Metal polyphenol cerium nanoparticles for treating psoriasis and preparation method thereof

Abstract

The invention relates to the technical field of medicine, in particular to metal polyphenol cerium nano-particles for treating psoriasis and a preparation method thereof.The metal polyphenol cerium nano-particles are prepared from tannic acid, cerous nitrate and PEG8000, the feeding molar ratio of the tannic acid to the cerous nitrate is 1: (2-2.5), the pH value of a reaction system in the preparation process is 5.0-6.0, and the particle size of the nano-particles is 180-220 nm; according to the method, the feeding molar ratio of tannic acid to cerium nitrate is regulated to be 1: (2-2.5), so that phenolic hydroxyl groups of the tannic acid and cerium ions form stable coordinate bonds, triangular nano-particles with regular structures are constructed, and the particle size is accurately controlled within the range of 180-220 nm. The particle size range not only ensures effective retention of nanoparticles in local skin and improves the drug action concentration, but also avoids difficulty in skin barrier penetration caused by overlarge particle size, thereby solving the problem of low local bioavailability of traditional drugs. Due to the stable coordination structure, leakage of metal ions is reduced, toxic and side effects of the medicine are reduced, and the medication safety is improved.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical technology, specifically to a cerium polyphenol nanoparticle for treating psoriasis and its preparation method. Background Technology

[0002] Psoriasis is a common chronic inflammatory skin disease characterized by a long course and high recurrence rate. Clinical manifestations include skin erythema, scaling, and intense itching, severely impacting patients' quality of life. Current clinical treatments mainly include corticosteroids and vitamin D3 derivatives (such as calcipotriol). However, long-term use of these drugs can easily cause side effects such as skin atrophy, telangiectasia, and liver and kidney damage, and their efficacy is limited for some severely affected patients, making it difficult to meet clinical treatment needs.

[0003] With the development of nanomedicine technology, nanomedicines have become a research hotspot in the treatment of psoriasis due to their advantages of strong targeting and high bioavailability. Metal polyphenol nanoparticles, as novel nanomaterials, combine the catalytic activity of metal ions with the anti-inflammatory properties of polyphenols, showing potential application value in the treatment of inflammatory diseases. However, the current preparation process of metal polyphenol nanoparticles often suffers from problems such as uneven particle size distribution, poor stability, and short in vivo circulation time. Furthermore, some nanomaterials lack sufficient biocompatibility, easily triggering immune responses, thus limiting their clinical translation. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a metal polyphenol cerium nanoparticle for treating psoriasis and a method for preparing the same.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A metal polyphenol cerium nanoparticle for treating psoriasis is prepared from tannic acid, cerium nitrate and PEG8000, wherein the molar ratio of tannic acid to cerium nitrate is 1:2-2.5, the pH value of the reaction system during the preparation process is 5.0-6.0, and the particle size of the nanoparticle is 180-220 nm.

[0007] As a further technical solution, the tannic acid reacts with cerium nitrate in an aqueous solution to form a complex, and PEG8000 is grafted onto the surface of the complex, with a grafting rate of PEG8000 of 15%-25%. The grafting rate is determined by high performance liquid chromatography under the following conditions: C18 column, mobile phase of methanol:water volume ratio of 60:40, column temperature of 30℃, and detection wavelength of 280nm.

[0008] As a further technical solution, the amount of PEG8000 added is 1.0-1.5 times the mass of tannic acid.

[0009] As a further technical solution, the nanoparticles are triangular, and when the dispersion concentration in the aqueous solution is 0.1-0.5 mg / mL, the precipitation amount is ≤5% after standing for 72 hours; the precipitation amount is determined by centrifugation at 8000 rpm for 10 minutes.

[0010] As a further technical solution, the hemolysis rate of the nanoparticles is ≤2%; the hemolysis rate is determined by an in vitro hemolysis test of rabbit erythrocytes, and the test conditions are a nanoparticle concentration of 0.5 mg / mL and incubation at 37°C for 1 hour.

