Application of CGRP in relieving immunological rejection of implantable neural electrode

Abstract

The invention discloses an application of CGRP in relieving immunological rejection of an implantable neural electrode. The new application of the CGRP in immunological rejection of the implantable neural electrode and improvement of the performance of the implantable neural electrode is discovered and confirmed for the first time. The invention provides a new direction for research and development of biocompatibility or enhanced implantable neural electrodes, the CGRP is expected to become a safer and more effective medicine for relieving immunological rejection of the implantable neural electrodes or improving the performance of the implantable neural electrodes, and the CGRP has a wide application prospect in the aspect of implantable neural electrodes.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine technology, and in particular, the present invention relates to the application of CGRP in alleviating immune rejection of implanted neural electrodes. Background Art

[0002] Implantable neural electrodes are medical devices used to collect and stimulate neural signals. They are widely used in neuroscience research and clinical treatment. Implantable neural electrodes can be used to treat neurological diseases such as Parkinson's disease and epilepsy by regulating abnormal neural network activity and alleviating symptoms through electrical stimulation. In the field of brain-computer interface, implantable neural electrodes can realize information interaction between the brain and the computer, help patients with motor disabilities restore their motor skills, and even achieve ultra-fast learning. However, implantable neural electrodes also face some challenges during use, such as how to increase electrode density and sampling resolution, reduce tissue damage, and optimize biocompatibility and stability. Therefore, it is crucial to find substances that can improve the density, function and biocompatibility of implantable neural electrodes.

[0003] Calcitonin gene related peptide (CGRP) is the first active polypeptide discovered by humans using molecular biology methods. It is composed of 37 amino acids, has a molecular weight of about 3800 Daltons, and a biological half-life of about 18 minutes. It is widely present in various systems of the human body, has strong physiological activity, and is of great significance in the diagnosis and treatment of diseases. However, its function in implantable electrodes is still unclear. Summary of the invention

[0004] In order to make up for the deficiencies of the prior art, the purpose of the present invention is to provide an application of CGRP in improving the performance of implantable neural electrodes and alleviating the immune rejection of implantable neural electrodes.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: The first aspect of the present invention provides any one of the following applications.

[0006] Furthermore, the application includes: 1) The use of CGRP in the preparation of products for treating, preventing, alleviating and / or alleviating immune rejection of implantable neural electrodes; 2) Application of CGRP in the preparation of products to improve the performance of implantable neural electrodes.

[0007] Furthermore, the implantable neural electrodes include brain implant electrodes, sacral nerve stimulation electrodes, and cochlear implant electrodes.

[0008] Preferably, the implantable neural electrode is a brain implanted electrode.

[0009] Furthermore, the treatment, prevention, alleviation and / or relief of immune rejection of implanted neural electrodes includes reducing the recruitment of local microglia and / or astrocytes in the implanted electrodes, reducing local blood-brain barrier leakage and / or vascular damage in the implanted electrodes.

[0010] Furthermore, the improvement of the performance of the implantable neural electrode includes increasing the output rate of the spike potential recorded by the implantable neural electrode, increasing the amplitude of the action potential recorded by the implantable neural electrode, and increasing the signal-to-noise ratio of the signal recorded by the implantable neural electrode.

[0011] Furthermore, the products include medicines and special medical foods.

[0012] Furthermore, the drug can be used directly or in the form of a pharmaceutical composition.

[0013] Furthermore, the pharmaceutical composition comprises an effective amount of CGRP.

[0014] Preferably, the pharmaceutical composition further comprises a pharmaceutically acceptable carrier.

[0015] The present invention experimentally proves for the first time the new use of CGRP in alleviating immune rejection of implanted neural electrodes and improving the performance of neural electrodes. Administration of CGRP while implanting neural electrodes can increase the output rate of spike action potentials, action potential amplitude and the signal-to-noise ratio of electrode recording signals, while reducing the recruitment of local microglia and astrocytes in the implanted electrode and local blood-brain barrier leakage and vascular damage in the implanted electrode.

[0016] In the present invention, a spike potential is a rapid potential change generated by a neuron when it is stimulated. It is part of the action potential and usually lasts for about 1-2 milliseconds. The output rate of the spike action potential refers to the frequency or proportion of the discharge activity of the neuron recorded by the electrode. A high output rate means that the electrode can effectively capture more neural activity information, which is crucial for studying the coding mechanism of neurons and the dynamic behavior of neural networks. The action potential amplitude reflects the intensity of the membrane potential change when the neuron discharges. The amplitude can provide information about the intensity of neuronal activity and the distance between the electrode and the neuron. High-amplitude signals 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. It measures the ratio of useful information (neuronal discharge activity) to noise (non-useful information) in the signal. A 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.

