Bacterial cellulose-based composite nano-emulsion as well as preparation method and application thereof

Abstract

The invention provides a bacterial cellulose-based composite nano-emulsion and a preparation method and application thereof, and relates to the technical field of nano-emulsions.The preparation method comprises the steps that S1, Sanzan gum is dissolved in water, a completely hydrated Sanzan gum solution is prepared, and the mass concentration of Sanzan gum in the Sanzan gum solution is 0.1%-0.3%; s2, the bacterial cellulose suspension is added into the Sanzan gum solution, the mass concentration of bacterial cellulose in the final composite suspension reaches 0.1%-0.5%, and the bacterial cellulose is nano bacterial cellulose; and S3, mixing the composite suspension and an oil phase according to a ratio of 9: 1, and homogenizing to obtain the bacterial cellulose-based composite nano-emulsion. The nano-emulsion is high in biological safety, environmentally friendly, degradable, capable of being prepared at low cost, high in emulsion stability and capable of being stored for a long time.

Description

Technical Field

[0001] The present invention relates to the technical field of nanoemulsions, and in particular to a bacterial cellulose-based composite nanoemulsion and a preparation method and application thereof. Background Art

[0002] Nanoemulsion is a colloidal delivery system based on emulsions, which is particularly suitable for various natural compounds due to its high loading capacity and efficient protection. In recent years, the rapid development of nanotechnology has opened up new application prospects for modern plant protection. Nanoscale materials have many new physical and chemical properties due to their small size and special structure, such as large specific surface area, high reactivity, small size effect and quantum effect. As a new type of drug delivery system, nanoemulsion has many advantages, such as increasing the solubility of poorly soluble drugs, improving bioavailability, sustained release and targeting, but it also has some disadvantages and limitations: 1. Some chemically synthesized surfactants or emulsifiers may have adverse effects on human health, pose biosafety risks, and may pollute the environment. Therefore, in practical applications, they may face challenges such as regulations, safety assessments, and large-scale production; 2. Although nanoemulsions may exhibit certain stability during preparation, they are essentially thermodynamically unstable systems and are easily affected by external conditions such as changes in temperature and pH, leading to stratification or aggregation. In addition, they may also encounter stability problems during long-term storage, such as aggregation of droplets or growth of particle size, which will affect their performance; 3. The preparation of nanoemulsions usually requires specific processes, such as high-energy emulsification or low-energy emulsification technology, which may require specific equipment and conditions, increasing the complexity and cost of preparation. Although nanoemulsions have great potential in different aspects such as drug delivery and sustained release of effective ingredients, the above-mentioned shortcomings and challenges still need to be overcome in practical applications. The stability, safety and cost-effectiveness of nanoemulsions need to be further improved to promote their widespread application in cosmetics, medicine and other fields. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art or related technology, and provides a bacterial cellulose-based composite nanoemulsion and a preparation method and application thereof. The bacterial cellulose-based composite nanoemulsion has high biological safety, is environmentally friendly and degradable, can be prepared at low cost, and has high emulsification stability and can be stored for a long time.

[0004] The first aspect of the present invention discloses a method for preparing a bacterial cellulose-based composite nanoemulsion, comprising: S1, dissolving triazole gum in water to obtain a completely hydrated triazole gum solution, wherein the mass concentration of triazole gum in the triazole gum solution is 0.1% to 0.3%; S2, adding a bacterial cellulose suspension to the triazole gum solution, wherein the mass concentration of bacterial cellulose in the final composite suspension reaches 0.1% to 0.5%, and the bacterial cellulose is nano bacterial cellulose; S3, mixing the composite suspension with an oil phase in a ratio of 9:1 and homogenizing to obtain a bacterial cellulose-based composite nanoemulsion.

[0005] In this technical solution, bacterial cellulose (BC) is a biomacromolecule polymer with many excellent properties such as high purity, high crystallinity, high mechanical strength and good biocompatibility. BC can be further nano-processed to produce nano bacterial cellulose (BNC) products. The specific preparation method of BNC has been fully disclosed in patent ZL202410678111.1. It can be widely used in food and beverage, cosmetics, coatings, papermaking, biomedicine and other industries. Sanzan gum is an extracellular polymer synthesized by Sanzan Sphingomonas. Compared with other polysaccharide polymers, it has low extraction cost, high viscosity, and shear thinning properties. At the same time, it can form an elastic gel with strong elasticity and high hardness. It also has a unique amphiphilic structure, composed of polysaccharides, polypeptides and lipids, and can be used as an excellent emulsifier.

