A lentinan / sulphamic acid modified ZIF-8 antibacterial multi-structure nanoparticle and a preparation method thereof

Abstract

The present application relates to the technical field of nanomaterials, and particularly relates to a kind of amino sulfonic acid modified supported lentinan / ZIF-8 antibacterial multi-structure nanoparticle and a preparation method thereof.The preparation method of the nanoparticle comprises: 2-methyl imid with zinc nitrate hexahydrate reaction, and ZIF-8 is prepared;ZIF-8 is reacted with amino sulfonic acid, and amino sulfonic acid modified ZIF-8 is prepared;Amino sulfonic acid modified ZIF-8 is reacted with lentinan, and amino sulfonic acid modified supported lentinan / ZIF-8 antibacterial multi-structure nanoparticle is prepared.Amino sulfonic acid modification makes the surface of ZIF-8 introduce a large number of negative electric gene sulfonic acid group, and the electrostatic repulsion between particles is significantly enhanced, effectively inhibits the agglomeration of ZIF-8 particles, so that the dispersibility of amino sulfonic acid modified ZIF-8 nanoparticle in water is good, and the multi-structure nanoparticle prepared by compounding with lentinan has high antibacterial property.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials technology, specifically to a sulfamic acid-modified nanoparticle supported on a lentinan / ZIF-8 antibacterial multi-component structure and its preparation method. Background Technology

[0002] Shiitake mushrooms (Lentinula edodes), an important edible fungus in my country, have a long history of cultivation and are now widely used in the food and pharmaceutical fields globally. Shiitake mushrooms are rich in bioactive polysaccharides, especially β-glucan. Since the discovery of the anti-cancer bioactivity of lentinan in the 1970s, research on the activity of lentinan (LNT) has never ceased. Studies have shown that lentinan possesses a variety of significant bioactivities, including antioxidant, antitumor, anti-aging, anti-inflammatory, immunomodulatory, antiviral, hepatoprotective, and cholesterol-lowering effects.

[0003] Lentinan is an important active substance in shiitake mushrooms, but its large molecular size and poor water solubility often reduce its absorption by the body, preventing it from effectively exerting its active value. Nanotechnology can significantly improve the solubility and dissolution rate of poorly soluble drugs, increase drug circulation stability, prolong elimination half-life, and enhance bioavailability, thus laying a solid foundation for fully realizing the drug's efficacy.

[0004] In recent years, metal-organic frameworks (MOFs), as coordination polymers composed of organic ligands and inorganic metal ions, have attracted much attention in the biomedical field. MOFs possess advantages such as small particle size, good biocompatibility, high drug loading capacity, large specific surface area, and numerous unsaturated metal coordination sites. Zeolite-like imidazolium ester (ZIF) frameworks are an excellent type of MOF, with ZIF-8 being a typical representative, composed of 2-methylimidazolium groups and transition metal particles Zn. 2+ A self-assembled topological structure nanomaterial. Since the imidazole group is an important component of histidine in physiological systems, Zn... 2+ ZIF-8 is an important transition metal in the body, exhibiting good biocompatibility and safety in use. Furthermore, ZIF-8 possesses excellent pH sensitivity; its skeletal structure can be disrupted in acidic environments, allowing for targeted release of the drug in the slightly acidic environment of an infection, achieving targeted therapy, reducing dosage, and enhancing efficacy. However, the dispersibility and drug loading of ZIF-8 prepared using traditional methods are not ideal and require further improvement. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures and their preparation method, thereby solving the problems of insufficient dispersibility and drug loading of ZIF-8 in existing technologies.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure includes the following steps:

[0008] Step (1): Dissolve 2-methylimidazole in methanol to obtain a 2-methylimidazole solution;

[0009] Zinc nitrate hexahydrate is dissolved in deionized water to obtain a zinc nitrate solution;

[0010] Zinc nitrate solution was added to 2-methylimidazole solution under stirring conditions. After the reaction was completed, the solution was centrifuged, washed, and dried to obtain powdered ZIF-8.

[0011] Step (2): Add ZIF-8 and aminosulfonic acid to DMF (N,N-dimethylformamide), stir evenly, react, filter, wash, dry, and obtain powdered aminosulfonic acid modified ZIF-8.

