Crocus sativus petal polysaccharide loaded curcumin gel bead as well as preparation method and application thereof

Abstract

The invention relates to the technical field of biology, in particular to saffron petal polysaccharide loaded curcumin gel beads as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing stigma croci petals and water, heating in a water bath, refluxing, filtering, extracting, carrying out rotary evaporation and concentration, taking supernate, adding absolute ethyl alcohol, standing, precipitating, carrying out centrifugal suction filtration, collecting polysaccharide, adding water for redissolving, carrying out rotary evaporation to remove ethyl alcohol, and freeze-drying for later use; uniformly mixing the freeze-dried saffron petal polysaccharide solution with a curcumin solution to obtain a petal polysaccharide-curcumin solution; sequentially adding sodium alginate and a calcium lactate solution into the petal polysaccharide-curcumin, uniformly mixing, and cross-linking to obtain the negative petal polysaccharide-curcumin composite gel beads. The curcumin is loaded by the sodium alginate, calcium lactate and crocus sativus petal polysaccharide composite material, so that the hardness and the structural stability of the gel beads are enhanced, the encapsulation efficiency of the curcumin is improved, targeted slow release is favorably realized, and a practical scheme is provided for efficient delivery of natural active ingredients.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of biotechnology, in particular to a crocus petal polysaccharide loaded curcumin gel bead and a preparation method and application thereof. BACKGROUND

[0002] Crocus sativus L. (Crocus sativus L. ) is a plant of the Iridaceae family, usually with dried stigmas as a medicine, which is a precious traditional Chinese medicinal material with the functions of promoting blood circulation to remove blood stasis, relieving stagnation and resolving knots, and cooling blood and detoxifying. However, the yield of stigmas is low, and the non-medicinal parts such as petals, stamens and corms of the whole flower account for more than 90%, which have a wide development and utilization value. Studies have shown that crocus petals are rich in polysaccharides and other active ingredients, and have good pharmacological activities, which can improve depression, inflammation, hypertension and other diseases.

[0003] Curcumin is a bright yellow pigment present in the rhizome of turmeric. Although curcumin in the form of turmeric is known for its medicinal value, a large number of studies by different research teams have shown that it is a drug with multiple target effects, which has an important influence on health and disease management. Curcumin has now entered the market as a health supplement, however, free curcumin has inherent defects such as poor solubility, limited stability and low bioavailability, which is particularly prominent in the gastrointestinal environment. It is prone to premature release under the acidic conditions in the stomach, which on the one hand leads to the destruction of the structure of curcumin and the loss of activity due to the strong oxidizing and degrading effects of gastric acid, and on the other hand, it is released in advance before reaching the target site (intestine), which greatly reduces the effective concentration of curcumin in the body, and seriously limits the full play of its anti-inflammatory effect and clinical application value.

[0004] Sodium alginate is a natural slightly soluble polysaccharide with unique gelation properties, and has the advantages of easy availability, low price and non-toxicity. The gel beads prepared therefrom have a unique cross-linked structure, which has good stability and flexibility, so that bioactive molecules can be loaded inside the gel beads and stably exist in a suitable environment, thereby providing an ideal environment for various biological reactions. With the synergistic effect of physical adsorption and chemical combination, the three-dimensional framework of the gel beads can firmly fix the bioactive factors and the like therein.

[0005] At present, crocus is generally prepared into total glycoside tablets, which are used as blood-activating and stasis-removing traditional Chinese medicines, and are suitable for the auxiliary treatment of cardiovascular diseases and microcirculation disorders, but often lack of targeted controlled release of drugs, and have a relatively large stimulation to the gastrointestinal tract. SUMMARY

[0006] In view of the problems existing in the prior art, the purpose of the present application is to design a technical scheme of a crocus petal polysaccharide loaded curcumin gel bead and a preparation method and application thereof.

[0007] The application specifically adopts the following technical solutions to achieve the above technical effects. In a first aspect, the application provides a preparation method of crocin petal polysaccharide loaded curcumin gel beads, comprising the following steps: S1, after mixing crocin petals and deionized water, water bath heating and refluxing, filtering extraction, rotary evaporation concentration, taking supernatant, adding anhydrous ethanol, placing precipitation, centrifugal filtration, collecting polysaccharide, adding water, removing ethanol by rotary evaporation, and freeze-drying for standby; S2, the freeze-dried crocin petal polysaccharide solution and curcumin solution are mixed uniformly, and the crocin petal polysaccharide-curcumin solution is obtained. S3, the crocin petal polysaccharide-curcumin is added into sodium alginate and calcium lactate solution in turn and mixed uniformly, and the negative crocin petal polysaccharide-curcumin composite gel beads are obtained by crosslinking.

