Hyperbranched hemicellulose polymer as well as preparation method and application thereof

Abstract

The invention relates to the technical field of organic polymer materials, and discloses a hyperbranched hemicellulose polymer as well as a preparation method and application thereof. The hyperbranched hemicellulose polymer provided by the invention has a structural formula as shown in a formula I, and the degree of substitution is 0.58-0.80. The invention provides a method for preparing hyperbranched hemicellulose-based hydrogel by taking hemicellulose extracted from waste liquid as a raw material to synthesize a hyperbranched hemicellulose polymer and taking the hyperbranched hemicellulose polymer as a skeleton. The preparation method provided by the invention has the advantages of simple process, abundant raw material sources, low price, greenness, environmental protection and the like. The prepared hyperbranched hemicellulose-based hydrogel is not only biodegradable, but also has good biocompatibility and water solubility. The hyperbranched hemicellulose hydrogel drug-loading system has good swelling reversibility, pH responsiveness and temperature responsiveness, the selection range of loaded drugs is wide, and the hyperbranched hemicellulose hydrogel drug-loading system has wide application potential.

Description

Technical Field

[0001] The invention relates to the technical field of organic polymer materials, and specifically discloses a hyperbranched hemicellulose polymer, a preparation method and application thereof. Background Art

[0002] As the world's environment continues to deteriorate, the problem of energy shortage has become increasingly prominent. Making full use of resources and turning waste into treasure has received widespread attention from all over the world, and the demand for recycling resources is increasing day by day. With the continuous increase in the production of viscose fibers in my country, the amount of waste liquid generated in the viscose fiber production process in my country has increased year by year. The waste liquid from viscose fiber production contains a certain amount of hemicellulose (2%~5%). If it is recycled and utilized, it is not only a strategy to reduce the carbon emissions of the industry, but also to avoid the waste of biomass resources.

[0003] Hydrogel is a water-insoluble three-dimensional network of hydrophilic polymers formed by physical or chemical crosslinking of one or more polymer molecules. It can interact with water or other low molecular weight solvents and swell until equilibrium is reached. Hydrogel has a wide range of application prospects, such as drug controlled release, wound dressings, adsorption materials, sensor materials, catalyst carriers, etc. However, due to the shortcomings of hemicellulose in water solubility, thermoplasticity and surface activity, it is not suitable to be directly used as the skeleton of hydrogel. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention prepares a hyperbranched hemicellulose polymer by hyperbranching the recovered hemicellulose, and uses the hyperbranched hemicellulose polymer as a skeleton to prepare a hyperbranched hemicellulose-based hydrogel, which is further applied to the controlled release of drugs. The present invention aims to provide a new application strategy for the hemicellulose recovered from the waste liquid of viscose fiber production, and improve the comprehensive utilization rate of the waste liquid of viscose fiber production.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a hyperbranched hemicellulose polymer, the structural formula of which is shown in Formula I:

[0006] Formula I; Among them, R1 is ; n is an integer between 80 and 140; R2 is ; The degree of substitution of the hyperbranched hemicellulose polymer is 0.58-0.80.

[0007] The hyperbranched hemicellulose polymer provided by the invention is prepared from natural polymerized polysaccharide-hemicellulose, is composed of 80 to 140 structural units, has a substitution degree of 0.58 to 0.80, and a molecular weight of 93200 to 126000, and its specific molecular configuration is suitable for the preparation of hydrogels.

[0008] In a second aspect, the present invention provides a method for preparing the hyperbranched hemicellulose polymer, the preparation method comprising the following steps: Step 1, esterifying hemicellulose with pyromellitic anhydride at 48°C to 52°C to obtain modified hemicellulose; Step 2: reacting the modified hemicellulose with alkyl diamine, 1-ethyl-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide at 30° C. to 40° C. to obtain a first-generation hyperbranched hemicellulose polymer; Step 3, reacting the first-generation hyperbranched hemicellulose polymer with pyromellitic anhydride, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide at 30° C. to 40° C. to obtain a hyperbranched hemicellulose polymer precursor; Step 4: Mix the hyperbranched hemicellulose polymer precursor with alkyl diamine, 1-ethyl-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide, and react at 38° C. to 42° C. to obtain a hyperbranched hemicellulose polymer.

