Starch hydrogel embolization microspheres and methods of making the same
Starch hydrogel embolization microspheres were prepared by mixing amylopectin and a crosslinking agent in an aqueous solution and then reversibly polymerizing them with an oil phase solution. This method solves the problems of insufficient particle size control and catheter permeability of existing starch embolization microspheres, improves the overall performance of the microspheres, and makes them suitable for uterine fibroid embolization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-11
- Publication Date
- 2026-03-24
AI Technical Summary
Existing starch embolization microspheres have shortcomings in particle size control, catheter permeability, and performance characterization, and their application areas are limited, making it difficult to meet the needs of uterine fibroid embolization.
Starch hydrogel embolization microspheres were prepared by mixing amylopectin and a crosslinking agent in an aqueous solution and then reverse polymerizing them with an oil phase solution. The molding and performance of the microspheres were optimized by controlling the ratio of the oil phase to the water phase, the reaction temperature, and the reaction time.
It improves the suspension properties, catheter permeability, in vitro enzymatic hydrolysis time, and stability of microspheres, expanding its application range, especially its applicability to uterine fibroid embolization.
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Figure CN116942888B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of embolic microspheres, in particular, to a starch hydrogel embolic microsphere and a preparation method thereof. BACKGROUND
[0002] Transcatheter arterial embolization (TAE) has been widely accepted due to its efficacy in treating various diseases including tumors, vascular lesions and hemorrhage. In order to treat safely and effectively, it is important to select a suitable embolic material. Uterine fibroids are benign muscle tumors that grow on the wall of the uterus. Uterine fibroids can grow as a single tumor or multiple tumors. Uterine fibroids can be as small as an apple seed or as large as a grapefruit. In abnormal cases, uterine fibroids can become very large. An increasingly accepted treatment for uterine fibroids is uterine fibroid embolization (UFE). The main purpose of UFE is to reduce the size of uterine fibroids and treat uterine hemorrhage. In essence, UFE involves the placement of a catheter into the uterine artery and the injection of embolic microspheres into the uterine artery to achieve uterine fibroid devascularization and gradual shrinkage.
[0003] Starch, as a widely used excipient in drug production, is abundant in source, low in price, non-toxic, has good biocompatibility and biodegradability, and meets all the requirements of drug delivery systems. As a new type of degradable embolic microsphere product, starch microspheres have many characteristics that other embolic microspheres do not have. In the application research as embolic microspheres, they are increasingly showing their superiority and becoming a hot research topic at home and abroad.
[0004] The currently marketed starch embolic microspheres are EmboCept S® (PharmaCept, Berlin, Germany), which has an in vitro half-degradation period of 35 minutes and only one size of 50 μm, which is only suitable for arterial infusion chemotherapy embolization treatment (TACE) of liver and lung, and the product size and application field are very limited.
[0005] Other starch microspheres also generally have the problems of irregular spherical shape and difficulty in accurately controlling the particle size, and lack of evaluation indexes such as elasticity and catheter passability in the performance characterization of starch microspheres. SUMMARY
[0006] The purpose of the embodiments of the present application is to provide a starch hydrogel embolic microsphere and a preparation method thereof.
[0007] In a first aspect, the present application provides a preparation method of a starch hydrogel embolic microsphere, comprising:
[0008] S1: water phase configuration, the branched amylose and crosslinking agent are mixed in the aqueous solution to obtain a water phase solution;
[0009] S2: oil phase configuration, the oil phase solution includes a dispersing agent and an oily solvent;
[0010] S3: reverse polymerization, the water phase is added to the oil phase under stirring, and the oil phase: water phase is 3-5:1;
[0011] S4: terminating the reverse polymerization reaction, and filtering and washing the sieve to obtain a starch hydrogel plug microsphere.
[0012] In the above technical solution, the branched amylose is used to prepare the starch hydrogel plug microsphere, which is beneficial to obtain a better microsphere, and the yield is improved; further, in the above technical solution, the suspension, catheter passability, in-vitro enzymatic hydrolysis time, room temperature stability, and 4℃ stability of the microsphere are good, and the comprehensive performance of the microsphere is higher. The microsphere prepared in the application has super-soft performance, excellent catheter passability, and longer degradation time, which is beneficial to the application of UFE.
