A pyridyl cationic saccharide-containing polymer, its preparation method and application

Abstract

The present application provides a pyridyl cationic sugar-containing polymer, a preparation method thereof and an application thereof, belonging to the field of antibacterial technology. Insoluble polycaprolactone-b-poly(4-vinylpyridine) gradually undergoes an N-quaternization reaction with an unprotected halogen-functionalized monosaccharide in a solvent to form a sugar-containing copolymer micelle in a suspended form. The prepared pyridyl cationic sugar-containing polymer has high antibacterial activity, low hemolytic ability and good biocompatibility, and can be applied to the preparation of antibacterial drugs and the preparation of antibacterial medical devices. Moreover, the preparation method of the pyridyl cationic sugar-containing polymer of the present application is simple, and the prepared pyridyl cationic sugar-containing polymer has a stable structure.

Description

Technical Field

[0001] This application relates to the field of antibacterial technology. Specifically, it relates to a pyridyl cationic sugar-containing polymer, its preparation method and application. Background Art

[0002] In recent years, modifying sugar-containing compounds on the surface of nano-objects, such as polysaccharide compounds that form a furry filamentous shell composed of sulfated mucopolysaccharides at the top of epithelial cells, has the significance of bionics in synthesizing these functional structures. The "glycoside cluster effect" refers to the interaction between multivalent lectin-carbohydrates, which has been proven to significantly improve the binding affinity of synthetic sugar structures with the corresponding lectins. Due to the recognition target of the influence between lectins or carbohydrate-binding proteins, the glycoside cluster effect is often used to design novel sugar-containing micelles with improved binding affinity. However, due to the high activity of hydroxyl groups, the solvent selection of sugar-containing monomers, and the cumbersome synthesis process of monosaccharides, it further limits the research progress of sugar-containing nano-assemblies. Summary of the Invention

[0003] This application provides a pyridyl cationic sugar-containing polymer, its preparation method and application, which have high antibacterial activity, low hemolytic ability and good biocompatibility.

[0004] The embodiments of this application are implemented as follows:

[0005] In the first aspect, the examples of this application provide a pyridyl cationic sugar-containing polymer, and its structural formula is as follows:

[0006]

[0007] M is selected from Cl, Br or I.

[0008] x is an integer from 10 to 60, and y is an integer from 5 to 60.

[0009] In the above technical solution, the pyridyl cationic sugar-containing polymer of this application has high antibacterial activity, low hemolytic ability and good biocompatibility, and can be applied to the preparation of antibacterial drugs and antibacterial medical devices.

[0010] Combined with the first aspect, in the first possible example of the first aspect of this application, x is an integer from 20 to 40, and y is an integer from 8 to 20.

[0011] In the above example, when x is an integer from 20 to 40 and y is an integer from 8 to 20, the pyridyl cationic sugar-containing polymer has good hydrophilicity and a narrow molecular weight distribution.

[0012] In a second aspect, the examples of the present application provide a method for preparing the above-mentioned pyridyl cationic sugar-containing polymer, which includes: polycaprolactone-b-poly(4-vinylpyridine) and a halogen-functionalized monosaccharide undergo a self-assembly reaction in a solvent to form a sugar-containing copolymer micelle.

[0013] The structural formula of polycaprolactone-b-poly(4-vinylpyridine) is as follows:

[0014]

[0015] The structural formula of the halogen-functionalized monosaccharide is as follows:

[0016]

[0017] M is selected from Cl, Br or I;

[0018] x is an integer from 10 to 60, and y is an integer from 5 to 60.

[0019] In the above technical solution, the insoluble polycaprolactone-b-poly(4-vinylpyridine) gradually undergoes an N-quaternization reaction with the unprotected halogen-functionalized monosaccharide in the solvent to form a sugar-containing copolymer micelle in a suspended form. The method for preparing the pyridyl cationic sugar-containing polymer of the present application is simple, and the prepared pyridyl cationic sugar-containing polymer has a stable structure.

[0020] Combined with the second aspect, in the first possible example of the second aspect of the present application, the temperature of the above self-assembly reaction is 60°C to 100°C, and the time is 72 h to 168 h.

[0021] Combined with the second aspect, in the second possible example of the second aspect of the present application, the above solvent is water.

[0022] In the above example, the self-assembly reaction can be carried out in an aqueous solvent, and the aqueous solvent, as an environmentally friendly solvent, is almost pollution-free to the environment.

[0023] Combined with the second aspect, in the third possible example of the second aspect of the present application, after the self-assembly reaction is completed, the obtained product is dialyzed with pure water to obtain a sugar-containing copolymer micelle.

[0024] In the above example, dialysis with pure water can remove the excessive halogen-functionalized monosaccharide in the reaction system.

[0025] Combined with the second aspect, in the fourth possible example of the second aspect of the present application, the above polycaprolactone-b-poly(4-vinylpyridine) is prepared by the following method:

[0026] Using polycaprolactone-Cl to initiate the polymerization of vinylpyridine to obtain a block copolymer polycaprolactone-b-poly(4-vinylpyridine).

[0027] In combination with the second aspect, in the fifth possible example of the second aspect of the present application, the above-mentioned polycaprolactone-Cl is prepared by the following method:

[0028] Using 2-hydroxyethyl-2-chloropropionic acid as a bifunctional initiator, the hydrophobic polycaprolactone-Cl is obtained by initiating the polymerization of caprolactone monomers through living ring-opening polymerization.

[0029] In the third aspect, the examples of the present application provide an application of the above-mentioned pyridinium cationic saccharide polymer in the preparation of antibacterial drugs.