[0009] The invention utilizes hemicellulose extracted from waste liquid as a raw material to synthesize hyperbranched hemicellulose polymer, thereby realizing the reuse of waste resources and effectively improving the utilization rate of plant resources in the viscose fiber industry.

[0010] Preferably, step 1 specifically comprises: mixing hemicellulose with pyromellitic anhydride, and carrying out an esterification reaction at 48° C. to 52° C. in the presence of lithium chloride and N-bromosuccinimide to obtain the modified hemicellulose; Wherein, the mass ratio of hemicellulose, lithium chloride and N-bromosuccinimide is 100:50~90:5~9; The mass ratio of the hemicellulose to pyromellitic anhydride is 100:70 to 100:75.

[0011] Preferably, the hemicellulose comprises the following components in percentage by weight: xylose 74% to 80%, mannose 11% to 12%, glucose 6% to 12%, galactose 1.2% to 1.3%, and the remainder is glucuronic acid.

[0012] The hemicellulose in the present invention is obtained by extracting wastewater from viscose fiber production. The present invention has no special limitation on the specific method of the extraction, and any extraction method known to those skilled in the art can be used. In the present invention, the hemicellulose extraction method preferably comprises: using wastewater from viscose fiber production with a hemicellulose content of 20 to 50 g / L and an alkali content of 200 to 250 g / L, pre-treating the wastewater with a filter having a filtration area of ​​0.8 m 2 The alkali-containing hemicellulose concentrate is concentrated by a membrane separation device, wherein the operating temperature of the membrane separation device is 50°C, the inlet pressure is 6 bar, and the outlet pressure is 4 bar. Water 3 to 4 times the volume of the viscose fiber production waste liquid is added, and continuous dialysis filtration is performed to obtain an alkali-containing hemicellulose concentrate. The alkali-containing hemicellulose concentrate is washed with ethanol and vacuum dried at 40°C for 24 hours to obtain hemicellulose.

[0013] Preferably, in step 2, the mass ratio of the modified hemicellulose to alkyl diamine, 1-ethyl-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 100:40-90:60-70:0.33-0.38; In step 3, the mass ratio of the first-generation hyperbranched hemicellulose polymer to pyromellitic anhydride, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide is 100:190-290:60-150:0.6-0.65; In step 4, the mass ratio of the hyperbranched hemicellulose polymer precursor to alkyl diamine, 1-ethyl-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 100:60-110:50-120:0.45-0.55; The alkyl diamine in the present invention may include ethylene diamine, hexamethylene diamine or 1,2-propylene diamine.

[0014] In a third aspect, the present invention provides use of the hyperbranched hemicellulose polymer in a hyperbranched hemicellulose-based hydrogel.

[0015] The hyperbranched hemicellulose-based hydrogel provided by the present invention not only has good biocompatibility, but is also biodegradable and environmentally friendly.

[0016] In a fourth aspect, the present invention further provides a hyperbranched hemicellulose-based hydrogel, wherein the hyperbranched hemicellulose-based hydrogel comprises the hyperbranched hemicellulose polymer described above or the hyperbranched hemicellulose polymer prepared in the method for preparing the hyperbranched hemicellulose polymer described above.

[0017] In a fifth aspect, the present invention also provides a method for preparing the hyperbranched hemicellulose-based hydrogel, the preparation method comprising the following steps: Step A, mixing the hyperbranched hemicellulose polymer with distilled water and gelatin, and reacting at 50° C. to 70° C. to obtain a hemicellulose-based hydrogel precursor; Step B: adding glutaraldehyde to the hemicellulose hydrogel precursor to cross-link and obtain a hyperbranched hemicellulose-based hydrogel.

[0018] Traditional high-drug-loading, high-sustained-release gels usually require special polymer design or composite nanoparticles in a specific way, with complex preparation processes and high raw material costs. The hyperbranched hemicellulose-based hydrogel provided by the present invention can realize the preparation of carrier materials through a relatively simple synthesis process. During the preparation, hyperbranched hemicellulose polymer is used as the skeleton and gelatin is used as the cross-linking monomer. The raw materials used in the preparation are abundant in source, easy to obtain, green and environmentally friendly, and low in price. The obtained hyperbranched hemicellulose-based hydrogel is not only biodegradable, but also has good biocompatibility and water solubility. Its swelling rate can reach 166.49% within 12 hours at 25°C.

