Double-layer rollable protein film and method of making the same
By preparing and processing silk fibroin films to form a double-layer rollable protein film, the problems of swelling and poor adhesion of silk fibroin films in water are solved, thus achieving long electrode life and good adhesion.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGXI SILK BIOTECHNOLOGY CO LTD
- Filing Date
- 2023-12-06
- Publication Date
- 2026-07-14
AI Technical Summary
Silk protein membranes are prone to swelling when wetted with water, which can lead to wire breakage, and planar protein membranes do not adhere well to tissues.
Two silk protein films were prepared, swollen and pre-stretched after a water vapor crosslinking reaction to form an initial bilayer protein film. Then, water vapor crosslinking was performed to obtain a bilayer rollable protein film.
It improves the lifespan of the electrode and its adhesion to the target tissue. By controlling the deformation, the membrane becomes closer to the tissue geometry, thus enhancing the adhesion effect.
Smart Images
Figure CN117653796B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of materials technology, and in particular to a bilayer rollable protein membrane and its preparation method. Background Technology
[0002] Silk fibroin is a novel material with excellent biocompatibility. It possesses numerous advantages, including low susceptibility to immune responses, biodegradability, drug-carrying capacity, and superior mechanical properties, making it an excellent choice for manufacturing medical devices. Currently, silk fibroin is used in the manufacture of various medical devices, including bone screws and sutures. In addition, silk fibroin membranes can serve as substrates for flexible electronic devices, with applications including transient soluble electronic devices.
[0003] However, there are still some drawbacks to using silk protein membranes for the above purposes:
[0004] (1) Cross-linked protein membranes without special treatment swell when wetted with water. Wires and other materials on the surface of the membrane will break due to stretching, leading to device failure.
[0005] (2) The adhesion effect of planar protein membranes to tissues needs to be improved. Summary of the Invention
[0006] This invention provides a bilayer rollable protein membrane and its preparation method, which enables the surface of the bilayer rollable protein membrane to remain unchanged or shrink when it is used as an electrode substrate, thereby improving the service life of the electrode; and improving the adhesion effect of the bilayer rollable protein membrane electrode to the target tissue during implantation.
[0007] On one hand, the present invention provides a method for preparing a bilayer rollable protein membrane, the method comprising:
[0008] Prepare two silk protein films;
[0009] The two silk protein films were placed in a vacuum vessel and subjected to a water vapor crosslinking reaction to obtain two crosslinked silk protein films. The reaction time was a first preset time.
[0010] The two cross-linked silk fibroin films are immersed in water for a second preset time to allow them to fully swell, resulting in two swollen protein films; the two swollen protein films include a first protein film and a second protein film;
[0011] The first protein membrane is pre-stretched along a preset direction to obtain a first stretched protein membrane; the size of the first stretched protein membrane is determined based on the thickness of the first protein membrane and the curvature of the double-layer rollable protein membrane.
[0012] The first stretched protein membrane and the second protein membrane are adhered together to form an initial bilayer protein membrane;
[0013] The initial bilayer protein membrane was placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane.
[0014] Optionally, the step of adhering the first stretched protein membrane to the second protein membrane to form an initial bilayer protein membrane includes:
[0015] Based on the first stretched protein membrane and the second protein membrane, a first cut protein membrane and a second cut protein membrane are obtained;
[0016] A protein solution is uniformly coated onto a target-cut protein membrane to obtain a coated protein membrane; the target-cut protein membrane is either the first-cut protein membrane or the second-cut protein membrane.
[0017] The remaining cut protein membrane is attached to the coated protein membrane to form the initial bilayer protein membrane; the remaining cut protein membrane is the protein membrane other than the target cut protein membrane among the first cut protein membrane and the second cut protein membrane.
[0018] Optionally, obtaining a first cut protein membrane and a second cut protein membrane based on the first stretched protein membrane and the second protein membrane includes:
[0019] The first stretchable protein membrane is fixed to the first clamp, and the second protein membrane is fixed to the second clamp; both the first clamp and the second clamp are circular structures.
[0020] The unfixed portion of the first stretched protein membrane outside the first clamp is cut to obtain the first cut protein membrane.
