Matrine nanogel sustained-release agent as well as preparation method and application thereof
By constructing a non-covalently bonded dual-network gel system, the stability and efficacy cycle of matrine pesticide formulations were solved, achieving efficient drug retention and sustained release effects, and reducing the risk of environmental pollution.
Patent Information
- Application Number
- CN202510960187.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-11
- Publication Date
- 2025-11-14
AI Technical Summary
Existing matrine pesticide formulations have poor stability, short efficacy period, and low leaf retention rate. Furthermore, traditional formulations lack effective protective measures, leading to environmental pollution risks and inefficient absorption.
A dual-network gel system was constructed using a non-covalent bonding approach. Carboxymethyl cellulose and polyethyleneimine formed a three-dimensional network structure, which was combined with boric acid, tea saponin and tannic acid to form a pH-responsive small molecule gel. Matrine molecules were embedded and lignin sulfonic acid was used to enhance adhesion and stability.
It improves the stability and efficacy period of matrine, enhances its adhesion and wettability on plant surfaces, reduces drug burst release, and lowers the risk of environmental pollution.
Smart Images
Figure CN120937840A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of pesticide technology, specifically relating to a matrine nanogel sustained-release agent, its preparation method, and its application. Background Technology
[0002] Matrine, a quinolone alkaloid derived from the legumes *Sophora flavescens* and *Sophora alopecuroides*, has gradually become a research hotspot in the field of green plant protection due to its broad spectrum of biological activities. Driven by the concept of sustainable agricultural development, this compound has been positioned as one of the core candidates for novel natural pesticides due to its environmental compatibility, low ecotoxicity, and multi-target characteristics. The insecticidal effect of matrine is mainly manifested by inhibiting the activity of insect acetylcholinesterase (AChE), interfering with nerve signal transmission, leading to insect paralysis and death, or damaging the midgut cell structure of insects, inhibiting digestive enzyme activity, resulting in poor nutrient absorption and death. Major target pests include aphids, spider mites, diamondback moths, and cabbage caterpillars, among other common agricultural pests. Matrine also has certain antibacterial effects; it can disrupt the permeability of pathogenic cell membranes, leading to leakage of contents, or inhibit fungal spore germination and mycelial growth (such as powdery mildew and gray mold).
[0003] Currently, matrine pesticide formulations are mainly in aqueous, soluble, and powder forms. While compounding technology is maturing, formulation innovation lags behind. Advanced technologies such as nano-loaded pesticides, microencapsulation, and slow-release granules are not fully utilized to improve performance, resulting in formulation upgrades lagging behind the needs of green agriculture. Traditional matrine pesticide formulations primarily rely on physical mixing with other pesticide components (such as combined use with chemical insecticides), lacking targeted compounding designs based on synergistic mechanisms. Matrine molecules are sensitive to environmental factors such as light and humidity, easily undergoing photolysis and hydrolysis reactions. Existing formulations lack effective protective measures, and the dispersion system design of traditional formulations is inadequate, leading to significant loss of active ingredients and adjuvants during application, exacerbating the risk of ecological pollution. Furthermore, traditional formulations lack surface modification or carrier assistance, resulting in insufficient adhesion and penetration of the pesticide solution on leaf surfaces or insect epidermis, making it difficult for the active ingredient to reach the site of action. This inefficient absorption further exacerbates the problems of poor stability and short half-life of matrine, creating a vicious cycle of "low utilization rate → frequent application → environmental risk." Therefore, it is necessary to develop a method for preparing matrine formulations with good stability, long efficacy period, and high leaf retention rate. Summary of the Invention
[0004] The first technical problem to be solved by this invention is to provide a matrine nanogel sustained-release agent with good stability, long efficacy period and high leaf retention rate. The second technical problem to be solved by this invention is to provide a method for preparing the matrine nanogel sustained-release agent, which achieves the sustained-release performance of drug molecules through non-covalent bonding. The third technical problem to be solved by this invention is to provide the application of the matrine nanogel sustained-release agent in pesticide adjuvants.
[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0006] A method for preparing a matrine nanogel sustained-release agent includes the following steps:
[0007] 1) Disperse tea saponin and tannic acid in a boric acid aqueous solution to obtain a suspension; add NaOH to adjust the pH, and then perform a water bath to obtain a transparent solution;
[0008] 2) Carboxymethyl cellulose and polyethyleneimine are crosslinked to obtain CMC-PEI crosslinked material;
[0009] 3) Mix the transparent solution obtained in step 1) and the CMC-PEI crosslinker obtained in step 2) in deionized water to form a colloidal dispersion; then add matrine and sodium lignosulfonate to obtain a matrine nanogel delivery system.