[0006] The method for preparing the bacterial cellulose-based composite nanoemulsion provided by the present invention preferably further comprises: dissolving a fat-soluble active substance in the oil phase, wherein the mass concentration of the fat-soluble active substance in the bacterial cellulose-based composite nanoemulsion is 0.1% to 0.5%.

[0007] The method for preparing the bacterial cellulose-based composite nanoemulsion provided by the present invention preferably further comprises: adding a water-soluble component to the tri-gluconate solution or composite suspension, wherein the mass concentration of the water-soluble component in the bacterial cellulose-based composite nanoemulsion is 0.1% to 0.5%.

[0008] According to the method for preparing the bacterial cellulose-based composite nanoemulsion provided by the present invention, preferably, the mass concentration of the bacterial cellulose in the bacterial cellulose suspension is 1%; the mass concentration of the bacterial cellulose in the composite suspension is 0.1%, 0.2% or 0.5%.

[0009] According to the method for preparing the bacterial cellulose-based composite nanoemulsion provided by the present invention, preferably, in the tri-zan gum solution, the mass concentration of tri-zan gum is 0.2%.

[0010] According to the method for preparing the bacterial cellulose-based composite nanoemulsion provided by the present invention, preferably, in step S1, the tri-glucoside powder is dissolved in deionized water at a temperature of 25° C., and stirred and allowed to stand to obtain a tri-glucoside solution.

[0011] According to the method for preparing the bacterial cellulose-based composite nanoemulsion provided by the present invention, preferably, in step S3, a homogenizer is used to homogenize the mixture at a speed of 5 m / s for 3 min to obtain the bacterial cellulose-based composite nanoemulsion.

[0012] According to the method for preparing the bacterial cellulose-based composite nanoemulsion provided by the present invention, preferably, the oil phase comprises n-hexane and / or isohexadecane.

[0013] The second aspect of the present invention further discloses a bacterial cellulose-based composite nanoemulsion, which is prepared according to the preparation method of the bacterial cellulose-based composite nanoemulsion disclosed in any of the above technical solutions.

[0014] The third aspect of the present invention also discloses that the bacterial cellulose-based composite nanoemulsion provided by the above technical solution can be used to construct a drug delivery system or prepare cosmetics. Specifically, the use of bacterial cellulose-based composite nanoemulsion to construct a nano drug delivery system can effectively improve the quality and efficiency of chemical pesticides, save and reduce emissions, and reduce residual pollution. Under the action of functional additives such as surfactants, water-insoluble pesticides are solubilized in water at a nanoscale to form an emulsion liquid preparation, which improves the dispersibility of the active ingredients of the pesticide when used with water, produces low surface tension and good wettability, and further improves the attachment, deposition and penetration of pesticides on the target surface. In cosmetic products, nano bacterial cellulose (BNC) has a good protective effect against ultraviolet rays, and can be further improved after being combined with pectin, and can be used as a sunscreen.

[0015] The beneficial effects achieved by the present invention include at least: using natural products bacterial cellulose and tri-zan gum obtained by microbial fermentation as the main components, a bacterial cellulose-based composite nanoemulsion with high biosafety, environmentally friendly and degradable, high emulsification stability and long-term storage is prepared. The preparation process is simple, no special equipment is required, and it is easy to operate; the droplet size is small, the dispersion is uniform and the stability is high; it can improve the solubility and bioavailability of bioactive substances. Bacterial cellulose and tri-zan gum are both food-grade ingredients that are generally recognized as safe (GRAS), the preparation process is simple and energy-efficient, and the stability, safety and cost-effectiveness of the obtained nanoemulsion are all significantly superior, and it can be widely used in the fields of cosmetics, medicine, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of microscopic observation of a bacterial cellulose-based composite nanoemulsion according to an embodiment of the present invention is shown.