[0008] Further, the ratio of crocin petal to deionized water in step S.1 is 1:35-45.

[0009] Further, the water bath heating condition in step S.1 is 85-95℃, heating refluxing at least 2 times, and extracting for 2-3h each time.

[0010] Further, anhydrous ethanol is added in step S.1 to an alcohol concentration of 75-85%.

[0011] Further, the concentrations of crocin petal polysaccharide solution and curcumin solution in step S.2 are 2mg / mL and 1mg / mL respectively, and the volume ratio of crocin petal polysaccharide solution to curcumin solution is 1-300:1.

[0012] Further, the mass-volume concentration of sodium alginate in step S.3 is 1-3%.

[0013] Further, the calcium ion concentration in step S.3 is 2-6%.

[0014] Further, the crosslinking time in step S.3 is 10-50min.

[0015] The second aspect of the application provides a crocin petal polysaccharide loaded curcumin gel bead.

[0016] The third aspect of the application provides an application of the crocin petal polysaccharide loaded curcumin gel bead in preparing a curcumin intestinal tract targeted delivery carrier.

[0017] The application has the following beneficial effects: (1) The application loads curcumin through sodium alginate, calcium lactate and crocin petal polysaccharide composite material, which not only enhances the hardness and structural stability of the gel beads, but also improves the encapsulation efficiency of curcumin.

[0018] (2) The safflower petal polysaccharide and curcumin are loaded on the composite matrix of safflower petal polysaccharide and sodium alginate, the raw materials are natural, biocompatible and degradable, the safflower petal polysaccharide has activity, and the safflower petal polysaccharide and curcumin synergistically play physiological effects, and meet the application requirements of functional food and medical carriers.

[0019] (3) Compared with the single matrix gel beads, the safflower petal polysaccharide-curcumin gel beads have a more compact and uniform microstructure, can reduce the premature release of curcumin in the gastrointestinal tract, realize targeted slow release, greatly improve the intestinal targeting delivery carrier water solubility and bioavailability of curcumin, and provide a practical scheme for efficient delivery of natural active ingredients. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a single factor test diagram for gel bead preparation; A: sodium alginate concentration, B: calcium ion concentration, C: crosslinking time.

[0021] Figure 2 It is a response surface analysis diagram of sodium alginate gel bead process optimization; A, C, E are response surface diagrams of the interaction between the three factors of RSM, and B, D, F are contour diagrams.

[0022] Figure 3 It is a safflower petal polysaccharide-curcumin solution ratio diagram.

[0023] Figure 4 It is a CSPP-CUR particle size diagram.

[0024] Figure 5 It is an IR spectrum diagram of safflower petal polysaccharide-curcumin gel beads (CSPP-CUR Cbs), safflower petal polysaccharide (CSPP), sodium alginate (SA) and curcumin (CUR).

[0025] Figure 6 It is an XRD spectrum diagram of safflower petal polysaccharide-curcumin gel beads (CSPP-CUR Cbs), safflower petal polysaccharide (CSPP), sodium alginate (SA) and curcumin (CUR).

[0026] Figure 7 It is a whole scanning and 100 mu m scanning electron microscope image; a, d: sodium alginate gel beads, b, e: curcumin gel beads, c, f: polysaccharide loaded curcumin gel beads.

[0027] Figure 8 It is a safflower petal polysaccharide-curcumin gel bead swelling rate diagram under different PH conditions.

[0028] Figure 9 It is a safflower petal polysaccharide-curcumin gel bead and curcumin gel bead curcumin release rate diagram in gastric juice.

[0029] Figure 10The figure of the release rate of curcumin in the crocus petal polysaccharide-curcumin gel beads and the curcumin gel beads. DETAILED DESCRIPTION

[0030] Other advantages and benefits of the present application will become apparent to those skilled in the art upon consideration of the disclosure and the detailed description of the application herein. The present application can be practiced with additional specific embodiments and applications, and in different ways, and modifications can be made in the details of the application without departing from the spirit of the application. It is to be understood that the following examples and features thereof can be combined with each other, where possible, without conflict. The methods used in the examples of the present application are conventional unless otherwise specified, and the reagents used are commercially available.