[0010] Furthermore, in step 1), the mass ratio of tea saponin to tannic acid is 4 to 7:1.
[0011] Furthermore, in step 1), the pH is adjusted to 8.
[0012] Furthermore, in step 1), the concentration of boric acid is 0.01–0.05 M.
[0013] Furthermore, in step 2), the mass ratio of carboxymethyl cellulose to polyethyleneimine is 4 to 6:1.
[0014] Furthermore, in step 2), the carboxymethyl cellulose has a molecular weight of 250,000 and a viscosity of 1,500–3,100 mPas.
[0015] Furthermore, in step 3), the volume ratio of the transparent solution to the CMC-PEI crosslinker is 1:39.
[0016] Furthermore, in step 3), the reaction temperature for forming the colloidal dispersion is 25–30°C, and the reaction time is 0.5–1 h.
[0017] Furthermore, the method for preparing the matrine nanogel sustained-release agent yields the matrine nanogel sustained-release agent.
[0018] Furthermore, the application of the matrine nanogel sustained-release agent in pesticide adjuvants.
[0019] Compared with the prior art, the present invention has the following advantages:
[0020] (1) This invention utilizes the alkaline properties of matrine to construct a double network gel system through intermolecular forces, and uses matrine to self-assemble into a drug-loaded gel by non-covalent bonding, forming an encapsulation structure, which effectively improves its stability. At the same time, the non-covalent bonding form achieves the sustained-release performance of drug molecules.
[0021] (2) In this invention, carboxymethyl cellulose and polyethyleneimine are dissolved in an aqueous solution, and molecular chain entanglement is induced through hydrogen bonding, van der Waals forces and electrostatic interactions to form a three-dimensional network structure gel dispersion, which provides mechanical support and drug loading sites; boric acid is used as a crosslinking agent to connect tannic acid and tea saponin through dynamic covalent bonds (boronic acid ester bonds) to form a small molecule gel with pH responsiveness, which enhances the environmental adaptability of the system.
[0022] (3) In this invention, matrine molecules are embedded in the pores of the gel network. By utilizing their alkaline properties, they form ionic bonds with the gel components, thereby improving drug loading efficiency. Furthermore, lignin sulfonic acid is added, which forms a dense coating layer on the gel surface through its amphiphilic structure, reducing drug burst release and enhancing leaf surface adhesion. This further ensures the stability of matrine molecules and provides better affinity and wettability to the plant surface. Attached Figure Description
[0023] Figure 1 A process flow diagram for preparing matrine nanogel sustained-release agent according to this application;
[0024] Figure 2 Matrine nanogel sustained-release agent prepared in Example 1 of this application shows matrine release curves at different pH values;
[0025] Figure 3 This is a comparative deposition rate diagram of the nanogel sustained-release agents prepared in Examples 1-7 of this application on the leaf surface;
[0026] Figure 4 The graph shows the comparative deposition performance of matrine nanogel sustained-release agent prepared in Example 1 of this application and various solvent systems on photinia leaves; wherein, Figure (A) is a physical image of the deposition effect of different samples on the surface of photinia leaves, and Figure (B) shows the numerical values of the deposition rate of different samples on the surface of photinia leaves.
[0027] Figure 5The contact angle diagrams of the matrine nanogel sustained-release agent prepared in Example 1 of this application on the glass slide and the surface of the photinia leaf are shown. Among them, Figure (A) is a physical diagram of the contact angle of different samples on the glass slide and the surface of the photinia leaf, and Figure (B) is a diagram of the numerical values of the contact angle of different samples on the glass slide and the surface of the photinia leaf.
[0028] Figure 6 This is a graph showing the survival rate of zebrafish treated with different concentrations of matrine nanogel sustained-release agent and pure matrine in Example 1 of this application. Detailed Implementation
[0029] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are implemented based on the technical solutions of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.
[0030] In the following examples, carboxymethyl cellulose (CMC) was purchased from Aladdin, with a viscosity of 1500–3100 mPa·s and a molecular weight of 250,000; matrine was purchased from Maclean, with a purity of 98%; tea saponin was purchased from Shanghai Yuanye Biotechnology Co., Ltd., BR, with a purity of 65%; tannic acid was purchased from Maclean, AR, with a purity of 98%; boric acid was purchased from Sinopharm Chemical Reagent Co., Ltd., AR, with a purity of 99%; and polyethyleneimine (PEI) was purchased from Maclean, M… W The value is 70,000, with 50% aqueous phase.
