Temperature-sensitive gel composition for adjuvant therapy of radiation proctitis and preparation method thereof

Abstract

The invention relates to the technical field of temperature-sensitive gel, in particular to a temperature-sensitive gel composition for adjuvant therapy of radiation proctitis and a preparation method of the temperature-sensitive gel composition. The temperature-sensitive gel composition is prepared from the following raw material components in parts by weight: 1.6 to 3.2 parts of curcumin and sodium alginate, 2 to 4 parts of CS-PCA-Arg, 45 to 90 parts of poloxamer 407, 3 to 6 parts of carbomer 940 and 6 to 12 parts of sodium hyaluronate. The prepared temperature-sensitive gel composition has good stability and can be used for adjuvant therapy of radiation proctitis.

Description

Technical Field

[0001] The present invention relates to the technical field of thermosensitive gels, and in particular to a thermosensitive gel composition for assisting in the treatment of radiation proctitis and a preparation method thereof. Background Art

[0002] Radiation proctitis (RP) refers to a rectal complication that occurs during or after radiotherapy for patients with pelvic malignancies. Erosions, ulcers, or bleeding may occur in the rectal mucosa. Clinical manifestations include abdominal pain, diarrhea, bloody stools, and mucus, pus, and blood in the stool, severely impacting patients' quality of life. Radiation proctitis can be acute or chronic, depending on the severity of onset. Acute RP typically develops one to two weeks after radiotherapy, with symptoms including diarrhea, tenesmus, painful defecation, and mucus and blood in the stool. Approximately 80% of patients experience acute diarrhea during radiotherapy. Chronic RP, which typically develops months to years after radiotherapy, presents with rectal stenosis, dyspnea, and even intestinal obstruction. Currently, ideal medications and treatments for RP are lacking, both domestically and internationally. In clinical practice, steroids and symptomatic supportive care are the primary treatments for RP, alleviating symptoms, but these are not ideal. Hormone therapy is associated with high dependency, long treatment duration, and numerous side effects. Symptomatic treatments such as antibiotics, hemostatic drugs, and film-forming agents cannot fundamentally repair the damaged mucosa. Summary of the Invention

[0003] In view of the deficiencies in the prior art, the present invention provides a thermosensitive gel composition for assisting in the treatment of radiation proctitis and a preparation method thereof.

[0004] The present invention is achieved through the following technical solutions: A thermosensitive gel composition for assisting the treatment of radiation proctitis. The preparation raw materials include the following components in parts by weight: 1.6-3.2 parts of curcumin@sodium alginate, 2-4 parts of CS-PCA-Arg, 45-90 parts of poloxamer 407, 3-6 parts of carbomer 940, and 6-12 parts of sodium hyaluronate.

[0005] Furthermore, the raw materials for preparing the curcumin@sodium alginate include the following components in parts by weight: 2-3 parts of sialic acid, 1-1.5 parts of chitosan, 6-9 parts of sodium alginate, and 1-1.5 parts of curcumin.

[0006] Furthermore, the preparation method of curcumin@sodium alginate comprises the following steps: L1. Chitosan was dissolved in 1% v / v acetic acid to obtain CS solution. Sialic acid was dissolved in MES buffer (pH 6), EDC·HCl and NHS were added, and the mixture was stirred for 30 min. The mixture was then added to the CS solution and stirred at pH 6 for 24 h. The mixture was dialyzed against deionized water for 3 days and freeze-dried under vacuum to obtain SA-chitosan. L2. The SA-chitosan and sodium alginate obtained in step L1 were added to distilled water and stirred evenly. Tween 80 was added and mixed thoroughly. Curcumin was added and mixed thoroughly. Ultrasonic mixing was performed and homogenized at 10,000 rpm at 4°C for 30 min. The mixture was added dropwise to a 2 wt% CaCl2 solution. The mixture was stirred at 100 rpm at room temperature for 2 h and centrifuged at 3,000 rpm for 5 min. The precipitate was washed with deionized water and ethanol and dried in vacuo to obtain curcumin@sodium alginate.

[0007] Furthermore, in step L1, the mass concentration of the chitosan in the 1% v / v acetic acid solution is 20 mg / mL.