[0019] Preferably, the mass ratio of the hyperbranched hemicellulose polymer to gelatin is 1:2 to 1:5; The mass ratio of the hyperbranched hemicellulose polymer to glutaraldehyde is 1:2.8 to 1:3.2.

[0020] In a sixth aspect, the present invention also provides the use of the hyperbranched hemicellulose-based hydrogel in the preparation of drug controlled-release materials.

[0021] The present invention takes avermectin and salicylic acid as model drugs, respectively, and uses the above-mentioned hyperbranched hemicellulose-based hydrogel to load model drugs to prepare drug-loaded hydrogel. In the drug-loaded hydrogel, the drug is embedded inside the hydrogel, and the mesh structure of the hydrogel provides a natural channel for drug delivery, and its tortuous pores can reduce the diffusion rate of the drug, while the responsive contraction and swelling to external stimuli can control the closing and opening of the pores, and realize the controlled release of the drug. The blocking effect of the hydrogel on the diffusion of solutes can be used to achieve a high drug loading while reducing the drug release rate. The drug-loaded hydrogel provided by the present invention shows good swelling reversibility, pH responsiveness, temperature responsiveness and drug release performance, and the loaded drug selection range is wide.

[0022] In view of the fact that the hyperbranched hemicellulose-based hydrogel provided by the present invention has good biocompatibility, is biodegradable, has a simple preparation process and relatively low production cost, it can be foreseen that the hyperbranched hemicellulose-based hydrogel has the potential for wide application in the field of drug controlled release. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is the infrared spectrum of the hyperbranched hemicellulose polymer I in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] In order to better illustrate the embodiments of the present invention, further examples are given below.

[0027] Example 1 This embodiment provides a method for preparing a hyperbranched hemicellulose-based hydrogel, and the specific method is as follows: 1. Preparation of hyperbranched hemicellulose polymers Step 1: Take 14.9 g of hemicellulose, add 500 mL of N,N-dimethylformamide, 10.9 g of pyromellitic anhydride, 10.32 g of lithium chloride and 1.032 g of N-bromosuccinimide, heat and stir at 50°C and 800 r / min for 2.5 h to obtain 19.08 g of modified hemicellulose; Step 2: Take 8.4 g of modified hemicellulose, add 200 mL of anhydrous ethanol, 5.5 g of 1,2-propylenediamine, 5.5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 30 mg of N-hydroxysuccinimide, heat and stir at 35 ° C and 800 r / min for 3 h to obtain 10.45 g of first-generation hyperbranched hemicellulose polymer; Step 3: Take 4.75 g of the first-generation hyperbranched hemicellulose polymer, add 200 mL of anhydrous ethanol, 10.9 g of pyromellitic anhydride, 5.0 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 30 mg of N-hydroxysuccinimide, heat and stir at 35 ° C and 800 r / min for 3 h to obtain 9.47 g of hyperbranched hemicellulose polymer precursor; Step 4: Take 6 g of hyperbranched hemicellulose polymer precursor, add 200 mL of anhydrous ethanol, 5.5 g of 1,2-propylenediamine, 5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 30 mg of N-hydroxysuccinimide, heat and stir the reaction at 40°C and 800 r / min for 3 h to obtain 8.9 g of hyperbranched hemicellulose polymer, recorded as hyperbranched hemicellulose polymer I.

[0028] The hemicellulose in step 1 is obtained by extracting waste liquid from viscose fiber production, and its composition is 74.02% xylose, 11.78% mannose, 11.61% glucose, 1.29% galactose, and the remainder is glucuronic acid.

[0029] The infrared structure of hyperbranched hemicellulose polymer I was analyzed, and its infrared spectrum is as follows: Figure 1 shown.