[0013] In other embodiments of the application, the crosslinking agent is at least one of sodium trimetaphosphate and sodium tripolyphosphate.
[0014] In other embodiments of the application, the crosslinking agent is sodium trimetaphosphate and sodium tripolyphosphate, and the ratio of sodium trimetaphosphate to sodium tripolyphosphate is 10-100:1.
[0015] In other embodiments of the application, the dispersing agent is a Span-60 and Tween60 composition, and the ratio of Span-60 to Tween60 is 2-10:1.
[0016] In other embodiments of the application, in the reverse polymerization, the reaction temperature is 25℃-70℃.
[0017] In other embodiments of the application, the reverse polymerization includes:
[0018] The water phase solution and the oil solution are mixed at 25℃-70℃, and after stirring for at least 3 hours, natural cooling and stirring are performed.
[0019] In other embodiments of the application, the natural cooling and stirring include:
[0020] The whole process is continuously stirred for at least 12 hours.
[0021] In other embodiments of the application, the reverse polymerization reaction is terminated by adding water or ethanol to the reverse polymerization reaction system.
[0022] Secondly, this application provides a starch hydrogel embolization microsphere, which is formed by polymerizing branched starch with a crosslinking agent.
[0023] In other embodiments of this application, the crosslinking agent is sodium trimetaphosphate and sodium tripolyphosphate. Attached Figure Description
[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 The image shows the starch hydrogel embolization microspheres of Comparative Example 1 under an optical microscope.
[0026] Figure 2 The image shows the starch hydrogel embolization microspheres of Comparative Example 2 under an optical microscope.
[0027] Figure 3 This is an image of the starch hydrogel embolization microspheres from Example 1 under an optical microscope;
[0028] Figure 4 This is an image of the starch hydrogel embolization microspheres from Example 2 under an optical microscope;
[0029] Figure 5 This is an image of the starch hydrogel embolization microspheres from Example 3 under an optical microscope;
[0030] Figure 6 This is an image of the starch hydrogel embolization microspheres from Example 4 under an optical microscope;
[0031] Figure 7 This is an image of the starch hydrogel embolization microspheres from Example 5 under an optical microscope;
[0032] Figure 8 This is an image of the starch hydrogel embolization microspheres from Example 6 under an optical microscope;
[0033] Figure 9 This is an image of the starch hydrogel embolization microspheres from Example 7 under an optical microscope;
[0034] Figure 10 This is an image of the starch hydrogel embolization microspheres from Example 8 under an optical microscope;
[0035] Figure 11 An image of the prepared starch hydrogel embolization microspheres under an optical microscope before the elasticity experiment;
[0036] Figure 12 Image taken under an optical microscope during the elasticity experiment of the prepared starch hydrogel embolization microspheres. Detailed Implementation
[0037] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0038] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0039] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0040] In the description of the embodiments of this application, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this application is usually placed in when in use, or the orientation or positional relationship that is commonly understood by those skilled in the art. It is only for the convenience of describing this application and simplifying the description, and is not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.
[0041] In the description of the embodiments of this application, embolization microspheres, hydrogel microspheres and microspheres refer to the same thing and can all be understood as embolization microspheres.
[0042] This application provides a method for preparing starch hydrogel embolization microspheres, including:
[0043] S1: Aqueous phase preparation: Amylopectin and crosslinking agent are thoroughly mixed in an aqueous solution to obtain an aqueous solution;
[0044] S2: Oil phase configuration, the oil phase solution includes dispersant and oily solvent;
[0045] S3: Reverse polymerization, under stirring conditions, the aqueous phase is added to the oil phase, and the ratio of oil phase to aqueous phase is 3~5:1;
[0046] S4: Terminate the reverse polymerization reaction, filter, wash and sieve to obtain starch hydrogel embolization microspheres.
[0047] In the above technical solution, using amylopectin to prepare starch hydrogel embolization microspheres is beneficial for obtaining better-formed microspheres and improving yield. Furthermore, the above technical solution exhibits excellent performance in various aspects, including suspension, catheter permeability, in vitro enzymatic hydrolysis time, room temperature stability, and 4℃ stability, resulting in higher overall performance of the microspheres. The microspheres prepared in this application possess ultra-flexible properties, excellent catheter permeability, and a longer degradation time, which is beneficial for the application of UFE.