[0021] The unfixed portion of the second protein membrane outside the second clamp is cut to obtain the second cut protein membrane.
[0022] Optionally, after attaching the remaining cut protein membrane to the coated protein membrane to form the initial bilayer protein membrane, the method further includes:
[0023] The clamps corresponding to the initial bilayer protein membrane are fixed by clamping plates to form a protein membrane assembly;
[0024] The protein membrane assembly was dried to obtain a dried assembly.
[0025] The initial bilayer protein membrane is placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane, comprising:
[0026] The dried assembly was placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane.
[0027] Optionally, the step of drying the protein membrane assembly to obtain a dried assembly includes:
[0028] The protein membrane assembly is placed on a flat first silicone block; wherein the initial bilayer protein membrane in the protein membrane assembly is attached to the first silicone block;
[0029] The second silicone block is placed on the surface of the initial bilayer protein membrane away from the first silicone block. The residual air bubbles in the initial bilayer protein membrane are squeezed to the edge by pressing the second silicone block to obtain the processed assembly.
[0030] The processed assembly is then dried to obtain a dried assembly.
[0031] Optionally, placing the dried assembly in the vacuum vessel and performing a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane includes:
[0032] Remove the first and second silica gel blocks from the drying assembly to obtain the clamped protein membrane assembly;
[0033] The clamp protein membrane assembly is placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain the bilayer rollable protein membrane.
[0034] Optionally, placing the initial bilayer protein membrane in the vacuum vessel and performing a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane includes:
[0035] The initial bilayer protein membrane is placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to form a secondary crosslinked protein membrane.
[0036] After drying the secondary cross-linked protein membrane, the protein membrane located in the middle region of the fixture is removed to obtain a double-layered rollable protein membrane.
[0037] Optionally, after drying the secondary cross-linked protein membrane, the protein membrane located in the middle region of the fixture is removed to obtain a double-layered, rollable protein membrane, including:
[0038] After drying the secondary cross-linked protein membrane, a dried cross-linked protein membrane is obtained.
[0039] Remove a portion of the dried, cross-linked protein membrane located in the middle region of the fixture to obtain an initial rollable protein membrane;
[0040] The initial rollable protein membrane is cut along the target direction, and a double-layer rollable protein membrane with a target helix angle is formed by adjusting the cutting angle.
[0041] Optionally, the first preset duration is 24±10 hours, and the second preset duration is 24±10 hours.
[0042] On the other hand, a bilayer rollable protein membrane is provided, which is prepared by the above-described preparation method.
[0043] The bilayer rollable protein membrane and its preparation method provided by this invention have the following technical effects:
[0044] This invention first prepares two silk fibroin films; then places the two silk fibroin films in a vacuum vessel and performs a water vapor crosslinking reaction to obtain two crosslinked silk fibroin films, with a reaction time of a first preset time; the two crosslinked silk fibroin films are then immersed in water for a second preset time to allow them to fully swell, resulting in two swollen protein films; each swollen protein film includes a first protein film and a second protein film; the first protein film is pre-stretched along a preset direction to obtain a first stretched protein film; the size of the first stretched protein film is determined based on the thickness of the first protein film and the curvature of the double-layer rollable protein film; the first stretched protein film is adhered to the second protein film to form an initial double-layer protein film; the initial double-layer protein film is placed in a vacuum vessel and subjected to a water vapor crosslinking reaction to obtain a double-layer rollable protein film. This invention uses a pre-stretching process to ensure that the surface of the bilayer rollable protein membrane used as an electrode substrate remains unchanged or shrinks when exposed to water, without breaking, thereby improving the service life of the electrode. This invention also improves the adhesion between the bilayer rollable protein membrane electrode and the target tissue during implantation by making the bilayer rollable protein membrane geometrically closer through controllable deformation. Attached Figure Description
[0045] To more clearly illustrate the technical solutions and advantages in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art 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.