[0011] A method for using cerium polyphenol nanoparticles to treat psoriasis includes the following steps:

[0012] (1) Dissolve tannic acid and cerium nitrate in deionized water according to the molar ratio of the feed, adjust the pH of the solution to 5.0-6.0, stir at 1000 rpm for 15 minutes, and continuously disperse by ultrasonication for 10 minutes during the process;

[0013] (2) Add PEG8000 aqueous solution with a concentration of 8-10 mg / mL to the mixture in step (1), continue stirring for 75 minutes, and maintain the reaction temperature at 25-30℃;

[0014] (3) Filter using a 0.22 μm filter membrane and collect the filtrate;

[0015] (4) Centrifuge the filtrate at 12,000 rpm for 30 minutes at 20-25℃ and collect the precipitate;

[0016] (5) Wash the precipitate three times with deionized water and freeze-dry it under vacuum for 12-16 hours to obtain the nanoparticles.

[0017] As a further technical solution, in step (1), the concentration of the mixed solution of tannic acid and cerium nitrate is 0.5-0.8 mg / mL, and the pH value is adjusted by 0.1 mol / L hydrochloric acid solution or 0.1 mol / L sodium hydroxide solution.

[0018] As a further technical solution, in step (1), the ultrasonic dispersion is a continuous ultrasonic mode with a power of 200W and a frequency of 40kHz.

[0019] As a further technical solution, the vacuum freeze drying in step (5) is carried out under the conditions of -50~-40℃ and 10-20Pa.

[0020] As a further technical solution, the conductivity of the supernatant after washing in step (5) is ≤20μS / cm.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This invention, by controlling the molar ratio of tannic acid to cerium nitrate to 1:2-2.5 and designing a reaction system with a pH of 5.0-6.0, enables the phenolic hydroxyl groups of tannic acid to form stable coordination bonds with cerium ions, thereby constructing well-structured triangular nanoparticles with a precisely controlled particle size within the range of 180-220 nm. This particle size range ensures effective retention of the nanoparticles on the skin, increasing drug concentration, while avoiding the difficulty of skin barrier penetration caused by excessively large particle sizes, thus solving the problem of low local bioavailability of traditional drugs. Simultaneously, the stable coordination structure reduces the leakage of metal ions, lowers the toxic side effects of the drug, and improves medication safety.

[0023] By grafting PEG8000 onto the surface of the nanoparticles, and controlling its addition amount to 1.0-1.5 times the mass of tannic acid with a grafting rate of 15%-25%, a hydrophilic protective layer is formed on the nanoparticle surface, effectively reducing the probability of particle aggregation. This results in a precipitation rate of ≤5% after 72 hours when the nanoparticles are dispersed in aqueous solution at a concentration of 0.1-0.5 mg / mL, significantly improving the product's storage stability. Furthermore, it reduces the non-specific binding of nanoparticles to immune cells in vivo, prolonging their circulation time and enhancing the targeted delivery of anti-inflammatory active ingredients. The anti-inflammatory and antioxidant properties of tannic acid synergistically work with the catalytic scavenging function of cerium ions to effectively inhibit inflammatory responses at psoriasis lesions. The grafting of PEG8000 further amplifies this synergistic effect, making the therapeutic efficacy of the nanoparticles superior to single-component or ungrafted PEG nanomaterials.

[0024] The preparation process of this invention achieves efficient preparation and purification of nanoparticles by optimizing stirring speed, ultrasonic parameters, centrifugation conditions, and vacuum freeze-drying parameters. Specifically, a stirring speed of 1000 rpm combined with ultrasonic dispersion at 200W power ensures uniform mixing of raw materials and thorough reaction; a centrifugation speed of 12000 rpm and the use of a 0.22μm filter membrane effectively remove impurities and substandard particles, ensuring product purity; and vacuum freeze-drying at -50~-40℃ and 10-20Pa avoids morphological damage and agglomeration of nanoparticles during drying. The entire process is simple, with easily controllable conditions, enabling large-scale production. The prepared nanoparticles exhibit a hemolysis rate of ≤2% and show no significant pathological damage to major organs such as the heart, liver, spleen, lungs, and kidneys in mice, demonstrating both excellent therapeutic efficacy and biosafety. This successfully solves many technical challenges of existing psoriasis treatments, such as significant side effects, poor stability of nanomedicines, and complex preparation processes, and has broad clinical application prospects.