[0048] Furthermore, in some embodiments of this application, the preparation method of starch hydrogel embolization microspheres includes the following preparation steps:
[0049] Step S1: Aqueous phase preparation. The amylopectin and crosslinking agent are thoroughly mixed in an aqueous solution to obtain an aqueous solution.
[0050] In some embodiments of this application, the above-mentioned amylopectin is mixed with a crosslinking agent in an aqueous solution in the form of an amylopectin solution.
[0051] In some embodiments of this application, the preparation of the amylopectin solution includes:
[0052] Mix amylopectin with an alkaline solution.
[0053] Furthermore, in some embodiments of this application, the alkaline solution includes sodium hydroxide.
[0054] For example, in some embodiments of this application, amylopectin is mixed evenly with an aqueous sodium hydroxide solution.
[0055] Furthermore, in some embodiments of this application, the above-mentioned amylopectin and alkaline solution are mixed at a mass ratio of (8-10):1.
[0056] Further, alternatively, in some embodiments of this application, the above-mentioned amylopectin and alkaline solution are mixed at a mass ratio of 8:1, 9:1 or 10:1.
[0057] Furthermore, in some embodiments of this application, the amylopectin mentioned above is selected from corn amylopectin.
[0058] Further, alternatively, in some embodiments of this application, amylopectin and sodium hydroxide can be mixed, stirred and heated until gelatinized and transparent, and then allowed to stand and cool for later use.
[0059] For example, add 10g of corn amylopectin and 1g of NaOH to 100ml of distilled water, stir and heat until gelatinized and transparent, then let stand and cool for later use.
[0060] In other optional embodiments of this application, the alkali described above can also be other alkaline solutions applicable in the art.
[0061] Furthermore, in some embodiments of this application, the crosslinking agent is at least one of sodium trimetaphosphate and sodium tripolyphosphate.
[0062] For example, in some embodiments of this application, the crosslinking agent is selected from either sodium trimetaphosphate or sodium tripolyphosphate.
[0063] For example, in some embodiments of this application, the crosslinking agent described above is a mixture of sodium trimetaphosphate and sodium tripolyphosphate.
[0064] Furthermore, in some embodiments of this application, the crosslinking agent is sodium trimetaphosphate and sodium tripolyphosphate, wherein the ratio of sodium trimetaphosphate to sodium tripolyphosphate is 10 to 100:1.
[0065] Further optionally, in some embodiments of this application, the crosslinking agent is sodium trimetaphosphate and sodium tripolyphosphate, wherein the ratio of sodium trimetaphosphate to sodium tripolyphosphate is 10 to 90:1.
[0066] For example, in some embodiments of this application, the crosslinking agent is sodium trimetaphosphate and sodium tripolyphosphate, wherein the ratio of sodium trimetaphosphate to sodium tripolyphosphate is 10:1, 20:1, 30:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1 or any two of the above ratios.
[0067] For example, under stirring conditions, 12.5 ml of an aqueous solution containing 0.3 g sodium tripolyphosphate (STMP) and 0.03 g sodium tripolyphosphate (STPP) was added to 12.5 ml of corn starch solution, and stirred for 5 minutes to mix thoroughly.
[0068] Furthermore, in some embodiments of this application, amylopectin includes corn amylopectin.
[0069] In other optional embodiments of this application, the amylopectin described above can be selected from other amylopectins similar to corn amylopectin, such as cassava amylopectin.
[0070] Furthermore, in some optional embodiments of this application, the above-mentioned method for preparing amylopectin includes:
[0071] Starch and solvent were mixed, stirred, and centrifuged. The supernatant was collected and added to alcohol. After standing, it was centrifuged again. The precipitate was washed with alcohol to remove the solvent and then filtered. The filter cake was dissolved, allowed to stand, and thymol was added and stirred until homogeneous. After standing, the filtrate was collected. The filtrate was extracted with ether to remove thymol. Alcohol was added to the aqueous phase until the flocculent precipitate no longer increased. After standing, the filtrate was filtered and dried to obtain a white powder, namely amylopectin.