[0030] Depend on Figure 1 Medium, 3417cm -1 and 1587cm -1 The NH stretching and NH bending vibrations correspond to 1633 cm -1 and 2913cm -1 They correspond to the stretching vibrations of the amide group and the aliphatic methylene CH, respectively. Figure 1 It can be seen that the hyperbranched hemicellulose polymer I has the characteristic peaks of hemicellulose superimposed and has amino characteristics.

[0031] It was determined that the degree of polymerization of the hyperbranched hemicellulose polymer I was 128 and the degree of substitution was 0.8.

[0032] 2. Preparation of hyperbranched hemicellulose-based hydrogels Step A, taking 3 g of hyperbranched hemicellulose polymer I, adding 120 mL of distilled water and 12 g of gelatin, heating and stirring at 60° C. and 800 r / min for 1 h to obtain a hemicellulose-based hydrogel precursor; Step B: adding 9 g of glutaraldehyde to the hemicellulose hydrogel precursor to cross-link to obtain a hyperbranched hemicellulose-based hydrogel, which is recorded as hyperbranched hemicellulose-based hydrogel I.

[0033] The hyperbranched hemicellulose-based hydrogel I was completely dried, and the dried hydrogel was placed in a phosphate buffer solution with a pH of 6. The swelling rate was measured after 1 hour. The swelling rate calculation formula was: (m2-m1) / m1×100%, where m1 is the mass of the dried hydrogel (g), and m2 is the mass of the hydrogel after immersion (g). The test showed that the swelling rate of the hyperbranched hemicellulose-based hydrogel I was 52.99%.

[0034] Example 2 This embodiment provides a method for preparing a hyperbranched hemicellulose-based hydrogel, and the specific method is as follows: 1. Preparation of hyperbranched hemicellulose polymers Step 1: Take 14.9 g of hemicellulose, add 500 mL of N,N-dimethylformamide, 10.4 g of pyromellitic anhydride, 7.45 g of lithium chloride and 1.341 g of N-bromosuccinimide, heat and stir at 52 ° C and 800 r / min for 2 h to obtain 18.14 g of modified hemicellulose; Step 2: Take 8.4 g of modified hemicellulose, add 200 mL of anhydrous ethanol, 3.36 g of 1,2-propylenediamine, 5.88 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 27.7 mg of N-hydroxysuccinimide, heat and stir at 30 ° C and 800 r / min for 4 h to obtain 9.32 g of first-generation hyperbranched hemicellulose polymer; Step 3: Take 4.75 g of the first-generation hyperbranched hemicellulose polymer, add 200 mL of anhydrous ethanol, 9.02 g of pyromellitic anhydride, 2.85 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 28.5 mg of N-hydroxysuccinimide, heat and stir at 30 ° C and 800 r / min for 3.5 h to obtain 9.02 g of hyperbranched hemicellulose polymer precursor; Step 4: Take 6 g of hyperbranched hemicellulose polymer precursor, add 200 mL of anhydrous ethanol, 3.6 g of 1,2-propylenediamine, 3 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 27 mg of N-hydroxysuccinimide, heat and stir the reaction at 38°C and 800 r / min for 3 h to obtain 7.84 g of hyperbranched hemicellulose polymer, recorded as hyperbranched hemicellulose polymer II.

[0035] The hemicellulose in step 1 is obtained by extracting waste liquid from viscose fiber production, and its composition is 80.01% xylose, 11.02% mannose, 6.25% glucose, 1.21% galactose, and the remainder is glucuronic acid.

[0036] Infrared structural analysis of hyperbranched hemicellulose polymer II revealed that the hyperbranched hemicellulose polymer II had superposition of characteristic peaks of hemicellulose and had amino characteristics.

[0037] It was determined that the degree of polymerization of the hyperbranched hemicellulose polymer II was 140 and the degree of substitution was 0.65.

[0038] 2. Preparation of hyperbranched hemicellulose-based hydrogels Step A, taking 3 g of hyperbranched hemicellulose polymer II, adding 120 mL of distilled water and 15 g of gelatin, heating and stirring at 60° C. and 1000 r / min for 1 h to obtain a hemicellulose-based hydrogel precursor; Step B: adding 8.4 g of glutaraldehyde to the hemicellulose hydrogel precursor to cross-link to obtain a hyperbranched hemicellulose-based hydrogel, which is recorded as hyperbranched hemicellulose-based hydrogel II.