[0031] Example 1 Preparation of crocus petal polysaccharide-loaded curcumin gel beads S1, the crocus petals and water were added to a conical flask at a solid-liquid ratio of 1:40, heated in a water bath at 90°C and refluxed twice, each for 2h, and the extract was filtered and concentrated by rotary evaporation. The supernatant was collected, and anhydrous ethanol was added while stirring to make the alcohol concentration 80%, and then placed at 4°C for 24h. The polysaccharide was collected by centrifugal filtration, redissolved in water, and the ethanol was removed by rotary evaporation and freeze-dried for use; S2, the freeze-dried crocus petal polysaccharide solution 2mg / mL was mixed with curcumin solution 1mg / mL at a volume ratio of 200:1 to obtain a crocus petal polysaccharide-curcumin solution; S3, the crocus petal polysaccharide-curcumin was added to 1.5% sodium alginate and calcium lactate solution (calcium ion mass concentration 5%) in turn and mixed evenly, and crosslinked for 20min to obtain crocus petal polysaccharide-curcumin composite gel beads.

[0032] Example 2 Preparation of crocus petal polysaccharide and determination of its content I. Preparation of crocus petal polysaccharide Accurately weigh 6.2508g of crocus petal powder into a 500ml beaker, add 250ml of deionized water, mix well, and then transfer the solution to a 500ml conical flask and heat in a 90°C water bath for reflux extraction twice, each for 2h. The extract was filtered through filter paper and concentrated to 40mL under reduced pressure at 50°C. The supernatant was collected, anhydrous ethanol was added while stirring to make the alcohol concentration 80%, and then placed at 4°C for 24h, centrifuged at 8000r / min for 10min, and the polysaccharide was collected by filtration. The polysaccharide was redissolved in water, the ethanol was removed by rotary evaporation, and then freeze-dried to obtain 0.496g of polysaccharide.

[0033] II. Determination of the content of polysaccharide The difference between the total sugar content and the reducing sugar content in the determination of the content of polysaccharide is the content of polysaccharide.

[0034] (1) Total sugar content determination: anthrone-sulfuric acid method was used to determine the total sugar content. Precisely take 40, 80, 120, 160, 200 μL of glucose control solution into 6 5 mL glass test tubes, respectively, according to, respectively, take glucose standard solution, each add deionized water to 200 μL, shake well; then add 100 μL of 5% phenol solution and 700 μL of concentrated sulfuric acid, mix well; place in a 40°C water bath for 30 min, take out, immediately place in ice water bath for 5 min, take out. Using the corresponding reagent as blank, the absorbance was measured at 490 nm by using an enzyme marker. Each sample was measured 3 times. The glucose concentration (µg / mL) was used as the abscissa, and the absorbance value was used as the ordinate to draw the standard curve. Substituting the total sugar standard curve equation Y=0.0063x+0.0042 (R 2 =0.9993) into the equation, the total sugar content was calculated.

[0035] (2) Reducing sugar content determination: DNS method was used to precisely take 0.4, 0.6, 0.8, 1, 1.2, 1.4 mL of 1 mg / mL glucose solution, respectively. The volume was supplemented to 2 mL with ultrapure water, and 2 mL of DNS reagent was added, respectively. After mixing, it was placed in a boiling water bath for accurate heating for 5 min, then quickly placed in an ice bath for cooling for 10 min. 1 mL of the reaction solution was taken and diluted 5 times with 4 mL of ultrapure water. After standing at room temperature, the absorbance at 550 nm was measured. The glucose solution concentration (mg / mL) was used as the abscissa, and the absorbance was used as the ordinate to draw the reducing sugar standard curve. Substituting the reducing sugar standard curve equation Y=0.4854x-0.0289 (R 2 =0.9994) into the equation, the reducing sugar content was calculated.

[0036] The results showed that the total sugar content was 35.10%, the reducing sugar content was 0.123%, and the crocus petal polysaccharide content was 34.32%.

[0037] Example 3 Preparation conditions of gel beads (1) Single factor test With hardness as the determination index, the effects of different calcium ion concentrations, curing times and curing temperatures on the hardness of sodium alginate gel beads were explored.

