Construction method and application of tannic acid-mediated curcumin-embedded starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsule
Through the tanninic acid-mediated self-assembly microcapsule technology of starch-chisal oligosaccharide layer-based self-assembly microcapsules, the problems of curcumin storage stability and bioavailability are solved, effective embedding and controlled release of curcumin are achieved, and its application value in food is improved.
Patent Information
- Application Number
- CN202510200339.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2025-04-15
AI Technical Summary
Curcumin is susceptible to environmental factors, has poor storage stability, low oral bioavailability, and has poor water solubility, which limits its application in food. Existing carrier materials have problems with increasing the risk of lipid intake and poor controlled release performance.
The self-assembled microcapsules of the polysaccharide layer by tanninic acid is used to form nanocomposite particles through tanninic acid and curcumin to increase the water solubility of curcumin. The differently charged chitosaccharide and carboxymethyl starch are used as carriers to construct the polysaccharide base layer self-assembled microcapsules to achieve effective embedding and controlled release of curcumin.
It improves the storage stability and bioavailability of curcumin, achieves stability and controlled release effects in food matrix and gastrointestinal tract, and reduces the risk of early leakage and inactivation of curcumin.
Smart Images
Figure CN119817805A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of constructing layer-by-layer self-assembled microcapsules, and specifically relates to a method for constructing a tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsule for embedding curcumin and an application thereof. Background Art
[0002] With the development of society and the continuous improvement of people's living standards, people are paying more and more attention to nutrition and health. Proteins and peptides, polysaccharides, lipids, polyphenols, etc. with specific physiological functions are widely used in food systems for the development of functional foods. Curcumin is a polyphenol compound derived from plants of the Zingiberaceae and Araceae families. It has good anti-inflammatory, antioxidant, and anti-cancer biological activities and is a highly potential food functional factor. However, curcumin is easily affected by environmental factors such as light, heat, and pH, and is easily inactivated during storage, and has low oral bioavailability; and its water solubility is poor, making it difficult to disperse in food systems, which greatly limits its application in food.
[0003] At present, most of the carriers for oral delivery of curcumin are liposomes, emulsions or nano-micelles. Such carriers usually need to be prepared by lipids or lipid-containing carrier materials, which will introduce a large amount of lipid substances into the food system, increasing the health risks caused by excessive lipid intake; and most of them will quickly disintegrate under the dilution of food matrix or gastrointestinal digestive juice, strong acid, lipase, salt ions, etc., which is not conducive to the controlled release of functional substances. In addition, the preparation process requires emulsifiers or other structural stabilizers, and the preparation process is relatively complicated.
[0004] As a new technology, layer-by-layer self-assembly technology can achieve molecular level interactions in a liquid system, thereby controlling the aggregate structure of assembled microcapsules, so that the release properties of microcapsules can be controlled in the digestive tract to achieve the purpose of improving bioavailability. Polysaccharide-based electrostatic layer-by-layer self-assembly microcapsules are mainly constructed through electrostatic interactions between carrier materials and functional substances, and can achieve efficient encapsulation and controlled release of functional substances by adjusting the molecular structure of carrier materials, assembly conditions, and the number of assembly layers. At present, the polysaccharide carriers used in electrostatic layer-by-layer self-assembly technology mainly include chitosan and its derivatives, carrageenan, pectin and its derivatives, starch and its derivatives, etc. Among them, starch and chitosan are both polysaccharides widely present in nature, with the characteristics of safety, non-toxicity, good biocompatibility, and biodegradability. However, due to the strong water solubility of polysaccharide carriers, the current polysaccharide electrostatic layer-by-layer self-assembly technology is mainly used for the encapsulation and delivery of hydrophilic substances, and there is no report on the encapsulation and delivery of hydrophobic substances. Therefore, the premise of using polysaccharide-based electrostatic layer-by-layer self-assembled microcapsules to encapsulate and control the release of curcumin is to solve the problem of curcumin's water solubility.