[0030] In the fourth aspect, the examples of the present application provide an application of the above-mentioned pyridinium cationic saccharide polymer in the preparation of antibacterial medical devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0032] Figure 1 It is the roadmap for synthesizing the pyridinium cationic saccharide polymer of the present application;

[0033] Figure 2 It is the GPC chromatogram of PCL-CL and PCL 35 -b-P4VP n ;

[0034] Figure 3 It is the FTIR spectrum of PCL 35 , PCL 35 -b-P4VP 13 and PCL 35 -b-P4VP 13 -G;

[0035] Figure 4 It is the 35 H NMR spectrum of PCL 35 and PCL 13 -b-P4VP 1 ;

[0036] Figure 5 It is the 35 H NMR spectrum of PCL 13 -b-P4VP 1 -G;

[0037] Figure 6 It is the obtained PCL35 TEM image of -b-P4VP8-G;

[0038] Figure 7 PCL obtained; 35 -b-P4VP 11 TEM image of -G;

[0039] Figure 8 PCL obtained; 35 -b-P4VP 13 TEM image of -G;

[0040] Figure 9 PCL after 24 h of reaction; 35 TEM image of -b-P4VP8-G;

[0041] Figure 10 PCL after 48 h of reaction; 35 TEM image of -b-P4VP8-G;

[0042] Figure 11 PCL after 72 h of reaction; 35 TEM image of -b-P4VP8-G;

[0043] Figure 12 PCL after 96 h of reaction; 35 TEM image of -b-P4VP8-G;

[0044] Figure 13 PCL; 35 DLS analysis chart of -b-P4VP8-G after binding with ConA for 12 hours;

[0045] Figure 14 PCL; 35 -b-P4VP 11 DLS analysis chart of -G after binding with ConA for 12 hours;

[0046] Figure 15 PCL; 35 -b-P4VP 13 DLS analysis chart of -G after binding with ConA for 12 hours;

[0047] Figure 16 PCL; 35 Antibacterial kinetics chart of -b-P4VP8-G against Escherichia coli MIC;

[0048] Figure 17 PCL; 35 -b-P4VP 11 Antibacterial kinetics chart of -G against Escherichia coli MIC;

[0049] Figure 18 For PCL 35 -b-P4VP 13 -G antibacterial kinetics graph of MIC against Escherichia coli;

[0050] Figure 19 For PCL 35 -b-P4VP8-G antibacterial kinetics graph of MIC against Staphylococcus aureus;

[0051] Figure 20 For PCL 35 -b-P4VP 11 -G antibacterial kinetics graph of MIC against Staphylococcus aureus;

[0052] Figure 21 For PCL 35 -b-P4VP 13 -G antibacterial kinetics graph of MIC against Staphylococcus aureus;

[0053] Figure 22 For PCL 35 -b-P4VP8-G hemolysis experiment histogram of defibrinated sheep blood cells;

[0054] Figure 23 For PCL 35 -b-P4VP 11 -G hemolysis experiment histogram of defibrinated sheep blood cells;

[0055] Figure 24 For PCL 35 -b-P4VP 13 -G hemolysis experiment histogram of defibrinated sheep blood cells. Detailed implementation manners

[0056] In recent years, modifying the surface of nano-objects with sugar-containing compounds, such as polysaccharide compounds of the furry filamentous shell composed of sulfated mucopolysaccharides at the top of epithelial cells, the synthesis of these functional structures has bionic significance. The "glycoside cluster effect" refers to the interaction between multivalent lectin-carbohydrate, which has been proven to significantly improve the binding affinity of the synthesized sugar structure and the corresponding lectin. Due to the recognition target of the influence between lectin or carbohydrate-binding proteins, the glycoside cluster effect is often used to design novel sugar-containing micelles with improved binding affinity. However, due to the high activity of hydroxyl groups, the solvent selection of sugar-containing monomers, and the cumbersome synthesis process of monosaccharides, the research progress of sugar-containing nano-assemblies has been further restricted.

[0057] The inventors have found that in the synthesis of sugar-modified amphiphilic block copolymers, the polymerization-induced self-assembly technique (PISA) is an excellent method for preparing polymer micelles. The amphiphilic sugar-modified block copolymers can be synthesized by the PISA method based on "protection-deprotection" chemistry to achieve the self-assembly of sugar-containing micelles.

[0058] However, although the PISA method using "protection-deprotection" to prepare sugar-containing micelles has great application potential and development significance, the reaction for preparing sugar-containing polymer micelles by directly reacting with unprotected sugars is more simplified. In addition, there are differences in the solvent selectivity between the (unprotected) sugar-containing chain segments and hydrophobic chain segments of block polymers, so it is difficult to prepare sugar-containing nano-micelles in aqueous solution by the PISA method.

[0059] Therefore, the present application provides a pyridyl cationic sugar-containing polymer, its preparation method and application. It forms a sugar-containing copolymer micelle in a suspended form by the N-quaternization reaction of insoluble polycaprolactone-b-poly(4-vinylpyridine) with unprotected halogen-functionalized monosaccharides in a solvent. The prepared pyridyl cationic sugar-containing polymer has a stable structure, high antibacterial activity, low hemolytic ability and good biocompatibility.

[0060] The following specifically describes a pyridyl cationic sugar-containing polymer, its preparation method and application according to the embodiments of the present application:

[0061] The present application provides a pyridyl cationic sugar-containing polymer, and its structural formula is as follows:

[0062]

[0063] M is selected from Cl, Br or I.

[0064] As an example, M can be Cl, Br or I.

[0065] Optionally, M is selected from Br.