[0008] Furthermore, in step L1, the mass concentration of sialic acid in MES buffer is 20-30 mg / mL.

[0009] Furthermore, in step L1, the mass ratio of sialic acid, EDC·HCl and NHS is 4:3:1.8.

[0010] Furthermore, in step L2, the mass concentration of sodium alginate in distilled water is 15 mg / mL.

[0011] Furthermore, in step L2, the concentration of Tween 80 in distilled water is 0.5% v / v.

[0012] Furthermore, in step L2, the volume ratio of the CaCl2 solution to distilled water is 3:1.

[0013] Furthermore, the raw materials for preparing the CS-PCA-Arg include the following components in parts by weight: 1.2-1.8 parts of chitosan, 0.4-0.6 parts of protocatechuic acid, and 0.5-0.8 parts of arginine.

[0014] Furthermore, the preparation method of CS-PCA-Arg comprises the following steps: V1. Chitosan was dissolved in 1% v / v acetic acid to obtain a chitosan solution. EDC·HCl and NHS were dissolved in MES buffer (pH 5.5) to obtain an EDC / NHS solution. Under a nitrogen atmosphere, protocatechuic acid was dissolved in ethanol and added to the EDC / NHS solution. The solution was stirred in an ice-water bath in the dark for 1 hour, then added to the chitosan solution. The solution was stirred at room temperature in the dark for 24 hours, dialyzed against deionized water for 2 days, and freeze-dried under vacuum to obtain CS-PCA. V2. Under a nitrogen atmosphere, add 20 mg / mL of CS-PCA obtained in step V1 to 1% v / v acetic acid solution in the dark and stir to obtain mixture A. Dissolve arginine in MES buffer (pH 5), add EDC·HCl and NHS, and stir for 2 h to obtain mixture B. Add mixture B to mixture A, stir in the dark for 24 h, dialyze against deionized water for 3 days, and freeze-dry to obtain CS-PCA-Arg.

[0015] Furthermore, in step V1, the mass concentration of the chitosan in the 1% v / v acetic acid solution is 20 mg / mL.

[0016] Furthermore, in step V1, the mass concentration of the EDC·HCl in the MES buffer solution is 12.5 mg / mL.

[0017] Furthermore, in step V1, the mass concentration of protocatechuic acid in ethanol is 0.1 g / mL.

[0018] Furthermore, in step V1, the mass ratio of protocatechuic acid, EDC·HCl and NHS is 0.4:0.5:0.3.

[0019] Furthermore, in step V2, the mass concentration of arginine in MES buffer is 20 mg / mL.

[0020] Furthermore, in step V2, the mass ratio of arginine EDC·HCl to NHS is 0.4:0.67:0.4.

[0021] Furthermore, the present invention also provides a method for preparing the thermosensitive gel composition for assisting in the treatment of radiation proctitis, comprising the following steps: S1. CS-PCA-Arg was added to deionized water and sonicated at 300 W at room temperature for 10 min. Curcumin@sodium alginate was added while stirring. The mixture was stirred at 200-300 rpm for 1 h. The mixture was filtered, washed with deionized water, and dried under vacuum to obtain coated curcumin@sodium alginate. The mixture was then dispersed in deionized water at a ratio of 50 mg / mL to obtain a dispersion. S2. Add poloxamer 407 to deionized water and allow to swell overnight at 4°C to obtain component A. Add carbomer 940 to deionized water and allow to swell overnight at 4°C. Add 5% triethanolamine solution and stir to obtain component B. Add sodium hyaluronate to deionized water and allow to swell overnight at 4°C to obtain component C. S3. Component A, component B, and component C obtained in step S2 are mixed, the dispersion obtained in step S1 is added, and the mixture is stirred evenly to obtain a thermosensitive gel composition for the adjuvant treatment of radiation proctitis.

[0022] Furthermore, in step S1, the mass concentration of the CS-PCA-Arg in deionized water is 10 mg / mL.

[0023] Furthermore, in step S2, the mass concentration of poloxamer 407 in deionized water is 0.45 g / mL.

[0024] Furthermore, in step S2, the mass concentration of the carbomer 940 in deionized water is 60 mg / mL.

[0025] Furthermore, in step S2, the mass concentration of the sodium hyaluronate in deionized water is 40 mg / mL.

