A method for regulating the time-release behavior of lutein by 3D printing interval multi-layer structure

Abstract

This invention discloses a method for regulating the temporal release behavior of lutein using a 3D-printed spaced multilayer structure, belonging to the field of food 3D printing technology. The method includes the following steps: (1) preparation of an empty gel layer; (2) preparation of a lutein-loaded gel layer; and (3) dual-nozzle 3D printing. The 3D-printed spaced multilayer structure design provided by this invention can effectively alter the release behavior of lutein, causing it to exhibit a certain temporal "lag" during intestinal digestion and possessing good intestinal targeting, significantly improving the bioavailability of lutein, up to a maximum of 47.97%. This invention not only provides a new approach to solving the bottleneck problem of low bioavailability of lutein but also offers new technological strategies for expanding the innovative design of targeted delivery systems and developing personalized health products using 3D printing.

Description

Technical Field

[0001] This invention relates to the field of food 3D printing technology, and more specifically, to a method for regulating the temporal release behavior of lutein using a 3D printed spaced multilayer structure. Background Technology

[0002] Lutein is a functional compound beneficial to human health, possessing beneficial physiological functions such as improving cardiovascular disease, preventing cancer, and mitigating age-related macular degeneration. However, the chemical instability and low water solubility of lutein result in low bioavailability, only 2%–5%, which severely limits its physiological functions. Lutein bioavailability refers to the proportion of dietary lutein that is loaded into mixed micelles and absorbed by the small intestine. Promoting the formation of mixed micelles in the small intestine is key to improving its bioavailability. A lower number of mixed micelles formed during digestion leads to reduced lutein bioavailability.

[0003] Numerous studies have explored ways to improve the bioavailability of lutein through the development of delivery vectors such as emulsions, emulsion gels, and liposomes. While these delivery systems offer good sustained-release of lutein, the released lutein is not effectively dissolved in the mixed micelles formed by lipolysis products monoacylglycerols (MAGs), free fatty acids (FFAs), and bile salts. Most of the lutein remains in free form within the intestinal digestive fluids, resulting in low solubility in the mixed micelles and failing to achieve the desired bioavailability. Therefore, regulating the digestive properties of the delivery vector in the intestine, controlling lutein release, promoting the formation, dissolution, and transport of mixed micelles are crucial for improving lutein bioavailability.

[0004] Currently, most research focuses on the structure and interface design of delivery carriers, aiming to improve bioavailability by enhancing the stability and sustained-release properties of active substances such as carotenoids. Reports indicate that the release of drugs / nutrients is influenced not only by the properties of the delivery carrier but also by its geometry. 3D printing, as a novel additive manufacturing technology, can digitally drive the design of complex layer-by-layer structures to customize the release characteristics of active substances. 3D printing technology can achieve complex release pattern sequences through careful design of shapes and structures, surpassing classic continuous release curves, such as constant release, decreasing release, and time-sequential release. Therefore, altering or controlling the release pattern and rate of lutein through 3D structural design will be an important innovative approach. Summary of the Invention

[0005] Technical issues

[0006] This project differs from traditional colloidal delivery systems in its interface structure design. It uses medium-chain triglycerides as the oil phase and whey protein isolate as the aqueous phase. After high-pressure microfluidic homogenization, guar gum is added to form an emulsion gel, serving as the empty lutein carrier layer. Corresponding emulsion gels with added lutein serve as the lutein loading layer. Dual-nozzle 3D printing technology is used to alternately print the lutein loading and empty carrier layers, constructing a 3D printing system with different spacing multilayer structures. Combined with an in vitro digestion model, the regulatory effect of the multilayer spacing structure on lutein release behavior is studied. The research results not only provide new ideas for solving the bottleneck of low bioavailability of lutein but also offer new technological strategies for expanding the innovative design of targeted delivery systems and developing personalized health products using 3D printing.