[0066] x is an integer from 10 to 60, and y is an integer from 5 to 60.

[0067] As an example, x can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60.

[0068] y can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60.

[0069] Optionally, x is an integer from 20 to 40, and y is an integer from 8 to 20.

[0070] When x is an integer from 20 to 40 and y is an integer from 8 to 20, the pyridyl cationic sugar-containing polymer has good hydrophilicity and a narrow molecular weight distribution.

[0071] The pyridyl cationic sugar-containing polymer of the present application has high antibacterial activity, low hemolytic ability and good biocompatibility, and can be used in the preparation of antibacterial drugs and antibacterial medical devices.

[0072] The present application also provides a preparation method of the above pyridyl cationic sugar-containing polymer, which includes: polycaprolactone-b-poly(4-vinylpyridine) and a halogen-functionalized monosaccharide undergo a self-assembly reaction in a solvent to form a sugar-containing copolymer micelle.

[0073] The structural formula of polycaprolactone-b-poly(4-vinylpyridine) is as follows:

[0074]

[0075] The structural formula of the halogen-functionalized monosaccharide is as follows:

[0076]

[0077] M is selected from Cl, Br or I;

[0078] x is an integer from 10 to 60, and y is an integer from 5 to 60.

[0079] Specifically, the self-assembly reaction includes adding polycaprolactone-b-poly(4-vinylpyridine) (PCL x -b-P4VP y ), the unprotected halogen-functionalized monosaccharide (A2-GluX) and the solvent into a container equipped with a stirrer to obtain a mixture, bubbling and degassing the mixture with high-purity N2, and then stirring and reacting at 60 °C to 100 °C for 60 °C to 100 °C, and taking a small amount of sample every 24 h for DLS analysis of size change. After the self-assembly reaction is completed, the product is dialyzed with pure water to remove the excess unprotected halogen-functionalized monosaccharide (A2-GluX) to obtain the sugar-containing copolymer micelle.

[0080] As an example, the temperature of the self-assembly reaction can be 60 °C, 65 °C, 70 °C, 75 °C or 80 °C.

[0081] The time of the self-assembly reaction can be 72 h, 84 h, 96 h, 108 h, 120 h, 132 h, 144 h, 156 h or 168 h.

[0082] The molar ratio of the 4VP units in poly(ε-caprolactone)-b-poly(4-vinylpyridine) (PCL x -b-P4VP y ) and the unprotected halogen-functionalized monosaccharide (A2-GluX) is 1:1 to 1:5.

[0083] Optionally, the molar ratio of the 4VP units in poly(ε-caprolactone)-b-poly(4-vinylpyridine) (PCL x -b-P4VP y ) and the unprotected halogen-functionalized monosaccharide (A2-GluX) is 1:2 to 1:4.

[0084] Optionally, the molar ratio of the 4VP units in poly(ε-caprolactone)-b-poly(4-vinylpyridine) (PCL x -b-P4VP y ) and the unprotected halogen-functionalized monosaccharide (A2-GluX) is 1:3.

[0085] The molar volume ratio of the 4VP units in poly(ε-caprolactone)-b-poly(4-vinylpyridine) (PCL x -b-P4VP y ) and the solvent is 0.004 mol / 10 mL to 0.004 mol / 50 mL.

[0086] Optionally, the molar volume ratio of the 4VP units in poly(ε-caprolactone)-b-poly(4-vinylpyridine) (PCL x -b-P4VP y ) and the solvent is 0.004 mol / 20 mL to 0.004 mol / 40 mL.

[0087] Optionally, the molar volume ratio of the 4VP units in poly(ε-caprolactone)-b-poly(4-vinylpyridine) (PCL x -b-P4VP y ) and the solvent is 0.004 mol / 30 mL.

[0088] Optionally, the solvent is water.

[0089] The self-assembly reaction can be carried out in an aqueous solvent, and the aqueous solvent, as an environmentally friendly solvent, is almost pollution-free to the environment.

[0090] The time for bubbling degassing is 10 min to 20 min.

[0091] Polycaprolactone-b-poly(4-vinylpyridine) is prepared by the following method:

[0092] Add tetramethylpyridine (4VP), CuM2, polycaprolactone-Cl (PCL x -Cl) and dimethyl sulfoxide into a Schlenk tube to obtain a mixture. Bubble degas the mixture with high-purity N2. Add degassed tris[2-(dimethylamino)ethyl]amine (Me6TREN) to the degassed mixture through a syringe to obtain a reaction solution. Then, add hydrochloric acid-pretreated copper wire to the reaction solution under nitrogen protection, and bubble degas the reaction solution with high-purity N2 again. Polymerize at 10 °C to 40 °C for 9 h to 15 h. After the polymerization reaction is completed, precipitate the product three times in a large amount of cold diethyl ether, and dry it under reduced pressure to obtain a light green powder. The light green powder is polycaprolactone-b-poly(4-vinylpyridine) (PCL x -b-P4VP y ).

[0093] As an example, the temperature of the polymerization reaction can be 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, 35 °C or 40 °C.

[0094] The time of the polymerization reaction can be 9 h, 10 h, 11 h, 12 h, 13 h, 14 h or 15 h.

[0095] The molar ratio of the -Cl units in tetramethylpyridine (4VP) and polycaprolactone-Cl (PCL x -Cl) is 70:1 to 110:1.

[0096] Optionally, the molar ratio of the -Cl units in tetramethylpyridine (4VP) and polycaprolactone-Cl (PCL x -Cl) is 80:1 to 100:1.

[0097] Optionally, the molar ratio of the -Cl units in tetramethylpyridine (4VP) and polycaprolactone-Cl (PCL x -Cl) is 90:1.

