shaking and washing for 3 to 10 minutes at 24 to 40°C, a frequency of 60 to 100 kHz, and an amplitude of 0.05 to 0.1 mm.

[0011] Preferably, as an improvement, in step three, the diameter of the microspheres in the mesoporous catechin microsphere solution is 150~260 nm.

[0012] Preferably, as an improvement, in step four, the volume ratio of the zinc acetate solution to the mesoporous catechin microsphere solution is 20:1 to 2:1.

[0013] Preferably, as an improvement, this solution also provides a novel metal-polyphenol microsphere, which is a mesoporous catechin / Zn microsphere prepared by the above method.

[0014] Preferably, as an improvement, this solution also provides an application of novel metal-polyphenol microspheres, including the application of the above-mentioned mesoporous catechin / Zn microspheres in any one of drug loading, anti-inflammatory, antibacterial, or as a biocoating.

[0015] The principles and advantages of this scheme are: 1. This method uses natural polyphenols and catechins as substrates to prepare mesoporous microspheres with a diameter of about 200 nm. These microspheres are non-biotoxic, biodegradable, and can be loaded with metal ions to give them better antibacterial, anti-inflammatory, and angiogenic functions.

[0016] 2. This solution combines Zn with mesoporous catechin microspheres to form mesoporous catechin / Zn microspheres, which allows zinc ions to form novel metal-polyphenol microspheres with the mesoporous catechin microspheres, further enhancing the antibacterial properties of mesoporous catechin and endowing it with antibacterial / angiogenic functions, thus facilitating the improvement of the material's biological properties. Attached Figure Description

[0017] Figure 1 This is a scan image of the metal-polyphenol microsphere material prepared in Example 1 of the present invention.

[0018] Figure 2 This is a scan image of the metal-polyphenol microsphere material prepared when NaCl was insufficient in Comparative Example 1 of this invention.

[0019] Figure 3 This is a scan image of the metal-polyphenol microsphere material prepared when there is too much NaCl in Comparative Example 2 of this invention.

[0020] Figure 4 This is a scan image of the metal-polyphenol microsphere material prepared when there is too little distilled water in the mixture in Comparative Example 3 of the present invention.

[0021] Figure 5 This is a scan image of the metal-polyphenol microsphere material prepared when the mixture in Comparative Example 4 of this invention contains a small amount of distilled water.

[0022] Figure 6 This is a scan image of the metal-polyphenol microsphere material prepared when there is too much distilled water in the mixture of Comparative Example 5 of the present invention.

[0023] Figure 7 This is a transmission electron microscope image of the metal-polyphenol microsphere material obtained in Example 1 of the present invention being "endocytosed" into the cytoplasm by cells after being co-cultured with cells for 6 hours.

[0024] Figure 8 The image shows the plate coating and scanning electron microscope images of the antibacterial effect of the metal-polyphenol microsphere material obtained in Example 1 of this invention.

[0025] Figure 9 This is a fluorescent staining image of the antioxidant effect of the metal-polyphenol microsphere material obtained in Example 1 of the present invention.

[0026] Figure 10 This is a flow cytometry analysis of the anti-inflammatory effect of the metal-polyphenol microsphere material obtained in Example 1 of the present invention.

[0027] Figure 11 This is a diagram showing the angiogenesis effect of the metal-polyphenol microsphere material obtained in Example 1 of the present invention.

[0028] Figure 12 This is a scan image of the mesoporous catechin microsphere solution obtained in Example 1 of the present invention, which is loaded with various metal cations to form microspheres. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the technical means used in the following embodiments and experimental examples are conventional means well known to those skilled in the art, and the materials and reagents used can all be obtained commercially.

[0030] Overview of the Plan This solution provides a novel method for preparing metal-polyphenol microspheres, comprising the following steps: Step 1: Disperse catechins, F127 and NaCl in a mixture of distilled water and ethanol to obtain mixture A; The mass ratio of catechin, F127 and NaCl in mixture A is 150~900:100~300:1000~3000; the volume ratio of distilled water and ethanol in mixture A is 6:4; and the concentration of catechin in mixture A is 150~900 mg / ml.

[0031] Step 2: Add toluene and formaldehyde to mixture A, and stir the emulsion at 500-1500 rpm for 30-90 minutes to obtain mixture B; In mixture B, the amount of toluene added is 10-30% of the volume of the mixture of distilled water and ethanol; and the amount of formaldehyde added is 1.5-4.0% of the volume of the mixture of distilled water and ethanol.

