Use of CGRP in reducing immune rejection of implanted neural electrodes

Abstract

The application discloses application of CGRP in reducing immune rejection of an implantable nerve electrode. The application firstly discovers and proves a new use of CGRP in immune rejection of an implantable nerve electrode and performance improvement of the implantable nerve electrode. The application provides a new direction for research and development of biocompatible or enhanced implantable nerve electrodes, and CGRP is expected to become a safer and more effective drug for reducing immune rejection of an implantable nerve electrode or improving performance of the implantable electrode, and has a wide application prospect in implantable nerve electrodes.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically, the application of CGRP in reducing immune rejection of implanted neural electrodes. Background Technology

[0002] Implantable neural electrodes are medical devices used to collect and stimulate neural signals, and they have wide applications in neuroscience research and clinical treatment. Implantable neural electrodes can be used to treat neurological diseases such as Parkinson's disease and epilepsy by modulating abnormal neural network activity through electrical stimulation to alleviate symptoms. In the field of brain-computer interfaces, implantable neural electrodes enable information interaction between the brain and computers, helping patients with motor disabilities regain motor abilities and even achieve ultra-fast learning. However, implantable neural electrodes also face some challenges in their use, such as how to improve electrode density and sampling resolution, reduce tissue damage, and optimize biocompatibility and stability. Therefore, finding substances that can improve the density, function, and biocompatibility of implantable neural electrodes is crucial.

[0003] Calcitonin gene-related peptide (CGRP) is the first bioactive polypeptide discovered in humans using molecular biology methods. It consists of 37 amino acids, has a molecular weight of approximately 3800 Daltons, and a biological half-life of about 18 minutes. It is widely distributed throughout various human systems, possesses potent physiological activity, and plays a significant role in disease diagnosis and treatment. However, its function in implantable electrodes remains unclear. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the purpose of this invention is to provide the application of CGRP in improving the performance of implantable neural electrodes and reducing immune rejection of implantable neural electrodes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The first aspect of the present invention provides any of the following applications.

[0007] Furthermore, the applications include:

[0008] 1) Application of CGRP in the preparation of products for the treatment, prevention, reduction and / or relief of immune rejection of implantable neural electrodes;

[0009] 2) Application of CGRP in the preparation of products that improve the performance of implantable neural electrodes.

[0010] Furthermore, the implantable neural electrodes include brain implantable electrodes, sacral nerve stimulation electrodes, and cochlear implantable electrodes.

[0011] Preferably, the implantable neural electrode is a brain implantable electrode.

[0012] Further, the treatment, prevention, reduction and / or alleviation of immune rejection of the implantable neural electrode comprises reducing the recruitment of microglia and / or astrocytes in the local area of the implanted electrode, reducing the blood-brain barrier leakage and / or vascular damage in the local area of the implanted electrode.

[0013] Further, the improvement of the performance of the implantable neural electrode comprises increasing the spike potential output rate of the recorded action potential, increasing the amplitude of the recorded action potential and increasing the signal-to-noise ratio of the recorded signal of the implantable neural electrode.

[0014] Further, the product comprises a drug.

[0015] Further, the drug can be used directly or in the form of a pharmaceutical composition.

[0016] Further, the pharmaceutical composition comprises an effective amount of CGRP.

[0017] Preferably, the pharmaceutical composition further comprises a pharmaceutically acceptable carrier.

[0018] The present application first discovers the new use of CGRP in reducing immune rejection of implantable neural electrodes and improving the performance of neural electrodes through experiments. The administration of CGRP at the same time of implanting neural electrodes can increase the spike potential output rate of the recorded action potential, the amplitude of the recorded action potential and the signal-to-noise ratio of the recorded signal of the electrode, while reducing the recruitment of microglia and astrocytes in the local area of the implanted electrode and the blood-brain barrier leakage and vascular damage in the local area of the implanted electrode.