[0098] The molar ratio of CuM2 and the -Cl units in polycaprolactone-Cl (PCL x -Cl) is 0.8:1 to 1.2:1. Optionally, the molar ratio of CuM2 and the -Cl units in polycaprolactone-Cl (PCL x -Cl) is 0.9:1 to 1.1:1.

[0099] Optionally, the molar ratio of CuM2 and the -Cl units in polycaprolactone-Cl (PCL xThe molar ratio of the -Cl units in -Cl) is 1:1.

[0100] Polycaprolactone-Cl (PCL x The molar volume ratio of the -Cl units in -Cl) and dimethyl sulfoxide is 1 mmol:10 mL to 1 mmol:50 mL.

[0101] Optionally, the molar volume ratio of the -Cl units in polycaprolactone-Cl (PCL x -Cl) and dimethyl sulfoxide is 1 mmol:20 mL to 1 mmol:40 mL.

[0102] Optionally, the molar volume ratio of the -Cl units in polycaprolactone-Cl (PCL x -Cl) and dimethyl sulfoxide is 1 mmol:30 mL.

[0103] Polycaprolactone-Cl (PCL x The molar ratio of the -Cl units in -Cl) and Me6TREN is 1:0.16 to 1:0.2.

[0104] Optionally, the molar ratio of the -Cl units in polycaprolactone-Cl (PCL x -Cl) and Me6TREN is 1:0.17 to 1:0.19.

[0105] Optionally, the molar ratio of the -Cl units in polycaprolactone-Cl (PCL x -Cl) and Me6TREN is 1:0.18.

[0106] The length of the copper wire is 1 cm to 5 cm.

[0107] Optionally, the length of the copper wire is 2 cm to 4 cm.

[0108] Optionally, the length of the copper wire is 3 cm.

[0109] Polycaprolactone-Cl (PCL x The molar mass ratio of the -Cl units in -Cl) and the copper wire is 1 mmol / 100 mg to 1 mmol / 150 mg.

[0110] Optionally, the molar mass ratio of the -Cl units in polycaprolactone-Cl (PCL x -Cl) and the copper wire is 1 mmol / 120 mg to 1 mmol / 140 mg.

[0111] Optionally, the molar mass ratio of the -Cl units in polycaprolactone-Cl (PCL x -Cl) and the copper wire is 1 mmol / 130 mg.

[0112] The time for bubbling degassing is 10 min to 20 min.

[0113] Polycaprolactone-Cl is prepared by the following method:

[0114] In a dried container equipped with a stirrer, ε-caprolactone (ε-CL) and dried tetrahydrofuran (THF) are added to prepare a mixture. After bubbling degassing the mixture with high-purity N2 for 15 min, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is added to the container, and the system temperature is maintained at 10 °C to 40 °C. 2-Hydroxyethyl 2-chloropropionate dried by molecular sieve is added to the container, and ring-opening polymerization reaction is carried out for 10 h to 14 h. After the reaction is completed, the container is placed in liquid nitrogen to terminate the reaction. A large amount of n-hexane is poured into the product for precipitation to obtain a gray polymerization product. Then the gray polymerization product is redissolved in THF and then placed in n-hexane for precipitation again. This process is repeated three times. After drying under reduced pressure to constant weight, a white powder is obtained. The white powder is polycaprolactone-Cl (PCLx-Cl).

[0115] As an example, the temperature of the ring-opening polymerization reaction can be 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, 35 °C or 40 °C.

[0116] The time for the ring-opening polymerization reaction is 10 h, 11 h, 12 h, 13 h or 14 h.

[0117] The molar volume ratio of ε-caprolactone and tetrahydrofuran (THF) is 0.18 mol:10 mL to 0.18 mol:20 mL.

[0118] Optionally, the molar volume ratio of ε-caprolactone and tetrahydrofuran (THF) is 0.18 mol:12 mL to 0.18 mol:18 mL.

[0119] Optionally, the molar volume ratio of ε-caprolactone and tetrahydrofuran (THF) is 0.18 mol:15 mL.

[0120] The molar ratio of ε-caprolactone and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is 180:0.04 to 180:0.05.

[0121] Optionally, the molar ratio of ε-caprolactone and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is 180:0.045.

[0122] The molar ratio of ε-caprolactone and 2-hydroxyethyl 2-chloropropionate dried by molecular sieve is 15:1 to 25:1.

[0123] Optionally, the molar ratio of ε-caprolactone and 2-hydroxyethyl 2-chloropropionate dried by molecular sieve is 18:1 to 22:1.

[0124] Optionally, the molar ratio of ε-caprolactone to 2-hydroxyethyl 2-chloropropionate dried by molecular sieve is 20:1.

[0125] The time for bubbling degassing is 10 min to 20 min.

[0126] Please refer to Figure 1 , in the preparation method of the pyridyl cationic sugar-containing polymer of the present application, DBU is used as a catalyst, tetrahydrofuran is used as a solvent, and ε-CL undergoes a living ring-opening polymerization reaction at 25 °C to obtain an ATRP macroinitiator (PCL x -Cl). Using PCL x -Cl as a macromolecular mcroATRP initiator, using 4VP, PCL x -Cl, CuM2, and Me6TREN as raw materials, a block polymer precursor is prepared by the Cu(0)-RDRP method, and block polymers with different molecular weights can be obtained. The preparation method of the pyridyl cationic sugar-containing polymer of the present application is simple, and the prepared pyridyl cationic sugar-containing polymer has a stable structure.

[0127] The present application also provides an application of the above pyridyl cationic sugar-containing polymer in the preparation of antibacterial drugs.