[0007] Technical solution

[0008] The technical problem to be solved by the present invention is achieved through the following technical solution:

[0009] A method for regulating the time-sequential release behavior of lutein using 3D-printed spaced multilayer structures, characterized by comprising the following steps:

[0010] 1. The preparation steps of the empty-loaded layer gel are as follows:

[0011] (1) The isolated whey protein was uniformly dispersed in sodium phosphate buffer (PBS, 0.02M, pH 7.0) as the aqueous phase;

[0012] (2) Medium-chain triglycerides were selected as the oil phase. A certain volume fraction of the oil phase was mixed with a certain WPI concentration of the aqueous phase. The volume fraction of the oil phase was 15%-18%, and the WIP concentration was 10%-12%.

[0013] (3) The two mixed phases were successively subjected to high-speed dispersion (9000 rpm, 5 min) and high-pressure micro-jet homogenization (18000 psi, 2 cycles) to form a uniform emulsion.

[0014] (4) Add guar gum (5%, w / v) to the emulsion and disperse at high speed (9000 rpm, 3 min) to dissolve it completely;

[0015] (5) The solution obtained in (4) is heated in a water bath at 90°C for 30 minutes. During the heating process, it is sealed with plastic wrap to avoid moisture loss. The solution is placed at 4°C for 4 hours to form an empty layer emulsion gel.

[0016] 2. The steps for preparing the lutein-supported gel are as follows:

[0017] (1) The isolated whey protein was uniformly dispersed in sodium phosphate buffer (PBS, 0.02M, pH 7.0) as the aqueous phase;

[0018] (2) A certain amount of lutein is dissolved in medium-chain triglycerides as an oil phase, and a certain volume fraction of the oil phase is mixed with a certain WIP concentration of an aqueous phase. The lutein loading is 1.0-1.5%, the volume fraction of the oil phase is 15%-18%, and the WIP concentration is 10%-12%.

[0019] (3) The two mixed phases were successively subjected to high-speed dispersion (9000 rpm, 5 min) and high-pressure micro-jet homogenization (18000 psi, 2 cycles) to form a uniform emulsion.

[0020] (4) Add guar gum (5%, w / v) to the emulsion and disperse at high speed (9000 rpm, 3 min) to dissolve it completely;

[0021] (5) The solution obtained in (4) is heated in a water bath at 90°C for 30 minutes. During the heating process, it is sealed with plastic wrap to avoid moisture loss. The solution is placed at 4°C for 4 hours to form a lutein-loaded emulsion gel.

[0022] 3. The specific steps of 3D printing are as follows:

[0023] (1) Using lutein load layer and empty load layer as printing materials, computer-aided design layer data control is used to design the multi-layer structure of the load layer and empty load layer. The total number of layers is designed to be 4 to 5 layers. The outermost layer is determined to be the empty load layer. Then, according to the principle of the interval between the empty load layer and the load layer, the number of interval layers and the positioning of the empty load layer and the load layer are designed.

[0024] (2) The 3D printing model is determined to be a cylinder with a diameter of 11 mm and a height of 6.5 mm. Dual-nozzle 3D printing is carried out under the conditions of printing temperature of 25℃, nozzle diameter of 0.84 mm and printing speed of 15 mm / s. The overall filling density of the model is 100%, and a gel system with different spacing and multi-layer structure is printed.

[0025] Beneficial effects of the present invention

[0026] Compared with existing technologies, this invention provides a method for regulating the temporal release behavior of lutein using 3D-printed spaced multilayer structures, which has the following beneficial effects:

[0027] 1. The 3D-printed spaced multilayer structure design of the present invention can effectively change the release behavior of lutein, making lutein exhibit a certain temporal "lag" during the intestinal digestion stage, thereby achieving the customized target of the lutein release curve.

[0028] 2. The spaced multilayer structure design of the present invention significantly reduces the release rate of lutein during the gastric digestion stage, down to a minimum of 7.26%, thereby improving intestinal targeting.

[0029] 3. This invention significantly improves the bioavailability of lutein, up to 47.97%.

[0030] Therefore, the multi-layered structure design with spacing in 3D printing can effectively regulate lutein release behavior and improve lutein bioavailability. This invention innovatively combines 3D printing technology with a delivery system, providing a technical strategy for developing a wider range of personalized 3D-printed health products. Attached Figure Description

[0031] Figure 1 Schematic diagram of the design model of the multi-layered structure

[0032] Figure 2 Lutein release characteristics of multilayer structures with different spacing Detailed Implementation

[0033] The invention will be further described below in conjunction with the specification, but the scope of protection claimed by the present invention is not limited to the scope described in the embodiments.

