Hydrogen-bonded organic framework supported nanoseelenium material, and preparation method and application thereof

Abstract

The application relates to the technical field of nanomaterials, in particular to a hydrogen-bonded organic framework loaded nanoseelenium material and a preparation method and application thereof, wherein the preparation method comprises the following steps: preparing a hydrogen-bonded organic framework material HOF; resuspending the prepared HOF in a bovine serum albumin aqueous solution, stirring and reacting, centrifugal washing and concentrating, and resuspending in a buffer solution; on the basis of the above solution, adding a sodium selenite solution dissolved in the buffer solution to continue stirring, adding a reducing agent to react, and growing nanoseelenium SeNPs on the surface of the HOF in situ; centrifugal washing and purifying the obtained product, resuspending in a polyethylene glycol aqueous solution to react, centrifugal washing and concentrating, and obtaining HOF@SeNPs. The prepared HOF@SeNPs are suitable for the fields of plant selenium-rich cultivation, crop heavy metal pollution control, animal cadmium poisoning relief, selenium-rich animal product feeding and the like, and provide a new idea for green agriculture and environment remediation and selenium element strengthening of agricultural products.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials technology, specifically to a hydrogen-bonded organic framework-supported selenium nanomaterial, its preparation method, and its application. Background Technology

[0002] Cadmium (Cd) is a highly toxic heavy metal element widely found in industrial waste emissions (such as smelting, electroplating, and battery manufacturing) and residues from polluted fertilizers applied to farmland. Cd readily accumulates in farmland soil, enters plants through root absorption, and is further transferred to animals and humans through the food chain, causing a series of health problems such as kidney damage, osteoporosis, and reproductive toxicity. In plants, Cd can interfere with root growth, inhibit photosynthesis, and induce oxidative stress, severely affecting crop yield and quality. Its accumulation, especially in staple crops like rice, has become a significant threat to global food safety. Currently used Cd removal and remediation strategies include chemical precipitation, ion exchange, physical adsorption, and phytoremediation. However, these methods have several limitations. For example, precipitation or exchange methods are suitable for high-concentration Cd pollution but have limited efficiency in low-concentration systems (such as the rhizosphere / tissue microenvironment of plants); adsorption materials often suffer from poor reusability, poor biocompatibility, and insufficient selectivity; and phytoremediation has a long cycle, depends on specific plant species, and is difficult to rapidly regulate.

[0003] In recent years, nanomaterials have shown significant potential in the control of heavy metal pollution due to their unique size effect and surface properties. Among them, selenium nanoparticles (SeNPs), as a green nanomaterial possessing metal complexing ability, antioxidant activity, and biocompatibility, have attracted widespread attention. Studies have shown that SeNPs can bind with Cd... 2+ SeNPs form stable complexes, inhibiting the interaction between Cd and biomolecules. Simultaneously, they effectively alleviate Cd-induced oxidative stress and cytotoxicity by activating the glutathione system and upregulating antioxidant enzyme activity. However, using SeNPs alone still presents challenges in aqueous systems, including aggregation, uneven particle size, activity decay, and uncontrollable release. Therefore, there is an urgent need to develop a more stable and controllable SeNP loading system to improve its detoxification efficiency and broaden its applications.

[0004] Hydrogen-bonded organic frameworks (HOFs) are a class of porous organic materials constructed by the self-assembly of small organic molecules through non-covalent hydrogen bonds. They possess advantages such as high specific surface area, good biocompatibility, and surface modifiability. Compared with metal-organic frameworks (MOFs), HOFs do not involve metal ions in their synthesis, are produced under mild conditions, have highly controllable structures, and exhibit flexible frameworks and tunable pore sizes, showing promising potential in fields such as drug delivery, ion recognition, and catalysis.

[0005] Patent publication number WO 2023 / 082219 A1 discloses a method and application for efficiently preparing metal-organic framework (MOF) nanocomposites loaded with selenium atoms. Specifically, it discloses that combining catalytically active MOF nanomaterials with selenium results in metal-organic framework-loaded selenium nanocomposites exhibiting better cell protection against neuroblastoma and good efficacy in stroke treatment. However, existing technologies do not disclose hydrogen-bonded organic framework-loaded selenium nanomaterials suitable for applications such as selenium-enriched plant cultivation, heavy metal pollution control in crops, and Cd toxicity mitigation in animal cells. Summary of the Invention

[0006] To address the aforementioned shortcomings of existing technologies, the present invention aims to provide a hydrogen-bonded organic framework-supported selenium nanomaterial (HOF@SeNPs), its preparation method, and its applications. This addresses the technical problems of existing selenium nanomaterials, such as easy aggregation in aquatic environments, poor biological stability, and insufficient targeted application, while simultaneously enhancing its ability to synergistically remove heavy metal cadmium and regulate selenium nutrition in plant and animal systems.