[0025] Instruction manual illustrations

[0026] Figure 1 Infrared spectrum of tannic acid;

[0027] Figure 2 Infrared spectrum of cerium nitrate;

[0028] Figure 3 Infrared spectrum of tannic acid-cerium nitrate;

[0029] Figure 4 Example 1: Particle size distribution of TA-Ce nanoparticles;

[0030] Figure 5 TA-Ce nanoparticle C element mapping diagram;

[0031] Figure 6 Mapping diagram of O element in TA-Ce nanoparticles;

[0032] Figure 7 Ce element mapping diagram of TA-Ce nanoparticles;

[0033] Figure 8 Multi-element (C, O, Ce) mapping diagram of TA-Ce nanoparticles;

[0034] Figure 9 TEM image of TA-Ce nanoparticles (magnification 50.00KX, scale bar 100nm);

[0035] Figure 10 TEM image of TA-Ce nanoparticles (magnification 20.00KX, scale bar 200nm);

[0036] Figure 11 SEM image of TA-Ce nanoparticles (magnification 10.00 KX, scale bar 1 μm);

[0037] Figure 12 H&E stained sections of mouse back skin (7 days, including normal group, model group, TA-Ce group, and calcipotriol group);

[0038] Figure 13 H&E stained sections of mouse ears (including normal group, model group, TA-Ce group, and calcipotriol group);

[0039] Figure 14 Comparison of histopathological sections of mouse skin tissue (including normal group, model group, TA-Ce group, and calcipotriol group);

[0040] Figure 15 Comparison of H&E stained sections of mouse liver and spleen (including normal group, model group, TA-Ce group, and calcipotriol group);

[0041] Figure 16Comparative cross-sectional images of mouse skin treatment effects (7 days, including normal group, model group, TA-Ce group, and calcipotriol group);

[0042] Figure 17 Comparison of H&E stained sections of heart, liver, spleen, lung, and kidney from mice in the normal group and the TA-Ce group. Detailed Implementation

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] This invention provides a metal polyphenol cerium nanoparticle for treating psoriasis and its preparation method. The nanoparticle is prepared from tannic acid, cerium nitrate and PEG8000. The preparation method is simple to operate and the conditions are easy to control. The obtained nanoparticle has good stability and low toxicity, and can be effectively used for the treatment of psoriasis.

[0045] Raw materials and properties of nanoparticles:

[0046] This invention does not impose any special restrictions on the sources of tannic acid, cerium nitrate, and PEG8000; commercially available products well known to those skilled in the art can be used.

[0047] The preferred molar ratio of tannic acid to cerium nitrate is 1:2-2.5. The preferred pH value of the reaction system during preparation is 5.0-6.0, which is preferably adjusted using a 0.1 mol / L hydrochloric acid solution or a 0.1 mol / L sodium hydroxide solution.

[0048] The preferred amount of PEG8000 is 1.0-1.5 times the mass of tannic acid. Tannic acid reacts with cerium nitrate in aqueous solution to form a complex, and PEG8000 is grafted onto the surface of the complex. The grafting rate of PEG8000 is preferably 15%-25%. The grafting rate is determined by high performance liquid chromatography (HPLC) under the following conditions: C18 column, mobile phase of methanol and water (volume ratio 60:40), column temperature 30℃, and detection wavelength 280nm.

[0049] The prepared nanoparticles are preferably triangular in shape, with a preferred particle size of 180-220 nm. When the nanoparticles are dispersed in aqueous solution at a concentration of 0.1-0.5 mg / mL, the precipitation amount after 72 hours is ≤5%, determined by centrifugation at 8000 rpm for 10 minutes. The hemolysis rate of the nanoparticles is ≤2%, determined by an in vitro hemolysis assay using rabbit erythrocytes at a concentration of 0.5 mg / mL and incubation at 37°C for 1 hour.

[0050] Preparation methods of nanoparticles:

[0051] The present invention provides a method for preparing cerium polyphenol nanoparticles for treating psoriasis, comprising the following steps:

[0052] Tannic acid and cerium nitrate were dissolved in deionized water at the specified molar ratio. The pH of the solution was adjusted to 5.0-6.0, and the mixture was stirred at 1000 rpm for 15 minutes, with continuous ultrasonic dispersion for 10 minutes during the process. The preferred concentration of the mixed solution of tannic acid and cerium nitrate was 0.5-0.8 mg / mL. The ultrasonic dispersion was performed in continuous ultrasonic mode, with a preferred power of 200 W and a preferred frequency of 40 kHz.

[0053] Add an aqueous solution of PEG8000 with a concentration of 8-10 mg / mL to the mixture from step 1, and continue stirring for 75 minutes while maintaining the reaction temperature at 25-30°C.