[0012] Step (3): Dissolve lentinan (LNT) in ethanol to obtain lentinan-ethanol solution;

[0013] The aminosulfonic acid-modified ZIF-8 was added to a lentinan-ethanol solution and reacted. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain powdered aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0014] Preferably, in step (1), the molar ratio of 2-methylimidazole in the 2-methylimidazole solution to zinc nitrate hexahydrate in the zinc nitrate solution is 8:1, and the reaction conditions are at room temperature and at a stirring speed of 800-1200 r / min for 15-25 min.

[0015] Preferably, in step (1), when preparing the 2-methylimidazole solution, the mass-to-volume ratio of 2-methylimidazole to methanol is (0.3-0.4) g / 10 mL, and when preparing the zinc nitrate solution, the mass-to-volume ratio of zinc nitrate hexahydrate to deionized water is (0.1-0.2) g / 5 mL.

[0016] Preferably, in step (2), the mass ratio of ZIF-8, aminosulfonic acid, and DMF is (3-3.3):(5.4-5.9):(140-160), and the reaction conditions are 1.5-2.5 h at a temperature of 75-85 °C.

[0017] Preferably, in step (3), the mass ratio of aminosulfonic acid modified ZIF-8 to lentinan in lentinan-ethanol solution is (1-4):(1-2), and the reaction conditions are stirring at 40-50℃ for 16-32 hours in the dark.

[0018] Preferably, in step (3), the mass concentration of lentinan in the lentinan-ethanol solution is 0.5-2.5 mg / mL.

[0019] The present invention also discloses a method for preparing nanoparticles with aminosulfonic acid modified and loaded with lentinan / ZIF-8 antibacterial multi-component structure, as described above.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] Based on the numerous advantages of ZIF-8 material, this invention first prepares ZIF-8, and then modifies the surface of ZIF-8 with aminosulfonic acid. The oxygen atoms with lone pair electrons on the sulfonic acid group can form coordinate bonds with zinc ions on the ZIF-8 surface, thereby fixing the sulfonic acid group on the ZIF-8 surface and preparing aminosulfonic acid modified ZIF-8 with good dispersibility. This ZIF-8 is then used as a drug delivery carrier for lentinan, constructing aminosulfonic acid modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0022] Sulfamic acid modification introduces a large number of sulfonic acid groups onto the surface of ZIF-8, significantly increasing the negative charge density and enhancing the electrostatic repulsion between particles, effectively inhibiting the aggregation of ZIF-8 particles. Sulfamic acid modification also endows the ZIF-8 surface with more polar groups (such as sulfonic acid groups), enhancing its affinity for polar lentinan molecules and promoting their interaction. Furthermore, sulfamidic acid modification may optimize the pore structure or surface charge distribution of ZIF-8, providing more suitable loading sites for lentinan and reducing lentinan loss during loading. Sulfamic acid-modified ZIF-8, as a carrier, exhibits high encapsulation efficiency for lentinan, and the nanoparticle system with the sulfamidic acid-modified lentinan / ZIF-8 antibacterial multi-component structure demonstrates high dispersion stability, resulting in excellent antibacterial properties.

[0023] The modification of ZIF-8 by aminosulfonic acid is a surface modification, which is different from the improvement of the synthesis method in the prior art. Moreover, the modification treatment is carried out in DMF organic solvent, which is different from the aqueous system reaction in the prior art. This can avoid the acidity of sulfonic acid group in water from damaging the ZIF-8 skeleton structure. In addition, the nitrogen atom in the amino group (-NH2) of aminosulfonic acid contains lone pair electrons, which can also act as an electron donor to form a coordinate bond with zinc ions on the ZIF-8 surface, which can further improve the antibacterial properties. Attached Figure Description

[0024] Figure 1 The graph shows the zeta potential measurement results of ZIF-8 prepared in Example 1 and aminosulfonic acid modified ZIF-8 prepared in Example 2 of the present invention.

[0025] Figure 2 The image shows the encapsulation efficiency of the aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure prepared in Examples 3-15 of the present invention and the nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure prepared in Comparative Example 1.

[0026] Figure 3 This is a scanning electron microscope image of the aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure prepared in Example 10 of the present invention.

[0027] Figure 4 The images show the aminosulfonic acid-modified lentinan / ZIF-8 antibacterial multi-component nanoparticles prepared in Example 10 of the present invention, the lentinan / ZIF-8 antibacterial multi-component nanoparticles prepared in Comparative Example 1, and the blank group after treatment with methicillin-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus.