[0007] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0008] In a first aspect, a method for preparing hydrogen-bonded organic framework-supported selenium nanomaterials is provided, comprising the following steps:

[0009] Step 1: Preparation of hydrogen-bonded organic framework (HOF) materials;

[0010] Step 2: Resuspend the prepared HOF in bovine whey albumin aqueous solution, stir to react, centrifuge, wash and concentrate, and resuspend in buffer solution;

[0011] Step 3: Based on the solution prepared in step 2, add sodium selenite solution dissolved in buffer solution and continue stirring. Add reducing agent to react and allow the nano-selenium SeNPs to grow in situ on the HOF surface.

[0012] Step 4: Centrifuge, wash and purify the product obtained in Step 3, resuspend it in polyethylene glycol aqueous solution for reaction, centrifuge, wash and concentrate to obtain hydrogen-bonded organic framework material HOF@SeNPs loaded with selenium nanoparticles.

[0013] Further, in step 1, hydrogen-bonded organic framework material HOF is prepared using 1,3,6,8-tetra(terebenzoic acid)pyrene as the reactant and N,N-dimethylformamide solution and methanol as the reaction solvent.

[0014] Furthermore, in step 2, the buffer solution is a neutral buffer solution.

[0015] Furthermore, in step 3, the reducing agent is ascorbic acid or citric acid.

[0016] Secondly, a hydrogen-bonded organic framework-supported selenium nanomaterial HOF@SeNPs prepared by the above method is provided.

[0017] Thirdly, it provides applications for reducing cadmium toxicity in animal cells by supporting hydrogen-bonded organic frameworks with selenium nanomaterials HOF@SeNPs.

[0018] Furthermore, this material can accelerate the delivery efficiency of nano-selenium within cells in the presence of cadmium, promote the transfer of cadmium from inside cells to outside cells, and reduce the cadmium load within cells.

[0019] Fourthly, it provides applications for reducing cadmium content in plant systems by providing hydrogen-bonded organic framework-supported selenium nanomaterials HOF@SeNPs.

[0020] Furthermore, this material can be used to reduce cadmium accumulation in the aboveground parts of plants and increase selenium content.

[0021] Fifthly, it provides applications for hydrogen-bonded organic framework-supported selenium nanomaterials HOF@SeNPs in the preparation of plant nutrient regulators, heavy metal pollution protectants, functional feed additives, or environmental detoxification materials.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. Green and environmentally friendly with controllable costs: Whey is used as a natural stabilizer in the preparation process. It is widely available and inexpensive. No high temperature or toxic solvents are required. The process is safe and environmentally friendly and suitable for large-scale preparation.

[0024] 2. Particle size regulation and structural stability: Whey protein regulates the uniformity of SeNP particle size and inhibits aggregation, while HOF provides a dispersion and loading platform for it, enhancing structural stability and dispersibility;

[0025] 3. Significant synergistic effect: The constructed HOF@SeNPs material can simultaneously achieve selective scavenging of Cd and slow-release supply of Se, control cadmium enrichment in plants, and promote Cd excretion in cells, with significant dual functions of "detoxification + nutrition".

[0026] 4. Wide range of applications: It can be used as a plant nutrient regulator, a material for remediating Cd pollution in farmland, an animal feed additive, and an environmental functional material, and has good practical value and prospects for promotion. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating the preparation process of the HOF@SeNPs material of this invention.

[0028] Figure 2 This describes the color change process during the preparation of the HOF@SeNPs material of this invention.

[0029] Figure 3 This is a schematic diagram of the structure of the HOF@SeNPs material of the present invention;

[0030] Figure 4 This is a SEM image of the HOF@SeNPs material of this invention;

[0031] Figure 5 The analytical spectra of C, O, and Se elements in the HOF@SeNPs material of this invention are shown.