[0046] Figure 1 This is a schematic flowchart of a method for preparing a bilayer rollable protein membrane provided in the embodiments of this specification;
[0047] Figure 2 This is a schematic flowchart of another method for preparing a bilayer rollable protein membrane provided in the embodiments of this specification;
[0048] Figure 3 This is a test diagram of the curl radius of a product obtained by cutting the second protein membrane at a 90-degree angle to the pre-stretched edge, as provided in the embodiments of this specification.
[0049] Figure 4 This is a schematic diagram showing the different helix angles of the bilayer protein membrane provided in the embodiments of this specification after it comes into contact with water. Detailed Implementation
[0050] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0051] Example 1
[0052] like Figure 1 As shown, this embodiment provides a method for preparing a bilayer rollable protein membrane, which may include the following steps:
[0053] S1. Prepare two silk protein films;
[0054] S2. Place the two silk protein films in a vacuum vessel and perform a water vapor crosslinking reaction to obtain two crosslinked silk protein films. The reaction time is the first preset time.
[0055] S3. Soak the two cross-linked silk protein films in water for a second preset time to allow the two cross-linked silk protein films to fully swell, resulting in two swollen protein films; the two swollen protein films include a first protein film and a second protein film;
[0056] S4. The first protein membrane is pre-stretched along a preset direction to obtain a first stretched protein membrane; the size of the first stretched protein membrane is determined based on the thickness of the first protein membrane and the curvature of the double-layer rollable protein membrane.
[0057] For example, any soaked protein membrane can be stretched. Before stretching, the membrane is isotropic, and any direction can be selected as the preset stretching direction. The pre-stretching range can be determined based on the required shrinkage rate of the membrane. Unconstrained drying of the protein membrane can result in a maximum expansion of approximately 30%. Protein membranes that have been repeatedly soaked (e.g., for 24 hours as described above) and then air-dried with a fixed pre-stretching rate of 0 show almost no change in area. For instance, when the pre-stretching rate is approximately 100%, the protein membrane will shrink by approximately 25% along the pre-stretching direction upon contact with water. The dimensions of the first stretched protein membrane can be determined based on the thickness of the first protein membrane and the curvature of the double-layered rollable protein membrane, or it can be determined based on the thickness of the first protein membrane, the thickness of the second protein membrane, and the curvature of the double-layered rollable protein membrane.
[0058] S5. Adhere the first stretched protein membrane to the second protein membrane to form an initial bilayer protein membrane;
[0059] S6. The initial bilayer protein membrane is placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane.
[0060] In one exemplary embodiment, the two cross-linked silk protein films can be immersed in room temperature water for a second preset time, wherein the first preset time is 24±10 hours and the second preset time is 24±10 hours.
[0061] In one exemplary embodiment, a method for preparing two silk protein films may include: preparing a silk protein solution; transferring the silk protein solution into a mold and placing it under preset conditions for a preset time to obtain a silk protein film; the two silk protein films have the same shape, and their sizes may be the same or different; the thickness of the two silk protein films may be set according to the curvature of the double-layer rollable protein film product; the thickness of the two silk protein films may be the same or different.
[0062] In one exemplary embodiment, the method for preparing the silk fibroin solution includes:
[0063] The glue in silkworm cocoons is removed to form silk.
[0064] Dissolve the cleaned and dried silk in a lithium bromide solution and mix thoroughly.
[0065] The mixed solution was placed in an insulated box for heat preservation.
[0066] The mixed solution after heat preservation was dialyzed to obtain a silk fibroin suspension;
[0067] The silk fibroin suspension is purified by centrifugation at a preset temperature, and the supernatant is collected to obtain the silk fibroin solution.
[0068] In one exemplary embodiment, the step of adhering the first stretched protein membrane to the second protein membrane to form an initial bilayer protein membrane includes:
[0069] Based on the first stretched protein membrane and the second protein membrane, a first cut protein membrane and a second cut protein membrane are obtained;
[0070] A protein solution is uniformly coated onto a target-cut protein membrane to obtain a coated protein membrane; the target-cut protein membrane is either the first-cut protein membrane or the second-cut protein membrane.
[0071] The remaining cut protein membrane is attached to the coated protein membrane to form the initial bilayer protein membrane; the remaining cut protein membrane is the protein membrane other than the target cut protein membrane among the first cut protein membrane and the second cut protein membrane.