[0128] The present application provides an application of the above pyridyl cationic sugar-containing polymer in the preparation of antibacterial medical devices.

[0129] The following will describe the implementation scheme of the present application in detail in conjunction with examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. For those not specified in the examples, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified for the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0130] The following further describes in detail a pyridyl cationic sugar-containing polymer and its preparation method of the present application in conjunction with examples.

[0131] Example 1

[0132] The present application provides a pyridyl cationic sugar-containing polymer and its preparation method, which includes the following steps:

[0133] S1. Prepare polycaprolactone-Cl

[0134] A 100 mL round-bottom flask was dried overnight in an oven at 90 °C, equipped with a magnetic rotor and a sealed rubber stopper. After sealing, nitrogen was filled. ε-CL (20 mL, 0.18 mol) and dried THF (15 mL) were added to the dried round-bottom flask to prepare a mixture. After bubbling and degassing the mixture with high-purity N2 for 15 min, DBU (14.4 μL, 0.045 mmol) was added to the round-bottom flask, and the system temperature was maintained at 25 °C. 2-Hydroxyethyl 2-chloropropionate dried with molecular sieve (0.8 mL, 9 mmol) was added to the round-bottom flask, and ring-opening polymerization reaction was carried out for 12 h. After the reaction, the container was placed in liquid nitrogen to terminate the reaction. A large amount of n-hexane was poured into the product for precipitation to obtain a gray polymer product. Then the gray polymer product was redissolved in THF and then precipitated in n-hexane again. This process was repeated three times. After drying under reduced pressure to constant weight, a white powder was obtained. The white powder was polycaprolactone-Cl (PCL 35 -Cl).

[0135] S2. Preparation of polycaprolactone-b-poly(4-vinylpyridine)

[0136] 4VP (315.4 mg, ~3 mmol), CuBr2 (13.4 mg, 0.1 mol), PCL-Cl (400 mg, 0.1 mmol-Cl unit) and DMSO (3 mL) were added to a Schlenk tube to prepare a mixture. The mixture was bubbled and degassed with high-purity N2 for 15 min. Degassed Me6TREN (4.2 mg, 0.018 mmol) was added to the degassed mixture through a syringe to obtain a reaction solution. Then, hydrochloric acid-pretreated copper wire (3 cm, 13 mg) was added to the reaction solution under nitrogen protection, and the reaction solution was bubbled and degassed with high-purity N2 again for 15 min. The reaction was polymerized at 25 °C for 12 h. After the polymerization reaction was completed, the product was precipitated three times in a large amount of cold diethyl ether and dried under reduced pressure to obtain a light green powder. The light green powder was polycaprolactone-b-poly(4-vinylpyridine) (PCL 35 -b-P4VP8), and the yield was 99%.

[0137] S3. Preparation of pyridinium cationic sugar-containing polymer

[0138] PCL 35-b-P4VP8 (20 mg, ~0.05 mmol 4VP), A2-GluBr (41.8 mg, 0.15 mmol), and 10 mL of water were added to a 30 mL vial equipped with a magnetic stirring rotor to prepare a mixture. The mixture was bubbled with high-purity N2 for degassing, and then stirred at 80 °C for 120 h. A small amount of sample was taken every 24 h for DLS analysis of size changes. After the self-assembly reaction was completed, the product was dialyzed through pure water to remove excess unprotected halogen-functionalized monosaccharide (A2-GluX), and a sugar-containing copolymer micelle (PCL 35 -b-P4VP8-G) was prepared.

[0139] Example 2

[0140] This application provides a pyridyl cationic sugar-containing polymer and a preparation method thereof, which includes the following steps:

[0141] S1. Prepare polycaprolactone-Cl

[0142] Take a 100 ml round-bottom flask and dry it overnight in an oven at 90 °C. Equip it with a magnetic rotor and a sealing rubber stopper. After sealing, fill it with nitrogen. Add ε-CL (20 mL, 0.18 mol) and dried THF (15 mL) to the dried round-bottom flask to prepare a mixture. After bubbling and degassing the mixture with high-purity N2 for 15 min, add DBU (14.4 μL, 0.045 mmol) to the round-bottom flask, and keep the system temperature at 25 °C. Add 2-hydroxyethyl 2-chloropropionate (0.8 mL, 9 mmol) dried with molecular sieve to the round-bottom flask, and carry out ring-opening polymerization reaction for 12 h. After the reaction is completed, place the container in liquid nitrogen to terminate the reaction. Pour a large amount of n-hexane into the product to precipitate, and obtain a gray polymer product. Then redissolve the gray polymer product in THF and precipitate it in n-hexane again. This process is repeated three times, and after drying under reduced pressure to constant weight, a white powder is obtained. The white powder is polycaprolactone-Cl (PCL 35 -Cl).

[0143] S2. Prepare polycaprolactone-b-poly(4-vinylpyridine)

[0144] 4VP (40 mg, ~0.10 mmol), CuBr2 (13.4 mg, 0.1 mol), PCL-Cl (400 mg, 0.1 mmol-Cl unit), and DMSO (3 mL) were added to a Schlenk tube to prepare a mixture. The mixture was bubbled with high-purity N2 for 15 min for degassing. The degassed Me6TREN (4.2 mg, 0.018 mmol) was added to the degassed mixture through a syringe to prepare a reaction solution. Then, the hydrochloric acid-pretreated copper wire (3 cm, 13 mg) was added to the reaction solution under nitrogen protection, and the reaction solution was bubbled with high-purity N2 again for 15 min. The reaction was polymerized at 25 °C for 12 h. After the polymerization reaction was completed, the product was precipitated three times in a large amount of cold diethyl ether and dried under reduced pressure to obtain a light green powder. The light green powder was polycaprolactone-b-poly(4-vinylpyridine) (PCL 35 -b-P4VP 11 ), and the yield was 99%.