[0017] In the present invention, the microglia are immune cells in the central nervous system and play an important role in immune response. Astrocytes are involved in the formation and maintenance of the blood-brain barrier. Reducing the recruitment of these two 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. Reducing the leakage of the blood-brain barrier and vascular damage 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.

[0018] In the present invention, the term "treatment" refers to the process of intervening or changing a specific health state, including eliminating the cause, symptomatic treatment or supportive treatment.

[0019] In the present invention, the term "prevention" includes preclinical prevention and clinical prevention. Preclinical prevention refers to the prevention of preclinical or early clinical changes of the disease through early detection, early diagnosis and appropriate treatment, which can enable the disease to be discovered and treated at an early stage, avoid or reduce the occurrence of complications, sequelae and disability, or shorten the time of disability. Clinical prevention refers to the timely treatment of patients with immune rejection reactions to implanted neural electrodes with the help of various clinical treatment methods to prevent deterioration.

[0020] In the present invention, the term "relieve" refers to a reduction in measurable lesions compared to before treatment, which lasts for at least four weeks, and no new lesions appear during the period. In some embodiments, the severity or duration of the patient's disease manifestations is reduced by, for example, at least about 10%, at least about 30%, at least about 50%, or at least about 80%, compared to the absence of the active ingredient described in the present invention (such as CGRP).

[0021] In the present invention, the term "remission" means that the symptoms completely disappear, or the severity or duration of the patient's disease manifestations is reduced by at least 90%, lasting for at least four weeks, and no new lesions appear during this period.

[0022] In the present invention, the term "special medical food" refers to special medical purpose formula food, which refers to a formula food specially processed and prepared to meet the special needs of people with restricted food intake, digestive and absorption disorders, metabolic disorders or specific disease states for nutrients or diet. This type of food must be used under the guidance of a doctor or clinical nutritionist, and can be used alone or together with ordinary food or other special dietary food.

[0023] 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 that participates in carrying or transporting any subject composition from one organ or part of the body to another organ or part of the body, such as a liquid or solid filler, diluent, solvent or encapsulating material. Each excipient must be "acceptable" in the sense of being compatible with the other ingredients of the subject composition and not harmful to the patient.

[0024] In certain embodiments, the pharmaceutically acceptable excipient is non-pyrogenic. Some examples of materials that can be used 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 carboxymethylcellulose, ethyl cellulose, and cellulose acetate; (4) powdered tragacanth; (5) malt; (6) gelatin; (7) talc; (8) cocoa butter and suppository wax; (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 glycerol, sorbitol, mannitol and polyethylene glycol; (12) esters, such as ethyl oleate and ethyl laurate; (13) agar; (14) buffers, such as magnesium hydroxide and aluminum hydroxide; (15) alginic acid; (16) pyrogen-free water; (17) isotonic saline; (18) Ringer's solution; (19) ethanol; (20) phosphate buffer; (21) other non-toxic compatible substances used in pharmaceutical preparations.

[0025] In the present invention, the term "effective amount" refers to a dose that can achieve treatment, prevention, alleviation and / or relief of the immune rejection of the implantable electrode of the present invention in a subject. It depends on the patient, the severity of the condition and the route and medium used for administration. The amount of active compound in such a therapeutic composition is a suitable dose.

[0026] It should be noted that the present invention has no particular limitation on the specific dosage of the CGRP, and any dosage that can produce corresponding implantable electrode immune rejection treatment and / or prevention effects on subjects or other subjects is within the protection scope of the present invention.

[0027] A second aspect of the present invention provides a biocompatible implantable neural electrode.

[0028] Furthermore, the biocompatible implantable neural electrode includes an electrode body and a metal component with a CGRP coating.

[0029] Further, the metal component may include a first coating and a second coating.

[0030] Preferably, the first coating comprises an insulating material.

[0031] Preferably, the second coating layer comprises a degradable material and CGRP.

[0032] Furthermore, the insulating material includes Palaren and polyurethane.

[0033] Furthermore, the degradable material includes collagen, cellulose, chitosan, polyester, polylactic acid, and polyglycolic acid.

[0034] Furthermore, the first coating is used to prevent the current from damaging human organs during stimulation or signal collection by the implanted neural electrode.

[0035] Furthermore, the second coating can slowly release CGRP when degrading, which can be used to reduce and / or alleviate the immune rejection of the implanted neural electrode or improve the performance of the implanted neural electrode.