[0054] Filter using a 0.22 μm filter membrane and collect the filtrate.

[0055] Centrifuge the filtrate at 12,000 rpm for 30 minutes at 20-25°C and collect the precipitate.

[0056] The precipitate was washed three times with deionized water and then freeze-dried under vacuum for 12-16 hours to obtain nanoparticles. The conductivity of the supernatant after washing was ≤20 μS / cm. Vacuum freeze-drying was preferably carried out at -50 to -40°C and 10-20 Pa.

[0057] The preparation method provided by this invention is simple and highly reproducible. By controlling the raw material ratio and reaction parameters, it is possible to stably prepare high-performance cerium polyphenol nanoparticles. These nanoparticles not only solve the problem of insufficient efficacy of psoriasis treatment drugs, but also have good biocompatibility and stability, resulting in higher safety and broad application prospects.

[0058] To further illustrate the present invention, the following embodiments will be described in detail.

[0059] Example 1:

[0060] Weigh appropriate amounts of tannic acid and cerium nitrate, dissolve them in deionized water at a molar ratio of 1:2, and prepare a mixed solution with a concentration of 0.5 mg / mL. Adjust the pH of the solution to 5.0 using 0.1 mol / L hydrochloric acid solution. Place the mixed solution in a stirrer and stir at 1000 rpm for 15 minutes. During this period, turn on the ultrasonic device for continuous dispersion for 10 minutes at an ultrasonic power of 200 W and a frequency of 40 kHz.

[0061] Weigh out PEG8000 and dissolve it in deionized water to prepare an 8 mg / mL PEG8000 aqueous solution. The amount of PEG8000 added is 1.0 times the mass of tannic acid. Add the PEG8000 aqueous solution to the mixture from step 1 and continue stirring for 75 minutes, maintaining the reaction temperature at 25°C.

[0062] The reaction solution was filtered using a 0.22 μm filter membrane, and the filtrate was collected.

[0063] Transfer the filtrate to a centrifuge tube and centrifuge at 12,000 rpm for 30 minutes at 20°C. After centrifugation, collect the precipitate at the bottom.

[0064] The precipitate was washed with deionized water, and the washing was repeated three times until the conductivity of the supernatant after washing was ≤20 μS / cm. The washed precipitate was placed in a vacuum freeze dryer and freeze-dried at -50℃ and 10 Pa for 12 hours to obtain cerium polyphenol nanoparticles for the treatment of psoriasis.

[0065] The nanoparticles were found to be triangular in shape; when dispersed in aqueous solution at a concentration of 0.1 mg / mL, the precipitation rate was 3% after 72 hours; the hemolysis rate was 1.2%; and the grafting rate of PEG8000 was 15%.

[0066] Example 2:

[0067] Weigh appropriate amounts of tannic acid and cerium nitrate, and dissolve them in deionized water at a molar ratio of 1:2.5 to prepare a mixed solution with a concentration of 0.65 mg / mL. Adjust the pH of the solution to 5.5 using 0.1 mol / L sodium hydroxide solution. Place the mixed solution in a stirrer and stir at 1000 rpm for 15 minutes. During this time, use an ultrasonic device to continuously disperse the mixture for 10 minutes at a power of 200 W and a frequency of 40 kHz.

[0068] Weigh out PEG8000 and dissolve it in deionized water to prepare a PEG8000 aqueous solution with a concentration of 9 mg / mL. The amount of PEG8000 added is 1.25 times the mass of tannic acid. Add the PEG8000 aqueous solution to the mixture from step 1 and continue stirring for 75 minutes, maintaining the reaction temperature at 28°C.

[0069] The reaction solution was filtered using a 0.22 μm filter membrane, and the filtrate was collected.

[0070] Transfer the filtrate to a centrifuge tube and centrifuge at 12,000 rpm for 30 minutes at 23°C. After centrifugation, collect the precipitate at the bottom.

[0071] The precipitate was washed with deionized water, and the washing was repeated three times until the conductivity of the supernatant after washing was ≤20 μS / cm. The washed precipitate was placed in a vacuum freeze dryer and freeze-dried at -45℃ and 15 Pa for 14 hours to obtain cerium polyphenol nanoparticles for the treatment of psoriasis.