[0005] Tannic acid (TA) is considered one of the most effective natural polyphenols and is considered a generally recognized as safe (GRAS) substance by the U.S. Food and Drug Administration (FDA). TA molecules contain a large number of hydroxyl groups, which can solubilize hydrophobic molecules through hydrogen bonds and hydrophobic interactions and can be used as a hydrophobic excipient. At the same time, TA can also form nanoparticles by polymerizing with neutral or charged polymers or hydrophobic molecules through hydrogen bonds, electrostatic interactions, hydrophobic interactions, etc. In Curcumin-tannic acid-poloxamer nanoassemblies enhance curcumin's uptake and bioactivity against cancer cells in vitro (International Journal of Pharmaceutics, 2021, 610: 121255), Sunoqrot et al. used TA as an excipient to self-assemble with poloxamer polymers to form nanoparticles, thereby achieving solubilization and embedding of curcumin. However, poloxamer polymers are polyoxyethylene polypropylene ether block polymers with poor biocompatibility and are not biodegradable, which poses a great safety hazard. In addition, the constructed nanoparticles have relatively poor controlled release performance of curcumin in the gastrointestinal tract. Aiming at the loading and delivery problem of curcumin, the present invention designs a method for constructing tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules, which is of great significance for realizing the oral delivery of curcumin using polysaccharide-based layer-by-layer self-assembled microcapsules. Summary of the invention
[0006] In order to overcome the shortcomings of polysaccharide-based layer-by-layer self-assembled microcapsules in embedding hydrophobic substances, and the shortcomings of existing curcumin delivery carriers, the primary purpose of the present invention is to provide a method for constructing tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules for embedding curcumin, the method uses tannic acid as a curcumin solubilizer and forms curcumin / tannic acid composite nanoparticles, and then uses chitosan oligosaccharides and carboxymethyl starch with different charges as carriers to construct polysaccharide-based layer-by-layer self-assembled microcapsules for embedding curcumin. The microcapsules not only have a good embedding effect on curcumin, but also have good stability in food matrices and the gastrointestinal tract, improve the storage stability and bioavailability of curcumin, and can be further used to prepare liquid food additives.
[0007] The purpose of the present invention is achieved through the following technical solutions: A method for constructing a tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsule for embedding curcumin, characterized in that the specific steps are: Step S1, curcumin and tannic acid are dissolved in dimethyl sulfoxide (DMSO) respectively, and then the curcumin dimethyl sulfoxide solution and the tannic acid dimethyl sulfoxide solution are mixed evenly, the mixed solution is added dropwise into deionized water and stirred for reaction, and then the dimethyl sulfoxide in the reaction system is dialyzed with deionized water, and the curcumin / tannic acid composite nanoparticles (CT) are obtained after freeze-drying; Step S2, re-dispersing the curcumin / tannic acid composite nanoparticles obtained in step S1 in a phosphate buffer, and then adding dropwise to the phosphate buffer containing chitosan oligosaccharide, stirring at room temperature for reaction, and then centrifuging to obtain a layer of assembled microcapsules; Step S3, the one-layer assembled microcapsule obtained in step S2 is redispersed in a phosphate buffer, and then added dropwise into a phosphate buffer containing carboxymethyl starch, stirred at room temperature for reaction, and then centrifuged to obtain a two-layer assembled microcapsule.
[0008] Furthermore, the concentration of the dimethyl sulfoxide solution of curcumin is 1-10 mg / mL, the concentration of the dimethyl sulfoxide solution of tannic acid is 0.5-10 mg / mL, and the mass ratio of tannic acid to curcumin is 1:20-2:1.
[0009] Furthermore, the chitosan oligosaccharide is used as a carrier material, and its molecular weight is 1.0×10 3 ~2.0×10 4 g / mol, the degree of substitution of the amino group is 0.05-0.2, and the concentration is 0.05-5 mg / mL; the carboxymethyl starch is used as a carrier material, and its molecular weight is 4.0×10 4 ~2.0×10 6 g / mol, the degree of substitution of carboxymethyl groups is 0.06-0.30, and the concentration is 0.05-5 mg / mL.
[0010] Furthermore, the pH of the phosphate buffer is 3.0-8.0, and the concentration is 0.01-0.2 mol / L.
[0011] Furthermore, the stirring reaction time in step S1, step S2 and step S3 is 0.5 to 24 hours.