[0019] In the present application, the spike potential is a rapid potential change produced by neurons when stimulated, which is part of the action potential, usually lasting about 1-2 milliseconds. The spike potential output rate refers to the frequency or proportion of neuronal discharge activity recorded by the electrode. High output rate means that the electrode can effectively capture more neural activity information, which is crucial for studying the encoding mechanism of neurons and the dynamic behavior of neural networks. The amplitude of the action potential reflects the intensity of the membrane potential change when the neuron discharges. The size of the amplitude can provide information about the intensity of neuronal activity and the distance between the electrode and the neuron. Signals with high amplitude are usually easier to detect and can reduce the impact of noise on the signal. The signal-to-noise ratio is one of the key indicators for evaluating the quality of electrode recording, which measures the proportion of useful information (neuronal discharge activity) and noise (non-useful information) in the signal. High signal-to-noise ratio means that the proportion of useful information in the signal is high, and the impact of noise on the signal is small, which helps to improve the accuracy of data analysis and interpretation.

[0020] In the present application, the microglia cells are immune cells in the central nervous system, which play an important role in the immune response. Astrocytes are involved in the formation and maintenance of the blood-brain barrier. Reducing the recruitment of these two types of cells means that the drug can reduce local immune response and inflammation, thereby reducing immune rejection. The blood-brain barrier is an important barrier to prevent harmful substances from entering the brain, and reducing the leakage and vascular damage of the blood-brain barrier means that the drug can protect the integrity of the blood-brain barrier, prevent immune cells and other harmful substances from entering the brain tissue, thereby reducing immune rejection.

[0021] In the present application, the term "treatment" refers to the process of intervening or altering a particular health state, including eliminating the cause, symptomatic treatment or supportive treatment.

[0022] In the present application, the term "prevention" includes preclinical prevention and clinical prevention. Preclinical prevention refers to preventing changes in the preclinical or early clinical stage of the disease by early detection, early diagnosis and appropriate treatment, so that the disease can be detected and treated in the early stage, and the occurrence of complications, sequelae and disability can be avoided or reduced, or the time of disability can be shortened. Clinical prevention refers to timely treatment of patients with immune rejection reactions to implanted neural electrodes by various clinical treatment methods to prevent deterioration.

[0023] In the present application, the term "reducing" refers to a measurable decrease in a lesion that lasts at least four weeks without the appearance of new lesions, as compared to before treatment. In some embodiments, the severity or duration of a patient's disease manifestations is reduced, for example, by at least about 10%, at least about 30%, at least about 50%, or at least about 80%, as compared to the absence of the active ingredient (e.g., CGRP) described in the present application.

[0024] In the present application, the term "relieving" refers to the complete disappearance of symptoms, or a reduction in the severity or duration of a patient's disease manifestations by at least 90%, lasting at least four weeks without the appearance of new lesions.

[0025] In some embodiments, the pharmaceutically acceptable carrier (or excipient) is recognized in the art and includes, for example, a pharmaceutically acceptable material, composition or excipient, such as a liquid or solid filler, diluent, solvent or encapsulating material involved in carrying or transporting any subject composition from one organ, or portion of the body, to another organ, or portion of the body. Each excipient must be "acceptable" in the sense of being compatible with the other ingredients of the subject composition in the sense of being compatible with the other ingredients of the subject composition and not deleterious to the patient.

[0026] In certain embodiments, the pharmaceutically acceptable excipient is pyrogen-free. Some examples of materials which can serve as pharmaceutically acceptable excipients include: (1) sugars, such as lactose, glucose and sucrose; (2) starches, such as corn starch and potato starch; (3) cellulose and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate; (4) powdered tragacanth; (5) malt; (6) gelatin; (7) talc; (8) cocoa butter and suppository waxes; (9) oils, such as peanut oil, cottonseed oil, sunflower oil, sesame oil, olive oil, corn oil and soybean oil; (10) glycols, such as propylene glycol; (11) polyols, such as glycerin, sorbitol, mannitol and polyethylene glycol; (12) esters, such as ethyl oleate and ethyl laureate; (13) agar; (14) buffering agents, such as magnesium hydroxide and aluminum hydroxide; (15) alginic acid; (16) pyrogen-free water; (17) isotonic saline; (18) Ringer's solution; (19) ethyl alcohol; (20) phosphate buffer solutions; and (21) other non-toxic compatible solvents.