[0036] In some embodiments, the metal component is, for example, the metal body of the metal component, corresponding to the state of the metal raw material after the forming process and before the surface treatment. The corresponding metal component can be obtained by surface treatment of the metal component body. Exemplarily, the metal raw material can be processed into a shell shape or other required shape as the metal component body by forming processes such as stamping, forging, casting, and cutting. Then, the outer surface of the above-mentioned metal component body is textured to form a textured outer surface, and a coating is provided on at least a portion of the textured outer surface to form a metal component. In this application, the outer surface of the metal component refers to the surface exposed to the outside after it is processed into a shell shape or other required shape (the surface for direct contact with the human body after the metal component is implanted in the body), and the surface that cannot be exposed due to the inner side of the shell or the inner side of other shaped components is called the inner side, and the outer surface of the metal component is textured to form a textured outer surface.

[0037] 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 prevent the current during stimulation or signal collection from causing damage to human organs. The second coating includes a degradable polymer material and CGRP, and the degradable polymer material is, for example, collagen, cellulose, chitosan, polyester, polylactic acid or polyglycolic acid. CGRP is slowly released according to the designed sustained release rate to achieve the effect of improving the performance of the implantable neural electrode and reducing the immune rejection of the implantable neural electrode.

[0038] In some embodiments, one end of the electrode body is connected to a wire, and the other end is a free end. One side of the free end of the electrode body is provided with a plurality of electrical stimulation areas, and the remaining area is an insulating area. The surface of the metal substrate corresponding to the insulating area of ​​the electrode body is provided with the aforementioned first coating and second coating.

[0039] The third aspect of the present invention provides the use of CGRP.

[0040] Furthermore, the application includes: 1) Application in the preparation of metal parts coating; 2) Application in the preparation of biocompatible implantable neural electrodes.

[0041] Advantages and beneficial effects of the present invention: The present invention has discovered and confirmed for the first time the new use of CGRP in the immune rejection of implanted neural electrodes and in improving the performance of implanted neural electrodes. The present invention provides a new direction for the research and development of biocompatible or enhanced implanted neural electrodes. CGRP is expected to become a safer and more effective drug for reducing the immune rejection of implanted neural electrodes, and has broad application prospects in implanted neural electrodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It was shown that CGRP can enhance the action potential recorded by electrodes; Figure 2 It was shown that CGRP can increase the output rate of spike action potentials recorded by 8-channel electrodes; Figure 3 It showed that CGRP could increase the amplitude of spike potential recorded by electrodes; Figure 4 It showed that CGRP can improve the signal-to-noise ratio of electrode recording signals; Figure 5 It was shown that CGRP can reduce the recruitment of local microglia and astrocytes in the implanted electrodes; Figure 6 It shows that CGRP can reduce local blood-brain barrier leakage and vascular damage after electrode implantation. DETAILED DESCRIPTION

[0043] The present invention is further described below in conjunction with specific embodiments, which are only used to explain the present invention and cannot be understood as limiting the present invention. It can be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and purpose of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

[0044] The drugs, reagents and raw materials used in the present invention are easily obtained by ordinary technicians in the field and can be obtained from commercial channels unless otherwise specified. The experimental methods in the present invention that do not specify specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer. In particular, the following examples are only used to illustrate the present invention and should not limit the scope of the present invention in any way.

[0045] 1. Main instruments, reagents and materials 1. Instruments The brain stereotaxic apparatus and Pinnacle EEG recording system were purchased from Shenzhen Ruiwode Life Science Co., Ltd.

[0046] 2. Reagents CGRP was purchased from MCE, USA; IgG antibody, IBA-1 antibody, GFAP antibody, and Lectin antibody were purchased from Abcam, UK.

[0047] 3. Experimental mice 200 g male Sprague-Dawley rats were purchased from Beijing Sprague Biotechnology Co., Ltd.

[0048] 2. Experimental Methods 1. Rat Brain Electrode Implantation 1) Anesthesia: Sprague-Dawley mice were intraperitoneally injected with 1% sodium pentobarbital (50 mg / kg). Pinch the rat's tail with your fingers. No reaction indicates successful anesthesia, which lasts for about 10 minutes.

[0049] 2) Skin preparation: Hold the anesthetized rat with your left hand, and use the electric shaver in your right hand to shave the hair on the top of the head against the direction of the rat's hair (from back to front). The general shaving range is between the two ears, between the two eyes in front, and to the beginning of the neck in the back. If you want to achieve better cleanliness, you can apply a small amount of depilatory cream, and use saline to wash off the residue after use.

