A surface-insulated modified electrode and its preparation method and application

Abstract

The application discloses a surface insulation modified electrode and a preparation method and application thereof, and belongs to the technical field of electrodes for H2 production. The surface insulation modified electrode prepared by the preparation method has the advantages of uniform insulation layer coverage, controllable size stability, good conductivity, high stability, good biocompatibility, no cytotoxicity and electric stimulation toxicity, and high biological safety. By adjusting the area of the tip reaction zone and the applied voltage value, the prepared surface insulation modified electrode has different H2 production capacity and rate, and thus can realize precise and controllable release of H2 according to different tumor sizes and characteristics. The application provides a new strategy and technical support for realizing good treatment effect on different tumors, reducing unnecessary damage to healthy cells, and reducing the postoperative recurrence rate. The preparation method is simple and easy to operate, has low requirements on equipment, does not need high temperature and high pressure, has few or no side reactions, is high in efficiency, and is green and environment-friendly.

Description

Technical Field

[0001] This invention relates to the field of electrode technology for H2 production, and in particular to a surface-insulating modified electrode, its preparation method, and its application. Background Technology

[0002] Hydrogen (H2) is considered a relatively inert gas that can inhibit cell migration and regulate cell death, possessing anti-inflammatory and anti-tumor properties. It has been found to have therapeutic effects on various oxidative stress / inflammation-related diseases, including cancer, atherosclerosis, stroke, and diabetic neurodegenerative diseases. H2 therapy has attracted increasing attention due to its unique physicochemical properties, such as its ability to easily penetrate vascular cells and biological membranes, diffuse into the cell nucleus and mitochondria, and high safety, rapidly progressing from the laboratory to clinical applications. Traditional H2 therapy strategies mainly rely on hydrogen air or hydrogenated water for drug delivery, which consistently suffers from low utilization rates and poor targeting. Subsequent H2 therapies based on nanomaterials face the problem of high burden on the body from nanomaterials. Therefore, developing new, highly efficient, safe, and controllable H2 production materials and hydrogen supply devices is of significant practical importance for achieving precise treatment of different disease sites.

[0003] Electrochemical treatment (EChT) is a low-cost, simple, minimally invasive, effective, and highly targeted tumor ablation method. In the 1970s, Swedish physician Bjorn Nordenström first combined targeted electrochemical therapy with other treatments to treat 26 patients with primary lung tumors. Follow-up studies conducted 2-5 years after treatment revealed that tumors disappeared in 12 patients without regrowth. EChT involves inserting two or more electrodes locally into the tumor. Each electrode releases a stable direct current within the tumor. An electrolytic reaction within the tumor induces ion production, altering the pH of the surrounding environment. This leads to condensation of the tumor nucleus, destruction of the cell membrane, damage to mitochondria, and coagulation and necrosis of nucleoproteins. The tumor-suppressing mechanism of EChT is mainly related to the electrolytic products and pH changes, while the effective therapeutic components produced by the electrodes within the tumor are closely related to the electrode material. Due to its unique characteristics, EChT can be used for tumors unresponsive to surgery, radiotherapy, and / or chemotherapy. Therefore, developing novel electrochemical hydrogen production methods by utilizing the electrolytic properties of electrodes made of different materials holds promise for solving many challenges in the clinical treatment of diseases. Summary of the Invention

[0004] The purpose of this invention is to provide a surface-insulating modified electrode, its preparation method, and its application, to fill the current gap in the lack of precise control of H2 yield during electrode use for different tumor sizes and characteristics.

[0005] To achieve the above objectives, the present invention provides an insulating layer modified acupuncture needle, wherein the insulating layer modification region of the insulating layer modified acupuncture needle is sequentially modified with polydopamine, (3-aminopropyl)triethoxysilane and a silicone rubber insulating layer.

[0006] Preferably, the insulating layer modification area of ​​the acupuncture needle is located 0.5-1 cm from the needle tip to the needle handle.

[0007] The preparation method of the insulating layer modified acupuncture needle as described above includes the following steps: S1. Modify polydopamine: Suspend the insulating layer modification area and the tip reaction area of ​​the acupuncture needle in the hydrochloric acid dopamine solution, stir and assemble. After assembly, take it out and place it in an oven to obtain the polydopamine intermediate layer modified acupuncture needle. S2. The insulating layer modification region and tip reaction region of the polydopamine intermediate layer modified acupuncture needle obtained in S1 are suspended and inserted into an ethanol solution of (3-aminopropyl)triethoxysilane, and the reaction is carried out at room temperature in a sealed manner to obtain an APTES modified acupuncture needle. S3. The insulating layer modification area and tip reaction area of ​​the APTES modified acupuncture needle obtained in S2 are suspended and inserted into the xylene solution of dimethylsiloxane to obtain the insulating layer modified acupuncture needle.