[0017] Figure 2 A schematic diagram showing microscopic observation of an emulsion sample to which no bacterial cellulose was added.

[0018] Figure 3 A graph showing the sustained-release effect test of the bacterial cellulose-based composite nanoemulsion according to an embodiment of the present invention is shown.

[0019] Figure 4 One of the test graphs of the ultraviolet protection effect of the bacterial cellulose-based composite nanoemulsion according to an embodiment of the present invention is shown.

[0020] Figure 5 One of the test graphs of the ultraviolet protection effect of the bacterial cellulose-based composite nanoemulsion according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0021] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Example 1

[0023] According to one embodiment of the present invention, a composition of a bacterial cellulose-based composite nanoemulsion is disclosed, including: 0.1-0.5% bacterial cellulose, 0.1-0.3% trisammonium gum, 5-20% oil phase component, and 0.1-0.5% other functional components in terms of mass concentration. The oil phase component is n-hexane and / or isohexadecane; the other functional components include: fat-soluble components such as carotene can be dissolved in the oil phase as needed to obtain corresponding effects, and other functional components can be added to the emulsification system to obtain different functional bacterial cellulose-based composite nanoemulsions.

[0024] Example 2

[0025] Another embodiment of the present invention also discloses a method for preparing a bacterial cellulose-based composite nanoemulsion, comprising:

[0026] The Sanzan gum powder was dissolved in deionized water under controlled temperature (25 °C) and stirred overnight to ensure complete hydration to obtain Sanzan gum solution;

[0027] Different proportions of bacterial cellulose suspension (1%, w / w) were added to the tri-zan gum solution to obtain different bacterial cellulose concentrations in the final composite suspension;

[0028] The composite suspension was mixed with different oil phases (n-hexane or isohexadecane) in a certain ratio, and the mixture was homogenized at a speed of 5 m / s for 3 min using a laboratory mixer (Bioprep-24 homogenizer) to prepare different bacterial cellulose-based composite nanoemulsions.

[0029] In addition, fat-soluble components such as carotene, astaxanthin, magnolol, etc. can be dissolved in the oil phase as needed to obtain corresponding effects, and other functional ingredients (for example, pectin, burdock polysaccharide, purslane polysaccharide, seaweed polysaccharide, etc.) can also be added to the emulsification system to obtain different functional bacterial cellulose-based composite nanoemulsions.

[0030] Example 3

[0031] According to another embodiment of the present invention, a more detailed method for preparing the bacterial cellulose-based composite nanoemulsion is also disclosed:

[0032] First, the Sanzan gum powder was dissolved in deionized water at a controlled temperature (25 °C) and stirred overnight to ensure complete hydration to obtain Sanzan gum solution (0.2%, w / w);

[0033] Then, different proportions of bacterial cellulose suspension (1%, w / w) were added to the tri-zan gum solution to obtain three different bacterial cellulose concentrations in the final composite suspension: 0.1%, 0.2%, and 0.5% (w / w);

[0034] Finally, the composite suspension was mixed with different oil phases (n-hexane or isohexadecane) at a ratio of 9:1, and the mixture was homogenized at a speed of 5 m / s for 3 min using a homogenizer to prepare different bacterial cellulose-based composite nanoemulsions.

[0035] In addition, fat-soluble active substances (e.g., β-carotene) can be dissolved in the oil phase as needed to obtain corresponding effects, and other functional ingredients (e.g., pectin) can also be added to the emulsification system to obtain different functional bacterial cellulose-based composite nanoemulsions.

[0036] Example 4

[0037] The bacterial cellulose-based composite nanoemulsion prepared in Example 3 was subjected to microscopic observation and an emulsification index test was performed to characterize its emulsification performance. The emulsification index is defined as the ratio of the height of the emulsion layer to the total height of the mixed liquid after standing for a certain period of time. In order to evaluate its microscopic appearance and droplet size distribution, the emulsion sample was observed using an optical microscope with a 40× objective lens using the Micro-Color Image Analysis System V5.2. Figure 1 The microscopic observation results of the bacterial cellulose-based composite nanoemulsion (with β-carotene added) obtained in Example 3 after standing for 30 days are shown: the bacterial cellulose-based composite nanoemulsion remains stable after standing for 30 days, and the emulsification index remains 100%.