[0039] The swelling ratio of the hyperbranched hemicellulose-based hydrogel II was measured according to the method described in Example 1. The swelling ratio of the hyperbranched hemicellulose-based hydrogel II was measured to be 52.37%.

[0040] Example 3 This embodiment provides a method for preparing a hyperbranched hemicellulose-based hydrogel, and the specific method is as follows: Step 1: Take 14.9 g of hemicellulose, add 500 mL of N,N-dimethylformamide, 11.2 g of pyromellitic anhydride, 13.41 g of lithium chloride and 0.745 g of N-bromosuccinimide, heat and stir at 48 ° C and 800 r / min for 1.8 h to obtain 18.21 g of modified hemicellulose; Step 2: Take 8.4 g of modified hemicellulose, add 200 mL of anhydrous ethanol, 7.56 g of hexamethylenediamine, 5.04 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 31.9 mg of N-hydroxysuccinimide, heat and stir at 40°C and 800 r / min for 3.5 h to obtain 10.78 g of first-generation hyperbranched hemicellulose polymer; Step 3: Take 4.75 g of the first-generation hyperbranched hemicellulose polymer, add 200 mL of anhydrous ethanol, 13.78 g of pyromellitic anhydride, 7.12 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 30.88 mg of N-hydroxysuccinimide, heat and stir at 40 ° C and 800 r / min for 2.5 h to obtain 8.74 g of hyperbranched hemicellulose polymer precursor; Step 4: Take 6 g of hyperbranched hemicellulose polymer precursor, add 200 mL of anhydrous ethanol, 6.6 g of hexamethylenediamine, 7.2 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 33 mg of N-hydroxysuccinimide, heat and stir the reaction at 42°C and 800 r / min for 3 h to obtain 8.33 g of hyperbranched hemicellulose polymer, recorded as hyperbranched hemicellulose polymer III.

[0041] The hemicellulose in step 1 is obtained by extracting waste liquid from viscose fiber production, and its composition is 78.24% xylose, 12.03% mannose, 6.02% glucose, 1.26% galactose, and the remainder is glucuronic acid.

[0042] Infrared structural analysis of hyperbranched hemicellulose polymer III revealed that hyperbranched hemicellulose polymer II had superposition of characteristic peaks of hemicellulose and had amino characteristics.

[0043] It was determined that the degree of polymerization of the hyperbranched hemicellulose polymer I was 80 and the degree of substitution was 0.58.

[0044] 2. Preparation of hyperbranched hemicellulose-based hydrogels Step A, taking 3 g of hyperbranched hemicellulose polymer III, adding 120 mL of distilled water and 12 g of gelatin, heating and stirring at 50° C. and 1000 r / min for 1 h to obtain a hemicellulose-based hydrogel precursor; Step B: adding 9.6 g of glutaraldehyde to the hemicellulose hydrogel precursor to cross-link to obtain a hyperbranched hemicellulose-based hydrogel, which is recorded as hyperbranched hemicellulose-based hydrogel III.

[0045] The swelling ratio of the hyperbranched hemicellulose-based hydrogel III was measured according to the method described in Example 1. The swelling ratio of the hyperbranched hemicellulose-based hydrogel III was measured to be 49.14%.

[0046] Example 4 This embodiment provides a method for preparing a hyperbranched hemicellulose-based hydrogel, and the specific method is as follows: Step 1: Take 14.9 g of hemicellulose, add 500 mL of N,N-dimethylformamide, 10.7 g of pyromellitic anhydride, 11.92 g of lithium chloride and 0.894 g of N-bromosuccinimide, heat and stir at 50°C and 800 r / min for 2.5 h to obtain 18.73 g of modified hemicellulose; Step 2: Take 8.4 g of modified hemicellulose, add 200 mL of anhydrous ethanol, 6.13 g of ethylenediamine, 5.21 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 30.2 mg of N-hydroxysuccinimide, heat and stir at 37°C and 800 r / min for 3.5 h to obtain 9.77 g of first-generation hyperbranched hemicellulose polymer; Step 3: Take 4.75 g of the first-generation hyperbranched hemicellulose polymer, add 200 mL of anhydrous ethanol, 11.88 g of pyromellitic anhydride, 5.7 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 29 mg of N-hydroxysuccinimide, heat and stir at 37 ° C and 800 r / min for 3 h to obtain 9.28 g of hyperbranched hemicellulose polymer precursor; Step 4: Take 6 g of hyperbranched hemicellulose polymer precursor, add 200 mL of anhydrous ethanol, 4.86 g of ethylenediamine, 5.7 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 31.2 mg of N-hydroxysuccinimide, heat and stir the reaction at 40°C and 800 r / min for 3 h to obtain 8.14 g of hyperbranched hemicellulose polymer, recorded as hyperbranched hemicellulose polymer IV.