[0012] The invention discloses an application of the tannic acid-mediated curcumin-embedded starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules in the preparation of food additives, wherein the curcumin-embedded layer-by-layer self-assembled microcapsules can effectively protect the free radical scavenging ability of curcumin during storage and realize controlled release of curcumin in the gastrointestinal tract.
[0013] The application of the tannic acid-mediated curcumin-embedded starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules in the preparation of liquid food additives is specifically to place the prepared microcapsules embedded with curcumin in liquid food (such as beverages), which can effectively prevent the premature leakage and inactivation of curcumin, and realize controlled release of curcumin in the gastrointestinal tract through changes in the pH responsiveness and interaction of the carrier material.
[0014] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The method for constructing curcumin-embedded starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules mediated by tannic acid provided by the present invention uses tannic acid and curcumin to form nanocomposite particles, thereby increasing the dispersibility of curcumin in aqueous solution, making it possible to use polysaccharide-based layer-by-layer self-assembled microcapsules to embed and control the release of curcumin; (2) The method for constructing the starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules mediated by tannic acid for encapsulating curcumin provided by the present invention uses natural polysaccharide derivatives as carrier materials, and encapsulates curcumin mainly through electrostatic interaction. The microcapsules have a certain resistance to digestion in the body and do not bring additional burden to the body. The microcapsules have the advantages of good biocompatibility, biodegradability, and wide sources. (3) The method for constructing the tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules encapsulating curcumin provided by the present invention can adjust the encapsulation rate and controlled release effect of the microcapsules on curcumin, the microcapsule stability and targeted release ability by adjusting the molecular weight, group substitution degree and assembly conditions (such as concentration, pH, ion concentration, etc.) of the carrier material, so as to be suitable for application in different food systems and improve the application and bioavailability of curcumin in industry. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 The surface potential of the curcumin-embedded layer-by-layer self-assembled microcapsules mediated by tannic acid prepared in Examples 1 to 3 at different pH values.
[0016] Figure 2 Transmission electron microscope images of the tannic acid-mediated layer-by-layer self-assembled microcapsules encapsulating curcumin prepared in Examples 1 to 3.
[0017] Figure 3 The cumulative release amount of curcumin by the tannic acid-mediated curcumin-embedded layer-by-layer self-assembled microcapsules prepared in Examples 1 to 3 under the pH conditions of simulated human digestive fluid. DETAILED DESCRIPTION
[0018] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto. The reagents used in the examples can be purchased from the market unless otherwise specified. Example 1
[0019] 1 mL of DMSO solution of curcumin (1 mg / mL) and 1 mL of DMSO solution of tannic acid (0.5 mg / mL) were mixed and added dropwise into 10 mL of deionized water. The mixture was stirred at 300 r / min for 2 h. The DMSO was removed by dialysis with deionized water and the curcumin / tannic acid composite nanoparticles (CT) were obtained after freeze-drying. CT was redispersed in 5 mL of phosphate buffer (pH = 3.0, 0.01 mol / L) and added dropwise into a chitosan oligosaccharide solution (molecular weight 1.0 × 10 3 g / mol, amine group substitution degree of 0.05, concentration of 5 mg / mL), and continued to stir at room temperature for 2 h, and centrifuged at 8000 rpm for 10 min to obtain a layer of assembled microcapsules; the layer of assembled microcapsules was redispersed in phosphate buffer (pH = 3.0, 0.01 mol / L), and added dropwise to a carboxymethyl starch solution (molecular weight 4.0×10 4 g / mol, degree of substitution of carboxymethyl groups is 0.06, and the concentration is 5 mg / mL), and the reaction is continuously stirred at room temperature for 2 hours. The reaction is centrifuged at 8000 rpm for 10 minutes to obtain two-layer assembled microcapsules, namely, tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules encapsulating curcumin.