[0145] S3. Preparation of pyridinium cationic sugar-containing polymer

[0146] PCL 35 -b-P4VP 11 (27.5 mg, ~0.069 mmol 4VP), A2-GluBr (57.5 mg, 0.207 mmol), and 10 mL of water were added to a 30 mL vial equipped with a magnetic stirring rotor to prepare a mixture. The mixture was bubbled with high-purity N2 for degassing, and then stirred at 80 °C for 120 h. A small amount of sample was taken every 24 h for DLS analysis of size change. After the self-assembly reaction was completed, the product was dialyzed through pure water to remove the excess unprotected halogen-functionalized monosaccharide (A2-GluX) to obtain a sugar-containing copolymer micelle (PCL 35 -b-P4VP8-G).

[0147] Example 3

[0148] This application provides a pyridinium cationic sugar-containing polymer and its preparation method, which includes the following steps:

[0149] S1. Preparation of polycaprolactone-Cl

[0150] A 100 ml round-bottom flask was dried overnight in an oven at 90 °C, equipped with a magnetic rotor and a sealing rubber stopper. After sealing, nitrogen was filled into it. ε-CL (20 mL, 0.18 mol) and dried THF (15 mL) were added to the dried round-bottom flask to prepare a mixture. After the mixture was bubbled with high-purity N2 for 15 min for degassing, DBU (14.4 μL, 0.045 mmol) was added to the round-bottom flask, and the system temperature was maintained at 25 °C. Molecular sieves were added to the round-bottom flask The dried 2-hydroxyethyl 2-chloropropionate (0.8 mL, 9 mmol) was subjected to ring-opening polymerization for 12 h. After the reaction was completed, the container was placed in liquid nitrogen to terminate the reaction. A large amount of n-hexane was poured into the product for precipitation, and a gray polymeric product was obtained. Then, the gray polymeric product was redissolved in THF and precipitated in n-hexane again. This process was repeated three times. After drying under reduced pressure to a constant weight, a white powder was obtained. The white powder was polycaprolactone-Cl (PCL 35 -Cl).

[0151] S2. Preparation of polycaprolactone-b-poly(4-vinylpyridine)

[0152] 4VP (60 mg, ∼0.15 mmol), CuBr2 (13.4 mg, 0.1 mmol), PCL-Cl (400 mg, 0.1 mmol -Cl unit), and DMSO (3 mL) were added to a Schlenk tube to prepare a mixture. The mixture was bubbled with high-purity N2 for 15 min for degassing. Degassed Me6TREN (4.2 mg, 0.018 mmol) was added to the degassed mixture through a syringe to prepare a reaction solution. Then, a hydrochloric acid-pretreated copper wire (3 cm, 13 mg) was added to the reaction solution under nitrogen protection, and the reaction solution was bubbled with high-purity N2 again for 15 min. The reaction was polymerized at 25 °C for 12 h. After the polymerization reaction was completed, the product was precipitated three times in a large amount of cold diethyl ether and dried under reduced pressure to obtain a light green powder. The light green powder was polycaprolactone-b-poly(4-vinylpyridine) (PCL 35 -b-P4VP 13 ), and the yield was 99%.

[0153] S3. Preparation of pyridinium cationic sugar-containing polymer

[0154] PCL 35 -b-P4VP 13 (32.5 mg, ∼0.081 mmol 4VP), A2-GluBr (67.8 mg, 0.24 mmol), and 10 mL of water were added to a 30 mL vial equipped with a magnetic stirring rotor to prepare a mixture. The mixture was bubbled with high-purity N2 for degassing, and then stirred at 80 °C for 120 h. A small amount of sample was taken every 24 h for DLS analysis of size change. After the self-assembly reaction was completed, the product was dialyzed against pure water to remove the excess unprotected halogen-functionalized monosaccharide (A2-GluX), and a sugar-containing copolymer micelle (PCL 35 -b-P4VP8-G) was prepared.

[0155] Test Example 1

[0156] PCL was separately used for 35-Cl, the block copolymers PCL prepared in Examples 1 to 3 35 -b-P4VP9, PCL 35 -b-P4VP 11 and PCL 35 -b-P4VP 13 were subjected to gel permeation chromatography testing, and for PCL 35 -Cl, the PCL prepared in Example 3 35 -b-P4VP 13 and PCL 35 -b-P4VP 13 -G were subjected to infrared spectroscopy testing and nuclear magnetic resonance hydrogen spectroscopy testing. Figure 2 are the GPC chromatograms of PCL-CL and PCL 35 -b-P4VP n . Figure 3 are the FTIR spectra of PCL 35 , PCL 35 -b-P4VP 13 and PCL 35 -b-P4VP 13 -G. Figure 4 are the 35 H NMR spectra of PCL 35 and PCL 13 -b-P4VP 1 . Figure 5 are the 35 H NMR spectra of PCL 13 -b-P4VP 1 -G. Figure 6 are the TEM images of the prepared PCL 35 -b-P4VP8-G. Figure 7 are the TEM images of the prepared PCL 35 -b-P4VP 11 -G. Figure 8 are the TEM images of the prepared PCL 35 -b-P4VP 13 -G.

[0157] As shown by Figure 2 , the polydispersity indices of PCL 35 -Cl, PCL 35 -b-P4VP9, PCL 35 -b-P4VP 11 and PCL 35 -b-P4VP 13 are all < 2.