[0008] Preferably, the tip reaction zone in S1-S3 is the 0.5-1cm portion of the acupuncture needle tip, which remains covered with insulating adhesive when suspended in the corresponding solution.

[0009] Preferably, the dopamine hydrochloride solution in S1 is prepared by dissolving dopamine hydrochloride in Tris-HCl buffer, and the concentration of dopamine hydrochloride is 0.1-0.3 mg / mL; the stirring and assembly conditions are room temperature, 180-200 rpm for 10-14 hours; and the oven conditions are set to 50-80℃ for one hour.

[0010] Preferably, the concentration of (3-aminopropyl)triethoxysilane in the ethanol solution of (3-aminopropyl)triethoxysilane in S2 is 90-110 mM; the reaction is carried out at room temperature in a closed environment for 1-3 hours.

[0011] Preferably, the xylene solution of dimethylsiloxane in S3 is obtained by dissolving hydrogen-terminated polydimethylsiloxane and vinyl-terminated polydimethylsiloxane in xylene and then adding a catalyst to dissolve them.

[0012] Preferably, the molar ratio of hydrogen-terminated polydimethylsiloxane to vinyl-terminated polydimethylsiloxane is 1:1, and the concentration of each is 90-110 mM; the catalyst is a platinum(O)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex.

[0013] Application of an insulating layer modified acupuncture needle as described above in the preparation of an electrochemical therapy device.

[0014] Therefore, the surface insulating modified electrode, its preparation method, and its application provided by this invention have the following specific technical effects: (1) Using the preparation method provided by the present invention, polydopamine, (3-aminopropyl)triethoxysilane and silicone rubber insulating layer are sequentially modified on the surface of stainless steel acupuncture needle. The prepared surface insulating layer modifies the electrode insulating layer with uniform coverage, stable and controllable size, good conductivity, high stability, good biocompatibility, no cytotoxicity and electrostimulation toxicity, and high biological safety. (2) By using the method provided by the present invention, by adjusting the area of ​​the tip reaction zone and applying the voltage value, the prepared surface insulating modified electrode can have different H2 production capabilities and rates, thereby enabling precise and controllable release of H2 for different tumor sizes and characteristics. This provides a new strategy and technical support for achieving good therapeutic effects on different tumors, reducing unnecessary damage to healthy cells, and reducing postoperative recurrence rate. (3) The preparation method provided by the present invention is simple and easy to operate, has low equipment requirements, does not require high temperature and high pressure, has few or no side reactions, is highly efficient, and is green and environmentally friendly.

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the acupuncture needles in Example 1; Figure 2 These are SEM images and surface elemental distribution diagrams of the acupuncture needles and modified acupuncture needles in Example 1; where A is the SEM image of the unmodified acupuncture needle; B is the SEM image of the acupuncture needle modified with a polydopamine intermediate layer; C is the SEM image of the acupuncture needle modified with an insulating layer; D is the surface distribution diagram of silicon (Si); E is the surface distribution diagram of iron (Fe); F is the surface distribution diagram of nitrogen (N); and G is the surface distribution diagram of oxygen (O). Figure 3 This is the XPS elemental analysis diagram from Example 2; where A is the polydopamine intermediate layer modified acupuncture needle; and B is the insulating layer modified acupuncture needle. Figure 4 These are conductivity test images of the acupuncture needle (electrode) with insulating layer modification in Example 3; where A is a photo of the multimeter positive electrode placed at the end of the acupuncture needle and the negative electrode contacting the tip reaction area; and B is a photo of the multimeter positive electrode placed at the end of the acupuncture needle and the negative electrode contacting the insulating layer. Figure 5 These are the electrolysis process diagram and cytotoxicity diagram of the insulating layer modified acupuncture electrode in Example 4; where A is the electrolysis process diagram; and B is the cytotoxicity diagram. Figure 6 This is a diagram showing hydrogen production on acupuncture electrodes with insulating layers modified in different tip reaction regions in Example 5. Detailed Implementation

[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] To make the objectives, technical solutions, and advantages of this application clearer, more thorough, and more complete, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. The following detailed descriptions are all illustrations of embodiments, intended to provide further detailed explanation of the present invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0020] The instruments, equipment, reagents, and materials used in the examples were all obtained commercially.