[0031] Figure 1 The process flow diagram for preparing matrine nanogel sustained-release agent includes the following steps:
[0032] (1) Disperse tea saponin and tannic acid in a boric acid aqueous solution to obtain a suspension; add NaOH to adjust the pH, and then perform a water bath to obtain a transparent solution;
[0033] (2) Carboxymethyl cellulose and polyethyleneimine are crosslinked to obtain CMC-PEI crosslinked material;
[0034] (3) The transparent solution obtained in step (1) and the CMC-PEI crosslinker obtained in step (2) are mixed in deionized water to form a colloidal dispersion; then matrine and sodium lignin sulfonate are added to obtain a matrine nanogel delivery system.
[0035] Example 1
[0036] A method for preparing a matrine nanogel sustained-release agent includes the following steps:
[0037] (1) Preparation of precursor solution
[0038] 36 mg of tea saponin (TS) and 6 mg of tannic acid (TA) were weighed and dispersed in 1 mL of 0.025 M boric acid aqueous solution to form a light yellow suspension. 0.5 M NaOH solution was added dropwise to the suspension to adjust the pH of the system to 8.0. The system was then placed in a 70 °C water bath and stirred continuously for 5 min to obtain a homogeneous and transparent yellow solution (TS@TA).
[0039] (2) Polymer crosslinking reaction
[0040] 30 mg of carboxymethyl cellulose (CMC) was mixed with 5 mg of polyethyleneimine (PEI) to form a CMC-PEI crosslink.
[0041] (3) Self-assembly and drug delivery encapsulation
[0042] Mix 1 mL of the yellow solution (TS@TA) obtained in step (1) with 39 mL of the CMC-PEI crosslinker obtained in step (2), and stir at 25 °C for 1 h to form a colloidal dispersion (CP@TT). Add 0.1 g of matrine (MT) to the dispersion to form CPTT@MT, and then add 80 mg of sodium lignosulfonate (SLS) and stir for 2 h to finally obtain a matrine nanogel delivery system with sustained-release function (CPTT@MT@SLS).
[0043] Example 2
[0044] In preparing the matrine nanogel delivery system with sustained-release function, the mass of tea saponin in step (1) was replaced with 24 mg, and the rest of the preparation method and parameters were the same as in Example 1.
[0045] Example 3
[0046] In preparing the matrine nanogel delivery system with sustained-release function, the mass of tea saponin in step (1) was replaced with 30 mg, and the rest of the preparation method and parameters were the same as in Example 1.
[0047] Example 4
[0048] In preparing the matrine nanogel delivery system with sustained-release function, the mass of tea saponin in step 1) was replaced with 42 mg, and the rest of the preparation method and parameters were the same as in Example 1.
[0049] Example 5
[0050] In preparing the matrine nanogel delivery system with sustained-release function, the boric acid concentration in step (1) was changed to 0.01M, and the rest of the preparation method and parameters were the same as in Example 1.
[0051] Example 6
[0052] In preparing the matrine nanogel delivery system with sustained-release function, the boric acid concentration in step (1) was changed to 0.05M, and the rest of the preparation method and parameters were the same as in Example 1.
[0053] Example 7
[0054] In preparing the matrine nanogel delivery system with sustained-release function, the mass of carboxymethyl cellulose in step (2) was replaced with 20 mg, and the rest of the preparation methods and parameters were the same as in Example 1.
[0055] Example 8
[0056] The sustained-release behavior of the matrine nanogel sustained-release agent CPTT@MT@SLS prepared in Example 1 was evaluated using dialysis. The method included: encapsulating 5 mL of MT@CPTT@SLS gel solution (2.5 mg / mL) in a dialysis bag with a molecular weight cutoff of 8000, and immersing it in 100 mL of PBS release medium. Tests were conducted at different pH gradients (5.7, 7.0, and 8.0). Dialysis fluid was collected periodically (5 mL each time), and an equal volume of fresh medium was added. The actual concentration of MT in the release solution was quantitatively detected using a UV spectrophotometer, and the cumulative drug release rate was calculated by time-concentration integration. The results are as follows: Figure 2 As shown.