[0072] The nanoparticles were found to be triangular in shape; when dispersed in aqueous solution at a concentration of 0.3 mg / mL, the precipitation rate was 4% after 72 hours; the hemolysis rate was 1.5%; and the grafting rate of PEG8000 was 20%.

[0073] Example 3:

[0074] Weigh appropriate amounts of tannic acid and cerium nitrate, and dissolve them in deionized water at a molar ratio of 1:2 to prepare a mixed solution with a concentration of 0.8 mg / mL. Adjust the pH of the solution to 6.0 using 0.1 mol / L hydrochloric acid solution. Place the mixed solution in a stirrer and stir at 1000 rpm for 15 minutes. During this time, turn on the ultrasonic device for continuous dispersion for 10 minutes at an ultrasonic power of 200 W and a frequency of 40 kHz.

[0075] Weigh out PEG8000 and dissolve it in deionized water to prepare a PEG8000 aqueous solution with a concentration of 10 mg / mL. The amount of PEG8000 added is 1.5 times the mass of tannic acid. Add the PEG8000 aqueous solution to the mixture from step 1 and continue stirring for 75 minutes, maintaining the reaction temperature at 30°C.

[0076] The reaction solution was filtered using a 0.22 μm filter membrane, and the filtrate was collected.

[0077] Transfer the filtrate to a centrifuge tube and centrifuge at 12,000 rpm for 30 minutes at 25°C. Collect the precipitate at the bottom after centrifugation.

[0078] The precipitate was washed with deionized water, and the washing was repeated three times until the conductivity of the supernatant after washing was ≤20 μS / cm. The washed precipitate was placed in a vacuum freeze dryer and freeze-dried at -40℃ and 20 Pa for 16 hours to obtain cerium polyphenol nanoparticles for the treatment of psoriasis.

[0079] The nanoparticles were found to be triangular in shape; when dispersed in aqueous solution at a concentration of 0.5 mg / mL, the precipitation rate was 5% after 72 hours; the hemolysis rate was 1.8%; and the grafting rate of PEG8000 was 25%.

[0080] Efficacy and toxicity verification test of cerium polyphenol nanoparticles in the treatment of psoriasis;

[0081] I. Experimental Objective:

[0082] To verify the therapeutic effect and biosafety of the cerium polyphenol nanoparticles prepared in this invention on psoriasis.

[0083] II. Experimental Materials and Design:

[0084] Experimental materials:

[0085] The experimental animals were male BALB / c nude mice, 6-8 weeks old, weighing 18-22g, totaling 24 (including reserve animals). The test drug was the cerium metal polyphenol nanoparticles prepared in Example 1, the positive control drug was commercially available calcipotriol, and the modeling drug was imiquimod.

[0086] Experimental Design:

[0087] Adaptation period: After the mice are purchased and brought to the laboratory, they are kept in stable condition for three days before the experiment is conducted.

[0088] Grouping: Mice were randomly divided into four groups of six each. Each group received a different treatment every day for seven days.

[0089] Normal group: No treatment is given, and the animals are fed in a conventional manner.

[0090] Model group: Imiquimod was applied to the skin on the back at 8:00 AM every day to establish a psoriasis model.

[0091] Drug group: Imiquimod was applied to the skin on the back of the mice at 8:00 a.m. every day, and the metal polyphenol cerium nanoparticles (dispersion concentration of 0.3 mg / mL) prepared in Example 2 were sprayed on the back of the mice at 5:00 p.m. every day.

[0092] Calcipotriol group (positive control group): Imiquimod was applied to the skin on the back at 8:00 a.m. every day, and 0.05 ml of commercially available calcipotriol was applied at 5:00 p.m. every day.

[0093] III. Sample Collection and Subsequent Testing:

[0094] Sacrifice time: Seven days after the start of the experiment, all mice were sacrificed.

[0095] Tissue collection: Skin from the back (application site), ears (application site), spleen, liver, heart, lungs, and kidneys were collected from mice. Samples from the heart, lungs, and kidneys were only collected from the normal control group and the drug treatment group.

[0096] Subsequent testing: The collected tissues were subjected to H&E staining.

[0097] Back skin and ear tissue: used to observe the improvement of skin lesions and evaluate the effectiveness of drug treatment.

[0098] Spleen and liver tissues: used to observe tissue morphological changes and assess drug toxicity.

[0099] Heart, liver, spleen, lung, and kidney tissues from the normal group and the drug group: comparative analysis of drug toxicity was conducted to determine the effects of nanoparticles on major organs.