[0072] In one exemplary embodiment, obtaining a first cut protein membrane and a second cut protein membrane based on the first stretched protein membrane and the second protein membrane includes:
[0073] The first stretched protein membrane is fixed to the first clamp, and the second protein membrane is fixed to the second clamp;
[0074] The unfixed portion of the first stretched protein membrane outside the first clamp is cut to obtain the first cut protein membrane.
[0075] The unfixed portion of the second protein membrane outside the second clamp is cut to obtain the second cut protein membrane.
[0076] In the embodiments described in this specification, both the first clamp and the second clamp are circular structures with grooves on their circumferences, which allow the protein membrane to be fixed onto the clamps. The first clamp and the second clamp can be clamps of the same size.
[0077] In one exemplary embodiment, after attaching the remaining cut protein membrane to the coated protein membrane to form the initial bilayer protein membrane, the method further includes:
[0078] The clamps corresponding to the initial bilayer protein membrane are fixed by clamping plates to form a protein membrane assembly;
[0079] The protein membrane assembly was dried to obtain a dried assembly.
[0080] The initial bilayer protein membrane is placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane, comprising:
[0081] The dried assembly was placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane.
[0082] In one exemplary embodiment, the step of drying the protein membrane assembly to obtain a dried assembly includes:
[0083] The protein membrane assembly is placed on a flat first silicone block; wherein the initial bilayer protein membrane in the protein membrane assembly is attached to the first silicone block;
[0084] The second silicone block is placed on the surface of the initial bilayer protein membrane away from the first silicone block. The residual air bubbles in the initial bilayer protein membrane are squeezed to the edge by pressing the second silicone block to obtain the processed assembly.
[0085] The processed assembly is then dried to obtain a dried assembly.
[0086] In this illustrative embodiment, in order to ensure that the protein membrane does not deform during the drying process, the drying temperature can be set to 25-40°C and the drying time can be 24-48 hours.
[0087] In one exemplary embodiment, placing the dried assembly in the vacuum vessel and performing a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane includes:
[0088] Remove the first and second silica gel blocks from the drying assembly to obtain the clamped protein membrane assembly;
[0089] The clamp protein membrane assembly is placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain the bilayer rollable protein membrane.
[0090] In the embodiments of this specification, the clamp protein membrane assembly can be subjected to at least one water vapor crosslinking reaction. After the crosslinking reaction, it can be dried for about 24-48 hours to obtain a double-layer rollable protein membrane, thereby improving the adhesive strength between the two membranes in the assembly.
[0091] In one exemplary embodiment, the step of placing the initial bilayer protein membrane in the vacuum vessel and performing a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane includes:
[0092] The initial bilayer protein membrane is placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to form a secondary crosslinked protein membrane.
[0093] After drying the secondary cross-linked protein membrane, the protein membrane located in the middle region of the fixture is removed to obtain a double-layered rollable protein membrane.
[0094] In one exemplary embodiment, after drying the secondary cross-linked protein membrane, the protein membrane located in the middle region of the fixture is removed to obtain a double-layered rollable protein membrane, comprising:
[0095] After drying the secondary cross-linked protein membrane, a dried cross-linked protein membrane is obtained.
[0096] Remove a portion of the dried, cross-linked protein membrane located in the middle region of the fixture to obtain an initial rollable protein membrane;
[0097] The initial rollable protein membrane is cut along the target direction, and a double-layer rollable protein membrane with a target helix angle is formed by adjusting the cutting angle.
[0098] In the embodiments described in this specification, the target helix angle can be set according to actual needs, specifically by adjusting the cutting angle to control the size of the target helix angle.
[0099] The method provided in this embodiment can be used to prepare a bilayer rollable protein membrane, which is formed by the adhesion of two protein membranes. The bilayer rollable protein membrane has a target helix angle, which can be set according to actual needs. Specifically, the size of the target helix angle can be controlled by adjusting the cutting angle.