[0038] Under the conditions of different sodium alginate concentrations (1%, 1.5%, 2%, 2.5%, 3%), calcium ion concentration 2%, and crosslinking time 10 min; the results are shown in A of Figure 1 , the hardness first increases and then decreases, and the hardness is maximum when the sodium alginate concentration is 1.5%.

[0039] Under the conditions of different calcium ion concentrations (2%, 3%, 4%, 5%, 6%), sodium alginate concentration 1.5%, and crosslinking time 10 min; the results are shown inFigure 1 As shown in B, the hardness first increases and then decreases, reaching its maximum when the calcium ion concentration is 5%.

[0040] Under different cross-linking times (10, 20, 30, 40, 50 min), the sodium alginate concentration was 1.5% and the calcium ion concentration was 5%. The results are as follows: Figure 1 As shown in C, the hardness first increases and then decreases, reaching its maximum at a crosslinking time of 20 minutes.

[0041] (2) Response surface Based on the results of single-factor experiments, a response surface methodology was designed. Sodium alginate concentration (%), calcium ion concentration (%), and cross-linking time (min) were selected as independent variables, and hardness was used as the response value. The optimal preparation process conditions for gel beads were explored by designing response surface combination using Design-Expert 13 software. The response surface factors and levels design and experimental results are shown in Tables 1 and 2.

[0042] Table 1 Response Surface Factors and Level Design

[0043] Table 2 Box-Behnken Design Schemes and Response Values

[0044] Using Design Expert 13.0 software, regression fitting was performed on the experimental data in Table 2 to obtain a quadratic multinomial regression equation for the three independent variables:

[0045] The results of the analysis of variance for this regression model are shown in Table 3. The results show that B, C, and their mutual terms BC and A... 2 B 2 C 2 All of these have a highly significant impact on the hardness of the gel beads. P <0.01). The overall coefficient of determination R of the model. 2 =0.9966, Corrected coefficient of determination R Adj 2 =0.9923, prediction determination coefficient R Pred 2 The coefficient of variation (CV) is 0.6528%, indicating a highly significant multiple regression relationship between the dependent variable and each independent variable. The model fit is good, and the experimental error is small. Therefore, this regression equation can accurately describe the relationship between each factor and the response value, and is suitable for the process analysis and optimization of sodium alginate gel beads.

[0046] Table 3. Analysis of variance of the regression equations

[0047] (2) Response surface analysis of each factor interaction and prediction of the best process conditions The response surface and contour map of the interaction between the three factors investigated by Box-Benhnken experimental design are shown in Figure 2. Figure 2 Based on the 3D response surface, contour map and analysis of each interaction value, the significance order of the three-group interaction is: BC > AB > AC. P

[0048] Based on the regression model established by Design expert 13.0 software, the optimal extraction process conditions are predicted as follows: sodium alginate concentration 1.8%, calcium ion concentration 4.8%, and cross-linking time 20 min. Under these conditions, the predicted value of gel bead hardness is 149.95 g, and the actual measured value is 149.75 ± 0.421 g (n = 3), which is close to the predicted value with small deviation, indicating that the regression simulation fitting effect is good, and the extraction process conditions determined by the response surface method have high accuracy and reliability.

[0049] Example 4: Analysis of the encapsulation efficiency and particle size of crocin-loaded safflower petal polysaccharide I. Preparation method Preparation of crocin-loaded safflower petal polysaccharide nanocomposite (CSSP-CUR): 0.0300 g of CSPP was accurately weighed and dissolved in 15 ml of pure water to prepare a CSPP aqueous solution with a concentration of 2 mg / ml. 0.0100 g of CUR was accurately weighed and added to 10 ml of absolute ethanol to prepare a CUR absolute ethanol solution with a concentration of 1 mg / ml. An appropriate amount of CSPP aqueous solution and CUR ethanol solution was taken to make the volume ratio of CSPP to CUR as 200:1. The CUR ethanol solution was transferred to the CSPP aqueous solution, and the mixture was sealed in the dark. When the temperature of the water bath constant temperature shaker reached 37°C, the mixture was shaken at 200 rpm for half an hour. The sample was carefully transferred to a centrifuge tube and centrifuged at 10,000 rpm for 15 minutes. The precipitate that did not bind was discarded, and the obtained clear liquid was the CSPP-CUR nanocomposite solution. The nanocomposite solution was freeze-dried and stored in a 4°C refrigerator for future use.

