Inflammation active targeting antibacterial medicine composition, preparation method and application

Abstract

The invention relates to the technical field of antibacterial drugs, in particular to an inflammation active targeting antibacterial drug composition, a preparation method and application. The composition comprises an anti-inflammatory drug and a carrier thereof, wherein the carrier is glucan carboxymethylated by halogenated organic acid and sodium salt thereof. The halogenated organic acid is preferably dichloroacetic acid, and the medicine is a hydroxyl-containing antibiotic and comprises doxycycline, thiamphenicol and kitasamycin. And the glucan is beta-glucan. According to the composition, carboxymethylated glucan is combined with a medicine to form a nanoparticle structure, recognition of a reticuloendothelial system can be avoided, the circulation time of the medicine in a blood system can be prolonged, inflammation parts are targeted through macrophages, the curative effect of the medicine is enhanced, and side effects are reduced. The preparation method comprises the steps of preparation of carboxymethylated glucan and ester bond connection of the carboxymethylated glucan and the medicine. The composition can be used for preparing medicines for treating inflammation caused by bacteria, viruses and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of antimicrobial drugs, and in particular to an inflammation actively targeted antimicrobial drug composition, a preparation method and application thereof. Background Art

[0002] Inflammation is a local infectious reaction caused by pathogenic microorganisms such as bacteria, viruses, mycoplasmas, and fungi, which can lead to excessive recruitment and differentiation of macrophages in local lesions. Antibiotics are effective in anti-inflammatory treatment. For example, doxycycline, thiamphenicol, and kitasamycin are different types of antibiotics that exert their antibacterial effects by inhibiting the synthesis of bacterial proteins. They bind to different subunits of bacterial ribosomes, blocking different links in the protein synthesis process, thereby inhibiting bacterial growth and reproduction and eliminating inflammation.

[0003] Existing antibiotic antimicrobial drugs generally have systemic effects and are widely distributed in the body. Long-term use can cause toxic side effects such as liver and kidney damage, dysbacteriosis, and allergic reactions. They may also be identified as foreign bodies and cleared by the reticuloendothelial system, making it impossible to accurately deliver the drug to the site of inflammation, resulting in uneven distribution of the drug in the body, reducing drug utilization and efficacy, and producing certain side effects.

[0004] When using antimicrobial drugs, the course of treatment should be shortened as much as possible to avoid increasing the incidence of drug-resistant strains and reduce adverse drug reactions. Based on this, it is necessary to provide an anti-inflammatory drug composition that is effective against pathogenic bacteria in inflammatory sites, increases circulation time in the blood system, targets inflammatory sites to enhance drug efficacy and shorten medication time. Summary of the invention

[0005] In order to solve the problems existing in the background technology, the present invention provides an inflammation active targeted antibacterial drug composition, which includes an anti-inflammatory drug and a carrier thereof, wherein the carrier is a dextran carboxymethylated with a halogenated organic acid and its sodium salt.

[0006] In a preferred embodiment, the carboxyl substitution degree of the carboxymethylated dextran is 20% to 60%, which refers to the ratio of hydroxyl groups in the dextran molecule replaced by carboxymethyl groups, that is, the percentage of the number of substituted hydroxyl groups to the total number of hydroxyl groups.

[0007] In a preferred embodiment, the mass of the drug carried by the carrier accounts for 5% to 80% of the total mass of the composition.

[0008] In a preferred embodiment, the halogenated organic acid is dichloroacetic acid.

[0009] In a preferred embodiment, the drug is a hydroxyl-containing antibiotic, including any one of doxycycline, thiamphenicol and kitasamycin.

[0010] In a preferred embodiment, the glucan is β-glucan, and its molecular weight is 8000 to 60000 Da.

[0011] Application of inflammation active targeted antibacterial drug composition in the preparation of anti-inflammatory drugs.