[0026] Furthermore, in step S2, the volume ratio of the triethanolamine solution to deionized water is 2:1.

[0027] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a thermosensitive gel composition for auxiliary treatment of radiation proctitis and a preparation method thereof. Through the scientific ratio and synergistic effect of specific components, combined with the characteristics of thermosensitive gel, efficient auxiliary treatment of radiation proctitis is achieved, while ensuring good biosafety and stability. Among the raw materials used in the thermosensitive gel composition prepared by the present invention, chitosan is a natural polysaccharide with good biocompatibility and degradability; curcumin, protocatechuic acid, arginine, etc. are all substances of natural origin or good biocompatibility; poloxamer, carbomer and other materials are also widely used in pharmaceutical preparations with high biosafety. The present invention uses water-soluble and highly biocompatible sialic acid (SA) to modify chitosan (CS) through EDC·HCl / NHS to prepare SA-chitosan, improve the water solubility of chitosan, use SA-chitosan and sodium alginate as wall materials, encapsulate curcumin, sodium alginate and Ca 2+During cross-linking, SA-chitosan and sodium alginate form a network structure. SA-chitosan can fill surface pores, reduce the leakage of curcumin, increase the encapsulation efficiency of curcumin, and enhance storage stability. Sodium alginate is a natural anionic polysaccharide. The surface of the obtained curcumin@sodium alginate is negatively charged, which is conducive to the subsequent coating of CS-PCA-Arg. Curcumin, as a natural active ingredient, has anti-inflammatory, antioxidant and mucosal repair potential. The present invention uses SA-chitosan and sodium alginate as wall materials and curcumin as the core material to encapsulate curcumin to obtain curcumin@sodium alginate, which can enhance the adjuvant treatment effect. The present invention prepares CS-PCA-Arg by grafting protocatechuic acid onto chitosan. Protocatechuic acid, as a natural phenolic compound, has a catechol structure in its molecule that can effectively scavenge free radicals. Arginine is further grafted onto CS-PCA to enhance the water solubility of chitosan and the positive charge of CS-PCA-Arg, improving its affinity with the surface of curcumin@sodium alginate, allowing it to be effectively coated on the surface of curcumin@sodium alginate. Furthermore, the positive charge in CS-PCA-Arg and the catechol group in protocatechuic acid can enhance adhesion to the intestine, improve retention in the body, prolong the duration of action, and enhance the therapeutic effect. Simultaneously, the stability of the system is enhanced, reducing the leakage of curcumin. After forming a gel in the rectum, the thermosensitive gel of the present invention can slowly release curcumin and other active ingredients, alleviating the inflammatory response of the rectal mucosa and promoting mucosal repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a scanning electron micrograph of the curcumin@sodium alginate coated according to Example 1 of the present invention; Figure 2 The curcumin encapsulation efficiency of curcumin@sodium alginate described in Examples 1-3 of the present invention and Comparative Example 1; Figure 3 The stability of the coated curcumin@sodium alginate described in Example 1 and Comparative Examples 2-3 of the present invention; Figure 4 The therapeutic effects of the thermosensitive gel described in Example 1 and Comparative Examples 1-3 of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific examples, but the present invention is not limited to the following examples. It should be noted that, unless otherwise specified, the chemical reagents involved in the present invention were purchased through commercial channels.

[0031] Example 1: A thermosensitive gel composition for adjuvant treatment of radiation proctitis, wherein the raw materials for preparation include the following components in parts by weight: 3.2 parts of curcumin@sodium alginate, 4 parts of CS-PCA-Arg, 90 parts of poloxamer 407, 6 parts of carbomer 940, and 12 parts of sodium hyaluronate.

[0032] The raw materials for preparing curcumin@sodium alginate include the following components in parts by weight: 3 parts of sialic acid, 1.5 parts of chitosan, 9 parts of sodium alginate, and 1.5 parts of curcumin.