[0032] Step 3: Slowly add 400-600 μL of NH3·H2O dropwise to the above mixture B until the pH of mixture B is 9-11.5. Furthermore, NH3·H2O also acts as a catalyst throughout the experiment. After reacting at room temperature for 4-10 hours, centrifuge the solution at 12,000-14,000 rpm, then wash the product three times with a 1:1 mixture of water and ethanol. After shaking and washing, a solution of mesoporous catechin microspheres with a diameter of approximately 200 nm (e.g., ...) is obtained. Figure 1 The electron microscope image shows that the diameter of the mesoporous catechin microspheres is approximately 200 nm. Step 4: Add the saturated zinc acetate solution to the mesoporous catechin microsphere solution to obtain mesoporous catechin / Zn microspheres containing zinc ions.

[0033] This solution also provides a novel metal-polyphenol microsphere, which is a mesoporous catechin / Zn microsphere prepared by the above method.

[0034] This solution also provides an application of a novel metal-polyphenol microsphere, including the application of the above-mentioned mesoporous catechin / Zn microsphere in any of the following: drug loading, anti-inflammatory, antibacterial, or as a biocoating.

[0035] Example 1 This solution provides a novel method for preparing metal-polyphenol microspheres, comprising the following steps: Step 1: Disperse 150.0 mg of catechin, 100.0 mg of F127 and 1000 mg of NaCl in a mixture of 6.0 mL of distilled water and 4.0 mL of ethanol to obtain mixture A; Step 2: Add 1.00 mL of toluene and 150 μL of formaldehyde to mixture A, and stir the emulsion at 500 rpm for 30 min to obtain mixture B; Step 3: Slowly add 400 μL of NH3·H2O to the above mixture B, react at room temperature for 4 h, centrifuge the solution at 12,000 rpm, then wash the product 3 times with a 1:1 mixture of water and ethanol, and then wash with shaking to obtain a solution of mesoporous catechin microspheres with a diameter of about 200 nm. Step 4: Add the saturated zinc acetate solution to the mesoporous catechin microsphere solution to obtain mesoporous catechin / Zn microspheres containing zinc ions.

[0036] Comparative Example 1: Insufficient NaCl This comparative example is basically the same as Example 1, except that 500 mg of NaCl was added in this method. The STM image of the resulting mesoporous catechin / Zn microspheres is detailed below. Figure 2 The results showed that if too little NaCl was used, the resulting mesoporous catechin / Zn microspheres had an irregular structure.

[0037] Comparative Example 2: Too much NaCl This comparative example is basically the same as Example 1, except that 2000 mg of NaCl was added in this method. The STM image of the resulting mesoporous catechin / Zn microspheres is detailed below. Figure 3 The results showed that if too little NaCl was used, the resulting mesoporous catechin / Zn microspheres had an irregular structure.

[0038] Comparative Example 3: This comparative example is basically the same as Example 1, except that the mixture in step one of this method consists of 3.0 mL of distilled water and 7.0 mL of ethanol. The STM image of the resulting mesoporous catechin / Zn microspheres is detailed below. Figure 4 The results showed that if there was too little distilled water in the mixture, the resulting microspheres would have a non-porous structure.

[0039] Comparative Example 4: This comparative example is basically the same as Example 1, except that the mixture in step one of this method consists of 5.0 mL of distilled water and 5.0 mL of ethanol. The STM image of the resulting mesoporous catechin / Zn microspheres is detailed below. Figure 5 The results showed that if the amount of distilled water in the mixture was insufficient, the mesopores in the formed microsphere structure were not obvious.

[0040] Comparative Example 5: This comparative example is basically the same as Example 1, except that the mixture in step one of this method consists of 7.0 mL of distilled water and 3.0 mL of ethanol. The STM image of the resulting mesoporous catechin / Zn microspheres is detailed below. Figure 6 The results showed that if there was too much distilled water in the mixture, it would be difficult to form microsphere structures.