[0100] Determination of test results (in conjunction with the attached test diagram);

[0101] Based on the nanoparticle characterization data in the experimental images, H&E staining sections of animal tissues, and related detection images, the efficacy and biosafety of cerium polyphenol nanoparticles (TA-Ce) in treating psoriasis were determined as follows:

[0102] I. Determination of Nanoparticle Characterization Results (Supporting the Basis for Drug Efficacy);

[0103] Particle size distribution determination:

[0104] Tests were performed on Example 1, such as... Figure 4 Example 1 Particle size distribution map. As can be seen from the particle size distribution map, the particle size of TA-Ce nanoparticles is concentrated in the range of 180-220nm, indicating that the nanoparticle preparation process is stable, which provides a basis for its dispersibility and efficacy in vivo.

[0105] Infrared spectroscopy determination:

[0106] contrast Figure 1 Infrared spectrum of tannic acid Figure 2 Infrared spectrum of cerium nitrate and Figure 3 The infrared spectrum of tannic acid-cerium nitrate showed a new absorption peak at the characteristic wavenumber, and the original characteristic peak shifted, proving that tannic acid and cerium nitrate successfully combined to form a complex. At the same time, the corresponding characteristic peak changes also appeared after PEG8000 grafting, verifying the successful preparation of nanoparticles.

[0107] Morphology and element determination:

[0108] As can be seen from the scanning electron microscope (SEM) and transmission electron microscope (TEM) images, Figure 11 SEM image of TA-Ce nanoparticles (10.00KX) Figure 10 TEM image of TA-Ce nanoparticles (20.00KX) Figure 9 In the TEM image (50.00 KX) of TA-Ce nanoparticles, the nanoparticles are triangular in shape, regularly shaped, and uniformly dispersed, with no obvious aggregation; in the elemental mapping image, Figure 5 TA-Ce nanoparticle C element mapping diagram Figure 6 TA-Ce nanoparticle O element mapping diagram Figure 7 Ce element mapping diagram of TA-Ce nanoparticles Figure 8The multi-element combined mapping diagram of TA-Ce nanoparticles clearly detected the uniform distribution of elements such as C, O, and Ce, further confirming the structural integrity and compositional uniformity of the nanoparticles.

[0109] II. Evaluation of the treatment effect of psoriasis (based on skin tissue section images);

[0110] Determining the relationship between back skin and ear tissue:

[0111] Normal group: Figure 12 H&E stained section of mouse back skin (7 days) Figure 13 In the H&E stained sections of mouse ears, the normal group sections showed uniform epidermal thickness, no inflammatory cell infiltration, and intact skin structure.

[0112] Model group: In the above slices, the epidermis of the model group was significantly thickened, the stratum corneum was disordered, and a large number of inflammatory cells were observed to be aggregated in the dermis, which is consistent with the pathological characteristics of psoriasis.

[0113] TA-Ce group: Figure 14 Comparison of mouse skin tissue pathological sections Figure 16 In the comparative slicing images of mouse skin treated with TA-Ce (7 days), the epidermal thickness of the TA-Ce group was significantly thinner, approaching the level of the normal group. The stratum corneum arrangement became more regular, and the number of inflammatory cell infiltrations was greatly reduced. The improvement effect was similar to that of the positive control group (calcipotriol group).

[0114] Conclusion: TA-Ce nanoparticles can effectively improve skin lesions in a mouse model of psoriasis, demonstrating significant therapeutic effects.

[0115] III. Determination of biosafety (toxicity) (based on organ tissue sections and attached figures);

[0116] Spleen and liver tissue assessment:

[0117] Normal group: Figure 15 In the comparison images of H&E stained sections of mouse liver and spleen, the normal group showed clear lymphoid follicle structure in the spleen and neatly arranged hepatocytes in the liver, with no abnormal pathological changes.

[0118] Model group: In the above slices, the spleen lymphoid follicles of the model group showed mild disorder, and the liver hepatocytes showed a small amount of inflammatory infiltration.

[0119] TA-Ce group: The morphology of spleen and liver tissue in the above sections of the TA-Ce group was basically the same as that of the normal group, with no obvious pathological damage. The inflammatory response was significantly reduced compared with the model group, and there was no significant difference from the calcipotriol group.