[0027] In the present application, the term "effective amount" refers to a dosage that can achieve the treatment, prevention, reduction and / or alleviation of the immune rejection of the implantable electrode described in the present application in a subject. Depending on the patient, the severity of the condition and the route and medium of administration. The amount of active compound in such therapeutically effective composition is a suitable dose.

[0028] It should be noted that the present application does not have a particular limitation on the specific dosage of the CGRP described, and any dosage that can produce a corresponding therapeutic and / or prophylactic effect on the immune rejection of the implantable electrode in a subject or other subject is within the scope of protection of the present application.

[0029] The second aspect of the present application provides a biocompatible implantable neural electrode.

[0030] Further, the biocompatible implantable neural electrode comprises an electrode body and a metal component having a CGRP coating.

[0031] Further, the metal component can comprise a first coating and a second coating.

[0032] Preferably, the first coating comprises an insulating material.

[0033] Preferably, the second coating comprises a degradable material and a CGRP.

[0034] Further, the insulating material comprises Paralene, polyurethane.

[0035] Further, the degradable material comprises collagen, cellulose, chitosan, polyester, polylactic acid, polyglycolic acid.

[0036] Further, the first coating is used to avoid the damage of the current to the human organs when the implantable nerve electrode stimulates or collects signals.

[0037] Further, the second coating can slowly release CGRP when it degrades, which is used to reduce and / or relieve the immune rejection of the implantable nerve electrode or improve the performance of the implantable nerve electrode.

[0038] In some embodiments, the metal component is, for example, a metal body part of the metal component, which corresponds to the state after the metal raw material forming process and before the surface treatment. By surface treating the metal component body, a corresponding metal component can be obtained. For example, the metal raw material can be processed into a shell shape or other required shape by forming processes such as stamping, forging, casting, cutting, etc., as the metal component body. The outer surface of the metal component body is then textured to form a textured outer surface, and a coating is provided on at least a portion of the textured outer surface to form the metal component. In this application, the outer surface of the metal component refers to the surface exposed on the outside after being processed into a shell shape or other required shape (the surface used to directly contact the human body after the metal component is implanted into the body), and the surface located on the inside of the shell or the inside of other shaped components that cannot be exposed is referred to as the inside surface. The outer surface of the metal component is textured to form a textured outer surface.

[0039] In some embodiments, the textured outer surface of the metal component includes a first coating and a second coating. The second coating is located on the outer surface of the first coating, and the first coating is used for insulation between the metal component and the organism to avoid the damage of the current to the human organs when stimulating or collecting signals. The second coating includes a degradable polymer material, such as collagen, cellulose, chitosan, polyester, polylactic acid, or polyglycolic acid. The CGRP is slowly released according to the designed release rate, which achieves the effect of improving the performance of the implantable nerve electrode and reducing the immune rejection of the implantable nerve electrode.

[0040] In some embodiments, one end of the electrode body is connected to a lead wire, and the other end is a free end. A plurality of electric stimulation areas are provided on one side of the free end of the electrode body, and the remaining areas are insulated areas. The first coating and the second coating are provided on the surface of the metal substrate corresponding to the insulated areas of the electrode body.

[0041] The third aspect of the present application provides the use of CGRP.

[0042] Further, the use includes:

[0043] 1) in the preparation of a coating for a metal component;

[0044] 2) in the preparation of a biocompatible implantable nerve electrode.