[0032] Figure 6 This is a comparison diagram showing the effects of the HOF@SeNPs material of this invention on selenium enrichment and cadmium reduction in plant systems;

[0033] Figure 7 This is a comparative diagram showing the effect of the HOF@SeNPs material of the present invention on promoting the absorption and transport of Se and Cd at the animal cell level. Detailed Implementation

[0034] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0035] Example 1: Preparation method of HOF@SeNPs material

[0036] (1) Preparation of hydrogen-bonded organic framework materials (HOF)

[0037] 50 mg of 1,3,6,8-tetra(parabenzoic acid)pyrene (H4TBAPy) was dissolved in 15 mL of a mixed solvent of N,N-dimethylformamide (DMF) and methanol (volume ratio 3:2). After ultrasonic dissolution, the solution was allowed to stand at room temperature for 24 h to crystallize. The precipitate was collected by centrifugation and washed three times with ethanol and deionized water, respectively. The precipitate was then dried under vacuum at 80 °C for 12 h to obtain a light yellow powdery hydrogen-bonded organic framework material.

[0038] (2) Construction of whey-HOF suspension system

[0039] The above-mentioned HOF powder (10 mg) was added to 0.5 wt% bovine whey aqueous solution (a byproduct of yogurt production), dispersed under sonication for 10 min, and then magnetically stirred for 2 h to form a stable whey-HOF suspension. After the reaction, the free protein and impurities were removed by centrifugation, and the precipitate was resuspended in MES buffer at pH 5.8 for later use.

[0040] (3) In-situ reduction loading of nano-selenium

[0041] A 4 mM sodium selenite solution (using MES as solvent) was added to the whey-HOF system, followed by the slow addition of citric acid to a final concentration of 20 mM as a reducing agent. The mixture was magnetically stirred for 45 min at room temperature and allowed to stand for 6 h. During the process, the system color changed from pale yellow to reddish-brown, indicating the formation of nano-selenium (SeNPs).

[0042] (4) PEG surface modification

[0043] The reaction product was collected by centrifugation and resuspended in 0.5 wt% PEG-2000 aqueous solution. The mixture was stirred at room temperature for 4 h to complete the surface modification. Subsequently, the product was centrifuged, washed, and lyophilized to obtain reddish-brown HOF@SeNPs nanomaterials.

[0044] (5) Structural performance characterization

[0045] Figure 3 The nano-selenium particles were shown to be loaded in situ onto the HOF surface, with a particle size concentrated at 75±13 nm.

[0046] Figure 4 The HOF@SeNPs material exhibits a rod-like structure with visible SeNP particles adhering to its surface. The figure shows that the addition of stabilizers such as whey during the synthesis of HOF@SeNPs effectively inhibits excessive growth and aggregation of SeNPs, improving their dispersibility on the HOF material surface.

[0047] Figure 5 The EDS elemental distribution maps of C, O, and Se are shown. The signals of C and O elements delineate the organic framework morphology of HOF, while Se elements are mainly concentrated in the particle aggregation region, indicating that nano-selenium was successfully loaded onto the HOF surface.

[0048] The zeta potential test result was -10mV, indicating that the particles have good colloidal stability.

[0049] ICP-MS analysis showed that its selenium loading was 13.2 wt%.

[0050] Example 2: Application of HOF@SeNPs in cadmium control and selenium enrichment in rice

[0051] Nipponbare rice was selected as the model plant, and the following experimental treatments were set up under greenhouse hydroponic conditions:

[0052] CK: Blank control group;

[0053] Cd group: 0.5 mg·L⁻¹ CdCl₂ (based on Cd concentration) was added to the culture medium;

[0054] Cd+HOF@SeNPs group: 0.5 mg·L⁻¹ Cd plus 10 mg·L⁻¹ HOF@SeNPs;

[0055] Cd+SeNPs group: Free SeNPs were added to 0.5 mg·L-1 Cd (Se concentration was the same as in the HOF@SeNPs group).

[0056] HOF@SeNPs group: 10 mg·L⁻¹ HOF@SeNPs (based on Se concentration) was added to the culture medium;

[0057] SeNPs group: 10 mg·L⁻¹ SeNPs (based on Se concentration) were added to the culture medium.

[0058] The Cd and Se contents of the aboveground parts of rice were measured after 7 days of hydroponics, referring to... Figure 6 The results are as follows:

[0059] In the Cd+HOF@SeNPs group, the Cd accumulation in the aboveground parts of rice was reduced by about 35% compared with the Cd group, while the Se content was significantly increased compared with the CK group.

[0060] The Cd+SeNPs group also showed some effect, but not as much as the HOF@SeNPs group, especially in terms of Se accumulation and Cd reduction.