[0012] The method for preparing an inflammation active targeted antibacterial drug composition comprises the following steps:

[0013] S1: preparing carboxymethylated dextran, wherein the dextran and the halogenated organic acid and its sodium salt are connected through a carboxymethylation reaction;

[0014] S2: connecting the carboxymethylated dextran and the drug via an ester bond.

[0015] Furthermore, the specific process of step S1 is: weigh a certain amount of dextran, add a certain concentration of NaOH solution, and stir at room temperature; slowly add a mixed solution of halogenated organic acid and isopropanol, and stir at 50-60°C after the addition is completed; adjust the reaction system to neutral; pour in cold anhydrous ethanol, filter and wash the precipitated solid product several times, and put it into a vacuum oven to dry to obtain carboxymethyl dextran; the specific process of step S2 is: add carboxymethyl dextran, drugs, 3-ethylcarbodiimide and N-hydroxysuccinimide in a certain molar ratio, dissolve in DMSO and stir, dialyze with a dialysis bag, and freeze-dry to obtain an inflammation active targeted antibacterial drug composition.

[0016] In the preferred scheme, the specific process of step S1 is: weigh a certain amount of dextran, add a certain concentration of NaOH solution, and stir at room temperature for 1 hour; slowly add a mixed solution of dichloroacetic acid and isopropanol, and stir at 50-60°C for 5 hours after the addition is completed; the molar ratio of dextran to dichloroacetic acid is 1:1-1:10; adjust the reaction system to neutral; pour in cold anhydrous ethanol, filter and wash the precipitated solid product several times, put it into a vacuum oven at 50°C to dry to obtain carboxymethyl dextran; the specific process of step S2 is: add carboxymethyl dextran, doxycycline, 3-ethylcarbodiimide and N-hydroxysuccinimide in a certain molar ratio, dissolve in DMSO, stir at 35°C for 23 hours, dialyze with a dialysis bag for 48 hours, and freeze-dry to obtain an inflammation active targeted antibacterial drug composition.

[0017] The beneficial effects achieved by the present invention are:

[0018] The inflammation active targeted antibacterial drug composition of the present invention is formed by combining carboxymethylated dextran with a drug. After entering the animal body, it self-assembles into nanoparticles with a shell-core structure, and its particle size is less than 200nm. Due to the hydrophilic shell (carboxymethylated dextran) and hydrophobic core (drug) of the nanoparticles, this structure can escape the recognition of the reticuloendothelial system, thereby prolonging the circulation time of the drug in the blood system, enabling the drug to be accurately targeted to the inflammation site and quickly released, reducing the accumulation in non-inflammatory sites, thereby reducing the toxic and side effects of the drug on other organs of the whole body. The composition uses dextran carboxymethylated by halogenated organic acid and its sodium salt as a carrier, and the carrier has the ability to specifically target macrophages. When the drug enters the body, the dextran can be recognized and engulfed by the Dectin-1 receptor on the surface of the macrophage, thereby carrying the drug to the inflammation site. This targeting significantly increases the concentration of the drug at the lesion site and enhances the anti-inflammatory effect.

[0019] After traditional antibiotics enter the body, they are often recognized and cleared by the reticuloendothelial system, resulting in the inability to accurately deliver the drugs to the site of inflammation, reducing the utilization rate and efficacy of the drugs. The pharmaceutical composition of the present invention significantly improves the utilization rate and efficacy of the drugs by actively targeting and extending the circulation time, and reduces unnecessary side effects. The pharmaceutical composition of the present invention can be applied to the treatment of a variety of inflammatory diseases caused by pathogenic microorganisms such as bacteria, viruses, mycoplasmas, and fungi. In addition, due to the use of the broad-spectrum antibiotic doxycycline as a drug ingredient, its scope of application is more extensive.

[0020] The present invention covalently modifies the antibacterial drug and glucan for the first time, and the modified composition can reach the inflammation site with macrophages. Under the action of macrophage nonspecific esterase, the antibacterial drug is released, which can specifically eliminate the pathogenic microorganisms of the lesion, shorten the course of the disease, and reduce the systemic impact of the inflammation site on the diseased body.