[0100] Example 2
[0101] like Figure 2 As shown, this embodiment provides a method for preparing a bilayer rollable protein membrane, including the following steps:
[0102] (1) Prepare two uncrosslinked silk protein films ( Figure 2 (See Figure a) The degree of curling of the final product can be adjusted by adjusting the thickness of the two films;
[0103] In this embodiment, the method for preparing two silk protein films may include: preparing a silk protein solution; transferring the silk protein solution into a mold and placing it under preset conditions for a preset time to obtain a silk protein film; the two silk protein films have the same shape, but their sizes may be the same or different, and the thickness of the two silk protein films may be set according to the curvature of the double-layer rollable protein film product; the thickness of the two silk protein films may be the same or different.
[0104] In one exemplary embodiment, the method for preparing the silk fibroin solution includes:
[0105] The glue in silkworm cocoons is removed to form silk.
[0106] Dissolve the cleaned and dried silk in a lithium bromide solution and mix thoroughly.
[0107] The mixed solution was placed in an insulated box for heat preservation.
[0108] The mixed solution after heat preservation was dialyzed to obtain a silk fibroin suspension;
[0109] The silk fibroin suspension is purified by centrifugation at a preset temperature, and the supernatant is collected to obtain the silk fibroin solution.
[0110] (2) The silk protein film obtained in (1) is placed in a vacuum vessel containing water at the bottom, and a vacuum is drawn to moisten the inside for water vapor crosslinking for about 24 hours to obtain the crosslinked silk protein film. Figure 2 (b&c diagram)
[0111] (3) Immerse the protein membrane obtained in (2) in water to allow it to swell fully. Figure 2 (Figure d in the middle)
[0112] (4) Depending on the required shrinkage rate of the membrane, one of the protein membranes that has been fully swollen in (3) is pre-stretched to a certain extent in a specific direction. Figure 2 (e&f diagram)
[0113] (5) Fix the unstretched protein membrane to the clamp while it is under tension, and fix the stretched protein membrane to the clamp while it is under tension. Figure 2 (See Figure g). The degree of stretching of the latter can adjust the curl of the final product.
[0114] (6) Cut off any unfixed membrane outside the clamp. Figure 2 (middle h diagram);
[0115] (7) Coat the surface of one of the protein membranes with a protein solution evenly, avoiding the presence of air bubbles in the protein solution. Figure 2 (Image from the middle of the image).
[0116] (8) Slowly attach another protein membrane to the protein membrane coated with protein solution in (7), avoiding the generation of air bubbles during the attachment process. Figure 2 (middle j diagram);
[0117] (9) After the protein membrane is attached, fix all the clamps with clamps. Figure 2 (Middle K-chart)
[0118] (10) If it is necessary to control the amount of protein solution in the membrane, place the "protein membrane-clamp-plate" assembly obtained in (8) on a soft, flat silica gel block and make the protein membrane contact it. Figure 2 (Figure 1)
[0119] (11) Select soft, flat silicone blocks of different weights based on the required amount of protein solution, place them on the surface of the assembled protein membrane, and squeeze any remaining air bubbles inside the protein membrane to the edge while placing them. Figure 2 (m-diagram)
[0120] (12) Place the assembly obtained in (9) or (11) in a dry environment for about 24-48 hours until it is completely dry;
[0121] (13) After removing the silica gel block from the composite obtained in (12), place it in a vacuum vessel with water at the bottom, and perform secondary cross-linking of the protein membrane therein by water vapor cross-linking method. Figure 2 (OQ diagram)
[0122] (14) Take out the composite after secondary cross-linking in (13) and place it in a dry environment for about 24-48 hours until it is completely dry. Figure 2 (middle r diagram);
[0123] (15) Use a blade to remove the middle region of the protein membrane to obtain the desired bilayer rollable protein membrane. Figure 2 (Figure s in the middle).
[0124] (16) Cut the protein membrane obtained in (15) into the desired shape along different directions. The helix angle of the finished product can be adjusted by adjusting the cutting angle. Figure 2 (middle t diagram).