[0021] Example 1 The specific steps for preparing a surface-insulating modified electrode are as follows: (a) Preparation of polydopamine intermediate layer modified acupuncture needles.

[0022] The specific steps for modifying the surface of stainless steel acupuncture needles with a polydopamine intermediate layer are as follows: Dopamine hydrochloride was dissolved in 0.1M pH 8.5 Tris-HCl buffer to a final concentration of 0.2 mg / mL, denoted as the dopamine hydrochloride solution. The insulating layer modification region and the tip reaction region (already covered with insulating adhesive, located 1 cm from the tip) of the acupuncture needle (SS, acupuncture electrode) were then suspended in the dopamine hydrochloride solution and assembled with stirring at 200 rpm for 12 hours. After assembly, the acupuncture needle was removed and placed in an oven at 60℃ for one hour. Finally, a polydopamine layer rich in catechol, amine, imine, and quinone groups was formed on the surface of the insulating layer modification region of the acupuncture electrode. This yielded the polydopamine intermediate layer modified acupuncture needle. A schematic diagram of the insulating layer modification region and the tip reaction region of the acupuncture needle is shown below. Figure 1 .

[0023] (ii) Preparation of insulating layer modified acupuncture needles.

[0024] A cross-linked silicone rubber insulating layer was constructed in situ on the surface of the polydopamine interlayer modified by the acupuncture needle in step (i). The specific steps are as follows: 1) The insulating layer modification region and tip reaction region (already covered with insulating adhesive) of the polydopamine intermediate layer modified acupuncture needle prepared in step (I) are suspended and inserted into an ethanol solution of (3-aminopropyl)triethoxysilane (APTES) at a concentration of 100 mM. The reaction is carried out at room temperature and sealed for 2 hours to obtain an APTES-modified acupuncture needle. APTES acts as a silane coupling agent, reacting with the amino or catechol groups of the polydopamine intermediate layer to introduce amino or silanol groups. These groups can serve as sites for loading platinum-based catalysts or Lewis acids in the next step.

[0025] 2) The APTES-modified acupuncture needle prepared in step 1) is suspended and inserted into a xylene solution containing hydrogen-terminated polydimethylsiloxane and vinyl-terminated polydimethylsiloxane. The solution also contains 0.04 mM platinum(O)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex (as a catalyst, a platinum-based catalyst). The concentrations of both hydrogen-terminated and vinyl-terminated polydimethylsiloxane are 100 mM, with a molar ratio of 1:1. The platinum-based catalyst initiates a hydrosilylation reaction between the hydrogen-terminated and vinyl-terminated polydimethylsiloxanes, achieving in-situ construction of a cross-linked silicone rubber insulating layer, thus obtaining the insulating layer-modified acupuncture needle. This addition-type silicone rubber curing reaction is achieved through hydrosilylation, without side reactions, and exhibits good dimensional stability.

[0026] Scanning electron microscopy (SEM) was performed on untreated acupuncture needles (unmodified acupuncture needles), prepared polydopamine intermediate-layer modified acupuncture needles, and insulating-layer modified acupuncture needles, respectively. The results are as follows: Figure 2 As shown, part A represents the unmodified acupuncture needle, part B represents the acupuncture needle modified with a polydopamine intermediate layer, and it can be seen that a granular thin film layer is formed on the surface of the polydopamine intermediate layer modified acupuncture needle. Part C represents the acupuncture needle modified with an insulating layer, and it can be seen that the granular structure on the surface of the acupuncture needle modified with an insulating layer is covered, forming a uniform silicone rubber insulating layer. The elemental analysis results of the acupuncture needle modified with an insulating layer are as follows: Figure 2 As shown in the DG, silicon, nitrogen, and oxygen elements were successfully introduced into the surface of the acupuncture needle by modifying the insulating layer.

[0027] Example 2 X-ray photoelectron spectroscopy (XPS) analysis was performed on the polydopamine intermediate-layer modified acupuncture needles and insulating-layer modified acupuncture needles prepared in Example 1. The specific steps are as follows: The polydopamine intermediate-layer modified acupuncture needles and insulating-layer modified acupuncture needles prepared in Example 1, as well as the insulating-layer modified region of the unmodified acupuncture needle, were cut into 1 cm lengths using pliers and subjected to X-ray photoelectron spectroscopy (XPS) analysis to verify the chemical composition of the surface layer of each acupuncture needle. The results are as follows: Figure 3 As shown, nitrogen atoms were successfully introduced into the surface of the acupuncture needle modified with a polydopamine intermediate layer, while the nitrogen atom signal was covered and the silicon atom signal appeared on the surface of the acupuncture needle modified with an insulating layer, indicating that the insulating layer modification area of ​​the acupuncture needle modified with an insulating layer was successfully modified with silicone rubber.