[0028] Figure 5 The graph shows the bacterial survival rate determination results of the aminosulfonic acid modified lentinan / ZIF-8 antibacterial multi-component nanoparticles prepared in Example 10 of the present invention, the lentinan / ZIF-8 antibacterial multi-component nanoparticles prepared in Comparative Example 1, and the blank group after treatment with methicillin-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] This embodiment discloses a method for preparing ZIF-8, including the following steps:

[0032] 2-Methylimidazole was dissolved in methanol at a mass-to-volume ratio of 0.33 g / 10 mL to obtain a 2-methylimidazole solution.

[0033] Zinc nitrate hexahydrate was dissolved in deionized water at a mass-to-volume ratio of 0.15 g / 5 mL to obtain a zinc nitrate solution.

[0034] Zinc nitrate solution was added to 2-methylimidazole solution under stirring at 1000 r / min. The molar ratio of 2-methylimidazole in the 2-methylimidazole solution to zinc nitrate hexahydrate in the zinc nitrate solution was 8:1. The reaction was carried out at room temperature and stirring at 1000 r / min for 20 min. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the precipitate was collected, washed 5 times with ethanol, and then dried in a vacuum drying oven at 40℃ until constant temperature to obtain powdered ZIF-8.

[0035] Example 2

[0036] This embodiment discloses a method for preparing aminosulfonic acid modified ZIF-8, including the following steps:

[0037] Step (1): Dissolve 2-methylimidazole in methanol, with a mass-to-volume ratio of 2-methylimidazole to methanol of 0.33 g / 10 mL, to obtain a 2-methylimidazole solution;

[0038] Zinc nitrate hexahydrate was dissolved in deionized water at a mass-to-volume ratio of 0.15 g / 5 mL to obtain a zinc nitrate solution.

[0039] Zinc nitrate solution was added to 2-methylimidazole solution under stirring at 1000 r / min. The molar ratio of 2-methylimidazole in the 2-methylimidazole solution to zinc nitrate hexahydrate in the zinc nitrate solution was 8:1. The reaction was carried out at room temperature and stirring at 1000 r / min for 20 min. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the precipitate was collected, washed 5 times with ethanol, and then dried in a vacuum drying oven at 40℃ until constant temperature to obtain powdered ZIF-8.

[0040] Step (2): Add ZIF-8 and aminosulfonic acid to DMF. The mass ratio of ZIF-8, aminosulfonic acid and DMF is 3:5.4:145. Stir at 200 r / min until homogeneous, and react at 80℃ for 2 h. After the reaction is complete, filter under vacuum, wash with ethanol 5 times, and dry in a vacuum drying oven at 40℃ until constant temperature to obtain powdered aminosulfonic acid modified ZIF-8.

[0041] The aminosulfonic acid-modified ZIF-8 is designated as S-ZIF-8.

[0042] Example 3

[0043] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0044] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 2 mg / mL.

[0045] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution. The mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution was 4:1. The reaction was carried out at 45°C under dark conditions and stirred at 300 r / min for 24 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, and the precipitate was washed twice with ethanol. The precipitate was then dried in a vacuum drying oven at 40°C until it reached a constant temperature to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0046] Example 4

[0047] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0048] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 2 mg / mL.

[0049] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution with a mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution of 3:1. The reaction was carried out at 45°C under light-protected conditions with stirring at 300 r / min for 24 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, the precipitate was washed twice with ethanol, and then dried in a vacuum drying oven at 40°C until constant temperature to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0050] Example 5

[0051] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0052] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 2 mg / mL.

[0053] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution, with a mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution of 2:1. The reaction was carried out at 45°C under light-protected conditions and stirred at 300 r / min for 24 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, and the precipitate was washed twice with ethanol and then dried in a vacuum drying oven at 40°C until constant temperature was reached to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0054] Example 6

[0055] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0056] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 2 mg / mL.

[0057] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution, with the mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution being 1:1. The reaction was carried out at 45°C under light-protected conditions and stirred at 300 r / min for 24 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, and the precipitate was washed twice with ethanol and then dried in a vacuum drying oven at 40°C until constant temperature was reached to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0058] Example 7

[0059] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0060] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 2 mg / mL.