[0021] The β-glucan of the present invention can be specifically recognized by the Dectin-1 receptor on the surface of macrophages and then phagocytosed by macrophages. As macrophages accumulate at inflammatory sites, the composition can form nanoparticles with a particle size range that can escape recognition by the reticuloendothelial system, thereby increasing systemic circulation time.

[0022] The mechanism of action of the inflammation active targeted antibacterial drug composition of the present invention is as follows:

[0023] When entering the body, since dextran is hydrophilic and the modified drug doxycycline is hydrophobic, it will self-assemble into a shell-core structure nanoparticle with a particle size of less than 200nm, which plays a protective role for the drug. The hydrophilic shell of the nanoparticle formed after entering the body is carboxymethylated dextran, and the inside is doxycycline. Since the particle size of the nanoparticle is less than 200nm, it can escape the recognition of the reticuloendothelial system and increase the circulation time of the drug in the blood system. When the nanoparticles pass through the inflammatory site, dextran can be recognized by the pattern recognition receptor Dectin-1 on the macrophages, and then be internalized by the macrophages. Doxycycline is released under the action of macrophage non-specific esterase, achieving precise targeted anti-inflammatory effect on pathogenic bacteria in the inflammatory site. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A molecular state schematic diagram of the preparation process of an antibacterial drug composition that actively targets inflammation;

[0025] Figure 2 This is the infrared characterization diagram of the carboxymethyl dextran structure;

[0026] Figure 3 This is the transmission electron microscopy morphology of carboxymethyl dextran doxycycline nanoparticles;

[0027] Figure 4 is the particle size distribution diagram of carboxymethyl dextran doxycycline nanoparticles;

[0028] Figure 5 Bright field images of carboxymethyl dextran doxycycline targeting macrophages;

[0029] Figure 6 This is the drug release diagram of carboxymethyl dextran doxycycline. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. In addition, the forms of the various structures recorded in the following embodiments are merely illustrative, and the present invention is not limited to the various structures recorded in the following embodiments. All other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0031] The present invention provides an inflammation active targeted antibacterial drug composition, which includes an anti-inflammatory drug and a carrier thereof, wherein the carrier is a dextran carboxymethylated by a halogenated organic acid and its sodium salt. The carboxyl substitution degree of the carboxyl group of the carboxymethylated dextran is 20% to 60%, and the carboxyl substitution degree refers to the proportion of hydroxyl groups in the dextran molecule replaced by carboxymethyl groups, that is, the percentage of the number of substituted hydroxyl groups to the total number of hydroxyl groups. The mass of the drug carried by the carrier accounts for 5% to 80% of the total mass of the entire composition. The halogenated organic acid is dichloroacetic acid. The drug is a hydroxyl-containing antibiotic, including any one of doxycycline, thiamphenicol and kitasamycin. The dextran is β-glucan, and its molecular weight is 8000 to 60000 Da.

[0032] β-glucan is a natural high molecular compound. In addition to the advantages of biocompatibility, biodegradability, and non-immunogenicity, β-glucan can be specifically recognized by the Dectin-1 receptor on the surface of macrophages and then be phagocytosed by macrophages, thereby accumulating in inflammatory sites with macrophages. It can also escape recognition by the reticuloendothelial system and increase circulation time in the blood system.

[0033] As a carboxylating agent, dichloroacetic acid has the characteristics of low cost, fast reaction and good removal, and can efficiently introduce active carboxyl groups into dextran. Doxycycline is a broad-spectrum antibiotic commonly used in the treatment of bacterial, mycoplasma, chlamydia and other infections. It is currently one of the most widely used antibiotics for livestock and poultry. It is used to prevent and treat bacterial infections such as the respiratory tract, digestive tract, and urinary tract of livestock and poultry, especially for diseases such as Escherichia coli, Pasteurella, and mycoplasma infections. Doxycycline is widely distributed in the body, and long-term use has toxic side effects such as liver and kidney damage and allergic reactions.