[0072] Exemplary, in some embodiments of this application, corn amylopectin is prepared according to the following steps:
[0073] Accurately weigh 100g of purchased corn starch, add 3000mL of DMSO, and stir at 200RPM for 24 hours at room temperature. After stirring, centrifuge at 2000RPM, collect the supernatant, add it to twice the amount of n-butanol, let stand for 24 hours, centrifuge at 4000RPM, collect the precipitate, wash it three times with n-butanol to remove DMSO, filter, dissolve the filter cake in sufficient distilled water by boiling, let it stand and cool to 60℃, add 10g of thymol and stir thoroughly, let it stand at room temperature for 3 days, and filter to obtain the filtrate. Pre-cool the filtrate in a refrigerator at 4℃, then add an appropriate amount of diethyl ether to extract three times to remove thymol, collect the aqueous phase, add a large amount of ethanol until the flocculent precipitate no longer increases, let it stand at room temperature for 3 days, filter to obtain the filter cake, dry it, and obtain a white powder, which is the extracted corn amylopectin.
[0074] In other optional embodiments of this application, the corn amylopectin described above can also be obtained by purchasing commercially available products.
[0075] Step S2: Oil phase preparation, the oil phase solution includes a dispersant and an oily solvent.
[0076] Furthermore, in some embodiments of this application, the oil phase configuration includes: mixing a dispersant and an oily solvent to form a continuous oil phase.
[0077] Further, optionally, in some embodiments of this application, the oily solvent includes cyclohexane.
[0078] Further, alternatively, in some embodiments of this application, the dispersant is a combination of Span-60 and Tween60.
[0079] Furthermore, in some embodiments of this application, the ratio of Span-60 to Tween60 in the dispersant is 2 to 10:1.
[0080] Further optionally, in some embodiments of this application, the ratio of Span-60:Tween60 in the dispersant is 2.1 to 9.9:1.
[0081] For example, in some embodiments of this application, the ratio of Span-60:Tween60 in the dispersant is 3:1, 4:1, 5:1, 6:1, 7:1, 8:1 or 9:1.
[0082] For example, in some embodiments of this application, the oil phase is prepared by the following steps: under stirring conditions, 1g of Span-60 (sorbitan monostearate) and 0.5g of Tween-60 (polyoxyethylene sorbitan monostearate) are added to 100ml of cyclohexane to form a continuous oil phase.
[0083] Step S3: Reverse polymerization. Under stirring conditions, the aqueous phase is added to the oil phase, with an oil phase:water phase ratio of 3~5:1.
[0084] Furthermore, in some embodiments of this application, the reaction temperature in the reverse polymerization is 25°C to 70°C.
[0085] In some embodiments of this application, the aqueous phase obtained in step S1 and the oil obtained in step S2 are reverse polymerized at a reaction temperature of 26°C to 69°C.
[0086] For example, in some embodiments of this application, the aqueous phase obtained in step S1 and the oil obtained in step S2 are reverse polymerized at reaction temperatures of 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, and 60°C.
[0087] Further optionally, in some embodiments of this application, the oil phase:water phase ratio is 3.1~4.9:1.
[0088] For example, in some embodiments of this application, the oil phase:water phase ratio is 3.5:1, 4:1, 4.5:1 or 4.8:1.
[0089] Furthermore, in some embodiments of this application, reverse aggregation includes:
[0090] Mix the aqueous solution and the oil solution at 25℃~70℃, stir and react for at least 3 hours, then allow to cool naturally and stir again.
[0091] For example, in some embodiments of this application, the amylopectin solution is mixed with the oil phase at 25°C to 70°C, stirred and reacted for 3 hours, 4 hours, and 5 hours, and then allowed to cool naturally and stirred.
[0092] Furthermore, in some embodiments of this application, natural cooling and stirring include:
[0093] Stir continuously for at least 12 hours throughout the process.
[0094] Further alternatively, in some embodiments of this application, the mixture is allowed to cool naturally and stirred for 12, 15, 18, 20 or 24 hours.
[0095] For example, in some embodiments of this application, after stirring the oil phase for a period of time, the aqueous phase is added to the oil phase. After thorough mixing, the mixture is stirred and reacted, then stirred overnight at room temperature (greater than or equal to 12 hours) and allowed to stand.
[0096] Step S4: Terminate the reverse polymerization reaction, filter, wash and sieve to obtain starch hydrogel embolization microspheres.
[0097] Furthermore, in some embodiments of this application, the reverse polymerization reaction is terminated by adding water or ethanol to the reverse polymerization reaction system.