[0061] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution. The mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution was 1:2. The reaction was carried out at 45°C under light-protected conditions and stirred at 300 r / min for 24 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min. The supernatant was discarded, and the precipitate was washed twice with ethanol. The precipitate was then dried in a vacuum drying oven at 40°C until a constant temperature was reached to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0062] Example 8

[0063] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0064] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 0.5 mg / mL.

[0065] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution, with a mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution of 2:1. The reaction was carried out at 45°C under light-protected conditions and stirred at 300 r / min for 24 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, and the precipitate was washed twice with ethanol and then dried in a vacuum drying oven at 40°C until constant temperature was reached to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0066] Example 9

[0067] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0068] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 1 mg / mL.

[0069] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution, with a mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution of 2:1. The reaction was carried out at 45°C under light-protected conditions and stirred at 300 r / min for 24 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, and the precipitate was washed twice with ethanol and then dried in a vacuum drying oven at 40°C until constant temperature was reached to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0070] Example 10

[0071] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0072] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 1.5 mg / mL.

[0073] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution, with a mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution of 2:1. The reaction was carried out at 45°C under light-protected conditions and stirred at 300 r / min for 24 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, and the precipitate was washed twice with ethanol and then dried in a vacuum drying oven at 40°C until constant temperature was reached to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0074] Example 11

[0075] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0076] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 2.5 mg / mL.

[0077] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution, with a mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution of 2:1. The reaction was carried out at 45°C under light-protected conditions and stirred at 300 r / min for 24 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, and the precipitate was washed twice with ethanol and then dried in a vacuum drying oven at 40°C until constant temperature was reached to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0078] Example 12

[0079] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0080] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 1.5 mg / mL.

[0081] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution, with a mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution of 2:1. The reaction was carried out at 45°C under light-protected conditions and stirred at 300 r / min for 16 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, and the precipitate was washed twice with ethanol and then dried in a vacuum drying oven at 40°C until constant temperature to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0082] Example 13

[0083] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0084] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 1.5 mg / mL.

[0085] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution with a mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution of 2:1. The reaction was carried out at 45°C under light-protected conditions with stirring at 300 r / min for 20 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, the precipitate was washed twice with ethanol, and then dried in a vacuum drying oven at 40°C until constant temperature to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0086] Example 14

[0087] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0088] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 1.5 mg / mL.

[0089] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution with a mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution of 2:1. The reaction was carried out at 45°C under light-protected conditions with stirring at 300 r / min for 28 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, the precipitate was washed twice with ethanol, and then dried in a vacuum drying oven at 40°C until constant temperature to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0090] Example 15

[0091] This embodiment discloses a method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, including the following steps:

[0092] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 1.5 mg / mL.

[0093] The aminosulfonic acid-modified ZIF-8 obtained in Example 2 was added to a lentinan-ethanol solution with a mass ratio of aminosulfonic acid-modified ZIF-8 to lentinan in the lentinan-ethanol solution of 2:1. The reaction was carried out at 45°C under light-protected conditions with stirring at 300 r / min for 32 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, the precipitate was washed twice with ethanol, and then dried in a vacuum drying oven at 40°C until constant temperature to obtain aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0094] Comparative Example 1

[0095] This comparative example discloses a method for preparing nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, comprising the following steps:

[0096] Lentinan was dissolved in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 1.5 mg / mL.

[0097] The ZIF-8 prepared in Example 1 was added to a lentinan-ethanol solution with a mass ratio of ZIF-8 to lentinan in the lentinan-ethanol solution of 2:1. The reaction was carried out at 45°C under dark conditions with a stirring speed of 300 r / min for 24 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was discarded, the precipitate was washed twice with ethanol, and then dried in a vacuum drying oven at 40°C until constant temperature to obtain nanoparticles with an antibacterial multi-component structure of lentinan / ZIF-8.

[0098] Comparative Example 2

[0099] This comparative example discloses a method for preparing sulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, comprising the following steps:

[0100] Step (1): Dissolve 2-methylimidazole in methanol, with a mass-to-volume ratio of 2-methylimidazole to methanol of 0.33 g / 10 mL, to obtain a 2-methylimidazole solution;

[0101] Zinc nitrate hexahydrate was dissolved in deionized water at a mass-to-volume ratio of 0.15 g / 5 mL to obtain a zinc nitrate solution.