[0158] As Figure 2 and Figure 3As shown, an increase in molecular weight indicates the success of block polymer preparation. PCL 35 -b-P4VP 13 FT-IR spectrum of Figure 3 is as shown. After the N-quaternization reaction, an obvious vibration of pyridinium salt appears at 1640 cm -1 , indicating the success of N-quaternization self-assembly. The strong absorption peak at 3347 cm -1 corresponds to the stretching vibration of hydroxyl groups, indicating the presence of pendant alcohol or sugar units.

[0159] As Figure 4 and Figure 5 shown, by analyzing the 1 H NMR spectrum, the typical hydrogen proton peaks on the pyridine ring are at 6.5 - 7.0 ppm and 8.1 - 8.5 ppm ( Figure 4 ), and the typical peaks at 1.5, 1.7 and 2.2 ppm are the proton peaks of methylene groups generated by CL polymerization; in the 35 -b-P4VP 13 -G spectrum ( Figure 5 ), the proton peaks of the quaternized pyridine ring are between 8.7 - 9.1 ppm and 7.2 - 7.8 ppm (-N + =CH), which is consistent with the literature reports. A new spectral peak appears at 4.2 - 4.7 ppm, which is the result caused by the methylene protons (CH2-OH) in the bromosugar residue after quaternization.

[0160] As Figures 6 - 8 shown, the insoluble block polymer was dispersed in water, and N-quaternization self-assembly reaction with bromosugar was carried out at 80 °C to prepare sugar-containing polyionic liquid micelles. The gray suspended particles gradually disappeared in water, and the reaction solution turned into a light blue colloidal form, which is a significant feature of micelles. The purified product was characterized through a series of methods to determine the success of N-quaternization self-assembly.

[0161] The actual molecular weight information can be calculated by comparing the integral of the proton peak areas of methylene and pyridine rings, and the results are shown in Table 1.

[0162] Table 1 Molecular weights and molecular weight distributions of PCL 35 -Cl, PCL 35 -b-P4VP9, PCL 35 -b-P4VP 11 and PCL 35 -b-P4VP 13

[0163]

[0164] Experimental Example 2

[0165] To monitor the formation process of N - quaternary ammonium reaction - induced micelle self - assembly, the particle size and morphology of pyridyl - containing sugar - based polyionic liquid micelles at different time intervals were continuously analyzed using DLS and TEM tests. The results are shown in Table 2.

[0166] Table 2 PCL 35 Micelle size and particle size distribution of PCL

[0167]

[0168] As can be seen from Table 2, when bromosugar was added to an 80 °C aqueous solution containing PCL 35 -b-P4VP 13 , an immediate blue emulsion appeared. After 5 days of reaction, the average diameter was 1521 nm and the PDI was 0.16. At the same time, the TEM image also confirmed that the particle morphology was nanomicelles with a diameter of 50 nm. This clearly indicates the formation of an N - quaternary ammonium reaction - induced self - assembly structure. Combining 1 with the H NMR spectra ( Figure 4 and Figure 5 ), the appearance of the pyranose ring signal in the sugar group allows us to deduce that the polymer vesicles are hollow - sphere structures with pyridyl - sugar blocks on the outer layer and PCL groups on the inner layer. Other pyridyl - containing sugar - based polyionic liquids PCL 35 -b-P4VP8 - G and PCL 35 -b-P4VP 11 -G form micelle structures and exhibit similar self - assembly behavior after the N - quaternary ammonium reaction. This may be due to the fact that the short 4VP block has fewer grafted sugar groups, resulting in insufficient hydrophilicity.

[0169] Figure 9 Figure is the TEM image of PCL 35 -b-P4VP8 - G after 24 h of reaction, Figure 10 Figure is the TEM image of PCL 35 -b-P4VP8 - G after 48 h of reaction, Figure 11 Figure is the TEM image of PCL 35 -b-P4VP8 - G after 72 h of reaction, Figure 12 Figure is the TEM image of PCL 35 -b-P4VP8 - G after 96 h of reaction, Figure 6 Figure is the TEM image of PCL 35 -b-P4VP8 - G after 120 h of reaction. The particle size, PDI, and ζ - potential of pyridyl - containing sugar - based polyionic liquid particles in water were measured, and the results are shown in Table 3.

[0170] Table 3 PCL 35 -Cl, PCL 35-b-P4VP9, PCL 35 -b-P4VP 11 and PCL 35 -b-P4VP 13 in terms of particle size, PDI and ζ potential

[0171]

[0172] As can be seen from Figure 9 and Figure 10 , similar to PCL 35 -b-P4VP 13 -G, it can be seen from the TEM images that the block polyionic liquid PCL 35 -b-P4VP8-G or PCL 35 -b-P4VP 11 -G has a micelle structure. Therefore, only when the sugar-containing units of the sugar-containing copolymer have sufficient hydrophilicity is it possible to form self-assembled vesicles. This morphological difference is consistent with the general theory of "packing parameter", that is, the change in morphology is determined by the relative length or volume of the solvophilic and solvophobic segments. In addition, as can be seen from Table 3, with the increase of the sugar-containing segment, the micelle stability CMC and zeta potential increase, probably because the sugar-containing segment makes the micelle have more hydrophilicity and cationic groups.

[0173] Test Example 3

[0174] Sugar-containing aggregates are usually called multivalent ligands and can undergo a "sugar cluster reaction" with lectins (such as concanavalin A) to form aggregates. Using DLS analysis to monitor the change in turbidity of the mixed solution before and after, the mutual recognition between the sugar-containing polymer micelles and ConA was investigated, and the results Figures 13 - 15 .