[0047] The hemicellulose in step 1 is obtained by extracting waste liquid from viscose fiber production, and its composition is 74.52% xylose, 11.25% mannose, 11.95% glucose, 1.24% galactose, and the remainder is glucuronic acid.

[0048] Infrared structural analysis of hyperbranched hemicellulose polymer IV revealed that hyperbranched hemicellulose polymer II had superposition of characteristic peaks of hemicellulose and had amino characteristics.

[0049] It was determined that the degree of polymerization of the hyperbranched hemicellulose polymer I was 105 and the degree of substitution was 0.75.

[0050] 2. Preparation of hyperbranched hemicellulose-based hydrogels Step A, taking 3 g of hyperbranched hemicellulose polymer IV, adding 120 mL of distilled water and 6 g of gelatin, heating and stirring at 70° C. and 1000 r / min for 1 h to obtain a hemicellulose-based hydrogel precursor; Step B: adding 9 g of glutaraldehyde to the hemicellulose hydrogel precursor to cross-link to obtain a hyperbranched hemicellulose-based hydrogel, which is recorded as hyperbranched hemicellulose-based hydrogel IV.

[0051] The swelling ratio of the hyperbranched hemicellulose-based hydrogel IV was measured according to the method described in Example 1. The swelling ratio of the hyperbranched hemicellulose-based hydrogel IV was measured to be 46.04%.

[0052] Example 5 This embodiment provides an application of a hyperbranched hemicellulose-based hydrogel in controlled drug release, wherein the hyperbranched hemicellulose-based hydrogel I loaded with avermectin is used as an example for illustration. Further, the performance of the hyperbranched hemicellulose-based hydrogel drug delivery system is tested. The specific contents are as follows.

[0053] A certain mass of hyperbranched hemicellulose-based hydrogel I and avermectin model drug were placed in a phosphate buffer solution with a pH of 6, wherein the mass ratio of hyperbranched hemicellulose-based hydrogel I to avermectin model drug was 1:0.18; the mass volume ratio of hyperbranched hemicellulose-based hydrogel I to phosphate buffer solution was 1 g:0.5 L.

[0054] The swelling rate of the hyperbranched hemicellulose-based hydrogel I at different times, temperatures and pH values ​​and the controlled release concentration of the loaded avermectin drug were determined, specifically including: Testing the time sensitivity of the hydrogel: At 25°C, the hyperbranched hemicellulose-based hydrogel I was placed in a phosphate buffer solution with a pH of 6, and the swelling rate of the hydrogel was measured every two hours.

[0055] Test the temperature sensitivity of the hydrogel: The hyperbranched hemicellulose-based hydrogel I was placed in a phosphate buffer solution with a pH of 6, and the swelling rate of the hydrogel was measured at 20°C, 30°C, 40°C, 50°C, and 60°C for 1 h.

[0056] Testing the pH sensitivity of the hydrogel: At 25°C, the hyperbranched hemicellulose-based hydrogel I was placed in phosphate buffer solutions of pH = 2, pH = 4, pH = 6, pH = 8, and pH = 10, respectively, and the swelling rate of the hydrogel was measured for 1 h.