[0102] Zinc nitrate solution was added to 2-methylimidazole solution under stirring at 1000 r / min. The molar ratio of 2-methylimidazole in the 2-methylimidazole solution to zinc nitrate hexahydrate in the zinc nitrate solution was 8:1. The reaction was carried out at room temperature and stirring at 1000 r / min for 20 min. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min, the precipitate was collected, washed 5 times with ethanol, and then dried in a vacuum drying oven at 40℃ until constant temperature to obtain powdered ZIF-8.

[0103] Step (2): Add ZIF-8 and p-toluenesulfonic acid to DMF. The mass ratio of ZIF-8, p-toluenesulfonic acid and DMF is 3:9.6:145. Stir at 200 r / min until homogeneous, and react at 80℃ for 2 h. After the reaction is complete, filter under vacuum, wash with ethanol 5 times, and dry in a vacuum drying oven at 40℃ until constant temperature to obtain powdered sulfonic acid modified ZIF-8.

[0104] Step (3): Dissolve lentinan in ethanol to obtain a lentinan-ethanol solution with a mass concentration of 1.5 mg / mL.

[0105] The sulfonic acid-modified ZIF-8 obtained in step (2) was added to the lentinan-ethanol solution. The mass ratio of the sulfonic acid-modified ZIF-8 to the lentinan in the lentinan-ethanol solution was 2:1. The reaction was carried out at 45°C under dark conditions and stirred at 300 r / min for 24 h. After the reaction was completed, the mixture was centrifuged at 10000 r / min for 15 min. The supernatant was discarded, and the precipitate was washed twice with ethanol. The precipitate was then dried in a vacuum drying oven at 40°C until the temperature was constant to obtain sulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure.

[0106] Characterization tests:

[0107] (1) Zeta potential measurement: The Zeta potentials of ZIF-8 prepared in Example 1 and S-ZIF-8 prepared in Example 2 were measured. The results of the Zeta potential measurement are as follows: Figure 1 As shown. By Figure 1It can be seen that the Zeta potential of ZIF-8 prepared in Example 1 is approximately 9 mV, while the Zeta potential of S-ZIF-8 prepared in Example 2 is significantly reduced to -25 mV. This is because aminosulfonic acid modification introduces a large number of sulfonic acid groups onto the surface of ZIF-8, significantly increasing its surface negative charge density and enhancing the electrostatic repulsion between particles, effectively inhibiting particle aggregation. This change indicates that by regulating the Zeta potential through aminosulfonic acid modification, the dispersion stability of the aminosulfonic acid-modified nanoparticle system loaded with lentinan / ZIF-8 antibacterial multi-component structure can be significantly improved, providing a good performance foundation for subsequent experiments.

[0108] (2) Encapsulation efficiency determination: The encapsulation efficiency of the aminosulfonic acid-modified lentinan / ZIF-8 antibacterial multi-component nanoparticles prepared in Examples 3-15 and the lentinan / ZIF-8 antibacterial multi-component nanoparticles prepared in Comparative Example 1 was determined. Encapsulation efficiency refers to the percentage of the target substance successfully encapsulated by the carrier to the total amount added, reflecting the encapsulation ability of the carrier. The encapsulation efficiency was calculated based on the amount of lentinan (M1) and the amount of lentinan added (M0) in the aminosulfonic acid-modified lentinan / ZIF-8 antibacterial multi-component nanoparticles. The formula for calculating the encapsulation efficiency is: Encapsulation efficiency = M1 / M0. The results of the encapsulation efficiency determination are as follows: Figure 2 As shown. By Figure 2 It was found that the encapsulation efficiency of the nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure modified with aminosulfonic acid was all above 60%. Compared with Example 10, in Comparative Example 1, replacing the aminosulfonic acid-modified ZIF-8 with ZIF-8 resulted in a decrease in the encapsulation efficiency of lentinan from 83.1% to 77.5%. This is because aminosulfonic acid modification endows ZIF-8 with more polar groups (such as sulfonic acid groups), which on the one hand enhances the affinity for polar lentinan molecules and promotes the interaction between them; on the other hand, aminosulfonic acid modification may optimize the pore structure or surface charge distribution of ZIF-8, providing more suitable loading sites for lentinan and reducing the loss of lentinan during loading. This indicates that aminosulfonic acid modification can effectively enhance the encapsulation ability of ZIF-8 for lentinan.