[0125] For example, the thickness of the two silk protein films is about 75 micrometers, the pre-stretch of the first stretch protein film is about 50%, its shrinkage rate is about 20%, the second protein film has about 15% relaxation fixation, it will swell by about 15% when it comes into contact with water, and its curling radius after contact with water is about 2mm.
[0126] For example, the thickness of the two silk protein films is 75 micrometers each. The pre-stretch of the first protein film is 50%, and the second protein film has approximately 15% relaxation. They are cut at 0 degrees, 45 degrees, and 90 degrees relative to the pre-stretch, respectively. When the bilayer protein film is exposed to water, the corresponding helix angles are 0 degrees, 45 degrees, and 90 degrees. Figure 3 As shown, Figure 3 The curl radius test diagram is obtained by cutting the second protein membrane at approximately 90 degrees to the pre-stretched edge. The curl radius of the product is approximately 2 mm. Figure 4 As shown, Figure 4 This is a schematic diagram showing different helix angles of a bilayer protein membrane after it comes into contact with water.
[0127] The bilayer rollable protein membrane prepared in this embodiment can be used to fabricate neural electrodes. These neural electrodes are based on a bilayer membrane composed of a protein membrane that contracts upon deformation and a protein membrane that remains unchanged. When wet, the bilayer membrane rolls up with the inner side facing inwards, and the final degree of roll-up and helix angle can be controlled by adjusting the membrane thickness, stretching, and cutting angle. In the dry state, a conductive layer is prepared on the inner side of the membrane using methods such as electron beam evaporation to obtain the neural electrode. Because the protein membrane can be rolled up and deformed, it can more closely approximate the geometric shape of the target tissue (such as nerves or blood vessels), thereby improving the adhesion effect.
[0128] This invention employs a pre-stretching process to ensure that all three surfaces of the bilayer protein membrane remain unchanged or shrink upon contact with water, thereby achieving long-term reliability of surface-mounted electronic devices. The protein membrane prepared by this invention can be rolled and deformed, allowing it to more closely approximate the geometry of target tissues (such as nerves and blood vessels), thus improving adhesion. This invention uses water absorption as the inducing condition for deformation, making it easier and safer to implement compared to shape memory materials such as temperature memory materials.
[0129] The controllable deformable silk protein membrane of this invention retains the original advantages of silk protein, such as degradability, drug loading, and excellent mechanical properties, while adding the function of being able to be rolled up and deformed. This allows for the fabrication of silk protein-based devices with complex shapes, and achieves better adhesion and advantages such as simplified surgical procedures.
[0130] In summary, the bilayer rollable protein membrane and its preparation method provided by this invention have the following technical effects:
[0131] This invention first prepares two silk fibroin films; then places the two silk fibroin films in a vacuum vessel and performs a water vapor crosslinking reaction to obtain two crosslinked silk fibroin films, with a reaction time of a first preset time; the two crosslinked silk fibroin films are then immersed in water for a second preset time to allow them to fully swell, resulting in two swollen protein films; each swollen protein film includes a first protein film and a second protein film; the first protein film is pre-stretched along a preset direction to obtain a first stretched protein film; the size of the first stretched protein film is determined based on the thickness of the first protein film and the curvature of the double-layer rollable protein film; the first stretched protein film is adhered to the second protein film to form an initial double-layer protein film; the initial double-layer protein film is placed in a vacuum vessel and subjected to a water vapor crosslinking reaction to obtain a double-layer rollable protein film. This invention uses a pre-stretching process to ensure that the surface of the bilayer rollable protein membrane used as an electrode substrate remains unchanged or shrinks when exposed to water, without breaking, thereby improving the service life of the electrode. This invention also improves the adhesion between the bilayer rollable protein membrane electrode and the target tissue during implantation by making the bilayer rollable protein membrane geometrically closer through controllable deformation.
[0132] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a bilayer flexible protein membrane, characterized in that, The method includes: Prepare two silk protein films; The two silk protein films were placed in a vacuum vessel and subjected to a water vapor crosslinking reaction to obtain two crosslinked silk protein films. The reaction time was a first preset time. The two cross-linked silk fibroin films are immersed in water for a second preset time to allow them to fully swell, resulting in two swollen protein films; the two swollen protein films include a first protein film and a second protein film; The first protein membrane is pre-stretched along a preset direction to obtain a first stretched protein membrane; the size of the first stretched protein membrane is determined based on the thickness of the first protein membrane and the curvature of the double-layer rollable protein membrane. The first stretched protein membrane and the second protein membrane are adhered together to form an initial bilayer protein membrane; The initial bilayer protein membrane was placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane.