[0098] Further, alternatively, in some embodiments of this application, the alcohol includes ethanol.
[0099] For example, in some embodiments of this application, a certain amount of ethanol is added to the reactants, filtered, washed with ethanol, and then dried.
[0100] In other optional embodiments of this application, the alcohol described above may also be other alcohols or alcohol solutions.
[0101] Further, alternatively, in some embodiments of this application, the reaction product washed with ethanol and dried is reconstituted and sieved.
[0102] Further, optionally, the reaction product is reconstituted and sieved, including:
[0103] Add water to the reaction product, then sieve and collect the sieve residue.
[0104] Further alternatively, in some embodiments of this application, sieves with different pore sizes can be selected for sieving to obtain corn amylopectin hydrogel microspheres with different diameters and particle sizes.
[0105] The following specific embodiments are provided to better illustrate this application.
[0106] Extraction of Corn Amylopectin
[0107] Accurately weigh 100g of corn starch, add 3000mL of DMSO, and stir at 200RPM for 24 hours at room temperature. After stirring, centrifuge at 2000RPM, collect the supernatant, add it to twice the volume of n-butanol, let stand for 24 hours, centrifuge at 4000RPM, collect the precipitate, wash it three times with n-butanol to remove DMSO, filter, dissolve the filter cake in sufficient distilled water by boiling, let it stand and cool to 60℃, add 10g of thymol and stir thoroughly, let it stand at room temperature for 3 days, and filter to obtain the filtrate. Pre-cool the filtrate in a refrigerator at 4℃, then add an appropriate amount of diethyl ether to extract three times to remove thymol, collect the aqueous phase, add a large amount of ethanol until the flocculent precipitate no longer increases, let it stand at room temperature for 3 days, filter to obtain the filter cake, dry it, and obtain a white powder, which is the extracted corn amylopectin.
[0108] Preparation of corn amylopectin solution
[0109] Add 10g of corn amylopectin and 1g of NaOH to 100ml of distilled water, stir and heat until gelatinized and transparent, then let stand and cool for later use.
[0110] Preparation of cornstarch solution
[0111] Add 10g of cornstarch and 1g of NaOH to 100ml of distilled water, stir and heat until gelatinized and transparent, then let stand and cool for later use.
[0112] The following examples use the corn amylopectin obtained above to prepare starch hydrogel embolization microspheres.
[0113] Example 1
[0114] Under stirring conditions, 1 g of Span-60 and 0.5 g of Tween-60 were added to 100 ml of cyclohexane to form a continuous oil phase. After stirring for a period of time, 25 ml of the previously prepared corn amylopectin solution, 0.3 g of STMP, and 0.03 g of STPP were added to the oil phase sequentially. After thorough mixing, the mixture was stirred at 50°C for 3 hours, followed by stirring at room temperature overnight. After standing, a certain amount of ethanol was added, the mixture was filtered, washed three times with ethanol, and dried. The resulting powder was corn amylopectin microspheres. After redissolving in water and sieving, corn amylopectin hydrogel microspheres of different particle sizes could be obtained.
[0115] Example 2
[0116] Aqueous phase preparation: Under stirring conditions, add 12.5 ml of aqueous solution containing 0.3 g STMP to 12.5 ml of corn amylopectin solution and stir for 5 minutes to mix thoroughly.
[0117] Under stirring conditions, 1g of Span-60 and 0.5g of Tween-60 were added to 100ml of cyclohexane to form a continuous oil phase. After stirring for a period of time, 25ml of aqueous phase was added to the oil phase. After thorough mixing, the mixture was stirred, and the reaction temperature was 50℃ for 3 hours. Subsequently, the mixture was stirred overnight at room temperature, allowed to stand, and a certain amount of ethanol was added. The mixture was filtered, washed three times with ethanol, and then dried. The resulting powder was corn amylopectin microspheres. After redissolving in water and sieving, corn amylopectin hydrogel microspheres of different particle sizes could be obtained.
[0118] Example 3
[0119] Aqueous phase preparation: Under stirring conditions, add 12.5 ml of an aqueous solution containing 0.3 g STMP and 0.003 g STPP to 12.5 ml of corn amylopectin solution, and stir for 5 minutes to mix thoroughly.