[0038] like Figure 1 and Figure 2 As shown, the bacterial cellulose-based composite nanoemulsion obtained in Example 3 ( Figure 1) than the emulsion sample without bacterial cellulose ( Figure 2 ) is more stable. It can be seen from the figure that the sample without bacterial cellulose has a slight demulsification phenomenon on the surface, while the sample with bacterial cellulose is more uniform and dense. Microscopic observation shows that nano-scale bacterial cellulose can be evenly distributed in the emulsion, which may play a role in enhancing stability. The results show that the stability of the composite nanoemulsion with bacterial cellulose is better than that of the emulsion without bacterial cellulose, which can be further verified by the determination of rheological properties.

[0039] Example 5

[0040] According to another embodiment of the present invention, the rheological properties of the bacterial cellulose-based composite nanoemulsion obtained in Example 3 were also tested. The rheological measurement was performed using a stress-controlled Discovery HR-2 hybrid rheometer (TA Instruments) equipped with an aluminum plate fixture (diameter, 40 mm; parallel plate; gap, 1000 μm). The viscoelastic behavior of different bacterial cellulose-based composite nanoemulsions is presented by storage modulus (G′) and viscosity, which change with the changing frequency (0.01-100 rad / s) and can be used to characterize the stability of the emulsion. In this way, when the oil phase is n-hexane, as the concentration of bacterial cellulose in the bacterial cellulose-based composite nanoemulsion increases, the elastic modulus and viscosity of the emulsion are significantly improved. The addition of surface nano bacterial cellulose can act as a stabilizer and suspending agent to enhance the stability of the composite emulsion. When the oil phase component is replaced by n-hexane with iso-16 alkane, the same rule is presented, and it is found that the addition of pectin has no significant effect on the elastic modulus and viscosity of the composite emulsion.

[0041] Example 6

[0042] like Figure 3 As shown, according to one embodiment of the present invention, a sustained release effect test of bacterial cellulose-based composite nanoemulsion is also disclosed: the release rate and pattern of the oil phase component in the emulsion are tested by simulating the use conditions. The specific steps are as follows:

[0043] (1) Weighing the emulsion and oil: Accurately weigh a certain mass of the emulsion and oil and record the initial mass.

[0044] (2) Volatilization experiment: The emulsion and oil are placed at room temperature to evaporate for a certain period of time (such as 1 hour, 6 hours, 24 hours, etc.), and the masses are taken out at different time points.

[0045] (3) Calculate the loss rate: The sustained-release effect is evaluated by calculating the loss rate of oil and emulsion. The formula is as follows: Oil loss rate = (M Y −M Yt ) / M Y ×100%, emulsion loss rate = (MR −M Rt ) / (M R ×10%)×100% Where, M Y is the initial mass of oil, M Yt is the mass of oil at time t, M R is the initial mass of the emulsion, M Rt is the mass of the emulsion at time t, and 10% is the mass fraction of the oil in the emulsion. By comparing the loss rates of the oil and the emulsion at different time points, the sustained release effect of the emulsion on the oil is evaluated. The better the sustained release effect, the lower the loss rate of the oil in the emulsion.

[0046] This method is used to detect, Figure 3 The test results shown in the figure show that the composite emulsion can significantly improve the sustained release effect of oil. Compared with the control group, which lost 100% of oil in about 7 hours, the oil in the emulsion can lose only about 50% of oil in 24 hours. In addition, the sustained release effect of the composite nanoemulsion with bacterial cellulose added was significantly improved compared with the emulsion without bacterial cellulose, and the loss rate in 48 hours was reduced from 82.3% to 67.5%.

[0047] Example 7

[0048] like Figure 4 and Figure 5 As shown, according to one embodiment of the present invention, a test process of the ultraviolet protection effect of the bacterial cellulose-based composite nanoemulsion is also disclosed:

[0049] The UV transmittance (UVT) is used to characterize the UV protection effect of bacterial cellulose-based composite nanoemulsion. The specific test method includes the following steps:

[0050] 1. Sample preparation: First, you need to prepare the sample to be tested and ensure its representativeness and uniformity.