[0061] Furthermore, the increased Se content in different tissues of rice indicates that this HOF@SeNPs material performs well in improving the efficiency of Se accumulation in plants. Combined with its good biocompatibility and stability, this material can be used as a functional nano-fertilizer in selenium-enriched plant cultivation, improving crop selenium nutrition levels and ensuring its quality and safety.

[0062] In summary, the experimental results show that HOF@SeNPs have significant synergistic cadmium control and selenium enrichment functions in rice.

[0063] Example 3: Detoxification effect of HOF@SeNPs in mouse hepatocyte suspension system

[0064] Mouse liver tissue was collected and homogenized to construct a Cd-contaminated cell model, and the following treatment groups were set up:

[0065] CT group: The culture medium was only a PBS buffer system;

[0066] Cd group: 20 μM CdCl2 was added to the culture medium;

[0067] SeNPs group: 50 μg / mL was added to the culture medium. -1 SeNPs (mass concentration, expressed as Se);

[0068] HOF@SeNPs group: Add 50 μg / mL to the culture medium -1 HOF@SeNPs (mass concentration, concentration expressed as Se);

[0069] Cd+SeNPs group: 20 μM CdCl2 + 50 μg·mL were added to the culture medium. -1 Free SeNPs;

[0070] Cd+HOF@SeNPs group: 20 μM CdCl2 + 50 μg·mL were added to the culture medium. -1 HOF@SeNPs.

[0071] The cells were incubated for 1 h, 2 h, and 4 h, respectively, maintaining a temperature of 37°C with gentle shaking throughout the reaction. After incubation, the cells were centrifuged at 10,000–15,000 rpm for 10–15 min at 4°C. The lower layer of hepatocytes was collected, washed twice with PBS, and then the intracellular Se and Cd content was determined according to the standard. Figure 7 The results are as follows:

[0072] In the Cd+HOF@SeNPs group, the intracellular Se content in liver tissue cells significantly increased at 1 hour and remained stable at 2 and 4 hours. After 1 hour of incubation, the intracellular Se content in liver cells of the Cd+HOF@SeNPs group was approximately 8.6% higher than that of the HOF@SeNPs-only group, indicating that the rate of Se uptake by cells was significantly increased under Cd co-exposure conditions compared to the HOF@SeNPs-only treatment group, suggesting that HOF@SeNPs has the ability to accelerate Se entry into cells in the presence of Cd. Furthermore, the Cd concentration in hepatocytes remained stable or slightly increased at different time points. This, combined with existing literature reporting the mechanism by which nano-selenium promotes Cd detoxification [Zwolak, I. The Role of Selenium in Arsenic and Cadmium Toxicity: an Updated Review of Scientific Literature. Biological Trace Element Research, 2020, 193:44-63. https: / / doi.org / 10.1007 / s12011-019-01691-w][Zwolak, I. Disentangling the role of selenium in antagonizing the toxicity of arsenic and cadmium. Archives of Toxicology, 2025, 99:513-540. https: / / doi.org / 10.1007 / s00204-024-03918-9][Honglong Zhang, Jun Yan, Danna Xie, Xingwang Zhu, Guole] Nie, Haijun Zhang, Xun Li, Selenium restored mitophagic flux to alleviate cadmium-induced hepatotoxicity by inhibiting excessive GPER1-mediated mitophagy activation, Journal of Hazardous Materials, 2024, 475:134855. https: / / doi.org / 10.1016 / j.jhazmat.2024.134855. This suggests that the material has potential intracellular Cd complexation and transport capabilities, providing a basis for further Cd efflux.Meanwhile, the Se enrichment observed in a mouse hepatocyte model suggests that this material can also be used as a functional feed additive in the production of selenium-enriched animal products to improve the Se level in biological tissues, and has potential value for feed application.

[0073] In summary, this experiment verified the good biocompatibility, delivery capacity, selenium enrichment capacity, and regulatory potential of HOF@SeNPs on the biological behavior of heavy metals in cell models.