[0109] (3) Morphological observation: The morphology of the aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure prepared in Example 10 was observed by scanning electron microscopy. The results are as follows: Figure 4 As shown. By Figure 4 It can be seen that the nanoparticles modified with aminosulfonic acid and loaded with lentinan / ZIF-8 antibacterial multi-component structure have a diameter of about 200 nm and a uniform morphology.

[0110] (4) In vitro antibacterial performance test:

[0111] 4.1 The minimum inhibitory concentrations (MICs) of ZIF-8, lentinan, aminosulfonic acid modified lentinan / ZIF-8 antibacterial multi-component nanoparticles prepared in Example 1, lentinan / ZIF-8 antibacterial multi-component nanoparticles prepared in Example 10, lentinan / ZIF-8 antibacterial multi-component nanoparticles prepared in Comparative Example 1, sulfonic acid modified lentinan / ZIF-8 antibacterial multi-component nanoparticles prepared in Comparative Example 2, kanamycin, and ampicillin against methicillin-resistant Escherichia coli (MDR Escherichia coli) and methicillin-resistant Staphylococcus aureus (MDR Staphylococcus aureus) were determined respectively. Among them, the aminosulfonic acid-modified nanoparticle sample loaded with lentinan / ZIF-8 antibacterial multi-component structure prepared in Example 10 is designated LNT@NS-ZIF-8, the sulfonic acid-modified nanoparticle sample loaded with lentinan / ZIF-8 antibacterial multi-component structure prepared in Comparative Example 2 is designated LNT@S-ZIF-8, and the nanoparticle sample loaded with lentinan / ZIF-8 antibacterial multi-component structure prepared in Comparative Example 1 is designated LNT@ZIF-8. The measurement results are shown in Table 1.

[0112] Table 1

[0113]

[0114] As shown in Table 1, the aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure prepared in this invention exhibit good antibacterial properties. The MIC values ​​of the aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure against two drug-resistant bacteria, MDR *Escherichia coli* and MDR *Staphylococcus aureus*, were approximately 8 μg / mL and 12 μg / mL, respectively. The MIC values ​​of the sulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structure against MDR *Escherichia coli* and MDR *Staphylococcus aureus* were approximately 10 μg / mL and 18 μg / mL, respectively. The MIC values ​​for *Escherichia coli* and *Staphylococcus aureus* (MDR) were approximately 22 μg / mL and 34 μg / mL, respectively. ZIF-8 showed relatively low inhibitory effects against both MDR *E. coli* and MDR *S. aureus*. The MIC values ​​for lentinan against MDR *E. coli* and MDR *S. aureus* were approximately 30 μg / mL and 45 μg / mL, respectively. When lentinan was loaded onto ZIF-8 modified with sulfamic acid, the antibacterial efficacy of the resulting sulfamic acid-modified lentinan / ZIF-8 antibacterial multi-component structure nanoparticles was significantly enhanced. Compared to the sulfamic acid-modified lentinan / ZIF-8 antibacterial multi-component structure nanoparticles, the sulfamic acid-modified lentinan / ZIF-8 antibacterial multi-component structure nanoparticles lacked the amino group introduced by sulfamic acid (the nitrogen atom in the amino group of sulfamic acid contains a lone pair electron, which can also act as an electron donor to form a coordination bond with zinc ions on the ZIF-8 surface, further improving antibacterial activity), resulting in a decrease in antibacterial performance.

[0115] 4.2. The viable cell counts (CFU) of methicillin-resistant Escherichia coli (MDR Escherichia coli) and methicillin-resistant Staphylococcus aureus (MDR Staphylococcus aureus) after treatment with the aminosulfonic acid-modified lentinan / ZIF-8 antibacterial multi-component nanoparticle sample (denoted as LNT@NS-ZIF-8) prepared in Example 10 and the lentinan / ZIF-8 antibacterial multi-component nanoparticle sample (denoted as LNT@ZIF-8) prepared in Comparative Example 1, respectively, were determined. The bacterial survival rates of MDR Escherichia coli and MDR Staphylococcus aureus were calculated based on the viable cell counts before and after treatment. The results are as follows: Figure 4 and Figure 5 As shown. By Figure 4 and Figure 5The results showed that the survival rates of MDR *Escherichia coli* and MDR *Staphylococcus aureus* in the control group were extremely high, reaching 99.2% and 99.7%, respectively. LNT@ZIF-8 exhibited good antibacterial activity, with survival rates of 14.86% and 15.71% for MDR *Escherichia coli* and MDR *Staphylococcus aureus*, respectively. The antibacterial rate of LNT@NS-ZIF-8 was significantly increased, with a survival rate of only about 1.01% for methicillin-resistant *Escherichia coli* and about 1.30% for methicillin-resistant *Staphylococcus aureus*. This indicates that the antibacterial ability of the aminosulfonic acid-modified nanoparticles loaded with the lentinan / ZIF-8 antibacterial multi-component structure was enhanced after modification with aminosulfonic acid.