[0050] 3) Fixation: First, fix one ear bar, find the bony depression slightly forward and above the rat's ear canal (you can touch it with your hand), and stick the depression on one side to the fixed ear bar (applying a small amount of lidocaine ointment in advance can prevent the ear bar from irritating the rat). At this time, insert the other ear bar into the corresponding position, adjust the length of the ear bars on both sides to make them symmetrical, and fix the ear bar tightly. Gently move the rat's head left and right and up and down to avoid looseness and deflection. After fixing the rat's ear bar, the rat's upper incisors must also be fixed. Specific operation: insert the rat's upper incisors into the groove of the incisor bar, with the lower jaw under the incisor bar, and then lower the orbital fixing rods on both sides, press and fix them. Appropriately adjust each fixing point so that the entire skull surface of the rat remains horizontal, and the rat's head cannot be moved by force from all directions. Finally, apply erythromycin eye ointment or glycerin to the rat's eyes to prevent eye damage caused by long-term exposure to the surgical lamp and keep the eyes moist. In addition, use round-tipped forceps to pull the rat's tongue out of one side of its mouth to prevent suffocation during the operation.

[0051] 4) Craniotomy: Clean the surgical opening with 75% alcohol, use surgical scissors to cut the skin on the head, cut the skin directly above the skull, use hemostatic forceps to properly open the opening, use small scissors to cut the mucous membrane on the skull, and use cotton swabs to continuously rub the skull surface to fully expose the bone layer.

[0052] 5) Stereotaxic positioning: After the skull surface is fully dried, the sagittal suture (central axis), Bregma, and Lambda will be clearly visible. Then fix a thin stick on the clamp above the positioning instrument, move the tip of the thin stick to the front of the sagittal suture, and slowly move it backwards. If the tip of the thin stick is always on the sagittal suture during the movement, and the front and back heights from the skull surface are similar, it proves that the rat's head fixation meets the positioning requirements, otherwise make corresponding adjustments. Take the center of the bregma as the origin, and after positioning, mark the left and right positioning points (hippocampal recording electrode sites: anterior and posterior -3.20mm, lateral / medial 1.80mm, dorsal / ventral 3.0mm, bilateral symmetry).

[0053] 6) Drilling holes: Adjust the skull drill to a suitable speed and the correct direction. Drill 4 holes in the non-implantation area as the fixed positions of the skull pins. These positions should be evenly distributed in the non-implantation area of ​​the skull. During the drilling process, the electric drill should be held in one hand and the other hand should be used as a support to make the force of the drill bit as stable as possible. By intermittently lifting the drill bit, the local high temperature can be reduced, and it is easier to feel the actual pressure of the drill bit and avoid excessive force. If you suddenly feel a sense of suspension during the drilling process, you can stop, wipe the surrounding area and screw in the screws. When screwing the screws, the force should not be too large, and the screwdriver should be rotated continuously to avoid slipping. Stop when the screw has just passed through the skull, but has not yet squeezed the intracranial meninges. Grind the craniotomy on the marking line of the implantation position. During the grinding process, the drill bit should be changed back and forth to avoid local high temperature and damage to the brain tissue. When grinding downwards, do not rush to drill through, leaving a thinner layer. At this time, hook up the polished skull from one side and use fine tweezers to clip it from the hooked position. Finally, place a medical cotton ball soaked with saline at the opening of the cranial window to compress and stop bleeding. The size of the cranial window should be slightly larger than the cross-sectional area of ​​the electrode array.

[0054] 7) Install electrodes: Pay attention to the speed when drilling, and use an air bag to blow off the surface of the skull to remove powder. If there is bleeding, stop the bleeding with gelatin hemostatic cotton in time (there will be a sense of emptiness when the skull is pierced, so stop drilling in time). Then use a screwdriver to tighten the four stainless steel screws separately, and paint the screws and the electrode plate pads with silver paint to enhance their conductivity (be careful not to short-circuit), and start the next step of electrode wire implantation.

[0055] 8) Dental cement fixation: Use medical cotton balls to clean the skull surface and keep it dry, prepare a thinner dental cement, let it flow naturally into the gaps of the electrode array, and apply thicker dental cement to the periphery for fixation. In this process, try to avoid contact between dental cement and skin openings and mucous membranes, because the irritation of dental water may cause rats to shake. After a simple fixation of the electrode, you can carefully remove the electrode connection and clamp, and finally seal the entire exposed skull together with the screws and ground wires with dental cement.