[0028] Example 3 The conductivity and insulation effects of the modified and unmodified tip reaction regions of the insulating layer-modified acupuncture needle prepared in Example 1 were measured using a multimeter. The results are as follows: Figure 4 As shown, adjust the multimeter to the connected position. When the positive terminal of the multimeter is placed at the end of the acupuncture needle and the negative terminal contacts the tip reaction area ( Figure 4 (A) The green light on the multimeter illuminates, and the meter displays a measured resistance of 6.6Ω, indicating excellent conductivity. When the negative electrode is brought into contact with the insulating layer modification area ( Figure 4 (B) When the green light goes out, the meter displays a resistance of OL, indicating that the circuit has infinite resistance and is in a non-conductive state.

[0029] Example 4 The electrolysis process of the insulating layer-modified acupuncture needle prepared in Example 1 in simulated body fluids was analyzed using an electrochemical workstation. The specific steps are as follows: (1) First, two insulating-layer modified acupuncture needles were suspended and fixed in a test bottle containing simulated bodily fluid (commercially available product), one as the positive electrode and the other as the negative electrode. Voltages of 1.0, 2.0, and 3.0V were applied respectively, and the corresponding changes in current density were recorded. The results are as follows: Figure 5 As shown in Figure A, when the voltage is greater than 1.64V, the insulating layer-modified acupuncture needle will undergo an electrolytic reaction in simulated body fluid, and the electrolytic reaction process becomes more intense as the voltage increases.

[0030] (2) The biocompatibility of the insulating layer modified acupuncture needle / electrode prepared in Example 1 was investigated. The specific steps are as follows: Using the MTT assay, HepG2 human hepatocellular carcinoma cells and HL-7702 normal human hepatocytes were seeded at 5000 cells / well in 96-well plates. DMEM high-glucose medium (containing 10% fetal bovine serum + 1% penicillin / streptomycin) was added and mixed, then incubated at 37°C and 5% CO2 for 24 h. The DMEM high-glucose medium (containing 10% fetal bovine serum + 1% penicillin / streptomycin) was then replaced with DMEM medium containing acupuncture needles soaked in insulating material (soaked for 24 h, containing 10% fetal bovine serum + 1% penicillin / streptomycin) and cultured for another 24 h. Then, 10 μL of 5 mg / mL MTT was added to each well and incubated for another 4 h. Finally, 150 μL of DMSO was added to each well to dissolve the generated formazan, and the absorbance (OD) at 490 / 570 nm was measured using a microplate reader. Results are as follows: Figure 5 As shown in Figure B, the DMEM medium in which the insulating-modified acupuncture needles were immersed for 24 hours exhibited good biocompatibility with both human liver cancer cells and normal liver cells, without significant cytotoxicity. This result indicates that the insulating-modified acupuncture needles possess good biocompatibility.

[0031] Example 5 An insulating-modified acupuncture needle was prepared according to the method in Example 1, and the tip reaction zone was protected by coating the acupuncture needle with insulating adhesive. Three acupuncture needles with different tip reaction zone areas were obtained by adjusting the height of the insulating adhesive coating: large area (tip reaction zone height 7 mm), medium area (tip reaction zone height 4 mm), and small area (tip reaction zone height 2 mm). The hydrogen production of the insulating-modified acupuncture needles with the three different tip reaction zone areas was investigated, and the specific steps are as follows: The mass of the insulating-modified acupuncture needle was weighed. Then, the tip reaction area of ​​the insulating-modified acupuncture needle was immersed in a simulated body fluid at pH 5.5. The reaction apparatus was sealed, and a constant voltage of 3V was applied using a constant current and constant voltage apparatus for electrolysis for 10 minutes. The electrolyzed insulating-modified acupuncture needle was collected and weighed. The hydrogen production content was calculated using Faraday's law of electrolysis. The results are as follows: Figure 6 As shown: Acupuncture needles with an insulating layer modified with a 2 mm tip reaction area produced 1.89 ± 0.06 mL of hydrogen gas during 10 minutes of electrical stimulation at 3V; acupuncture needles with an insulating layer modified with a 4 mm tip reaction area produced 4.13 ± 0.13 mL of hydrogen gas; and acupuncture needles with an insulating layer modified with a 7 mm tip reaction area produced 8.03 ± 0.25 mL of hydrogen gas. The results show that as the reaction area height increases, the effective electrical stimulation reaction area increases, and the volume of hydrogen gas produced during electrical stimulation also increases. This result indicates that surface-insulated modified acupuncture needles with different reaction area areas were successfully prepared using the method described in Example 1.