[0033] The preparation method of curcumin@sodium alginate comprises the following steps: L1. Dissolve 1.5 g of chitosan in 75 mL of 1% v / v acetic acid to obtain CS solution. Dissolve 3 g of sialic acid in 100 mL of MES buffer (pH 6). Add 2.25 g of EDC·HCl and 1.35 g of NHS, stir for 30 min, and add to the CS solution. Stir and react at pH 6 for 24 h. Dialyze against deionized water for 3 days and freeze-dry under vacuum to obtain SA-chitosan. L2. Add 9 g of SA-chitosan and sodium alginate obtained in step L1 to 600 mL of distilled water and stir evenly. Add 3 mL of Tween 80 and mix thoroughly. Add 1.5 g of curcumin and stir thoroughly. Ultrasonicate and homogenize at 10,000 r / min at 4°C for 30 min. Add dropwise to 1800 mL of 2 wt% CaCl2 solution and stir at 100 r / min at room temperature for 2 h. Centrifuge at 3,000 r / min for 5 min. Wash the precipitate with deionized water and ethanol and dry in vacuo to obtain curcumin@sodium alginate.

[0034] The raw materials for preparing CS-PCA-Arg include the following components in parts by weight: 1.8 parts of chitosan, 0.6 parts of protocatechuic acid, and 0.8 parts of arginine.

[0035] The preparation method of CS-PCA-Arg comprises the following steps: V1. Dissolve 1.8 g of chitosan in 90 mL of 1% v / v acetic acid to obtain a chitosan solution. Dissolve 0.75 g of EDC·HCl and 0.45 g of NHS in 60 mL of MES buffer (pH 5.5) to obtain an EDC / NHS solution. Under a nitrogen atmosphere, dissolve 0.6 g of protocatechuic acid in 6 mL of ethanol and add the solution to the EDC / NHS solution. Stir in an ice-water bath in the dark for 1 h. This solution was then added to the chitosan solution and stirred at room temperature in the dark for 24 h. The solution was dialyzed against deionized water for 2 days and freeze-dried under vacuum to obtain CS-PCA. V2. Under a nitrogen atmosphere, add 20 mg / mL of CS-PCA obtained in step V1 to 1% v / v acetic acid solution in the dark with stirring to obtain mixed solution A. Dissolve 0.8 g of arginine in 40 mL of MES buffer (pH 5), add 1.34 g of EDC·HCl and 0.8 g of NHS, and stir for 2 h to obtain mixed solution B. Add mixed solution B to mixed solution A, stir in the dark for 24 h, dialyze against deionized water for 3 d, and freeze-dry to obtain CS-PCA-Arg.

[0036] This embodiment also provides a method for preparing the thermosensitive gel composition for adjuvant treatment of radiation proctitis, comprising the following steps: S1. Add 4 g of CS-PCA-Arg to 400 mL of deionized water and ultrasonicate at room temperature at 300 W for 10 min. Add 3.2 g of curcumin@sodium alginate while stirring. Stir at 300 rpm for 1 h. Filter, wash with deionized water, and vacuum dry to obtain coated curcumin@sodium alginate. The scanning electron microscopy image is shown in the figure. Figure 1 As shown, it was dispersed in deionized water at a ratio of 50 mg / mL to obtain a dispersion; S2. Add 90 g of Poloxamer 407 to 200 mL of deionized water and allow to swell overnight at 4°C to obtain component A. Add 6 g of Carbomer 940 to 100 mL of deionized water and allow to swell overnight at 4°C. Add 200 mL of 5% triethanolamine solution and stir thoroughly to obtain component B. Add 12 g of sodium hyaluronate to 300 mL of deionized water and allow to swell overnight at 4°C to obtain component C. S3. Component A, component B, and component C obtained in step S2 are mixed, the dispersion obtained in step S1 is added, and the mixture is stirred evenly to obtain a thermosensitive gel composition for the adjuvant treatment of radiation proctitis.

[0037] Example 2: A thermosensitive gel composition for adjuvant treatment of radiation proctitis, prepared from raw materials comprising the following components in parts by weight: 1.6 parts of curcumin@sodium alginate, 2 parts of CS-PCA-Arg, 45 parts of poloxamer 407, 3 parts of carbomer 940, and 6 parts of sodium hyaluronate.

[0038] The raw materials for preparing curcumin@sodium alginate include the following components in parts by weight: 2 parts of sialic acid, 1 part of chitosan, 6 parts of sodium alginate, and 1 part of curcumin.