[0045] The advantages and beneficial effects of the present application are as follows:

[0046] The present application first discovers and proves the new use of CGRP in immune rejection of implantable neural electrodes and improving the performance of implantable neural electrodes. The present application provides a new direction for the research and development of biocompatible or enhanced implantable neural electrodes, and CGRP is expected to become a safer and more effective drug for reducing immune rejection of implantable neural electrodes, and has a wide application prospect in implantable neural electrodes. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 It is shown that CGRP can improve the action potential recorded by the electrode;

[0048] Figure 2 It is shown that CGRP can improve the output rate of Spike sharp action potential recorded by an 8-channel electrode;

[0049] Figure 3 It is shown that CGRP can improve the Spike sharp potential amplitude recorded by the electrode;

[0050] Figure 4 It is shown that CGRP can improve the signal-to-noise ratio of the electrode recording signal;

[0051] Figure 5 It is shown that CGRP can reduce the recruitment of local microglia and astrocytes around the implanted electrode;

[0052] Figure 6 It is shown that CGRP can reduce the blood-brain barrier leakage and vascular injury around the implanted electrode. DETAILED DESCRIPTION

[0053] The present application will be further described below in conjunction with specific embodiments, which are only used to explain the present application and cannot be understood as limiting the present application. Those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

[0054] The drugs, reagents and raw materials used in the present application are easily obtained by those skilled in the art, and can be obtained from commercial channels if not otherwise specified, and the experimental methods not specified in the present application are usually carried out according to conventional conditions or according to the conditions recommended by the manufacturer. In particular, the following examples are only used to illustrate the present application and should not limit the scope of the present application in any way.

[0055] I. Main instruments, reagents and materials

[0056] 1. Instruments

[0057] Brain stereotaxic apparatus, Pinnacle electroencephalogram recording system were purchased from Shenzhen Ruivode Life Science and Technology Co., Ltd.

[0058] 2. Reagents

[0059] CGRP was purchased from MCE Company, USA; IgG antibody, IBA-1 antibody, GFAP antibody, Lectin antibody were purchased from Abeam Company, UK.

[0060] 3. Experimental mice

[0061] 200g male Sprague-Dawley rats were purchased from Shipeifu Beijing Biotechnology Co., Ltd.

[0062] II. Experimental methods

[0063] 1. Rat brain electrode implantation

[0064] 1) Anesthesia: Sprague-Dawley rats were intraperitoneally injected with 1% sodium pentobarbital (50mg / kg), and the rat's tail was pinched with a finger. If there was no response, the anesthesia was successful, and it took about 10 minutes.

[0065] 2) Skin preparation: Hold the anesthetized rat with the left hand, and hold the electric razor with the right hand against the direction of the rat's hair (from back to front) to shave the hair on the top of the head. The general shaving range is between the two ears, from the eyes to the neck. If you want to achieve better cleanliness, you can apply a small amount of depilatory cream, and then wash it off with saline.

[0066] 3) Fixation: First, fix one side of the ear bar, find the bony depression slightly forward and upward of the rat's ear canal (which can be touched by hand), and paste one side of the depression on the fixed ear bar (apply a small amount of lidocaine ointment in advance to avoid irritation of the rat by the ear bar). At this time, the other ear bar is also inserted into the corresponding position, and the length of the two ear bars is adjusted to be symmetrical, and the ear bar is fixed tightly. Gently move the rat's head left and right and up and down to avoid loosening and tilting. After fixing the rat's ear bar, the rat's upper incisors also need to be fixed. Specific operation: insert the rat's upper incisors into the slot of the incisor bar, and the lower jaw is below the incisor bar, then adjust the two sides of the eye socket fixation bar, press tightly and fix. Adjust the fixing points appropriately to keep the rat's entire skull surface level, and the rat's head cannot be moved from all directions. Finally, apply erythromycin ointment or glycerol to the rat's eyes to prevent eye damage caused by long-term exposure to the operating lamp and to keep the eyes moist. In addition, use a round-tipped forceps to pull the rat's tongue out of one side of the mouth to prevent suffocation during the operation.

[0067] 4) Craniotomy: 75% alcohol clean the incision site, using surgical scissors to cut the scalp, directly cut the skin over the skull, with hemostats to open the opening, using a small scissors to cut the mucosa on the skull, use a cotton swab to rub the surface of the skull, fully expose the bone layer.