[0034] The method for preparing an inflammation active targeted antibacterial drug composition comprises the following steps:

[0035] S1: preparing carboxymethylated dextran, wherein the dextran and the halogenated organic acid and its sodium salt are connected through a carboxymethylation reaction;

[0036] S2: connecting the carboxymethylated dextran and the drug via an ester bond.

[0037] Furthermore, the specific process of step S1 is: weigh a certain amount of dextran, add a certain concentration of NaOH solution, and stir at room temperature; slowly add a mixed solution of halogenated organic acid and isopropanol, and stir at 50-60°C after the addition is completed; adjust the reaction system to neutral; pour in cold anhydrous ethanol, filter and wash the precipitated solid product several times, and put it into a vacuum oven to dry to obtain carboxymethyl dextran; the specific process of step S2 is: add carboxymethyl dextran, drugs, 3-ethylcarbodiimide and N-hydroxysuccinimide in a certain molar ratio, dissolve in DMSO and stir, dialyze with a dialysis bag, and freeze-dry to obtain an inflammation active targeted antibacterial drug composition.

[0038] The specific process of step S1 is: weigh a certain amount of dextran, add a certain concentration of NaOH solution, and stir at room temperature for 1 hour; slowly add a mixed solution of dichloroacetic acid and isopropanol, and stir at 50-60°C for 5 hours after the addition is completed; the molar ratio of dextran to dichloroacetic acid is 1:1-1:10; adjust the reaction system to neutral; pour in cold anhydrous ethanol, filter and wash the precipitated solid product several times, put it in a vacuum oven at 50°C to dry to obtain carboxymethyl dextran; the specific process of step S2 is: add carboxymethyl dextran, doxycycline, 3-ethylcarbodiimide and N-hydroxysuccinimide in a certain molar ratio, dissolve in DMSO, stir at 35°C for 23 hours, dialyze with a dialysis bag for 48 hours, and freeze-dry to obtain an inflammation active targeted antibacterial drug composition.

[0039] DMSO, whose Chinese name is dimethyl sulfoxide, is an organic compound with the chemical formula (CH3)2SO. It is one of the most important polar aprotic solvents. It has a strong solubility and can dissolve many inorganic salts and organic substances. It is often used as a solvent or carrier for certain drugs. It has the characteristics of high boiling point, low freezing point, good thermal stability, aprotic, and miscible with water.

[0040] The present invention also provides the use of the inflammation active-targeting antibacterial drug composition in the preparation of anti-inflammatory drugs.

[0041] Example 1: This example provides an inflammation active targeted antibacterial drug composition, the preparation process is as follows: Figure 1: Weigh 2g of β-glucan with a molecular weight of 8000Da, add 10ml of 30% NaOH solution, and stir at room temperature for 1h. According to the volume ratio of dichloroacetic acid and isopropanol of 1:1.2, measure 10ml of dichloroacetic acid and 12ml of isopropanol to form a mixed solution, slowly add the mixed solution to the NaOH solution containing glucan, and after the addition is completed, place the reaction system in an oil bath and stir at 50°C for 5h. After the reaction is completed, neutralize with 5% HCl to make the reaction system neutral. Pour the pre-frozen anhydrous ethanol into the mixed solution and a white solid will precipitate immediately. The product is obtained by suction filtration and washed several times with ethanol to remove the solvent and impurities in the reaction process to obtain a white powdery solid. The product is placed in a vacuum oven at 50°C and dried for 24h.

[0042] Weigh 5 mg of carboxymethyl dextran and 20 mg of doxycycline and dissolve them in 3.5 mL of DMSO. Add 3.5 mg of EDC6 and 19.6 mg of NHS. Stir at 35°C for 23 h, dialyze with a dialysis bag for 48 h, and lyophilize for later use.