[0074] This invention enables the in-situ loading of SeNPs onto the surface of HOF materials, constructing a synergistic composite material (HOF@SeNPs). On one hand, the abundant carboxyl and other functional groups in the HOF structure not only form hydrogen bonds or electrostatic interactions with the SeNP surface, effectively limiting their aggregation and growth, and improving particle size uniformity and dispersion stability, but also allow for the further grafting of functional ligands (such as thiols, amino groups, and hydroxyl groups), endowing the composite material with excellent water solubility, biocompatibility, or targeted recognition capabilities. In agricultural or biomedical applications, the material's framework structure can also be compatible with loading pesticides, metal chelators, or tumor-targeting molecules, demonstrating strong potential for surface modification. On the other hand, the porous network structure and high dispersion of HOF effectively prevent toxicity issues caused by SeNP aggregation, while simultaneously improving its dissolution behavior and sustained-release efficiency in complex biological environments, significantly enhancing the bioavailability of Se. Furthermore, the in-situ growth of SeNPs maintains a highly active surface, enabling stable complexation with Cd. 2+ It also plays a long-term adsorption and transport regulation role in multi-interface reactions. Furthermore, in plant systems, this composite material can reduce Cd accumulation in the aboveground parts, alleviating Cd toxicity, and promote Se accumulation within plants, achieving a synergistic effect of "enhancing selenium and reducing cadmium." In animal cell models, this material can accelerate the delivery of nano-selenium into cells after cadmium exposure, providing a prerequisite for the subsequent formation and excretion of Cd-containing complexes. It demonstrates application potential in targeted delivery and synergistic elemental regulation under heavy metal environments, as well as cadmium detoxification. It can also be applied to animal feed, providing a new feed additive option for the production of selenium-enriched animal products.

[0075] In summary, this invention proposes a novel material construction method that combines natural whey regulation, in-situ loading of nano-selenium, and dispersion support of hydrogen-bonded frameworks. This method has advantages such as well-defined structure, synergistic function, green safety, and strong applicability, making it suitable for applications in multiple fields such as green agricultural development, heavy metal pollution control, nutritional fortification, and the production of functional agricultural products.

[0076] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0077] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing hydrogen-bonded organic framework-supported selenium nanomaterials, characterized in that, Includes the following steps: Step 1: Prepare hydrogen-bonded organic framework (HOF) materials using 1,3,6,8-tetra(terebenzoic acid)pyrene as reactant; Step 2: Resuspend the prepared HOF in bovine whey albumin aqueous solution, stir to react, centrifuge, wash and concentrate, and resuspend in buffer solution; Step 3: Based on the solution prepared in step 2, add sodium selenite solution dissolved in buffer solution and continue stirring. Add reducing agent to react and allow the nano-selenium SeNPs to grow in situ on the HOF surface. Step 4: Centrifuge, wash and purify the product obtained in Step 3, resuspend it in polyethylene glycol aqueous solution for reaction, centrifuge, wash and concentrate to obtain hydrogen-bonded organic framework material HOF@SeNPs loaded with selenium nanoparticles.

2. The method for preparing hydrogen-bonded organic framework-supported selenium nanomaterials according to claim 1, characterized in that, In step 1, hydrogen-bonded organic framework (HOF) materials are prepared using 1,3,6,8-tetra(terebenzoic acid)pyrene as the reactant and N,N-dimethylformamide solution and methanol as the reaction solvent.

3. The method for preparing hydrogen-bonded organic framework-supported selenium nanomaterials according to claim 1, characterized in that, In step 2, the buffer solution is a neutral buffer solution.

4. The method for preparing hydrogen-bonded organic framework-supported selenium nanomaterials according to claim 1, characterized in that, In step 3, the reducing agent is ascorbic acid or citric acid.

5. The hydrogen-bonded organic framework supported selenium nanomaterials HOF@SeNPs prepared by the method according to any one of claims 1-4.

6. The application of the hydrogen-bonded organic framework supported selenium nanomaterial HOF@SeNPs as described in claim 5 in the preparation of materials for reducing cadmium toxicity in animal cells.

7. The application according to claim 6, characterized in that, This material can accelerate the delivery efficiency of nano-selenium in cells in the presence of cadmium, promote the transfer of cadmium from inside cells to outside cells, and reduce the cadmium load in cells.

8. The application of the hydrogen-bonded organic framework supported selenium nanomaterial HOF@SeNPs as described in claim 5 in reducing cadmium content in plant systems.

9. The application according to claim 8, characterized in that, This material can be used to reduce cadmium accumulation in the aboveground parts of plants and increase selenium content.

10. The application of the hydrogen-bonded organic framework supported selenium nanomaterial HOF@SeNPs as described in claim 5 in the preparation of plant nutrient regulators, heavy metal pollution protectants, functional feed additives, or environmental detoxification materials.

Images