[0020] The layer-by-layer self-assembled microcapsules have a negative charge on the surface, an average particle size of 80nm, and an encapsulation rate of 80% for curcumin. When the layer-by-layer self-assembled microcapsules were added to Sprite at a volume of 1g / 100mL, the leakage of curcumin was 20% within 7 days, and the ability of curcumin to scavenge free radicals was retained at 83%. In in vitro simulated digestion, at gastric pH (1.2), due to the protonation of carboxymethyl starch on the surface of the microcapsules, the microcapsules were almost uncharged, and the cumulative release of curcumin in 24 hours was 22.5%; at small intestinal pH (6.8), the microcapsules were deprotonated, the surface potential was -3.5mV, and the cumulative release of curcumin in 24 hours was 34.9%; at colon pH (7.2), the surface potential was -6.0mV, the microcapsules continued to swell, and due to the change in electrostatic interaction between the carrier materials, the cumulative release of curcumin in 24 hours was 100%. Example 2
[0021] 1 mL of DMSO solution of curcumin (10 mg / mL) and 1 mL of DMSO solution of tannic acid (10 mg / mL) were mixed and added dropwise into 10 mL of deionized water. The mixture was stirred at 300 r / min for 2 h. The DMSO was removed by dialysis with deionized water and the curcumin / tannic acid composite nanoparticles (CT) were obtained after freeze-drying. CT was redispersed in 5 mL of phosphate buffer (pH = 8.0, 0.2 mol / L) and added dropwise into a chitosan oligosaccharide solution (molecular weight 2.0×10 4 g / mol, amine group substitution degree of 0.2, concentration of 3 mg / mL), and continued to stir at room temperature for 2 h, and centrifuged at 8000 rpm for 10 min to obtain a layer of assembled microcapsules; the layer of assembled microcapsules was redispersed in phosphate buffer (pH = 8.0, 0.2 mol / L), and added dropwise to a carboxymethyl starch solution (molecular weight of 2.0×10 6 g / mol, the degree of substitution of carboxymethyl groups is 0.3, and the concentration is 2 mg / mL), and the reaction is continuously stirred at room temperature for 2 hours. The reaction is centrifuged at 8000 rpm for 10 minutes to obtain a two-layer assembled microcapsule, namely, tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsule encapsulating curcumin.
[0022] The layer-by-layer self-assembled microcapsules have a negative charge on the surface, an average particle size of 150nm, and an encapsulation rate of 94% for curcumin. When the layer-by-layer self-assembled microcapsules were added to Sprite at a volume of 1g / 100 mL, the leakage of curcumin was 10% within 7 days, and the ability of curcumin to scavenge free radicals was retained at 90%. In in vitro simulated digestion, at gastric pH (1.2), due to the protonation of carboxymethyl starch on the surface of the microcapsules, the microcapsules were almost uncharged, and the cumulative release of curcumin in 24 hours was 24.7%; at small intestinal pH (6.8), the microcapsules were deprotonated, the surface potential was -26mV, and the cumulative release of curcumin in 24 hours was 28.0%; at colon pH (7.2), the surface potential was -33.1mV, the microcapsules continued to swell, and due to the change in electrostatic interaction between the carrier materials, the cumulative release of curcumin in 24 hours was 76.1%. Example 3
[0023] 1 mL of DMSO solution of curcumin (10 mg / mL) and 1 mL of DMSO solution of tannic acid (10 mg / mL) were mixed and added dropwise into 10 mL of deionized water. The mixture was stirred at 300 r / min for 2 h. The DMSO was removed by dialysis with deionized water and the curcumin / tannic acid composite nanoparticles (CT) were obtained after freeze-drying. CT was redispersed in 5 mL of phosphate buffer (pH = 5.0, 0.1 mol / L) and added dropwise into a chitosan oligosaccharide solution (molecular weight 8.0 × 10 3 g / mol, the degree of substitution of amino groups was 0.15, and the concentration was 0.05 mg / mL), and the reaction was continued with stirring at room temperature for 2 h. The microcapsules were centrifuged at 8000 rpm for 10 min to obtain a layer of assembled microcapsules. The layer of assembled microcapsules was redispersed in phosphate buffer (pH = 5.0, 0.1 mol / L) and added dropwise to a carboxymethyl starch solution (molecular weight 1.0×10 5 g / mol, the degree of substitution of carboxymethyl groups was 0.2, the concentration was 0.05 mg / mL, and the reaction was stirred continuously at room temperature for 2 hours, and centrifuged at 8000 rpm for 10 minutes to obtain a two-layer assembled microcapsule, namely, tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsule encapsulating curcumin.