[0120] Assessment of heart, lung, and kidney tissues (normal group vs. TA-Ce group);

[0121] Figure 17Comparison of H&E stained sections of heart, liver, spleen, lung, and kidney from mice in the normal group and the TA-Ce group shows:

[0122] Heart: Both groups of myocardial cells were neatly arranged, without pathological changes such as necrosis or inflammatory infiltration.

[0123] Lungs: Both groups of alveoli have intact structures, with no abnormalities such as alveolar wall thickening or inflammatory cell aggregation.

[0124] Kidneys: Both groups of glomeruli had normal structure, renal tubules showed no dilation or degeneration, and interstitial inflammatory infiltration was absent.

[0125] Conclusion: TA-Ce nanoparticles showed no significant toxicity to the major organs of mice and possessed good biosafety. The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. The preferred embodiments do not describe all details exhaustively, nor do they limit the invention to the specific embodiments described. Clearly, many modifications and variations can be made based on the content of this specification.

Claims

1. Metal polyphenol cerium nanoparticles for use in the treatment of psoriasis, characterized in that, The nanoparticles are prepared from tannic acid, cerium nitrate and PEG8000, the molar ratio of tannic acid to cerium nitrate is 1:2-2.5, the pH value of the reaction system during preparation is 5.0-6.0, and the particle size of the nanoparticles is 180-220 nm.

2. The metal polyphenol cerium nanoparticle of claim 1, wherein, The tannic acid and cerium nitrate are reacted in an aqueous solution to form a complex, and the complex is grafted with PEG8000 on the surface, and the grafting rate of PEG8000 is 15%-25%; the grafting rate is determined by high performance liquid chromatography, and the test conditions are as follows: the chromatographic column is a C18 column, the mobile phase is methanol: water with a volume ratio of 60:40, the column temperature is 30°C, and the detection wavelength is 280 nm.

3. The metal polyphenol cerium nanoparticle of claim 1, wherein, The addition amount of PEG8000 is 1.0-1.5 times the mass of tannic acid.

4. The metal polyphenol cerium nanoparticle of claim 1, wherein, The nanoparticles are triangular, and when the dispersion concentration in an aqueous solution is 0.1-0.5 mg / mL, the amount of precipitation after being placed for 72 hours accounts for ≤5%; the amount of precipitation is determined by centrifugation under the condition of 8000 rpm for 10 minutes.

5. The metal polyphenol cerium nanoparticle of claim 1, wherein, The hemolysis rate of the nanoparticles is ≤2%; the hemolysis rate is determined by a rabbit red blood cell in vitro hemolysis test under the condition of a nanoparticle concentration of 0.5 mg / mL and incubation at 37°C for 1 hour.

6. A method of preparing the metal polyphenol cerium nanoparticle for treating psoriasis according to any one of claims 1-5, characterized by, The method comprises the following steps: (1) Dissolve tannic acid and cerium nitrate in deionized water according to the molar ratio, adjust the pH of the solution to 5.0-6.0, stir at a speed of 1000 rpm for 15 minutes, and continuously disperse by ultrasonic during the stirring; (2) Add a PEG8000 aqueous solution with a concentration of 8-10 mg / mL to the mixture of step (1), continue to stir for 75 minutes, and keep the reaction temperature at 25-30°C; (3) Filter using a 0.22 μm filter membrane, and collect the filtrate; (4) Centrifuge the filtrate at a speed of 12000 rpm for 30 minutes at 20-25°C, and collect the precipitate; (5) Wash the precipitate with deionized water for 3 times, and vacuum freeze dry for 12-16 hours to obtain the nanoparticles.

7. The production method according to claim 6, characterized by, In step (1), the concentration of the mixed solution of tannic acid and cerium nitrate is 0.5-0.8 mg / mL, and the pH value is adjusted by 0.1 mol / L hydrochloric acid solution or 0.1 mol / L sodium hydroxide solution.

8. The preparation method according to claim 6, characterized in that, In step (1), the ultrasonic dispersion is in a continuous ultrasonic mode, the power is 200 W, and the frequency is 40 kHz.

9. The preparation method according to claim 6, characterized in that, In step (5), the vacuum freeze drying is carried out at a temperature of -50~-40°C and a pressure of 10-20 Pa.

10. The method of claim 6, wherein, In step (5), the conductivity of the supernatant after washing the precipitate is ≤20 μS / cm.

Images