[0057] Depend on Figure 2The nanogel exhibits significant pH-responsive release behavior: the release rate of MT is fastest at pH 8.0, with a cumulative release rate of 87.32% over 48 hours; the release rate is second fastest at pH 7.0, with a cumulative release rate of 67.58%; while in an acidic environment (pH 5.7), the release rate slows down significantly, with a cumulative release rate of only 61.19%. This phenomenon is attributed to the pH-dependent swelling characteristics of the gel network: when the ambient pH increases, the carboxylic acid groups (-carboxyl groups) in CMC ionize into carboxylate ions (-COO-), enhancing the electrostatic repulsion effect, leading to gel network swelling and accelerating MT release; while under acidic conditions, the protonation of the -carboxyl groups causes network contraction, inhibiting drug release. Furthermore, the cross-linked structure formed by TA and TS through hydrogen bonding and hydrophobic interactions, as well as the dissociation of hydrogen bonds in an alkaline environment, further promotes network loosening, synergistically improving drug release efficiency. This release pattern closely matches the pH characteristics of the microenvironment within plant leaves and pests—the normal physiological environment of leaves is close to neutral (pH 7.0), while the intestinal tract of pests is mostly alkaline (pH 8.0). The sustained-release characteristic under acidic conditions (pH 5.7) reduces pesticide loss from non-target environments (such as rainwater runoff). Compared to free MT, the sustained-release characteristic of MT@CPTT@SLS can significantly reduce the frequency and dosage of pesticide use, which is of great significance for reducing environmental pollution and non-target biotoxicity.
[0058] Example 9
[0059] Fresh photinia leaves were washed and air-dried. The initial weight of each leaf was recorded using a four-position balance, and then the leaves were immersed in different sample solutions from Examples 1–7 for 20 seconds. After immersion, the leaves were removed with tweezers, left to stand for 5 seconds, and weighed again. The deposition effect of the samples was evaluated based on the change in leaf weight before and after immersion. The results are as follows: Figures 3-4 As shown.
[0060] Depend on Figure 3The graphs show the comparative deposition rates of the nanogel sustained-release agents prepared in Examples 1-7 on the leaf surface. It can be seen that the deposition performance of the nanogel sustained-release agents on the Photinia leaf surface is significantly affected by the component ratio and dosage. Comparison of Examples 1-4 shows that as the proportion of tea saponin in the tea saponin / tannic acid composite system increases, the deposition efficiency exhibits a positive response, indicating that increasing the relative content of tea saponin can effectively optimize the adhesion and retention ability of the sustained-release agent on the leaf surface. Comparison of Examples 1 and 7 shows that the dosage of carboxymethyl cellulose (CMC) plays a crucial role in deposition performance: when the CMC dosage is 20 mg, the deposition rate of the prepared nanogel sustained-release agent on the leaf surface significantly decreases to approximately 20%; in contrast, the sustained-release agent prepared using 30 mg of CMC exhibits significantly better deposition performance. Based on the above synergistic effect, the final optimized formulation parameters are determined as follows: increasing the proportion of tea saponin in the tea saponin / tannic acid combination and using 30 mg of carboxymethyl cellulose as the preparation dosage.
[0061] Depend on Figure 4 The graph shows the comparative deposition performance of the matrine nanogel sustained-release agent prepared in Example 1 and various solvent systems on Photinia leaves. It can be seen that CPTT@MT@SLS showed significantly better deposition on the leaves than other treatment groups, with a deposition rate of 23.3%. This strong adhesion is attributed to the interaction between the three-dimensional network structure of CPTT@MT@SLS and the waxy layer on the leaf surface, as well as the hydrogen bonds formed between its abundant hydrophilic groups and higher fatty acids and alcohols on the leaf surface. These interactions enhance the adhesion and retention capacity of CPTT@MT@SLS on the leaf surface. In contrast, the TS@TA and blank treatment groups had relatively low deposition rates due to the lack of this synergistic effect of the three-dimensional network structure and hydrophilic groups.
[0062] Figure 5The contact angle diagrams of CP@TT and CPTT@MT@SLS prepared in Example 1 of this application on the surfaces of a glass slide and a photinia leaf, respectively, show that the contact angles of CP@TT and CPTT@MT@SLS are significantly smaller on the blank glass slide, indicating that they have optimal wettability on smooth surfaces. This is because the carboxylic acid groups of carboxymethyl cellulose (CMC) and the amino groups of polyethyleneimine (PEI) synergistically enhance the surface hydrophilicity. After loading matrine (MT), the contact angle of CPTT@MT@SLS further decreases (Δθ = 2.15°), attributed to the surface reconstruction of hydrophobic segments in the MT molecule, forming a micro-nano-scale rough structure, which promotes the transformation from the Cassie-Baxter wetting mode to the Wenzel mode. On the leaf surface, the water contact angle is 63.59°, due to the hydrophobic properties of its natural wax layer. The contact angle of the CP@TT-treated group decreases slightly to 61.45°, indicating that the polar groups of CMC and PEI partially penetrate the wax layer and bind to fatty acids through hydrogen bonds. The contact angle of CPTT@MT@SLS decreased significantly to 45.64° (Δθ=17.95°) because the hydrophobic components of MT (such as alkaloid rings) interact with the hydrophobic regions of the leaf wax layer through van der Waals forces, forming a more stable interfacial anchorage. Another reason is that the three-dimensional network structure of CPTT@MT@SLS may enhance its adhesion to complex surfaces through a mechanical interlocking effect.