[0120] Under stirring conditions, 1g of Span-60 and 0.5g of Tween-60 were added to 100ml of cyclohexane to form a continuous oil phase. After stirring for a period of time, 25ml of aqueous phase was added to the oil phase. After thorough mixing, the mixture was stirred, and the reaction temperature was 50℃ for 3 hours. Subsequently, the mixture was stirred overnight at room temperature without allowing it to stand. A certain amount of ethanol was added, and the mixture was filtered, washed three times with ethanol, and then dried. The resulting powder was corn amylopectin microspheres. After redissolving in water and sieving, corn amylopectin hydrogel microspheres of different particle sizes could be obtained.
[0121] Example 4
[0122] Aqueous phase preparation: Under stirring conditions, add 12.5 ml of an aqueous solution containing 0.3 g STMP and 0.015 g STPP to 12.5 ml of corn amylopectin solution, and stir for 5 minutes to mix thoroughly.
[0123] Under stirring conditions, 5g of Span-60 and 0.5g of Tween-60 were added to 100ml of cyclohexane to form a continuous oil phase. After stirring for a period of time, 25ml of aqueous phase was added to the oil phase. After thorough mixing, the mixture was stirred, and the reaction temperature was 50℃ for 24 hours. Subsequently, the mixture was stirred overnight at room temperature without allowing it to stand. A certain amount of ethanol was added, and the mixture was filtered, washed three times with ethanol, and then dried. The resulting powder was corn amylopectin microspheres. After redissolving in water and sieving, corn amylopectin hydrogel microspheres of different particle sizes could be obtained.
[0124] Example 5
[0125] Aqueous phase preparation: Under stirring conditions, add 12.5 ml of an aqueous solution containing 0.3 g STMP and 0.03 g STPP to 12.5 ml of corn amylopectin solution, and stir for 5 minutes to mix thoroughly.
[0126] Under stirring conditions, 5g of Span-60 and 1g of Tween-60 were added to 100ml of cyclohexane to form a continuous oil phase. After stirring for a period of time, 25ml of aqueous phase was added to the oil phase. After thorough mixing, the mixture was stirred, and the reaction temperature was 50℃ for 24 hours. Subsequently, the mixture was stirred overnight at room temperature without allowing it to stand. A certain amount of ethanol was added, and the mixture was filtered, washed three times with ethanol, and then dried. The resulting powder was corn amylopectin microspheres. After redissolving in water and sieving, corn amylopectin hydrogel microspheres of different particle sizes could be obtained.
[0127] Example 6
[0128] Aqueous phase preparation: Under stirring conditions, add 12.5 ml of an aqueous solution containing 0.6 g STMP and 0.06 g STPP to 12.5 ml of corn amylopectin solution, and stir for 5 minutes to mix thoroughly.
[0129] Under stirring conditions, 1g of Span-60 and 0.5g of Tween-60 were added to 100ml of cyclohexane to form a continuous oil phase. After stirring for a period of time, 20ml of aqueous phase was added to the oil phase. After thorough mixing, the mixture was stirred, and the reaction temperature was 50℃ for 24 hours. Subsequently, the mixture was stirred overnight at room temperature without allowing it to stand. A certain amount of ethanol was added, and the mixture was filtered, washed three times with ethanol, and then dried. The resulting powder was corn amylopectin microspheres. After redissolving in water and sieving, corn amylopectin hydrogel microspheres of different particle sizes could be obtained.
[0130] Example 7
[0131] Aqueous phase preparation: Under stirring conditions, add 12.5 ml of an aqueous solution containing 0.6 g STMP and 0.06 g STPP to 12.5 ml of corn amylopectin solution, and stir for 5 minutes to mix thoroughly.
[0132] Under stirring conditions, 2g of Span-60 and 1g of Tween-60 were added to 75ml of cyclohexane to form a continuous oil phase. After stirring for a period of time, 25ml of aqueous phase was added to the oil phase. After thorough mixing, the mixture was stirred, and the reaction temperature was 50℃ for 24 hours. Subsequently, the mixture was stirred overnight at room temperature without allowing it to stand. A certain amount of ethanol was added, and the mixture was filtered, washed three times with ethanol, and then dried. The resulting powder was corn amylopectin microspheres. After redissolving in water and sieving, corn amylopectin hydrogel microspheres of different particle sizes could be obtained.