[0039] The preparation method of curcumin@sodium alginate comprises the following steps: L1. Dissolve 1 g of chitosan in 50 mL of 1% v / v acetic acid to obtain CS solution. Dissolve 2 g of sialic acid in 100 mL of MES buffer (pH 6). Add 1.5 g of EDC·HCl and 0.9 g of NHS, stir for 30 min, and add to the CS solution. Stir and react at pH 6 for 24 h. Dialyze against deionized water for 3 days and freeze-dry under vacuum to obtain SA-chitosan. L2. Add 6 g of SA-chitosan and sodium alginate obtained in step L1 to 400 mL of distilled water and stir evenly. Add 2 mL of Tween 80 and mix thoroughly. Add 1 g of curcumin and stir thoroughly. Ultrasonicate and homogenize at 10,000 r / min at 4°C for 30 min. Add dropwise to 1200 mL of 2 wt% CaCl2 solution and stir at 100 r / min at room temperature for 2 h. Centrifuge at 3,000 r / min for 5 min. Wash the precipitate with deionized water and ethanol and dry in vacuo to obtain curcumin@sodium alginate.

[0040] The raw materials for preparing CS-PCA-Arg include the following components in parts by weight: 1.2 parts of chitosan, 0.4 parts of protocatechuic acid, and 0.5 parts of arginine.

[0041] The preparation method of CS-PCA-Arg comprises the following steps: V1. Dissolve 1.2 g of chitosan in 60 mL of 1% v / v acetic acid to obtain a chitosan solution. Dissolve 0.5 g of EDC·HCl and 0.3 g of NHS in 40 mL of MES buffer (pH 5.5) to obtain an EDC / NHS solution. Under a nitrogen atmosphere, dissolve 0.4 g of protocatechuic acid in 4 mL of ethanol and add the solution to the EDC / NHS solution. Stir in an ice-water bath in the dark for 1 h. This solution was then added to the chitosan solution and stirred at room temperature in the dark for 24 h. The solution was dialyzed against deionized water for 2 days and freeze-dried under vacuum to obtain CS-PCA. V2. Under a nitrogen atmosphere, add 20 mg / mL of CS-PCA obtained in step V1 to 1% v / v acetic acid solution in the dark with stirring to obtain mixed solution A. Dissolve 0.5 g of arginine in 25 mL of MES buffer (pH 5), add 0.8375 g of EDC·HCl and 0.5 g of NHS, and stir for 2 h to obtain mixed solution B. Add mixed solution B to mixed solution A, stir in the dark for 24 h, dialyze against deionized water for 3 d, and freeze-dry to obtain CS-PCA-Arg.

[0042] This embodiment also provides a method for preparing the thermosensitive gel composition for adjuvant treatment of radiation proctitis, comprising the following steps: S1. Add 2 g of CS-PCA-Arg to 200 mL of deionized water and sonicate at 300 W at room temperature for 10 min. Add 1.6 g of curcumin@sodium alginate while stirring. Stir at 200 rpm for 1 h. Filter, wash with deionized water, and vacuum dry to obtain coated curcumin@sodium alginate. Disperse in deionized water at a ratio of 50 mg / mL to obtain a dispersion. S2. Add 45 g of Poloxamer 407 to 100 mL of deionized water and allow to swell overnight at 4°C to obtain component A. Add 3 g of Carbomer 940 to 50 mL of deionized water and allow to swell overnight at 4°C. Add 100 mL of 5% triethanolamine solution and stir to obtain component B. Add 6 g of sodium hyaluronate to 150 mL of deionized water and allow to swell overnight at 4°C to obtain component C. S3. Component A, component B, and component C obtained in step S2 are mixed, the dispersion obtained in step S1 is added, and the mixture is stirred evenly to obtain a thermosensitive gel composition for the adjuvant treatment of radiation proctitis.

[0043] Example 3: A thermosensitive gel composition for adjuvant treatment of radiation proctitis, the preparation raw materials include the following components in parts by weight: 2.4 parts of curcumin@sodium alginate, 3 parts of CS-PCA-Arg, 67.5 parts of poloxamer 407, 4.5 parts of carbomer 940, and 9 parts of sodium hyaluronate.

[0044] The raw materials for preparing curcumin@sodium alginate include the following components in parts by weight: 2.5 parts of sialic acid, 1.25 parts of chitosan, 7.5 parts of sodium alginate, and 1.25 parts of curcumin.