[0034] Example 1

[0035] Medium-chain triglycerides were selected as the oil phase, and WPI was uniformly dispersed in sodium phosphate buffer (PBS, 0.02M, pH 7.0) as the aqueous phase. Then, 16% (v / v) of the oil phase was mixed with 12% WPI in the aqueous phase, and the mixture was sequentially treated by high-speed dispersion (9000 rpm, 5 min) and high-pressure microfluidic homogenization (18000 psi, 2 cycles) to form a homogeneous emulsion. Guar gum (5%, w / v) was added to the emulsion and dispersed at high speed (9000 rpm, 3 min) until fully dissolved. The mixture was then heated in a 90°C water bath for 30 min, sealed with plastic wrap during heating to prevent moisture loss. Finally, it was incubated at 4°C for 4 h to form an empty-loaded emulsion gel. The preparation process for the lutein-loaded emulsion gel was similar to that for the empty-loaded emulsion gel, with 1.0% lutein dissolved in medium-chain triglycerides as the oil phase, and subsequent steps were the same as for the empty-loaded gel.

[0036] Using lutein-loaded and unloaded layers as printing materials, computer-aided design (CAD) with layer-by-layer data control was employed to design a multi-layered structure with spacing between the load and unloaded layers. The 3D printing model was determined to be a cylinder with a diameter of 11 mm and a height of 6.5 mm. Dual-nozzle 3D printing was performed at a printing temperature of 25℃, a nozzle diameter of 0.84 mm, and a printing speed of 15 mm / s, with an overall infill density of 100%. The design of the number of printing layers between the unloaded and loaded layers followed the principle of alternating layers, as shown in the attached figure. Figure 1 (a) A 3D printing system with a spaced multilayer structure, exhibiting release behavior such as Figure 2As shown in the figure. The release rate of lutein in the system during gastric digestion was determined to be 7.45%, and the bioavailability was 47.15%.

[0037] Example 2

[0038] Medium-chain triglycerides were selected as the oil phase, and WPI was uniformly dispersed in sodium phosphate buffer (PBS, 0.02M, pH 7.0) as the aqueous phase. Then, 15% (v / v) of the oil phase was mixed with 10% WPI in the aqueous phase, and the mixture was sequentially treated by high-speed dispersion (9000 rpm, 5 min) and high-pressure microfluidic homogenization (18000 psi, 2 cycles) to form a homogeneous emulsion. Guar gum (5%, w / v) was added to the emulsion and dispersed at high speed (9000 rpm, 3 min) until fully dissolved. The mixture was then heated in a 90°C water bath for 30 min, sealed with plastic wrap during heating to prevent moisture loss. Finally, it was incubated at 4°C for 4 h to form an empty-loaded emulsion gel. The preparation process for the lutein-loaded emulsion gel was similar to that for the empty-loaded emulsion gel, with 1.2% lutein dissolved in medium-chain triglycerides as the oil phase, and subsequent steps were the same as for the empty-loaded gel.

[0039] Using lutein-loaded and unloaded layers as printing materials, computer-aided design (CAD) with layer-by-layer data control was employed to design a multi-layered structure with spacing between the load and unloaded layers. The 3D printing model was determined to be a cylinder with a diameter of 11 mm and a height of 6.5 mm. Dual-nozzle 3D printing was performed at a printing temperature of 25℃, a nozzle diameter of 0.84 mm, and a printing speed of 15 mm / s. The overall infill density of the model was 100%. The design of the number of printing layers between the unloaded and loaded layers followed the principle of alternating layers, as shown in the attached figure. Figure 1 (b) A 3D printing system with a spaced multilayer structure, exhibiting release behavior such as Figure 2 As shown in the figure. The release rate of lutein in the system during gastric digestion was determined to be 8.57%, and the bioavailability was 45.79%.