[0041] Experimental Example 1: Microsphere Properties The microspheres obtained in Example 1 were co-cultured with human umbilical vein endothelial cells (HUVECs). The experimental steps are as follows: To observe the phagocytic behavior of HUVEC cells on mesoporous catechin / Zn microspheres, bio-transmission electron microscopy (bio-TEM) was used for ultrastructural analysis of the cells. HUVEC cells were cultured at 1×10⁻⁶ cells / cells. 5 Cells were seeded at a density of 10 cells / mL in 6-well plates and incubated in DMEM medium containing 10% fetal bovine serum at 37°C with 5% CO2 for 24 hours until complete adhesion. The old medium was discarded. Fresh medium containing mesoporous catechin / Zn microspheres was added, and incubation continued for 6 hours to induce phagocytosis. After incubation, the supernatant was carefully aspirated, and the cells were gently washed three times (5 min each time) with pre-chilled phosphate buffer. Then, adherent cells were gently scraped using a cell scraper, and the cell suspension was transferred to a 1.5 mL centrifuge tube. The cell pellet was collected by centrifugation at 1500 rpm for 10 min. After aspirating the supernatant, 2.5% glutaraldehyde fixative at room temperature was slowly added along the wall of the centrifuge tube to completely submerge the cell pellet. The cells were fixed at 4°C for 2 hours. Subsequently, the cells were post-fixed with 1% osmium tetroxide for 1 hour, then embedded in epoxy resin using a gradient of ethanol and water. Sections were prepared and stained, and the phagocytosis of microspheres was observed and recorded using a transmission electron microscope (80 kV).

[0042] The results are as follows Figure 7 As shown in the figure. The results indicate that the mesoporous catechin / Zn microspheres can be effectively phagocytosed by cells, and the intact structure of the microspheres can be observed in lysosomes, confirming that the microspheres have good cell internalization ability.

[0043] Experimental Example 2: Antibacterial Function of Microspheres The microspheres obtained in Example 1 were subjected to plate coating and scanning electron microscopy. The experimental details are as follows: (1) Flat plate coating, including the following steps: The antibacterial properties of mesoporous catechin / Zn microspheres were determined using the plate coating method. Two groups of samples were set up: a physiological saline blank control group and a mesoporous catechin / Zn microsphere group. 1×10 6 CFU / mL S.aureus , E. coli and S.mutans Bacterial suspensions were prepared and incubated with physiological saline and mesoporous catechin / Zn microspheres for 6 hours, respectively. After incubation, S.aureus and E. coli The bacterial suspension was diluted 1:1000. S.mutans The bacterial suspension was diluted 1:100 and spread evenly on agar plates; after incubation at 37°C for 24 hours, the bacterial colonies on the plates were observed.

[0044] (2) Scanning electron microscopy, including the following steps: To further analyze the morphological changes of bacteria after the antibacterial test, SEM imaging technology was used for detection: co-cultured bacterial solutions from the control group and the experimental group were collected, washed three times with PBS, and fixed overnight at 4°C with 2.5% glutaraldehyde aqueous solution; then dehydrated in a gradient of 30%, 50%, 70%, 85%, and 95% ethanol (each concentration for 15 minutes), and finally treated twice with 100% ethanol (15 minutes each time); after the samples were sputter-coated with gold, SEM observation was performed.

[0045] The comparison results are as follows Figure 8 As shown in the figure. The results indicate that, compared with the control group, mesoporous catechin / Zn microspheres exhibited good antibacterial activity, and bacterial colonies were effectively inhibited. Figure 8 a); We observed the microstructure of bacteria after co-culturing with mesoporous catechin / Zn microspheres using scanning electron microscopy (SEM). Figure 8 (b) In the control group, all three types of bacteria maintained their morphology intact, retaining typical spherical (Staphylococcus aureus), rod-shaped (Escherichia coli), and oval (Streptococcus mutans) outlines, respectively. After treatment with mesoporous catechin / Zn microspheres, the bacterial morphology and structure were permanently disrupted, including cell rupture, wrinkling and shrinkage, and even complete lysis, directly demonstrating their excellent antibacterial properties. This formulation, by loading metal ions, endows them with superior antibacterial / anti-inflammatory / angiogenic functions.