[0045] The preparation method of curcumin@sodium alginate comprises the following steps: L1. Dissolve 1.25 g of chitosan in 62.5 mL of 1% v / v acetic acid to obtain CS solution. Dissolve 2.5 g of sialic acid in 100 mL of MES buffer (pH 6). Add 1.875 g of EDC·HCl and 1.125 g of NHS, stir for 30 minutes, and then add to the CS solution. Stir and react at pH 6 for 24 hours. Dialyze against deionized water for 3 days and freeze-dry under vacuum to obtain SA-chitosan. L2. Add 7.5 g of SA-chitosan and sodium alginate obtained in step L1 to 500 mL of distilled water and stir evenly. Add 2.5 mL of Tween 80 and mix thoroughly. Add 1.25 g of curcumin and stir thoroughly. Ultrasonicate and homogenize at 10,000 r / min at 4°C for 30 min. Add dropwise to 1500 mL of 2 wt% CaCl2 solution and stir at 100 r / min at room temperature for 2 h. Centrifuge at 3,000 r / min for 5 min. Wash the precipitate with deionized water and ethanol and dry in vacuo to obtain curcumin@sodium alginate.

[0046] The raw materials for preparing CS-PCA-Arg include the following components in parts by weight: 1.5 parts of chitosan, 0.5 parts of protocatechuic acid, and 0.6 parts of arginine.

[0047] The preparation method of CS-PCA-Arg comprises the following steps: V1. Dissolve 1.5 g of chitosan in 75 mL of 1% v / v acetic acid to obtain a chitosan solution. Dissolve 0.625 g of EDC·HCl and 0.375 g of NHS in 50 mL of MES buffer (pH 5.5) to obtain an EDC / NHS solution. Under a nitrogen atmosphere, dissolve 0.5 g of protocatechuic acid in 5 mL of ethanol and add the solution to the EDC / NHS solution. Stir in an ice-water bath in the dark for 1 h. This solution was then added to the chitosan solution and stirred at room temperature in the dark for 24 h. The solution was dialyzed against deionized water for 2 days and freeze-dried under vacuum to obtain CS-PCA. V2. Under a nitrogen atmosphere, add 20 mg / mL of CS-PCA obtained in step V1 to 1% v / v acetic acid solution in the dark with stirring to obtain mixed solution A. Dissolve 0.6 g of arginine in 30 mL of MES buffer (pH 5), add 1.005 g of EDC·HCl and 0.6 g of NHS, and stir for 2 h to obtain mixed solution B. Add mixed solution B to mixed solution A, stir in the dark for 24 h, dialyze against deionized water for 3 d, and freeze-dry to obtain CS-PCA-Arg.

[0048] This embodiment also provides a method for preparing the thermosensitive gel composition for adjuvant treatment of radiation proctitis, comprising the following steps: S1. Add 3 g of CS-PCA-Arg to 300 mL of deionized water and sonicate at 300 W at room temperature for 10 min. Add 2.4 g of curcumin@sodium alginate while stirring. Stir at 250 rpm for 1 h. Filter, wash with deionized water, and vacuum dry to obtain coated curcumin@sodium alginate. Disperse the mixture in deionized water at a ratio of 50 mg / mL to obtain a dispersion. S2. Add 67.5 g of Poloxamer 407 to 150 mL of deionized water and allow to swell overnight at 4°C to obtain component A. Add 4.5 g of Carbomer 940 to 75 mL of deionized water and allow to swell overnight at 4°C. Add 150 mL of 5% triethanolamine solution and mix thoroughly to obtain component B. Add 9 g of sodium hyaluronate to 225 mL of deionized water and allow to swell overnight at 4°C to obtain component C. S3. Component A, component B, and component C obtained in step S2 are mixed, the dispersion obtained in step S1 is added, and the mixture is stirred evenly to obtain a thermosensitive gel composition for the adjuvant treatment of radiation proctitis.

[0049] The only difference between Comparative Example 1 and Example 1 is that no SA-chitosan is added.

[0050] The only difference between Comparative Example 2 and Example 1 is that no arginine is added.

[0051] The only difference between Comparative Example 3 and Example 1 is that catechin is not added.