[0133] Example 8
[0134] Aqueous phase preparation: Under stirring conditions, add 12.5 ml of an aqueous solution containing 0.6 g STMP and 0.06 g STPP to 12.5 ml of corn amylopectin solution, and stir for 5 minutes to mix thoroughly.
[0135] Under stirring conditions, 1g of Span-60 and 0.5g of Tween-60 were added to 100ml of cyclohexane to form a continuous oil phase. After stirring for a period of time, 25ml of aqueous phase was added to the oil phase. After thorough mixing, the mixture was stirred, and the reaction temperature was 70℃ for 24 hours. Subsequently, the mixture was stirred overnight at room temperature without allowing it to stand. A certain amount of ethanol was added, and the mixture was filtered, washed three times with ethanol, and then dried. The resulting powder was corn amylopectin microspheres. After redissolving in water and sieving, corn amylopectin hydrogel microspheres of different particle sizes could be obtained.
[0136] Comparative Example 1
[0137] A method for preparing starch hydrogel embolization microspheres is provided, comprising the following steps:
[0138] Under stirring conditions, 1g of Span-60 and 0.5g of Tween-60 were added to 100ml of cyclohexane to form a continuous oil phase. After stirring for a period of time, 25ml of corn starch solution, 0.3g of sodium trimetaphosphate (STMPNa3P3O9), and 0.03g of sodium tripolyphosphate (STPPNa5P3O9) were added to the oil phase sequentially. 10 After thorough mixing, stir, react at 50℃ for 3 hours, then stir overnight at room temperature, let stand, add a certain amount of ethanol, filter, wash three times with ethanol, and dry. The resulting powder is corn starch microspheres. After redissolving in water and sieving, corn starch hydrogel microspheres of different particle sizes can be obtained.
[0139] Comparative Example 2
[0140] Aqueous phase preparation: Under stirring conditions, add 12.5 ml of an aqueous solution containing 0.3 g STMP and 0.03 g STPP to 12.5 ml of corn starch solution, and stir for 5 minutes to mix thoroughly.
[0141] Under stirring conditions, 1g of Span-60 and 0.5g of Tween-60 were added to 100ml of cyclohexane to form a continuous oil phase. After stirring for a period of time, 25ml of aqueous phase was added to the oil phase. After thorough mixing, the mixture was stirred, and the reaction temperature was 50℃ for 3 hours. Subsequently, the mixture was stirred overnight at room temperature, allowed to stand, and a certain amount of ethanol was added. The mixture was filtered, washed three times with ethanol, and then dried. The resulting powder was corn starch microspheres. After redissolving in water and sieving, corn starch hydrogel microspheres of different particle sizes could be obtained.
[0142] The properties of the corn starch hydrogel microspheres prepared in the above embodiments and comparative examples were tested.
[0143] Experimental Example 1: Microsphere Suspension Test
[0144] Take 2 mL of 300-600 μm hydrogel starch microspheres, add 2 mL of contrast agent (iohexol 300), mix well until stable, and use a 20 mL syringe to start timing in a vertical tube to observe the suspension state of the microspheres.
[0145] The results are shown in Table 1.
[0146] Table 1
[0147]
[0148] Experimental Example 2: Catheter Permeability Test
[0149] Connect the syringe containing the contrast agent-microsphere suspension to a 2.7F microcatheter, place the end of the microcatheter into a centrifuge tube, and then inject in a pulsed manner at a rate of 1 mL / 1 min. During the injection, observe the state of the microspheres as they enter the microcatheter and the state of the microspheres as they exit the microcatheter and enter the centrifuge tube (dispersed, adhered, clumped, stuck to the wall, blocked the tube), and then record the results.
[0150] The results are shown in Table 2.
[0151] Table 2
[0152]
[0153] Experimental Example 3: Microsphere Degradability Test
[0154] Take 1 mL of 300-600 μm microspheres, add them to 9 mL of artificial plasma, and incubate them in a shaker at 37 °C. Add α-amylase to prepare an enzyme concentration of 100 U / L. Every 24 hours, take 0.5 mL of the mixture and dilute it to 1 mL. Perform particle size analysis using the DLS method. Use the time when the average particle size drops to half of the initial value as the evaluation index of microsphere degradation.
[0155] The test results are shown in Table 3.