[0043] Example 2, this example provides an inflammation active targeted antibacterial drug composition, weighing 2g of β-glucan with a molecular weight of 40000Da, adding 10ml of NaOH solution with a concentration of 50%, and stirring at room temperature for 1h. According to the volume ratio of dichloroacetic acid and isopropanol of 1:1.2, 10ml of dichloroacetic acid and 12ml of isopropanol are measured to form a mixed solution, and the mixed solution is slowly added dropwise to the NaOH solution containing glucan. After the addition is completed, the reaction system is placed in an oil bath and stirred at 55°C for 5h. After the reaction is completed, 5% HCl is used for neutralization to make the reaction system neutral. Pour the pre-frozen anhydrous ethanol into the mixed solution and a white solid is immediately precipitated. The product is obtained by suction filtration and washed several times with ethanol to remove the solvent and impurities in the reaction process to obtain a white powdery solid, and the product is placed in a vacuum oven at 50°C and dried for 24h.

[0044] Weigh 5 mg of carboxymethyl dextran and 20 mg of doxycycline, dissolve in 3.5 mL of DMSO, add 63.5 mg of EDC and 19.6 mg of NHS, stir at 35° C. for 23 h, dialyze with a dialysis bag for 48 h, and lyophilize for later use.

[0045] Example 3, this embodiment provides an inflammation active targeted antibacterial drug composition, weighing 2g of β-glucan with a molecular weight of 40000Da, adding 10ml of NaOH solution with a concentration of 50%, and stirring at room temperature for 1h. According to the volume ratio of dichloroacetic acid and isopropanol of 1:1.2, 15ml of dichloroacetic acid and 18ml of isopropanol are measured to form a mixed solution, and the mixed solution is slowly added dropwise to the NaOH solution containing glucan. After the addition is completed, the reaction system is placed in an oil bath and stirred at 50°C for 5h. After the reaction is completed, 5% HCl is used for neutralization to make the reaction system neutral. Pour the pre-frozen anhydrous ethanol into the mixed solution and a white solid is immediately precipitated. The product is obtained by suction filtration and washed several times with ethanol to remove the solvent and impurities in the reaction process to obtain a white powdery solid, and the product is placed in a vacuum oven at 50°C and dried for 24h.

[0046] Weigh 5 mg of carboxymethyl dextran and 20 mg of doxycycline, dissolve in 3.5 mL of DMSO, add 63.5 mg of EDC and 19.6 mg of NHS, stir at 35° C. for 23 h, dialyze with a dialysis bag for 48 h, and lyophilize for later use.

[0047] Example 4, this embodiment provides an inflammation active targeted antibacterial drug composition, weighing 2g of β-glucan with a molecular weight of 40000Da, adding 10ml of NaOH solution with a concentration of 50%, and stirring at room temperature for 1h. According to the volume ratio of dichloroacetic acid and isopropanol of 1:1.2, 15ml of dichloroacetic acid and 18ml of isopropanol are measured to form a mixed solution, and the mixed solution is slowly added dropwise to the NaOH solution containing glucan. After the addition is completed, the reaction system is placed in an oil bath and stirred at 60°C for 5h. After the reaction is completed, 5% HCl is used for neutralization to make the reaction system neutral. Pour the pre-frozen anhydrous ethanol into the mixed solution and a white solid is immediately precipitated. The product is obtained by suction filtration and washed several times with ethanol to remove the solvent and impurities in the reaction process to obtain a white powdery solid, and the product is placed in a vacuum oven at 50°C and dried for 24h.

[0048] Weigh 5 mg of carboxymethyl dextran and 30 mg of doxycycline and dissolve them in 3.5 mL of DMSO, add 63.5 mg of EDC and 19.6 mg of NHS, stir at 35° C. for 23 h, dialyze with a dialysis bag for 48 h, and lyophilize for later use.