[0175] When a polymer containing a mannose ligand binds to a specific lectin, large particles / aggregates will be formed, thus forming a white suspension precipitate. The formation of the aggregate is mainly due to the multivalent interaction between multiple mannose pendant groups on the polymer and the binding sites on the lectin molecule, resulting in the cross-linking of the polymer chain and the lectin. Figures 13 - 15 shows the turbidity monitoring results of the mixture of three pyridyl sugar-containing polymer micelles and ConA for 12 hours. The increase in particle size after mixing indicates that the micelles only specifically bind to ConA. Comparing the aggregation behaviors of the three pyridyl sugar micelles and ConA at different time intervals, it can be clearly seen that the sugar micelles with a high sugar content form precipitates in a shorter time, that is, the polymer with a longer sugar-containing group has a stronger binding ability to ConA.

[0176] Test Example 4

[0177] The antibacterial effects of two cationic sugar-containing polymer micelles against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were investigated. The minimum inhibitory concentration (MIC) values of various micelles were determined by the half-dilution broth method, and the results are shown in Table 4.

[0178] Table 4 PCL 35 -b-P4VP8-G, PCL 35 -b-P4VP 11 -G and PCL 35 -b-P4VP 13 -G's MIC value, HC 50 and antibacterial selectivity

[0179]

[0180] As can be seen from Table 4, for the pyridyl sugar-containing micelle PCL 35 -b-P4VP8-G, the MIC values for both Escherichia coli and Staphylococcus aureus were 256 μg / mL. As the 4VP segment grew, the MIC values of PCL 35 -b-P4VP 11 -G and PCL 35 -b-P4VP 13 -G decreased from 256 μg / mL to 128 μg / mL, and the antibacterial efficiency increased significantly. Therefore, the cationic polymer with a longer 4VP segment has a stronger ability to attract bacteria, thereby enhancing the antibacterial activity against bacteria.

[0181] In addition, an enzyme-labeled spectrophotometer was used to analyze the antibacterial kinetics, continuously monitoring the change in the OD 600 value of the sample plate. As Figures 16 - 21 shown, when the antibacterial agent concentration was 1×MIC, the OD 600 basically remained unchanged, indicating that the antibacterial drug fully exerted its antibacterial mechanism and the bacteria no longer reproduced at this concentration. As the concentration of the antibacterial drug decreased, when the contact time between the antibacterial drug and Escherichia coli exceeded 100 min, the OD 600 value increased significantly with bacterial reproduction. For Staphylococcus aureus, the OD 600 increased rapidly after more than 200 minutes. From the hemolysis experiment histogram shown in Figures 22 - 24 , when the concentration of the PCL 35 -b-P4VP 13 -G micelle was close to 16*MIC, the hemolysis rate was still below 50%, and the selectivity index was the highest. This is because the block polymer has a high degree of cationization, introducing more hydrophilic sugar groups, generating more positive charges to attract and kill bacteria. The fewer hydrophobic segments did not cause toxicity to red blood cells. Therefore, the polymer nanoparticles with more sugar groups have stronger antibacterial activity and minimal cytotoxicity.

[0182] The above are only specific embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A pyridyl cationic sugar-containing polymer, characterized in that The structural formula of the pyridyl cationic sugar-containing polymer is as follows: M is selected from Cl, Br or I; x is an integer between 10 and 60, and y is an integer between 5 and 60.

2. The pyridyl cationic sugar-containing polymer according to claim 1, characterized in that x is an integer between 20 and 40, and y is an integer between 8 and 20.

3. A method for preparing the pyridyl cationic sugar-containing polymer according to claim 1 or 2, characterized in that: The preparation method of the pyridyl cationic sugar-containing polymer comprises: polycaprolactone-b-poly (4-vinyl pyridine) and halogen-functionalized monosaccharide undergo a self-assembly reaction in a solvent to form sugar-containing copolymer micelles; The structural formula of the polycaprolactone-b-poly(4-vinyl pyridine) is as follows: ； The structural formula of the halogen-functionalized monosaccharide is as follows: 。 4. The method for preparing a pyridyl cationic sugar-containing polymer according to claim 3, wherein: The temperature of the self-assembly reaction is 60° C. to 100° C., and the time is 72 h to 168 h.

5. The method for preparing a pyridyl cationic sugar-containing polymer according to claim 3, wherein: The solvent is water.

6. The method for preparing a pyridyl cationic sugar-containing polymer according to claim 3, wherein: After the self-assembly reaction is completed, the obtained product is dialyzed against pure water to obtain the sugar-containing copolymer micelles.

7. The method for preparing a pyridyl cationic sugar-containing polymer according to claim 3, wherein: The polycaprolactone-b-poly 4-vinyl pyridine is prepared by the following method: The block copolymer polycaprolactone-b-poly(4-vinylpyridine) was prepared by initiating the polymerization of vinylpyridine with polycaprolactone-Cl.

8. The method for preparing a pyridyl cationic sugar-containing polymer according to claim 7, wherein: The polycaprolactone-Cl is prepared by the following method: Using 2-hydroxyethyl-2-chloropropionate as a bifunctional initiator, the hydrophobic polycaprolactone-Cl is obtained by initiating polymerization of caprolactone monomers through living ring-opening polymerization.

9. Use of the pyridyl cationic sugar-containing polymer according to claim 1 or 2 in the preparation of antibacterial drugs.

10. Use of the pyridyl cationic sugar-containing polymer according to claim 1 or 2 in the preparation of antibacterial medical devices.

Images