[0052] Experimental Example 1: According to the method of Examples 1-3 and Comparative Example 1, curcumin @ sodium alginate was prepared, 0.01 g of the obtained product was added to 1.5 mL of anhydrous ethanol, placed in a freezer grinder, ground at -20°C for 5 min, ultrasonicated for 10 min, centrifuged to obtain the supernatant, washed the precipitate with an appropriate amount of anhydrous ethanol, mixed the washing liquid with the supernatant, measured the curcumin content m1, and calculated the curcumin encapsulation efficiency, encapsulation efficiency (%) = (m1 / m) × 100%, where m is the curcumin feed amount. The results are as follows Figure 2 shown.

[0053] Figure 2 The results showed that the curcumin encapsulation efficiency of Examples 1-3 was significantly better than that of Comparative Example 1. In Comparative Example 1, no SA-chitosan was added, and the curcumin encapsulation efficiency decreased, indicating that the SA-chitosan prepared in the present invention can effectively improve the encapsulation efficiency of the active ingredient.

[0054] Experimental Example 2: According to the method of Example 1 and Comparative Examples 2-3, coated curcumin@sodium alginate was prepared, the encapsulation efficiency was measured, and the solution was placed at room temperature. The encapsulation efficiency was measured again on the 7th, 14th, 30th, 60th and 90th day, and the encapsulation efficiency retention rate was calculated. Encapsulation efficiency retention rate (%) = (encapsulation efficiency after placement / encapsulation efficiency before placement) × 100%. The results are shown in Figure 2. Figure 3 shown.

[0055] Figure 3 The results showed that the encapsulation rate retention rate of Example 1 was significantly better than that of Comparative Examples 2-3. In Comparative Example 2, arginine was not grafted on chitosan, and the coating effect of curcumin @ sodium alginate was reduced, and the stability of the coated curcumin @ sodium alginate was reduced. In Comparative Example 3, protocatechuic acid was grafted on chitosan, and the stability of the coated curcumin @ sodium alginate was reduced, and the encapsulation rate retention rate was reduced.

[0056] Experimental Example 3: A radiation proctitis model was established using 6MV-X-ray irradiation. Female SD rats (6-8 weeks old, weighing 180-220 g) were anesthetized with an intraperitoneal injection of sodium pentobarbital (40 mg / kg). The rats were then positioned supine on a flat board. The irradiation field was adjusted from the pubic symphysis to the anus, with an area of ​​4 cm × 3 cm. The source-skin distance was 100 cm, the irradiation dose was 25 Gy, and the dose rate was 400 cGy / min. The model was successfully established if the rats showed decreased food and water intake and had mucus, loose stools, and bloody stools. The rats with successful modeling were randomly divided into 5 groups, each with 7 rats, namely the model group, the Example 1 group, and the Comparative Examples 1-3 group. A blank group (7 rats) without modeling was also set up. On the second day of modeling, the rats were administered with a rectal applicator. The Example 1 and Comparative Examples 1-3 groups were given 1.5 mL of the thermosensitive gel composition at a rectal position 3 cm away from the anus. The model group and the blank group were given an equal amount of normal saline. Before enema every day, the SD rats were stimulated around the anus with a cotton swab to allow the SD rats to empty their bowels as much as possible. The drug was administered once a day for 14 consecutive days. The rats were sacrificed by cervical dislocation, and rectal tissues were taken for HE staining. Histopathological changes were observed under an optical microscope. The rectal pathological state was graded according to the pathological state of radiation proctitis in rats, and the rectal pathological injury score was calculated. Grade 0: normal rectal mucosa, 0 points; Grade 1: very mild damage, very mild rectal inflammation and (or) very mild rectal gland damage, 1 point; Grade 2: mild damage, rectal inflammation or glandular changes are more obvious than Grade 1, 2 points; Grade 3: moderate damage, obvious rectal epithelial exfoliation, 3 points; Grade 4: severe damage, ulceration or necrosis, 4 points. The blank group was scored as 0, and the scores of the model group, Example 1 group, and Comparative Examples 1-3 groups were as follows: Figure 4 shown.