[0049] Performance test experiment:

[0050] The macrophages used were RAW264.7 cells, the molecular weight of β-glucan was in the range of 8000 to 60000 Da, and the porcine liver esterase was from Sigma.

[0051] The test methods used include the degree of substitution test of carboxymethyl dextran, the structural characterization of carboxymethyl dextran doxycycline, the drug loading test of carboxymethyl dextran doxycycline, the targeting test of carboxymethyl dextran doxycycline to macrophages, and the drug release test of carboxymethyl dextran doxycycline after hydrolysis by esterase.

[0052] 1) Degree of substitution (DS) test of carboxymethyl dextran:

[0053] Using the complexometric titration method, weigh the dried carboxymethyl dextran in a 200ml beaker, first moisten it with 1ml ethanol, pour 50ml distilled water into the beaker and stir, then add 20ml ammonia-ammonium chloride buffer solution to the beaker, and add the 0.1mol / L HCl solution prepared in advance to make the pH of the mixed solution reach 7.5-8.0. Then add 50ml of CuSO4 solution, pour the solution into a 250ml volumetric flask for dilution and make up the volume. After standing for 15min, take out 100ml of the test solution into a conical flask, add 0.1g of murexide indicator, and the solution changes from blue to yellow-green. Titrate with the 0.02mol / L EDTA solution prepared in advance. When the solution turns purple, it is the titration end point. At the same time, use CuSO4 solution for a control experiment under the same conditions.

[0054]

[0055] In the formula: a is the volume of EDTA solution consumed in titrating CuSO4 solution; b is the volume of EDTA solution consumed in titrating the test solution; c is the concentration of EDTA standard solution; m is the mass of carboxymethyl dextran weighed.

[0056] 2) Structural characterization of carboxymethyl dextran:

[0057] The structures of β-glucan, carboxymethylated glucan and carboxymethylated glucan doxycycline were characterized by infrared characterization.

[0058] 3) Drug loading test of carboxymethyl dextran doxycycline:

[0059] The drug loading of carboxymethyl dextran doxycycline was calculated by measuring the free doxycycline in the dialysate using high performance liquid chromatography. The specific determination method of doxycycline is shown in the Chinese Veterinary Pharmacopoeia, and the calculation formula is as follows:

[0060]

[0061] M2: Doxycycline feed amount; M1: Doxycycline amount in dialysate; W1: Doxycycline amount in carboxymethyl dextran

[0062] 4) Morphology test:

[0063] Carboxymethyl dextran doxycycline was dissolved in water to obtain nanoparticles, which were then dropped onto a sample-preparing copper mesh after ultrasonic dispersion. After the copper mesh was fully dried, the morphology and particle size of the sample were tested using a transmission electron microscope.

[0064] 5) Macrophage targeting test:

[0065] Carboxymethyl dextran doxycycline was labeled with the fluorescent substance N-methyl isatoic anhydride (MIA), carboxymethyl dextran doxycycline was dissolved in 0.1 mol / L borate solution, 10 g / L MIA was dissolved in DMSO, the mixture was mixed, and the mixture was added to the polysaccharide solution after standing at room temperature for 10 minutes; the fluorescently labeled carboxymethyl dextran doxycycline and macrophages were incubated together for 4 hours, and the intracellular drug accumulation was tested using a laser confocal microscope.

[0066] 6) Drug release test of carboxymethyl dextran doxycycline:

[0067] A certain concentration of carboxymethyl dextran doxycycline was mixed with 3.6 U mL -1 The esterase was incubated in pH 7.4 phosphate buffer for 8 h, and the amount of free doxycycline was determined at 2 h, 4 h, 6 h, and 8 h. The specific determination method of doxycycline can be found in the Chinese Veterinary Pharmacopoeia.