[0063] Example 10
[0064] Adult zebrafish were acclimatized in the laboratory for one week (27±1℃, 12-hour light-dark cycle) and exposed to different concentration gradients of MT@CPTT@SLS (1–5 mg / L) as described in Example 1. A blank control group (pure water) without any drugs was also set up. Each group contained 10 individuals with identical physiological conditions and were kept fasted. The number of deaths was recorded after 24, 48, 72, 96, and 108 hours. The experiment was repeated three times to verify the reliability of the results, thereby analyzing the acute toxic effects of nanomaterials on aquatic organisms. The results are as follows: Figure 6 As shown.
[0065] Depend on Figure 6It was found that CPTT@MT@SLS has low toxicity to zebrafish. At low concentrations, the survival rate of zebrafish in the CPTT@MT@SLS treatment group was significantly higher than that in the high concentration treatment group. For example, in a 1 mg / L CPTT@MT@SLS solution, the survival rate was 70% after 108 hours, while in solutions of 3 mg / L and 5 mg / L, the survival rate decreased to 30% and 0%, respectively. This result indicates that the toxicity of CPTT@MT@SLS is positively correlated with concentration, i.e., the higher the concentration, the greater the toxicity. Compared with the control group (Water), the survival rate of the 1 mg / L pure matrine (MT) treatment group was 90% after 96 hours and 80% after 120 hours, showing that MT itself has a certain degree of toxicity to zebrafish. While the survival rate of the CPTT@MT@SLS treatment group was slightly lower than that of the MT treatment group at the same concentration, it still maintained a high survival rate at low concentrations (1 mg / L), indicating that CPTT@MT@SLS has good biocompatibility for zebrafish at low concentrations.
[0066] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing a matrine nanogel sustained-release agent, characterized in that: Includes the following steps: 1) Disperse tea saponin and tannic acid in an aqueous boric acid solution to obtain a suspension; Add NaOH to adjust the pH, then perform a water bath to obtain a clear solution; 2) Carboxymethyl cellulose and polyethyleneimine are crosslinked to obtain CMC-PEI crosslinked material; 3) Mix the transparent solution obtained in step 1) and the CMC-PEI crosslinker obtained in step 2) in deionized water to form a colloidal dispersion; then add matrine and sodium lignosulfonate to obtain a matrine nanogel delivery system.
2. The method for preparing matrine nanogel sustained-release agent according to claim 1, characterized in that: In step 1), the mass ratio of tea saponin to tannic acid is 4-7:
1.
3. The method for preparing matrine nanogel sustained-release agent according to claim 1, characterized in that: In step 1), the pH is adjusted to 8.
4. The method for preparing matrine nanogel sustained-release agent according to claim 1, characterized in that: In step 1), the boric acid concentration is 0.01–0.05 M.
5. The method for preparing matrine nanogel sustained-release agent according to claim 1, characterized in that: In step 2), the mass ratio of carboxymethyl cellulose to polyethyleneimine is 4 to 6:
1.
6. The method for preparing matrine nanogel sustained-release agent according to claim 1, characterized in that: In step 2), the carboxymethyl cellulose has a molecular weight of 250,000 and a viscosity of 1,500–3,100 mPa·s.
7. The method for preparing matrine nanogel sustained-release agent according to claim 1, characterized in that: In step 3), the volume ratio of the transparent solution to the CMC-PEI crosslinker is 1:
39.
8. The method for preparing matrine nanogel sustained-release agent according to claim 1, characterized in that: In step 3), the reaction temperature for forming the colloidal dispersion is 25–30°C, and the reaction time is 0.5–1 h.
9. The method for preparing matrine nanogel sustained-release agent according to any one of claims 1 to 8, thereby obtaining matrine nanogel sustained-release agent.
10. The application of the matrine nanogel sustained-release agent according to claim 9 in pesticide adjuvants.