[0068] 5) Stereotaxic: After the skull surface is fully dried, the obvious sagittal suture (central axis), bregma and lambda will appear. Then fix a thin rod on the holder above the positioning instrument, move the tip of the thin rod to the front of the sagittal suture, slowly move it back, if the tip of the thin rod is always on the sagittal suture during the movement, and the front and back distances from the skull surface are similar, it proves that the rat's head is fixed according to the positioning requirements, otherwise adjust accordingly. Before halogen center as the origin, after positioning, mark the left and right positioning points (hippocampus recording electrode site: front and back-3.20mm, lateral / medial 1.80mm, back / abdomen 3.0mm, bilateral symmetry).

[0069] 6) Drilling: Adjust the skull drill to the appropriate speed and adjust the correct direction. Drill four holes in the non-implantation area as the fixation position of the skull screws. These points should be evenly distributed in the non-implantation area of the skull. During drilling, one hand holds the drill, and the other hand supports it to make the drilling force as stable as possible. By lifting the drill intermittently, local high temperature can be reduced, and it is easier to perceive the actual pressure of the drill bit, avoiding excessive force. When the drill suddenly feels suspended during drilling, stop and clean the surrounding area before tightening the screw. When tightening the screw, the force should not be too large, and the screwdriver should be rotated continuously to avoid slipping. After the screw has just penetrated the skull, but has not yet pressed the intracranial meninges, stop. Grind the skull at the marked line of the implantation site. During grinding, change the position of the drill bit back and forth to avoid local high temperature damage to brain tissue. Do not drill through too quickly, leave a thin layer, then hook the ground skull from one side and remove it with fine forceps. Finally, place a medical cotton ball at the skull window opening, wet it with saline, and use it to compress and stop bleeding. The size of the skull window should be slightly larger than the cross-sectional area of the electrode array.

[0070] 7) Install the electrode: Pay attention to the speed when drilling, and use the air bag to blow the skull surface to remove the powder. If there is bleeding, use gelatin hemostatic cotton to stop bleeding (there will be a feeling of falling when the skull is drilled, stop drilling immediately), then use a screwdriver to tighten the four stainless steel screws, and use silver paint to coat the screw and electrode pad pad to enhance its conductivity (note that do not short circuit), and then start the next step of electrode wire implantation.

[0071] 8) Dental cement fixation: Use medical cotton ball to clean the skull surface and keep it dry, prepare the dental cement with low viscosity, let it flow into the gap of the electrode array naturally, and coat the periphery with high viscosity dental cement for fixation. Avoid the contact between the dental cement and the skin opening and mucosa as much as possible, because the irritability of the dental cement may cause the rat to shake. After simple fixation of the electrode, the electrode connecting wire and holder can be carefully removed, and finally the entire exposed skull together with the screw and ground wire is sealed with dental cement.

[0072] 9) Suture wound: Remove the positioning instrument from the sutured wound rat, let it rest and recover quietly, and cover the electrode cap on the head to prevent other liquids from entering. Use iodophor to wipe and apply an appropriate amount of triple antibiotic ointment on the rat's head surgical opening and surrounding area, and also inject an appropriate amount of dexamethasone to prevent postoperative inflammation.

[0073] 2. Experimental design

[0074] The experimental rats were divided into two groups. Control group: implant electrodes into the rat brain; CGRP group: implant electrodes into the rat brain, and intraperitoneally inject CGRP (25ug / kg) for 1 week. Collect brain electrical signals every 2 days.

[0075] 3. Local immunofluorescence staining detection of rat brain electrode implantation

[0076] After the rat was anesthetized and heart perfusion was performed, the rat's brain tissue was carefully peeled off. The mouse brain tissue was fixed with 4% paraformaldehyde solution for 48h. Then, through dehydration-freezing section-membrane breaking-sealing-incubation of primary antibody-incubation of fluorescent secondary antibody-patch and mounting, it was observed and photographed under an optical microscope.