[0068] Degree of substitution of carboxymethyl dextran: The degree of substitution (DS) of the carboxymethyl dextran prepared in Examples 1-4 was tested:

[0069] The substitution degrees of the carboxymethyl dextran in Examples 1-4 are 0.25, 0.35, 0.5, and 0.55, respectively. Dichloroacetic acid can be used to carboxymethylate dextran, and the reaction conditions are simple, and the degree of carboxyl substitution can reach 0.55. The carboxylated dextran can be esterified with a hydroxyl-containing antibacterial drug to obtain an antibacterial drug that actively targets inflammation.

[0070] Drug loading capacity of carboxymethyl dextran doxycycline: The drug loading capacity of carboxymethyl dextran doxycycline prepared in Examples 1-4 was tested.

[0071] The drug loading of carboxymethyl dextran doxycycline in Examples 1-4 is 8.9%, 18.4%, 27.8% and 34.6% respectively. The drug loading of the active targeted antibacterial drug composition for inflammation provided by the present invention can be as high as 34.6%.

[0072] Structural characterization of carboxymethyl dextran: The carboxymethyl dextran and carboxymethyl dextran doxycycline prepared in Example 4 were subjected to infrared testing. Figure 2 , A is β-glucan, B is carboxymethyl glucan, and C is carboxymethyl glucan doxycycline. 3422.52cm -1The stretching vibration absorption peak of hydroxyl group is 2929.02cm -1 The stretching vibration absorption peak of the carbon-hydrogen bond on the sugar ring is 1654.37 cm -1 The characteristic peak of the hydroxyl group on the sugar ring is at 1634.66cm -1 The absorption peak at 1734.99cm is the characteristic peak of carboxyl group of carboxymethyl dextran; -1 and 1643.26cm -1 The stretching vibration of the amide bond of carboxymethyl dextran doxycycline and the generated ester bond. Through infrared characterization, it can be seen that dextran is modified by dichloroacetic acid carboxymethylation, and the doxycycline drug and carboxymethyl dextran are connected by an ester bond.

[0073] Morphology test of carboxymethyl dextran doxycycline: The carboxymethyl dextran doxycycline prepared in Example 4 was subjected to transmission electron microscopy scanning and particle size test. Figure 3 , carboxymethyl dextran doxycycline forms nanoparticles in aqueous solution, and the nanoparticles have uniform size and round shape. Figure 4 The particle size was normally distributed, with a particle size of 79.46±1.56nm and a PDI of 0.201±0.032. This particle size is conducive to the endocytosis of macrophages.

[0074] Macrophage targeting test: Taking the carboxymethyl dextran doxycycline prepared in Example 4 as an example, the fluorescently labeled carboxymethyl dextran doxycycline was incubated with macrophages for 4 h, and observed with a confocal microscope at 0 h, 1 h, 2 h and 4 h. Figure 5 As shown, there is no drug signal around the macrophages at 0 h. As time goes by, drug signals can be observed in the macrophages at 1 h, 2 h, and 4 h. The signal intensity becomes stronger over time, and the fluorescence at 4 h is the strongest, indicating that carboxymethyl dextran doxycycline can be targeted and taken up by macrophages and continuously accumulates in the cells.

[0075] Drug release test of carboxymethyl dextran doxycycline: Taking the carboxymethyl dextran doxycycline prepared in Example 4 as an example, carboxymethyl dextran doxycycline was mixed with 3.6 U·mL -1 The esterase was co-incubated in pH 7.4 phosphate buffer for 8 h, and samples were taken at different time points. The dynamic process of drug release of carboxymethyl dextran doxycycline was analyzed by high performance liquid chromatography (HPLC). Figure 6 As shown, at 2 hours, the cumulative release rate of doxycycline is 46%, which rises to 64.3% at 4 hours, 86% at 6 hours, and 95.6% at 8 hours, and the drug release is basically complete, and the drug release is rapid and complete. The active targeted antibacterial drug composition of the present application, taking carboxymethyl dextran doxycycline as an example, can break the ester bond under the action of exogenous esterase to release the drug doxycycline.