[0050] ​Preparation of standard curve: 0.0100 g of CUR standard was precisely weighed into a 10 ml volumetric flask, 10 ml of ethanol was added to make 1 mg / ml of CUR standard stock solution. The 1 mg / ml CUR standard stock solution was diluted with anhydrous ethanol to obtain a concentration gradient of 0.5, 1, 1.5, 2.0, 2.5 mg / ml of CUR standard solution. The absorbance value A(425nm) of the above-mentioned gradient concentration solution at λ = 425 nm was measured by enzyme marker with solvent as blank control. The content determination standard curve of CUR was drawn with the gradient concentration of CUR as the abscissa and the A(425nm) absorbance corresponding to each concentration as the ordinate, and the regression equation Y = 0.0799-0.0016(R 2 = 0.9996) was calculated.

[0051] Determination method of sample: 0.0100 g of CSPP-CUR was weighed and dissolved in 5 mL of water to prepare a 2 mg / mL CSPP-CUR aqueous solution, 2 mL of the CSPP-CUR aqueous solution was measured and 8 mL of anhydrous ethanol was added to prepare an ethanol solution of nanocomposite. After being uniformly mixed, centrifugation was performed at a speed of 10000 r for 15 min. The supernatant was collected and the absorbance value of the sample was measured at λ = 425 nm by the gradient concentration solution determination method. The encapsulation efficiency of the sample on CUR was calculated according to the following formula.

[0052] Encapsulation efficiency (%) = detected CUR mass / added CUR mass.

[0053] II. Results analysis The absorbance was measured at 425 nm wavelength with CUR as the standard. The standard curve was drawn with the CUR concentration as the abscissa and the absorbance value as the ordinate, and the regression equation y = 0.0799x - 0.0016 (R 2 = 0.9996) was calculated. The linear relationship was good in the range of 0.2-0.7 mg / mL, and the results showed that the encapsulation efficiency reached 81.66%.

[0054] The laser particle size analyzer (Zetasizer nano S90, Malvern Instruments, UK) was used to evaluate the dynamic light scattering (DLS) technology. Before analysis, the fresh CSPP-CUR nanoparticle suspension was diluted 10 times, and the experiment was repeated three times. The results are shown in Figure 3 , which shows that the average particle size of CSPP-CUR nanoparticles is 346.9 nm.

[0055] As shown in Figure 3 , the ratio of crocin petal polysaccharide to CUR has a significant effect on the encapsulation efficiency, and the highest encapsulation efficiency is obtained when the ratio is 200:1. Too high or too low ratio will reduce the encapsulation effect. Figure 4The average particle size of the safflower petal polysaccharide-curcumin nanoparticles was 354.1 ± 0.624 nm.

[0056] Example 5 Preparation of safflower petal polysaccharide-loaded curcumin gel beads and study on physicochemical properties Accurately weigh 0.08 mg of freeze-dried CSPP-CUR nanoparticles, add 40 mL of water, and prepare a 2 mg / mL CSPP-CUR aqueous solution. Add the obtained solution to sodium alginate to make the sodium alginate concentration 1.8%, and drop it into a 5% calcium ion solution using a disposable syringe to obtain safflower petal polysaccharide-loaded curcumin gel beads (CSPP-CUR Cbs). Collect the gel beads and freeze-dry them for later use. In the same way, prepare sodium alginate gel beads (SA Cbs) and curcumin gel beads (CUR Cbs).

[0057] (1) IR After the sample is completely mixed with potassium bromide, it is pressed into a tablet, and then analyzed by a Fourier transform infrared spectrometer in the range of 500-4000 cm -1 , and the results are shown in Figure 5 .

[0058] The infrared spectra of petal polysaccharide-curcumin gel beads (CSPP-CUR Cbs) and petal polysaccharide (CSPP), sodium alginate (SA), and curcumin (CUR) were analyzed. In the hydroxyl stretching vibration region (3200-3600 cm -1 ), CUR exhibits a characteristic peak of phenolic hydroxyl group at 3502.66 cm -1 , SA and CSPP exhibit broad peaks of polysaccharide hydroxyl group at 3462.15 cm -1 and 3437.08 cm -1 , respectively, while the peak of CSPP-CUR Cbs shifts to 3430.33 cm -1 , indicating that hydrogen bonds between hydroxyl groups are involved in the interaction; in the carbonyl stretching vibration region (1600-1800 cm -1 ), CUR exhibits a carbonyl characteristic peak at 1627.89 cm -1 , SA and CSPP exhibit carbonyl peaks at 1636.57 cm -1 and 1633.67 cm -1 , respectively, and the peak of CSPP-CUR Cbs is 1632.71 cm -1 , indicating that carbonyl groups also participate in intermolecular interaction. In summary, curcumin and petal polysaccharide, sodium alginate interact through hydroxyl, carbonyl and other functional groups, successfully constructing the CSPP-CUR gel bead complex system.