[0057] Figure 4 The results showed that the scores of Example 1 and Comparative Examples 1-3 were significantly lower than those of the model group, indicating that the thermosensitive gel composition prepared by the present invention can be effectively used for the adjuvant treatment of radiation proctitis. The thermosensitive gel composition can be retained in the rat body, prolonging the efficacy and improving the therapeutic effect.

[0058] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. A thermosensitive gel composition for adjuvant treatment of radiation proctitis, characterized in that: The raw materials for the preparation include the following components in parts by weight: 1.6-3.2 parts of curcumin@sodium alginate, 2-4 parts of CS-PCA-Arg, 45-90 parts of poloxamer 407, 3-6 parts of carbomer 940, and 6-12 parts of sodium hyaluronate; The preparation method of curcumin@sodium alginate comprises the following steps: L1. Dissolve 1-1.5 parts chitosan in 1% v / v acetic acid to obtain CS solution. Dissolve 2-3 parts sialic acid in MES buffer, add EDC·HCl and NHS, stir, and add to the CS solution. React with stirring at pH 6, dialyze, and freeze-dry to obtain SA-chitosan. L2. The SA-chitosan and sodium alginate obtained in step L1 were added to 6-9 parts of distilled water and stirred evenly, Tween 80 was added and mixed, 1-1.5 parts of curcumin was added, stirred, sonicated, homogenized, and added dropwise to the CaCl2 solution, stirred, centrifuged, washed, and dried to obtain curcumin @ sodium alginate; The preparation method of CS-PCA-Arg comprises the following steps: V1. Dissolve 1.2-1.8 parts chitosan in 1% v / v acetic acid to obtain a chitosan solution. Dissolve EDC·HCl and NHS in MES buffer to obtain an EDC / NHS solution. Dissolve 0.4-0.6 parts protocatechuic acid in ethanol, add the solution to the EDC / NHS solution, stir, and add the solution to the chitosan solution. Stir, dialyze, and freeze-dry to obtain CS-PCA. V2. Add the CS-PCA obtained in step V1 to a 1% v / v acetic acid solution and stir to obtain a mixture A. Dissolve 0.5-0.8 parts of arginine in MES buffer, add EDC·HCl and NHS, and stir for 2 h to obtain a mixture B. Add the mixture B to the mixture A, react, dialyze, and freeze-dry to obtain CS-PCA-Arg.

2. The thermosensitive gel composition for adjuvant treatment of radiation proctitis according to claim 1, characterized in that: In step L1, the mass ratio of sialic acid, EDC·HCl and NHS is 4:3:1.

8.

3. The thermosensitive gel composition for adjuvant treatment of radiation proctitis according to claim 2, characterized in that: In step L2, the mass concentration of sodium alginate in distilled water is 15 mg / mL.

4. The thermosensitive gel composition for adjuvant treatment of radiation proctitis according to claim 3, characterized in that: In step V1, the mass ratio of protocatechuic acid, EDC·HCl and NHS is 0.4:0.5:0.

3.

5. The thermosensitive gel composition for adjuvant treatment of radiation proctitis according to claim 4, characterized in that: In step V2, the mass ratio of arginine EDC·HCl to NHS is 0.4:0.67:0.

4.

6. A method for preparing the thermosensitive gel composition for adjuvant treatment of radiation proctitis according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. CS-PCA-Arg was added to deionized water, sonicated, and curcumin @ sodium alginate was added, stirred, filtered, washed, and dried to obtain coated curcumin @ sodium alginate, which was dispersed in deionized water to obtain a dispersion; S2. Poloxamer 407 was added to deionized water and swelled to obtain component A; Carbomer 940 was added to deionized water to swell, and triethanolamine solution was added and stirred to obtain component B; sodium hyaluronate was added to deionized water to swell to obtain component C; S3. Component A, component B, and component C obtained in step S2 are mixed, the dispersion obtained in step S1 is added, and the mixture is stirred evenly to obtain a thermosensitive gel composition for the adjuvant treatment of radiation proctitis.

7. The method for preparing the thermosensitive gel composition for adjuvant treatment of radiation proctitis according to claim 6, characterized in that: In step S2, the mass concentrations of poloxamer 407, carbomer 940, and sodium hyaluronate in deionized water are 0.45 g / mL, 60 mg / mL, and 40 mg / mL.

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