[0076] The raw material β-glucan used in the present invention has good biocompatibility and has specific targeting ability for macrophages. Its synthesis steps are simple, and the antibacterial drug doxycycline and carboxymethyl glucan are connected by ester bonds, which can be accumulated in the inflammation site and quickly released under the action of non-specific esterase. Compared with traditional antibacterial drugs, the inflammation active targeted antibacterial drug composition of the present invention can specifically eliminate the pathogenic microorganisms of the lesion.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An inflammation active targeted antibacterial drug composition, characterized in that: The invention comprises an anti-inflammatory drug and a carrier thereof. The carrier is dextran carboxymethylated by a halogenated organic acid and its sodium salt.

2. The inflammation active targeted antibacterial drug composition according to claim 1, characterized in that: The carboxyl substitution degree of the carboxymethylated dextran is 20% to 60%, which refers to the proportion of hydroxyl groups in the dextran molecule replaced by carboxymethyl groups, that is, the percentage of the number of substituted hydroxyl groups to the total number of hydroxyl groups.

3. The inflammation active targeted antibacterial drug composition according to claim 1, characterized in that: The percentage of the drug mass carried by the carrier to the total mass of the entire composition is 5% to 80%.

4. The inflammation active targeted antibacterial drug composition according to claim 1, characterized in that: The halogenated organic acid is dichloroacetic acid.

5. The inflammation active targeted antibacterial drug composition according to claim 1, characterized in that: The drug is a hydroxyl-containing antibiotic, including any one of doxycycline, thiamphenicol and kitasamycin.

6. The inflammation active targeted antibacterial drug composition according to claim 1, characterized in that: The glucan is β-glucan, and its molecular weight is 8000-60000Da.

7. Use of the inflammation active targeted antibacterial drug composition as described in any one of claims 1 to 6 in the preparation of anti-inflammatory drugs.

8. The method for preparing the inflammation active targeted antibacterial drug composition according to any one of claims 1 to 6, characterized in that: It includes the following steps: S1: preparing carboxymethylated dextran, wherein the dextran and the halogenated organic acid and its sodium salt are connected through a carboxymethylation reaction; S2: connecting the carboxymethylated dextran and the drug via an ester bond.

9. The method according to claim 8, characterized in that: The specific process of step S1 is: weigh a certain amount of dextran, add a certain concentration of NaOH solution, and stir at room temperature; slowly add a mixed solution of halogenated organic acid and isopropanol, and stir at 50-60°C after the addition is completed; adjust the reaction system to neutral; pour in cold anhydrous ethanol, filter and wash the precipitated solid product several times, put it in a vacuum oven and dry it to obtain carboxymethyl dextran; the specific process of step S2 is: add carboxymethyl dextran, drugs, 3-ethylcarbodiimide and N-hydroxysuccinimide in a certain molar ratio, dissolve in DMSO and stir, dialyze with a dialysis bag, and freeze-dry to obtain an inflammation active targeted antibacterial drug composition.

10. The method according to claim 8, characterized in that: The specific process of step S1 is: weigh a certain amount of dextran, add a certain concentration of NaOH solution, and stir at room temperature for 1 hour; slowly add a mixed solution of dichloroacetic acid and isopropanol, and stir at 50-60°C for 5 hours after the addition is completed; the molar ratio of dextran to dichloroacetic acid is 1:1-1:10; adjust the reaction system to neutral; pour in cold anhydrous ethanol, filter and wash the precipitated solid product several times, put it into a vacuum oven at 50°C to dry to obtain carboxymethyl dextran; the specific process of step S2 is: carboxymethyl dextran, doxycycline, 3-ethylcarbodiimide and N-hydroxysuccinimide are added in a ratio of 1:(1-10):(2-5):(1-5), dissolved in DMSO, stirred at 35°C for 23 hours, dialyzed with a dialysis bag for 48 hours, and freeze-dried to obtain an inflammation active targeted antibacterial drug composition.

Images