[0059] (2) XRD The samples were determined by using X-ray powder diffractometer under CuKa radiation. The analysis parameters were as follows: voltage 40 kV, current 200 mA, 2 theta range 5-60°, scanning rate 5° / min, and the results were as shown in Figure 6 .

[0060] The crystal structure and the interaction between components of the petal polysaccharide-curcumin gel beads (CSPP-CUR Cbs) were analyzed by comparing the XRD patterns of CSPP, SA and CUR. CUR showed a series of sharp and high-intensity characteristic diffraction peaks in the range of 5-40°, indicating that it was a crystalline substance; SA and CSPP only showed broad and diffuse peaks, indicating that both of them were amorphous structures. In the diffraction pattern of CSPP-CUR Cbs, the characteristic crystalline peaks of CUR completely disappeared, and only showed amorphous diffuse peaks similar to CSPP and SA, which indicated that curcumin was dispersed in the matrix of petal polysaccharide and sodium alginate in an amorphous state in the gel bead system, further proving that the three formed a uniform composite gel bead system through intermolecular interaction, the crystallinity of curcumin was destroyed, which was conducive to its dispersion in the system and the improvement of its bioavailability.

[0061] (3) SEM The microstructure characteristics of QC-CSPP nanoparticles were observed using a field emission scanning electron microscope (FE-SEM). Before observation, the sample was sprayed with a gold layer under vacuum conditions using a Polaron SC502 vacuum sputter coater, and then FE-SEM observation was performed, and the results were as shown in Figure 7 .

[0062] To explore the influence of the micro-morphology characteristics and components on the structure of the gel beads, the scanning electron microscope (SEM) images of sodium alginate gel beads, polysaccharide gel beads and polysaccharide-loaded curcumin gel beads were analyzed. From the overall morphology (Fig. a, b, c, scale 1.00 mm), it can be seen that the structure of sodium alginate gel beads is relatively loose and the surface is wrinkled, while the polysaccharide gel beads and the polysaccharide-loaded curcumin gel beads show a more rounded spherical structure, and the surface density of the latter is improved. Further observation of the microstructure (Fig. d, e, f, scale 100 μm) shows that the internal pores of sodium alginate gel beads are large and the structure is loose, while the polysaccharide gel beads form a network-like dense structure, and the network structure of the polysaccharide-loaded curcumin gel beads is more uniform and the density is further enhanced. In summary, the introduction of polysaccharide makes the morphology of the gel beads more regular, and the density and uniformity of the microstructure are further improved after loading curcumin, which may be due to the interaction between polysaccharide, curcumin and sodium alginate, which optimizes the gel network structure, laying a structural foundation for the subsequent performance.

[0063] (4) Swelling Respectively, 100 mg of dried petal polysaccharide-curry gel beads were added to pH = 2, 3, 4, 5 HCI-KCI buffer for 4 h, and the swollen beads were taken out at the same interval, wrapped with filter paper to remove the surface moisture of the beads, weighed the mass of the gel beads, and then put the beads back into the buffer, repeated three times for each group. The swelling degree was calculated by the following formula:

[0064] In the formula, M1 is the mass of the swollen beads (g); M2 is the mass of the dried beads (g).

[0065] The results are shown in Figure 8 It can be seen from the figure that the swelling rate of the gel beads under each pH condition showed an upward trend with the extension of time; at the same time, the swelling rate increased significantly with the increase of pH, and reached the highest level at pH = 5, and there was a significant difference between different pH groups (different letters). This shows that the petal polysaccharide-curry gel beads have obvious pH-dependent swelling characteristics, and the swelling capacity is stronger in alkaline environment. It is speculated that the reason may be that the change of pH value affects the dissociation degree of functional groups and the intermolecular interaction in the network structure of the gel beads, thereby regulating the swelling behavior. This characteristic provides a theoretical basis for its application in the field of targeted release.