[0077] III. Experimental results

[0078] From 0 to 30 days after electrode implantation, the effect of CGRP on the amplitude of action potential recorded by the electrode is as shown in Figure 1 It can be seen that CGRP can increase the amplitude of action potential recorded by the electrode. In addition, CGRP can increase the output rate of Spike sharp potential recorded by 8-channel electrode ( Figure 2 ), and can increase the Spike sharp action potential amplitude recorded by the electrode ( Figure 3 ). Further, it is found that CGRP can improve the signal-to-noise ratio of the electrode recording signal ( Figure 4 ). Next, explore the effect of CGRP on immune rejection of implanted electrodes, and find that CGRP can reduce the recruitment of microglial cells and astrocytes in the local area of implanted electrodes ( Figure 5 ), and can reduce blood brain barrier leakage (IgG) and vascular injury (Lectin) in the local area of implanted electrodes ( Figure 6 ).

[0079] The above description of the embodiments is only for understanding the method of the present application and its core idea. It should be noted that for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified in several ways, and these improvements and modifications will also fall within the protection scope of the claims of the present application.

Claims

1. The following application, characterized in that, The applications include: 1) Application of CGRP in the preparation of products for the treatment, prevention, reduction and / or relief of immune rejection of implantable neural electrodes; 2) Application of CGRP in the preparation of products that improve the performance of implantable neural electrodes.

2. The application according to claim 1, characterized in that, The implantable neural electrodes include brain implantable electrodes, sacral nerve stimulation electrodes, and cochlear implantable electrodes.

3. The application according to claim 1, characterized in that, The implantable neural electrode is a brain implantable electrode.

4. The application according to claim 1, characterized in that, The treatment, prevention, mitigation, and / or relief of immune rejection of implanted neuroelectrodes include reducing the recruitment of microglia and / or astrocytes at the implanted electrode site, reducing blood-brain barrier leakage and / or vascular damage at the implanted electrode site.

5. The application according to claim 1, characterized in that, The improvement of implantable neural electrode performance includes increasing the output rate of Spike potentials recorded by the implantable neural electrode, increasing the amplitude of action potentials recorded by the implantable neural electrode, and increasing the signal-to-noise ratio of the signals recorded by the implantable neural electrode.

6. The application according to claim 1, characterized in that, The products include pharmaceuticals.

7. The application according to claim 6, characterized in that, The drug can be used directly or in the form of a pharmaceutical composition.

8. The application according to claim 7, characterized in that, The pharmaceutical composition comprises an effective amount of CGRP.

9. The application according to claim 8, characterized in that, The pharmaceutical composition also includes a pharmaceutically acceptable carrier.

10. A biocompatible implantable neural electrode, characterized in that, The biocompatible implantable neural electrode includes an electrode body and a metal component with a CGRP coating.

11. The biocompatible implantable neural electrode according to claim 10, characterized in that, The metal component may include a first coating and a second coating.

12. The biocompatible implantable neural electrode according to claim 11, characterized in that, The first coating comprises an insulating material.

13. The biocompatible implantable neural electrode according to claim 11, characterized in that, The second coating comprises a biodegradable material and CGRP.

14. The biocompatible implantable neural electrode according to claim 12, characterized in that, The insulating materials include Parallelium and polyurethane.

15. The biocompatible implantable neural electrode according to claim 13, characterized in that, The biodegradable materials include collagen, cellulose, chitosan, polyester, polylactic acid, and polyglycolic acid.

16. The biocompatible implantable neural electrode according to claim 11, characterized in that, The first coating is used to prevent the current from damaging human organs during implanted neural electrode stimulation or signal collection. The second coating slowly releases CGRP as it degrades, which can reduce and / or alleviate immune rejection of implanted neural electrodes or improve their performance.

17. The application of CGRP, characterized in that, The applications include: 1) Application in the preparation of coatings for metal parts; 2) Application in the preparation of biocompatible implantable neural electrodes.

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