[0116] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing aminosulfonic acid-modified nanoparticles loaded with lentinan / ZIF-8 antibacterial multi-component structures, characterized in that, Includes the following steps: Step (1): Dissolve 2-methylimidazole in methanol to obtain a 2-methylimidazole solution; Zinc nitrate hexahydrate is dissolved in deionized water to obtain a zinc nitrate solution; Zinc nitrate solution was added to 2-methylimidazole solution under stirring conditions. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain ZIF-8. Step (2): Add ZIF-8 and aminosulfonic acid to DMF, stir, react, filter, wash, and dry to obtain aminosulfonic acid modified ZIF-8. Step (3): Dissolve lentinan in ethanol to obtain lentinan-ethanol solution; ZIF-8 modified with aminosulfonic acid was added to a lentinan-ethanol solution and reacted. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain nanoparticles with an aminosulfonic acid-modified lentinan / ZIF-8 antibacterial multi-component structure.

2. The method for preparing aminosulfonic acid-modified nanoparticles supported on a lentinan / ZIF-8 antibacterial multi-component structure according to claim 1, characterized in that, In step (1), the molar ratio of 2-methylimidazole in the 2-methylimidazole solution to zinc nitrate hexahydrate in the zinc nitrate solution is 8:

1.

3. The method for preparing aminosulfonic acid-modified nanoparticles supported on a lentinan / ZIF-8 antibacterial multi-component structure according to claim 1, characterized in that, In step (1), the reaction conditions are: at room temperature and at a stirring speed of 800-1200 r / min for 15-25 min.

4. The method for preparing aminosulfonic acid-modified nanoparticles supported on a lentinan / ZIF-8 antibacterial multi-component structure according to claim 1, characterized in that, In step (1), when preparing the 2-methylimidazole solution, the mass-to-volume ratio of 2-methylimidazole to methanol is (0.3-0.4) g / 10 mL.

5. The method for preparing aminosulfonic acid-modified nanoparticles supported on a lentinan / ZIF-8 antibacterial multi-component structure according to claim 1, characterized in that, In step (1), when preparing the zinc nitrate solution, the mass-to-volume ratio of zinc nitrate hexahydrate to deionized water is (0.1-0.2) g / 5 mL.

6. The method for preparing aminosulfonic acid-modified nanoparticles supported on a lentinan / ZIF-8 antibacterial multi-component structure according to claim 1, characterized in that, In step (2), the mass ratio of ZIF-8, aminosulfonic acid, and DMF is (3-3.3):(5.4-5.9):(140-160).

7. The method for preparing aminosulfonic acid-modified nanoparticles supported on a lentinan / ZIF-8 antibacterial multi-component structure according to claim 1, characterized in that, In step (2), the reaction conditions are 1.5-2.5 h at a temperature of 75-85 °C.

8. The method for preparing aminosulfonic acid-modified nanoparticles supported on a lentinan / ZIF-8 antibacterial multi-component structure according to claim 1, characterized in that, In step (3), the mass ratio of aminosulfonic acid modified ZIF-8 to lentinan in lentinan-ethanol solution is (1-4):(1-2), and the reaction conditions are stirring at 40-50℃ for 16-32 hours in the dark.

9. The method for preparing aminosulfonic acid-modified nanoparticles supported on a lentinan / ZIF-8 antibacterial multi-component structure according to claim 1, characterized in that, In step (3), the mass concentration of lentinan in the lentinan-ethanol solution is 0.5-2.5 mg / mL.

10. A nanoparticle with an aminosulfonic acid-modified lentinan / ZIF-8 antibacterial multi-component structure prepared by the method described in any one of claims 1-9.

Images