[0024] The layer-by-layer self-assembled microcapsules have a negative charge on the surface, an average particle size of 100nm, and an encapsulation rate of 89% for curcumin. When the layer-by-layer self-assembled microcapsules were added to Sprite at a volume of 1g / 100 mL, the leakage of curcumin was 15% within 7 days, and the ability of curcumin to scavenge free radicals was retained by 87%. In in vitro simulated digestion, at gastric pH (1.2), due to the protonation of carboxymethyl starch on the surface of the microcapsules, the microcapsules were almost uncharged, and the cumulative release of curcumin in 24 hours was 24.5%; under the condition of small intestinal pH (6.8), the microcapsules were deprotonated, the surface potential was -17.2mV, and the cumulative release of curcumin in 24 hours was 31.5%; under the condition of colon pH (7.2), the surface potential was -26.5mV, the microcapsules continued to swell, and due to the change of electrostatic interaction between the carrier materials, the cumulative release of curcumin within 24 hours was 61.8%.
[0025] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.
Claims
1. A method for constructing a tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsule for embedding curcumin, characterized in that The specific steps are: Step S1, curcumin and tannic acid are dissolved in dimethyl sulfoxide respectively, the dimethyl sulfoxide solution of curcumin and the dimethyl sulfoxide solution of tannic acid are mixed evenly, the mixed solution is added dropwise into deionized water and stirred for reaction, and then the dimethyl sulfoxide in the reaction system is removed by dialyzing with deionized water, and the curcumin / tannic acid composite nanoparticles are obtained after freeze-drying; Step S2, re-dispersing the curcumin / tannic acid composite nanoparticles obtained in step S1 in a phosphate buffer, and then adding dropwise to the phosphate buffer containing chitosan oligosaccharide, stirring at room temperature for reaction, and then centrifuging to obtain a layer of assembled microcapsules; Step S3, the one-layer assembled microcapsule obtained in step S2 is redispersed in a phosphate buffer, and then added dropwise into a phosphate buffer containing carboxymethyl starch, stirred at room temperature for reaction, and then centrifuged to obtain a two-layer assembled microcapsule.
2. The method for constructing the tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules embedding curcumin according to claim 1, characterized in that: The concentration of the dimethyl sulfoxide solution of curcumin is 1-10 mg / mL, the concentration of the dimethyl sulfoxide solution of tannic acid is 0.5-10 mg / mL, and the mass ratio of tannic acid to curcumin is 1:20-2:
1.
3. The method for constructing the tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules embedding curcumin according to claim 1, characterized in that: The chitosan oligosaccharide is used as a carrier material, and its molecular weight is 1.0×10 3 ~2.0×10 4 g / mol, the degree of substitution of the amino group is 0.05-0.2, and the concentration is 0.05-5 mg / mL; the carboxymethyl starch is used as a carrier material, and its molecular weight is 4.0×10 4 ~2.0×10 6 g / mol, the degree of substitution of carboxymethyl groups is 0.06-0.30, and the concentration is 0.05-5 mg / mL.
4. The method for constructing the tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules embedding curcumin according to claim 1, characterized in that: The pH of the phosphate buffer is 3.0-8.0, and the concentration is 0.01-0.2 mol / L.
5. The method for constructing the tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules encapsulating curcumin according to claim 1, characterized in that: The stirring reaction time in step S1, step S2 and step S3 is 0.5 to 24 hours.
6. Use of the tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules encapsulating curcumin constructed according to the method described in any one of claims 1 to 5 in the preparation of food additives, wherein the layer-by-layer self-assembled microcapsules encapsulating curcumin can effectively protect the free radical scavenging ability of curcumin during storage and achieve controlled release of curcumin in the gastrointestinal tract.
7. Use of the tannic acid-mediated starch-chitosan oligosaccharide layer-by-layer self-assembled microcapsules encapsulating curcumin constructed according to the method described in any one of claims 1 to 5 in the preparation of liquid food additives, wherein the layer-by-layer self-assembled microcapsules are placed in liquid food to effectively prevent premature leakage and inactivation of curcumin, and achieve controlled release of curcumin in the gastrointestinal tract through changes in the pH responsiveness and interaction of the carrier material.