[0046] Experimental Example 3: Anti-inflammatory function of microspheres The microspheres obtained in Example 1 were subjected to fluorescence staining and flow cytometry analysis. The experimental subjects used were RAW264.7 macrophages. The experimental procedures are as follows: (1) Fluorescent staining, including the following steps: In the immunofluorescence staining experiment, RAW_264.7 macrophages were cultured at a density of 2 × 10⁶ cells per well. 5Cells were seeded at a density of [number] cells / well in 6-well plates. After cell adhesion, they were stimulated with 100 ng / mL lipopolysaccharide (LPS, MCE, USA) for 24 hours. The culture medium in the wells was then discarded, and the cells were gently washed three times with phosphate-buffered saline (PBS). 2 mL of physiological saline or mesoporous catechin / Zn microsphere solution was then added to each well, and the cells were incubated for 48 hours. RAW_264.7 macrophages with added physiological saline served as the control group (CON group). Subsequent fixation and staining procedures were as follows: Cells were fixed with 4% paraformaldehyde at room temperature for 30 minutes, during which time they were washed three times with PBS for 5 minutes each time to completely remove the fixative. Immunostaining blocking buffer (Beyotime, China) was added for blocking at room temperature for 30 minutes, followed by overnight incubation at 4°C with CD86 antibody and CD206 antibody (both purchased from Beyotime, China). The next day, the cells were washed three times with PBST, fluorescently labeled secondary antibody was added and incubated in the dark for 1 hour; finally, the cell nuclei were stained with DAPI, and the morphology and fluorescence distribution of the stained cells were observed and recorded using an inverted fluorescence microscope.

[0047] (2) Flow cytometry analysis, including the following steps: RAW_264.7 macrophages from the control group and the mesoporous catechin / Zn microsphere group were collected and incubated for 30 minutes in an ice bath in the dark with fluorescently labeled antibodies against CD80 (a marker for M1 macrophages) and CD206 (a marker for M2 macrophages). After incubation, the fluorescence signal intensity of each group of cells was detected by flow cytometry, and the data were quantitatively analyzed using Flow_Jo software to clarify the effect of mesoporous catechin / Zn microspheres on macrophage polarization.

[0048] The comparison results are as follows Figure 9 and Figure 10 As shown. The results indicated that, compared with the control group, the CD86 staining intensity of the mesoporous catechin / Zn microsphere group was significantly reduced ( Figure 9 a), CD206 staining intensity was significantly enhanced ( Figure 9 b), indicating that mesoporous catechin / Zn microspheres can promote macrophage polarization towards M2 type while inhibiting it towards M1 type polarization (b). Figure 9 To further quantify the regulatory efficacy of different microneedle systems on macrophage polarization, we analyzed macrophage polarization status using flow cytometry, and the results were consistent with those obtained from fluorescence staining. This indicates that mesoporous catechin / Zn microspheres possess excellent anti-inflammatory effects. Figure 10 ).

[0049] Experimental Example 4: Angiogenic Function The microspheres obtained in Example 1 were subjected to scratch tests, Transwell experiments, and tube formation experiments. The experimental details are as follows: (1) Scratch test, the experimental steps are as follows: Subsequently, human umbilical vein endothelial cells (HUVECs) were 1×10 5 Cells were seeded at a density of 10 cells / well in six-well cell culture plates. Once cell confluence reached 90% or higher, a clear cell-free region was created using a 200 μL pipette tip along a top-to-bottom direction. The cells were then washed three times with pre-warmed phosphate-buffered saline (PBS) to thoroughly remove suspended cells. After washing, 2 mL of serum-free DMEM medium containing mesoporous catechin / Zn microspheres was added to each well. A control group (Con group) without mesoporous catechin / Zn microspheres was also included. The morphology and size of the cell migration regions in each group were observed and recorded using a phase-contrast microscope at 0, 12, and 24 hours of culture.

[0050] (2) Transwell experiment, the experimental steps are as follows: In the Transwell migration assay, different microneedle suspensions containing 10% fetal bovine serum (FBS) were added to the lower chamber, while 200 μL of a solution containing 2 × 10⁻⁶ fetal bovine serum (FBS) was added to the upper chamber. 4 Personal umbilical vein endothelial cells (HUVECs) were cultured in serum-free DMEM medium, ensuring free permeability of fluids and nutrients between the upper and lower chambers. After 24 hours of culture, HUVECs that had not migrated to the upper chamber side of the Transwell membrane were gently wiped away with a cotton swab. Cells on the lower chamber side were fixed with 4% paraformaldehyde (PFA) for 15 min, followed by crystal violet staining for 30 min. After rinsing with phosphate-buffered saline (PBS) to remove unbound dye, images were acquired under a microscope for cell observation.

[0051] (3) Tube forming experiment, the experimental steps are as follows: In the tube formation experiment, the matrix gel (Beyotime, China) was first thawed at 4°C. Then, 300 μL of matrix gel was added to each well of the pre-chilled 24-well plate, and the plate was incubated at 37°C for 30 minutes to solidify. Next, serum-starved human umbilical vein endothelial cells (HUVECs) were added at a ratio of 4 × 10⁶ cells per well. 4 Cells were gently seeded at a density of 1,000 cells onto the solidified matrix gel surface and incubated for 6 hours with solutions containing or without mesoporous catechin / Zn microspheres. To assess the formation of tubular structures, cells were first stained with a live cell staining reagent (Beyotime, China) and then imaged using a fluorescence microscope.