[0056] 9) Wound suturing: After the wound is sutured, the positioning device is removed from the rat and the rat is allowed to rest and recover. The electrodes on the head can be covered with an electrode cap to prevent other liquids from entering. The surgical opening and surrounding areas of the rat's head are wiped with iodine and an appropriate amount of triple antibiotics are applied. An appropriate amount of dexamethasone can also be injected to prevent postoperative inflammation.

[0057] 2. Experimental Design The experimental rats were divided into two groups. Control group: electrodes were implanted in the rat brain; CGRP group: electrodes were implanted in the rat brain and CGRP (25ug / kg) was injected intraperitoneally for 1 week. EEG signals were collected every 2 days.

[0058] 3. Local Immunofluorescence Staining Detection of Rat Brain Electrode Implantation After the rats were anesthetized and cardiac perfusion was performed, the brain tissue of the rats was carefully peeled off. The brain tissue of the mice was fixed with 4% paraformaldehyde solution for 48 hours. After that, the brain tissue was dehydrated, frozen sectioned, membrane broken, blocked, incubated with primary antibody, incubated with fluorescent secondary antibody, mounted and sealed, and observed under an optical microscope and photographed for preservation.

[0059] 3. Experimental Results Effects of CGRP on the amplitude of action potentials recorded by electrodes from 0 to 30 days after electrode implantation Figure 1 As shown, it can be seen that CGRP can increase the amplitude of action potentials recorded by electrodes. In addition, CGRP can increase the output rate of spike potentials recorded by 8-channel electrodes ( Figure 2 ), and can increase the amplitude of the spike action potential recorded by the electrode ( Figure 3 ). Furthermore, it was found that CGRP can improve the signal-to-noise ratio of electrode recording signals ( Figure 4 Next, we explored the effect of CGRP on the immune rejection of implanted electrodes and found that CGRP can reduce the recruitment of local microglia and astrocytes in the implanted electrodes ( Figure 5 ), and can reduce local blood-brain barrier leakage (IgG) and vascular damage (Lectin) of implanted electrodes ( Figure 6 ).

[0060] The description of the above embodiments is only used to understand the method and core idea of ​​the present invention. It should be pointed out that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications will also fall within the scope of protection of the claims of the present invention.

Claims

1. Any of the following applications, characterized in that: The applications include: 1) The use of CGRP in the preparation of products for treating, preventing, alleviating and / or alleviating immune rejection of implantable neural electrodes; 2) Application of CGRP in the preparation of products to improve the performance of implantable neural electrodes.

2. The use according to claim 1, characterized in that: The implantable neural electrodes include brain implant electrodes, sacral nerve stimulation electrodes, and cochlear implant electrodes; Preferably, the implantable neural electrode is a brain implanted electrode.

3. The use according to claim 1, characterized in that: The treatment, prevention, reduction and / or alleviation of the immune rejection of implanted neural electrodes includes reducing the recruitment of local microglia and / or astrocytes in the implanted electrodes, reducing the local blood-brain barrier leakage and / or vascular damage in the implanted electrodes.

4. The use according to claim 1, characterized in that: The improvement of the performance of the implanted neural electrode includes improving the output rate of the spike potential recorded by the implanted neural electrode, improving the amplitude of the action potential recorded by the implanted neural electrode, and improving the signal-to-noise ratio of the signal recorded by the implanted neural electrode.

5. The use according to claim 1, characterized in that: The products include medicines, special medical foods; Preferably, the drug can be used directly or in the form of a pharmaceutical composition; Preferably, the pharmaceutical composition comprises an effective amount of CGRP; Preferably, the pharmaceutical composition further comprises a pharmaceutically acceptable carrier.

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

7. The biocompatible implantable neural electrode according to claim 6, characterized in that: The metal component may include a first coating and a second coating; Preferably, the first coating comprises an insulating material; Preferably, the second coating layer comprises a degradable material and CGRP.

8. The biocompatible implantable neural electrode according to claim 7, characterized in that: The insulating material includes Palaren and polyurethane; Preferably, the degradable material comprises collagen, cellulose, chitosan, polyester, polylactic acid, polyglycolic acid.

9. The biocompatible implantable neural electrode according to claim 7, characterized in that: The first coating is used to prevent the current from damaging human organs when the implanted neural electrode is stimulating or collecting signals; The second coating can slowly release CGRP when it degrades, which can be used to reduce and / or alleviate the immune rejection of the implanted neural electrode or improve the performance of the implanted neural electrode.

10. The use of CGRP, characterized in that The applications include: 1) Application in the preparation of metal parts coating; 2) Application in the preparation of biocompatible implantable neural electrodes.

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