[0051] 2. Using a spectrophotometer: Use a UV-Vis spectrophotometer to measure. This instrument measures the ability of ultraviolet light of a specific wavelength (400nm and 300nm are selected, representing UVA and UVB, respectively) to pass through a sample.

[0052] 3. Measure transmittance: Place the sample in a quartz absorption cell and measure its UV transmittance at a specific wavelength using a spectrophotometer. Record the measurement results, usually expressed as a percentage transmittance (%T).

[0053] This method is used to detect, Figure 4The test results shown in the figure show that nano bacterial cellulose (BNC) has a good protection effect against ultraviolet rays, and the effect can be further improved after being combined with pectin. Figure 5 The test results shown in the figure show that adding BNC or pectin to the composite nanoemulsion, as well as the combination of the two, can obtain Figure 5 The experimental results shown in the figure show that the best protective effect can be achieved by adding BNC and pectin at the same time (the 4th pair of bars in the figure). Adding BNC or pectin alone cannot provide excellent protective effects. The best effect is obtained when the addition amount is 0.01% BNC + 0.05% pectin, which can reduce the UV transmittance to less than 10%, and the effect is better than commercially available sunscreen (using physical sunscreen, SPF35, PA+++, compared at the same sunscreen concentration). Therefore, bacterial cellulose-based composite nanoemulsion can be used in the development of sunscreen products.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a bacterial cellulose-based composite nanoemulsion, characterized in that: include: S1, dissolving trimethoprim in water to prepare a completely hydrated trimethoprim solution, wherein the mass concentration of trimethoprim in the trimethoprim solution is 0.1% to 0.3%; S2, adding a bacterial cellulose suspension to the tri-zan gum solution, wherein the mass concentration of the bacterial cellulose in the final composite suspension reaches 0.1% to 0.5%, and the bacterial cellulose is nano bacterial cellulose; S3, mixing the composite suspension and the oil phase in a ratio of 9:1 and homogenizing to prepare a bacterial cellulose-based composite nanoemulsion.

2. The method for preparing the bacterial cellulose-based composite nanoemulsion according to claim 1, characterized in that: Also includes: A fat-soluble active substance is dissolved in the oil phase, and the mass concentration of the fat-soluble active substance in the bacterial cellulose-based composite nanoemulsion is 0.1% to 0.5%.

3. The method for preparing the bacterial cellulose-based composite nanoemulsion according to claim 1, characterized in that: Also includes: A water-soluble component is added to the tri-zan gum solution or the composite suspension, and the mass concentration of the water-soluble component in the bacterial cellulose-based composite nanoemulsion is 0.1% to 0.5%.

4. The method for preparing the bacterial cellulose-based composite nanoemulsion according to claim 1, characterized in that: The mass concentration of bacterial cellulose in the bacterial cellulose suspension is 1%; the mass concentration of bacterial cellulose in the composite suspension is 0.1%, 0.2% or 0.5%.

5. The method for preparing the bacterial cellulose-based composite nanoemulsion according to claim 1, characterized in that: In the trimethoprim-sulfamethoxazole solution, the mass concentration of trimethoprim-sulfamethoxazole is 0.2%.

6. The method for preparing the bacterial cellulose-based composite nanoemulsion according to claim 1, characterized in that: In step S1, at a temperature of 25° C., the Sanzan gum powder is dissolved in deionized water to obtain the Sanzan gum solution.

7. The method for preparing the bacterial cellulose-based composite nanoemulsion according to claim 1, characterized in that: In step S3, the mixture was homogenized at a speed of 5 m / s for 3 min using a homogenizer to obtain a bacterial cellulose-based composite nanoemulsion.

8. The method for preparing the bacterial cellulose-based composite nanoemulsion according to claim 1, characterized in that: The oil phase includes n-hexane and / or isohexadecane.

9. The bacterial cellulose-based composite nanoemulsion prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the bacterial cellulose-based composite nanoemulsion according to claim 9 in the process of constructing a drug delivery system or in the process of preparing cosmetics.

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