[0156] Table 3
[0157]
[0158] Experiment Example 4: Microsphere Stability Test
[0159] Take 1 mL of 300-600 μm microspheres and 9 mL of physiological saline, add them to a vial, seal the vial, and store them at room temperature and 4°C. Take samples every 5 days to observe the morphology and particle size.
[0160] The results of the room temperature stability test are shown in Table 4.
[0161] The results of the stability test in a 4℃ refrigerator are shown in Table 5.
[0162] Table 4
[0163]
[0164] Table 5
[0165]
[0166] A summary of the morphology, clumping, yield, suspension, catheter permeability, in vitro enzymatic hydrolysis time, room temperature stability, and 4°C stability of each embodiment is shown in Table 6.
[0167] In Table 6, (1) morphology and whether it is clumped are detected by optical microscope, see the attached figure in the instruction manual; (2) yield is the starch microsphere molding yield of each example; (3) suspension is based on the microsphere suspension test results of Experiment Example 1; (4) conduit passability is based on the conduit passability test results of Experiment Example 2; (5) in vitro enzymatic hydrolysis time is based on the microsphere degradation test results of Experiment Example 3; (6) room temperature stability and 4℃ stability are based on the microsphere stability test results of Experiment Example 4.
[0168] Table 6
[0169]
[0170] As can be seen from the results in Table 6 above, the starch hydrogel embolization microspheres prepared in the embodiments of this application have improved yield, suspension, catheter permeability, in vitro enzymatic hydrolysis time, room temperature stability, and 4℃ stability, resulting in improved overall performance.
[0171] Furthermore, as can be seen from the accompanying drawings, Comparative Examples 1 and 2 did not exhibit a perfectly round morphology, retaining the original starch microparticle morphological characteristics and failing to achieve deep cross-linking. Example 2, by premixing a corn amylopectin solution with a cross-linking agent, yielded relatively round microspheres, but problems such as fragmentation and adhesion occurred. Examples 3-8, through further improvements to experimental parameters, increased the reaction heating time, and eliminated the reaction settling process, achieving the preparation of round, smooth, and highly absorbent / transparent corn amylopectin hydrogel microspheres.
[0172] Furthermore, referring to Figures 3-10 The starch hydrogel microspheres prepared in Examples 1-8 have a particle size distribution ranging from 20 to 2000 micrometers and possess good elasticity, capable of being compressed by more than 50% without deformation under external force. Figures 11-12 ).
[0173] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
Claims
1. A method for preparing starch hydrogel embolic microspheres, characterized in that, include: S1: Aqueous phase preparation: Amylopectin and crosslinking agent are thoroughly mixed in an aqueous solution to obtain an aqueous solution; the crosslinking agent is sodium trimetaphosphate and sodium tripolyphosphate, wherein the mass ratio of sodium trimetaphosphate to sodium tripolyphosphate is 10~100:
1. S2: Oil phase configuration, the oil phase solution includes a dispersant and an oily solvent; the dispersant is a combination of Span-60 and Tween60, the ratio of Span-60 to Tween60 is 2 to 10:1; S3: Reverse polymerization, under stirring conditions, the aqueous phase is added to the oil phase, wherein the ratio of oil phase to aqueous phase is 3~5:1; S4: Terminate the reverse polymerization reaction, filter, wash and sieve to obtain starch hydrogel embolization microspheres.
2. The method for preparing starch hydrogel embolic microspheres according to claim 1, characterized in that, In the reverse polymerization, the reaction temperature is 25℃~70℃.
3. The method for preparing starch hydrogel embolic microspheres according to claim 2, characterized in that, The reverse aggregation includes: The aqueous solution and the oil solution are mixed at 25°C to 70°C and stirred for at least 3 hours, then allowed to cool naturally and stirred again.
4. The method for preparing starch hydrogel embolic microspheres according to claim 3, characterized in that, The natural cooling and stirring process includes: Stir continuously for at least 12 hours throughout the process.
5. The method for preparing starch hydrogel embolic microspheres according to claim 1, characterized in that, The reverse polymerization reaction is terminated by adding water or ethanol to the reverse polymerization reaction system.
6. A starch hydrogel embolic microsphere, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 5.
Citation Information
Patent Citations
Absorbable starch microsphere hemostatic powder with antibacterial activity and application thereof
CN110115776A