[0057] Testing the drug release of the hydrogel: The hydrogel loaded with avermectin was placed in a phosphate buffer solution with a pH of 6 at 25°C, and the concentration of avermectin in the solution was measured at regular intervals. Test the thermosensitivity of drug release of the hydrogel: The hydrogel loaded with avermectin was placed in a phosphate buffer solution with a pH of 6, and the concentration of avermectin in the solution was measured after 8 hours at 20°C, 30°C, 40°C, and 50°C.

[0058] The formula for calculating the cumulative drug release rate is: c1v1 / M×100%, where c1 is the concentration of avermectin in the soaking solution (mg / L), v1 is the volume of the soaking solution (L), and M is the mass of avermectin added during the preparation process (g). The performance test results are shown in Table 1.

[0059] Table 1

[0060] As shown in Table 1, hyperbranched hemicellulose hydrogel I has good swelling reversibility, pH sensitivity and temperature sensitivity after loading avermectin. At 25°C, the swelling rate of the hydrogel was 166.49% after 12 hours; the hydrogel is pH sensitive, and when pH=2, the swelling rate is as high as 91.03% within 1 hour. The swelling rate of the hydrogel increases with the increase of temperature; the drug release rate is affected by temperature. At 20°C, the cumulative drug release rate is 30.17% after 8 hours, while at 50°C, the cumulative drug release rate is 66.56% after 8 hours. The hydrogel has good drug loading temperature sensitivity. In addition, the hyperbranched hemicellulose-based hydrogel has a good controlled release effect on the drug. At 25°C, the cumulative drug release rate can reach 72.34% in 45 days, which has good long-term sustained release.

[0061] After testing, the hyperbranched hemicellulose-based hydrogel II, hyperbranched hemicellulose-based hydrogel III and hyperbranched hemicellulose-based hydrogel IV prepared in Examples 2 to 4 also have good swelling reversibility, pH responsiveness and temperature responsiveness after loading avermectin. Among them, the hyperbranched hemicellulose-based hydrogel I has the best performance after loading avermectin.

[0062] Example 6 This embodiment provides an application of a hyperbranched hemicellulose-based hydrogel in controlled drug release, wherein the hyperbranched hemicellulose-based hydrogel I loaded with salicylic acid is used as an example for illustration. Further, the preparation method of the hyperbranched hemicellulose-based hydrogel drug-carrying system is basically the same as that of Example 5, except that the drug loading is 110 mg / g and the model drug is replaced with salicylic acid. With reference to Example 5, its performance was further tested. The specific test results are shown in Table 2.

[0063] Table 2

[0064] From the data in Table 2, it can be seen that hyperbranched hemicellulose hydrogel I has good swelling reversibility, pH responsiveness and temperature responsiveness after loading salicylic acid. Under 25℃, the swelling rate of the hydrogel reaches 176.63% in 12h; the hydrogel is sensitive to pH, and the swelling rate is the highest when pH=2; the swelling rate of the hydrogel increases with increasing temperature; the drug release rate is affected by temperature. At 20℃, the cumulative drug release rate is 50.09% at 8h, while at 50℃, the cumulative drug release rate is 68.34% at 8h, indicating that the hydrogel has good temperature sensitivity of drug loading; at the same time, the hyperbranched hemicellulose-based hydrogel has a good controlled release effect on drugs. At 25℃, the cumulative drug release rate can reach 83.21% in 45d, which has good long-term sustained release.

[0065] Comparative Example 1 This comparative example prepares an intelligent responsive biomass-based material and loads the model drug camptothecin according to the method described in Example 2 of Chinese invention patent CN202111001690.9, with a drug loading of 201 mg / g.

[0066] The release performance of the model drug camptothecin loaded on the prepared smart responsive hemicellulose-based material was compared with that of the hyperbranched hemicellulose hydrogel drug delivery system in Example 5 of the present invention. The cumulative drug release rates of the two drug-loaded hydrogels after 24 hours in a phosphate buffer solution with a pH of 6 at 0°C and 50°C were tested respectively; the test results are shown in Table 3.

[0067] Table 3

[0068] As can be seen from Table 3, the hyperbranched hemicellulose hydrogel drug delivery system provided in Example 5 of the present invention has a more controllable release and a more significant temperature sensitivity.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A hyperbranched hemicellulose polymer, characterized in that Its structure is shown in Formula I: Formula I; Among them, R1 is ; n is an integer between 80 and 140; R2 is ; The degree of substitution of the hyperbranched hemicellulose polymer is 0.58-0.