[0052] The comparison results are as follows Figure 11 As shown. The results indicate that, compared with the control group, the mesoporous catechin / Zn microsphere group effectively reduced the scratch area at both 12 and 24 hours. Figure 11a) indicates that mesoporous catechin / Zn microspheres promoted the migration of HUVECs. Transwell assays further validated the effect of mesoporous catechin / Zn microspheres on promoting HUVEC migration in vitro; the number of cells migrating after using mesoporous catechin / Zn microspheres was significantly greater than that in the control group. Figure 11 b). In addition, angiogenesis assays were used to evaluate in vitro angiogenesis-promoting capabilities ( Figure 11 c), consistent with the results of cell migration experiments, mesoporous catechin / Zn microspheres enhanced the angiogenesis capacity of cells.

[0053] Experimental Example 5: Comparison with Loading Other Metals Other metal cations (including Sr, Cu, Mn, Mg, Ca, Ce, and Fe) were loaded onto the mesoporous catechin microsphere solution obtained in Example 1. Details of the resulting mesoporous catechin / metal microspheres can be found in [link to example]. Figure 12 As shown in the figure. The results indicate that, in addition to zinc ions, the mesoporous catechin microspheres prepared by this method serve as an excellent microsphere platform, capable of loading a wide variety of different metal ions, and exhibiting good bioactivity even when loaded with other metal ions.

[0054] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for preparing novel metal-polyphenol microspheres, characterized by: The method comprises the following steps: Step one, dispersing catechin, F127 and NaCl in a mixture of distilled water and ethanol to obtain a mixed solution A; Step two, adding toluene and formaldehyde to the mixed solution A, stirring the emulsion at a speed of 500-1500 rpm for 30-90 min to obtain a mixed solution B; Step three, slowly adding NH3·H2O to the mixed solution B, and after reaction, centrifugal treatment and washing treatment to obtain a product, and then oscillation washing to obtain a mesoporous catechin microsphere solution; Step four, adding a saturated zinc acetate solution to the mesoporous catechin microsphere solution to obtain a mesoporous catechin / Zn microsphere containing zinc ions.

2. The method for preparing a novel metal-polyphenol microsphere according to claim 1, characterized in that: In step one, the mass ratio of catechin, F127 and NaCl in the mixed solution A is 150-900:100-300:1000-3000; the volume ratio of distilled water and ethanol in the mixed solution A is 6:4; and the concentration of catechin in the mixed solution A is 150-900 mg / ml.

3. The method according to claim 1, wherein the method is characterized by: In step two, the amount of toluene added to the mixed solution B is 10-30% of the volume of the mixture of distilled water and ethanol; and the amount of formaldehyde added to the mixed solution B is 1.5-4.0% of the volume of the mixture of distilled water and ethanol.

4. The method according to claim 1, wherein the method is characterized by: In step three, the amount of NH3·H2O added is such that the pH of the mixed solution B is 9-11.

5.

5. The method according to claim 1, wherein the method is characterized by: In step three, the reaction is carried out at room temperature for 4-10 h; the centrifugal treatment is centrifuging the solution at 12,000-14,000 rpm to collect the precipitate; and the washing treatment is washing the precipitate 2-3 times with a 1:1-1:2 mixture of water and ethanol.

6. The method for preparing novel metal-polyphenol microspheres according to claim 5, characterized by: In step three, the oscillation washing is carried out by adding a 50% ethanol solution to the product, and then oscillation washing at 24-40℃, a frequency of 60-100 kHz and an amplitude of 0.05-0.1 mm for 3-10 min.

7. The method according to claim 1, wherein the method is characterized by: In step three, the diameter of the microspheres in the mesoporous catechin microsphere solution is 150-260 nm.

8. The method of claim 1, wherein the method is characterized by: In step four, the volume ratio of the zinc acetate solution to the mesoporous catechin microsphere solution is 20:1-2:

1.

9. A novel metal-polyphenol microsphere characterized by: The mesoporous catechin / Zn microspheres prepared by the method of any one of claims 1-8.

10. Use of novel metal-polyphenol microspheres, characterized in that: The application of the mesoporous catechin / Zn microspheres prepared by the method of any one of claims 1-8 in any one of drug loading, anti-inflammatory, antibacterial and as a biological coating.

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