[0066] (5) In vitro digestion experiment In vitro simulation of gastrointestinal digestion of petal polysaccharide-curry gel beads was carried out. The digestion process was carried out in a constant temperature shaker at 37°C and 100 rpm in a dark environment.

[0067] Gastric juice phase simulation: gastric juice is composed of 2 mg / mL sodium chloride solution and 3.2 mg / mL pepsin, and the pH value is adjusted to 2.0 with hydrochloric acid (0.1 M). After oral digestion, the mixture (25 mL) was mixed with simulated gastric juice at a ratio of 1:1 (volume ratio) and continuously stirred at 100 rpm for 2 hours to simulate the gastric digestion process. During the digestion process, the sample was collected regularly. After gastric juice digestion, the pH value of the mixture was adjusted to 7.0 for subsequent small intestine digestion.

[0068] Small intestine liquid phase simulation: the simulated small intestine liquid contains 10 mg / mL bile salts and 3 mg / mL trypsin. The above digestion mixture (50 mL) is added to the small intestine liquid at a ratio of 1:1 (volume ratio). The pH value is adjusted to 7.0 and incubated at 37°C for 2 hours. The sample is still collected at fixed time intervals. Finally, the biological digestion is terminated by heating at 95°C for 5 min.

[0069] The results are shown in Figure 9 and 10It was observed that in the average gastric fluid environment, the curcumin release rate showed only a very slow upward trend over time, remaining at a low level at 120 min; however, in the average intestinal fluid environment, the curcumin release rate increased rapidly over time, reaching near-complete release at 120 min. This indicates that the petal polysaccharide-curcumin gel beads possess significant intestinal-targeted release characteristics, effectively inhibiting curcumin release in gastric fluid while achieving highly efficient curcumin release in intestinal fluid. This characteristic mainly stems from the dissociation differences of the gel bead network structure under different pH conditions, providing experimental evidence for its application as an intestinal-targeted delivery carrier for curcumin.

Claims

1. A process for the preparation of curcumin loaded gel beads of Safflower petals polysaccharides, characterized by, Comprising the following steps: S1, after mixing safflower petals and deionized water, water bath heating and reflux, filtration extraction, rotary evaporation concentration, taking supernatant, adding anhydrous ethanol, placing precipitation, centrifugal filtration, collecting polysaccharide, adding water, dissolving, rotary evaporation to remove ethanol, freeze-drying for standby; S2, the freeze-dried safflower petal polysaccharide solution and curcumin solution are mixed uniformly, and the petal polysaccharide-curcumin solution is obtained; S3, petal polysaccharide-curcumin is added into sodium alginate and calcium lactate solution in turn and mixed uniformly, and crosslinking is carried out to obtain negative petal polysaccharide-curcumin composite gel beads.

2. A process for the preparation of curcumin loaded saffron petal polysaccharide gel beads as claimed in claim 1 wherein, The ratio of safflower petal and deionized water in step S.1 is 1:35-45.

3. A process for the preparation of curcumin loaded crocin gel beads as claimed in claim 1 wherein, The water bath heating condition in step S.1 is 85-95℃, heating reflux at least 2 times, 2-3h each time.

4. A process for the preparation of curcumin loaded crocin gel beads as claimed in claim 1 wherein, The anhydrous ethanol is added to the alcohol concentration of 75-85% in step S.

1.

5. A process for the preparation of curcumin loaded crocus petal polysaccharide gel beads as claimed in claim 1 wherein, The concentration of safflower petal polysaccharide solution and curcumin solution in step S.2 is 2mg / mL and 1mg / mL respectively, and the volume ratio of safflower petal polysaccharide solution and curcumin solution is 1-300:

1.

6. A process for the preparation of curcumin loaded saffron petal polysaccharide gel beads as claimed in claim 1 wherein, The mass concentration of sodium alginate in step S.3 is 1-3%.

7. A process for the preparation of curcumin loaded crocus petal polysaccharide gel beads as claimed in claim 1 wherein, The concentration of calcium ion in step S.3 is 2-6%.

8. A process for the preparation of curcumin loaded saffron petal polysaccharide gel beads as claimed in claim 1 wherein, The crosslinking time in step S.3 is 10-50min.

9. A kind of safflower petal polysaccharide loaded curcumin gel beads prepared by the method of any one of claims 1-8.

10. The application of a kind of safflower petal polysaccharide loaded curcumin gel beads in claim 9 in the preparation of curcumin intestinal tract targeted delivery carrier.

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