2. The method according to claim 1, characterized in that, The step of adhering the first stretched protein membrane to the second protein membrane to form an initial bilayer protein membrane includes: Based on the first stretched protein membrane and the second protein membrane, a first cut protein membrane and a second cut protein membrane are obtained; A protein solution is uniformly coated onto a target-cut protein membrane to obtain a coated protein membrane; the target-cut protein membrane is either the first-cut protein membrane or the second-cut protein membrane. The remaining cut protein membrane is attached to the coated protein membrane to form the initial bilayer protein membrane; the remaining cut protein membrane is the protein membrane other than the target cut protein membrane among the first cut protein membrane and the second cut protein membrane.
3. The method according to claim 2, characterized in that, The process of obtaining a first cut protein membrane and a second cut protein membrane based on the first stretched protein membrane and the second protein membrane includes: The first stretched protein membrane is fixed to the first clamp, and the second protein membrane is fixed to the second clamp; The unfixed portion of the first stretched protein membrane outside the first clamp is cut to obtain the first cut protein membrane. The unfixed portion of the second protein membrane outside the second clamp is cut to obtain the second cut protein membrane.
4. The method according to claim 3, characterized in that, After attaching the remaining cut protein membrane to the coated protein membrane to form the initial bilayer protein membrane, the method further includes: The clamps corresponding to the initial bilayer protein membrane are fixed by clamping plates to form a protein membrane assembly; The protein membrane assembly was dried to obtain a dried assembly. The initial bilayer protein membrane is placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane, comprising: The dried assembly was placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane.
5. The method according to claim 4, characterized in that, The step of drying the protein membrane assembly to obtain a dried assembly includes: The protein membrane assembly is placed on a flat first silicone block; wherein the initial bilayer protein membrane in the protein membrane assembly is attached to the first silicone block; The second silicone block is placed on the surface of the initial bilayer protein membrane away from the first silicone block. The residual air bubbles in the initial bilayer protein membrane are squeezed to the edge by pressing the second silicone block to obtain the processed assembly. The processed assembly is then dried to obtain a dried assembly.
6. The method according to claim 5, characterized in that, The process of placing the dried assembly in the vacuum vessel and performing a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane includes: Remove the first and second silica gel blocks from the drying assembly to obtain the clamped protein membrane assembly; The clamp protein membrane assembly is placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to obtain the bilayer rollable protein membrane.
7. The method according to any one of claims 1-6, characterized in that, The step of placing the initial bilayer protein membrane in the vacuum vessel and performing a water vapor crosslinking reaction to obtain a bilayer rollable protein membrane includes: The initial bilayer protein membrane is placed in the vacuum vessel and subjected to a water vapor crosslinking reaction to form a secondary crosslinked protein membrane. After drying the secondary cross-linked protein membrane, the protein membrane located in the middle region of the fixture is removed to obtain a double-layered rollable protein membrane.
8. The method according to claim 7, characterized in that, After drying the secondary cross-linked protein membrane, the protein membrane located in the middle region of the fixture is removed to obtain a double-layered, rollable protein membrane, comprising: After drying the secondary cross-linked protein membrane, a dried cross-linked protein membrane is obtained. Remove a portion of the dried, cross-linked protein membrane located in the middle region of the fixture to obtain an initial rollable protein membrane; The initial rollable protein membrane is cut along the target direction, and a double-layer rollable protein membrane with a target helix angle is formed by adjusting the cutting angle.
9. The method according to any one of claims 1-6, characterized in that, The first preset duration is 24±10 hours, and the second preset duration is 24±10 hours.
10. A double-layered, rollable protein membrane, characterized in that, The bilayer rollable protein membrane is prepared using the preparation method described in any one of claims 1-9.