[0040] Example 3

[0041] Medium-chain triglycerides were selected as the oil phase, and WPI was uniformly dispersed in sodium phosphate buffer (PBS, 0.02M, pH 7.0) as the aqueous phase. Then, 17% (v / v) of the oil phase was mixed with 11% (v / v) of the WPI aqueous phase, and the mixture was sequentially treated by high-speed dispersion (9000 rpm, 5 min) and high-pressure microfluidic homogenization (18000 psi, 2 cycles) to form a homogeneous emulsion. Guar gum (5%, w / v) was added to the emulsion and dispersed at high speed (9000 rpm, 3 min) until fully dissolved. The mixture was then heated in a 90°C water bath for 30 min, sealed with plastic wrap during heating to prevent moisture loss. Finally, it was incubated at 4°C for 4 h to form an empty-loaded emulsion gel. The preparation process for the lutein-loaded emulsion gel was similar to that for the empty-loaded emulsion gel, with 1.5% lutein dissolved in medium-chain triglycerides as the oil phase, and subsequent steps were the same as for the empty-loaded gel.

[0042] Using lutein-loaded and unloaded layers as printing materials, computer-aided design (CAD) with layer-by-layer data control was employed to design a multi-layered structure with spacing between the load and unloaded layers. The 3D printing model was determined to be a cylinder with a diameter of 11 mm and a height of 6.5 mm. Dual-nozzle 3D printing was performed at a printing temperature of 25℃, a nozzle diameter of 0.84 mm, and a printing speed of 15 mm / s, with an overall infill density of 100%. The design of the number of printing layers between the unloaded and loaded layers followed the principle of alternating layers, as shown in the attached figure. Figure 1 (c) A 3D printing system with a spaced multilayer structure, exhibiting release behavior such as Figure 2 As shown in the figure. The release rate of lutein in the system during gastric digestion was determined to be 10.05%, and the bioavailability was 47.59%.

Claims

1. A method for regulating the temporal release behavior of lutein using 3D-printed spaced multilayer structures, characterized in that, Using dual-nozzle 3D printing technology, an alternating layer gel system with empty layer gel and lutein-loaded layer gel was constructed. The total number of layers in the alternating layer gel system was 4 or 5, and the outermost layer was set as an empty layer to achieve the regulation of the lutein release sequence. Specifically, the following steps are included: (1) Preparation of empty-loaded layer gel: 10%-12% whey protein isolate was uniformly dispersed in 0.02M, pH 7.0 sodium phosphate buffer as the aqueous phase; medium-chain triglycerides were used as the oil phase, and the oil phase was mixed with the above aqueous phase at a volume fraction of 15%-18%; the two mixed phases were then subjected to high-speed dispersion at 9000 rpm for 5 min and high-pressure microfluidic homogenization at 18000 psi for 2 cycles to form a uniform emulsion; 5% (w / v) guar gum was added to the emulsion and dispersed at 9000 rpm for 3 min to dissolve it completely; the solution was then heated in a 90℃ water bath for 30 min, sealed with plastic wrap during the heating process, and finally allowed to stand at 4℃ for 4 h to form an empty-loaded layer emulsion gel; (2) Preparation of lutein-loaded layer gel: 10%-12% whey protein isolate was uniformly dispersed in 0.02M, pH 7.0 sodium phosphate buffer as the aqueous phase; 1.0%-1.5% lutein was dissolved in medium-chain triglycerides as the oil phase, and the oil phase was mixed with the aqueous phase at a volume fraction of 15%-18%; the subsequent high-speed dispersion, high-pressure microfluidic homogenization, addition of guar gum, water bath heating and static gelation steps were the same as the preparation process of empty-loaded layer gel, and finally a lutein-loaded layer emulsion gel was formed. (3) 3D printing: Using the empty layer gel and lutein-loaded layer gel prepared in steps (1) and (2) as printing materials, a cylindrical model was constructed using computer-aided design software. The model had a diameter of 11 mm and a height of 6.5 mm. The model was sliced ​​and the path was planned according to the set interval multi-layer structure. The model was printed using a dual-nozzle 3D printer at a printing temperature of 25℃, a nozzle diameter of 0.84 mm, and a printing speed of 15 mm / s. The overall infill density of the model was 100%.

2. The method according to claim 1, characterized in that, Through the aforementioned multi-layered structure design, lutein exhibits a time-delayed release behavior during in vitro simulated intestinal digestion.

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