[0032] Therefore, the surface-insulating modified electrode prepared by the method provided in this invention has a uniform insulating layer coverage, stable and controllable dimensions, good conductivity, high stability, good biocompatibility, no cytotoxicity or electro-irritant toxicity, and high biosafety. By adjusting the area of ​​the tip reaction region and the applied voltage, the prepared surface-insulating modified electrode can have different H2 production capabilities and rates, thereby enabling precise and controllable H2 release for different tumor sizes and characteristics. This provides a new strategy and technical support for achieving good therapeutic effects on different tumors, reducing unnecessary damage to healthy cells, and lowering postoperative recurrence rates. The provided preparation method is simple and easy to operate, has low equipment requirements, does not require high temperature and high pressure, produces few or no side reactions, is highly efficient, and is environmentally friendly.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An acupuncture needle with an insulating layer, characterized in that: The insulating layer of the acupuncture needle is sequentially modified with polydopamine, (3-aminopropyl)triethoxysilane, and a silicone rubber insulating layer.

2. The insulating layer modified acupuncture needle according to claim 1, characterized in that: The insulating layer modification area of ​​the acupuncture needle is located 0.5-1 cm from the needle tip to the needle handle.

3. The method for preparing an insulating layer-modified acupuncture needle as described in claim 1 or 2, characterized in that, The steps are as follows: S1. Modify polydopamine: Suspend the insulating layer modification area and the tip reaction area of ​​the acupuncture needle in the hydrochloric acid dopamine solution, stir and assemble. After assembly, take it out and place it in an oven to obtain the polydopamine intermediate layer modified acupuncture needle. S2. The insulating layer modification region and tip reaction region of the polydopamine intermediate layer modified acupuncture needle obtained in S1 are suspended and inserted into an ethanol solution of (3-aminopropyl)triethoxysilane, and the reaction is carried out at room temperature in a sealed manner to obtain an APTES modified acupuncture needle. S3. The insulating layer modification area and tip reaction area of ​​the APTES modified acupuncture needle obtained in S2 are suspended and inserted into the xylene solution of dimethylsiloxane to obtain the insulating layer modified acupuncture needle.

4. The method for preparing an insulating layer-modified acupuncture needle according to claim 3, characterized in that: The tip reaction zone in S1-S3 is the 0.5-1cm portion of the acupuncture needle tip, which remains covered with insulating adhesive when suspended in the corresponding solution.

5. The method for preparing an insulating layer-modified acupuncture needle according to claim 3, characterized in that: The dopamine hydrochloride solution in S1 is prepared by dissolving dopamine hydrochloride in Tris-HCl buffer solution, with a concentration of 0.1-0.3 mg / mL. The stirring and assembly conditions are room temperature, 180-200 rpm for 10-14 hours, and oven conditions are set to 50-80℃ for one hour.

6. The method for preparing an insulating layer-modified acupuncture needle according to claim 3, characterized in that: The concentration of (3-aminopropyl)triethoxysilane in the ethanol solution of S2 is 90-110 mM; the reaction is carried out at room temperature in a closed environment for 1-3 hours.

7. The method for preparing an insulating layer-modified acupuncture needle according to claim 3, characterized in that, The xylene solution of dimethylsiloxane in S3 is obtained by dissolving hydrogen-terminated polydimethylsiloxane and vinyl-terminated polydimethylsiloxane in xylene, and then adding a catalyst to dissolve them.

8. The method for preparing an insulating layer-modified acupuncture needle according to claim 7, characterized in that, The molar ratio of hydrogen-terminated polydimethylsiloxane to vinyl-terminated polydimethylsiloxane is 1:1, and the concentration of both is 90-110 mM; the catalyst is a platinum(O)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane complex.

9. The application of an insulating layer modified acupuncture needle as described in claim 1 or 2 in the preparation of an electrochemical therapy device.

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