80.

2. The method for preparing a hyperbranched hemicellulose polymer according to claim 1, wherein The preparation method comprises the following steps: Step 1, reacting hemicellulose with pyromellitic anhydride at 48°C to 52°C to obtain modified hemicellulose; Step 2: reacting the modified hemicellulose with alkyl diamine, 1-ethyl-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide at 30° C. to 40° C. to obtain a first-generation hyperbranched hemicellulose polymer; Step 3, reacting the first-generation hyperbranched hemicellulose polymer with pyromellitic anhydride, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide at 30° C. to 40° C. to obtain a hyperbranched hemicellulose polymer precursor; Step 4: reacting the hyperbranched hemicellulose polymer precursor with alkyl diamine, 1-ethyl-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide at 38° C. to 42° C. to obtain a hyperbranched hemicellulose polymer.

3. The method for preparing a hyperbranched hemicellulose polymer according to claim 2, wherein: Step 1 specifically comprises: mixing hemicellulose with pyromellitic anhydride, reacting at 48° C. to 52° C. in the presence of lithium chloride and N-bromosuccinimide to obtain modified hemicellulose; Wherein, the mass ratio of hemicellulose, lithium chloride and N-bromosuccinimide is 100:50~90:5~9; and / or The mass ratio of the hemicellulose to pyromellitic anhydride is 100:70 to 100:

75.

4. The method for preparing a hyperbranched hemicellulose polymer according to claim 2 or 3, characterized in that: The hemicellulose comprises the following components in percentage by weight: 74% to 80% xylose, 11% to 12% mannose, 6% to 12% glucose, 1.2% to 1.3% galactose, and the remainder is glucuronic acid.

5. The method for preparing a hyperbranched hemicellulose polymer according to claim 2, wherein: In step 2, the mass ratio of the modified hemicellulose to alkyl diamine, 1-ethyl-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 100:40-90:60-70:0.33-0.38; and / or In step 3, the mass ratio of the first-generation hyperbranched hemicellulose polymer to pyromellitic anhydride, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide is 100:190-290:60-150:0.6-0.65; and / or In step 4, the mass ratio of the hyperbranched hemicellulose polymer precursor to alkyl diamine, 1-ethyl-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 100:60-110:50-120:0.45-0.55; Wherein, the alkyl diamine includes at least one of hexamethylenediamine, ethylenediamine or 1,2-propylenediamine.

6. Use of the hyperbranched hemicellulose polymer as claimed in claim 1 or the hyperbranched hemicellulose polymer prepared by the preparation method of the hyperbranched hemicellulose polymer according to any one of claims 2 to 5 in a hyperbranched hemicellulose-based hydrogel.

7. A hyperbranched hemicellulose-based hydrogel, characterized in that The hyperbranched hemicellulose-based hydrogel contains the hyperbranched hemicellulose polymer described in claim 1 or the hyperbranched hemicellulose polymer prepared by the preparation method of the hyperbranched hemicellulose polymer described in any one of claims 2 to 5.

8. The method for preparing a hyperbranched hemicellulose-based hydrogel according to claim 7, characterized in that: The preparation method comprises the following steps: Step A, mixing the hyperbranched hemicellulose polymer with gelatin, and reacting at 50° C. to 70° C. to obtain a hemicellulose-based hydrogel precursor; Step B: adding glutaraldehyde to the hemicellulose hydrogel precursor to cross-link and obtain a hyperbranched hemicellulose-based hydrogel.

9. The method for preparing a hyperbranched hemicellulose-based hydrogel according to claim 8, characterized in that: The mass ratio of the hyperbranched hemicellulose polymer to gelatin is 1:2 to 1:5; The mass ratio of the hyperbranched hemicellulose polymer to glutaraldehyde is 1:2.8 to 1:3.

2.

10. Use of the hyperbranched hemicellulose-based hydrogel prepared by the method for preparing a hyperbranched hemicellulose-based hydrogel as claimed in claim 8 or 9 in preparing a drug controlled release material.

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