Preparation method and application of flexible photoelectric patch for accelerating skin tissue repair

Abstract

The invention relates to the field of biomedical materials, and discloses a flexible photoelectric skin patch which is composed of a vertical amorphous silicon radial junction PIN structure photoelectric unit and a flexible transparent substrate. The preparation method of the flexible photoelectric skin patch mainly comprises the following steps: growing amorphous silicon radial junction nanowires on an oxidized silicon wafer substrate through a gas-liquid-solid (VLS) mechanism, then integrally transferring the amorphous silicon radial junction nanowires to the surface of a flexible and transparent substrate to obtain the flexible photoelectric patch which can be attached to the surface of skin in a shape-preserving manner, and accelerating the repair of a skin wound under illumination. The photoelectric device is prepared by adopting a low-temperature growth process, the cost is low, the preparation is simple, and the outstanding three-dimensional structure endows the device with excellent flexibility.

Description

Technical Field

[0001] The present invention relates to the field of biomedical materials, and in particular to a flexible photoelectric patch for accelerating skin tissue repair, a preparation method and an application thereof. Background Art

[0002] Deep skin trauma caused by disease or trauma is often accompanied by nerve damage, leading to irreversible loss of peripheral sensory nerves in the skin (Q. Zhao, et al, ACS nano, 2023, 17(22), 23115-23131).

[0003] External electrical stimulation is one of the most effective methods to promote neurite outgrowth, nerve regeneration and wound healing (MSEjneby, et al, Nature Biomedical Engineering, 2022, 6(6), 741–753). Photoelectric stimulation is a typical form of remote electrical stimulation, which can flexibly and precisely adjust the intensity, frequency, site of action and duration of electrical stimulation through light. Compared with battery-powered direct electrical stimulation, photoelectric stimulation eliminates the need to connect electronic implants to external devices for power supply and data transmission. This simplifies device design and manufacturing, reduces surgical complexity, and avoids the risk of postoperative infection caused by percutaneous wires (P. Wu, et al, Advanced Materials, 2024, 36(14), 2310483; ACS Applied Materials & Interfaces, 2024, 16(4), 4361-4374.).

[0004] Silicon materials are abundant in sources, have very good biocompatibility, a wide spectral absorption range, and are compatible with microfabrication processes. Currently, flexible crystalline silicon photodiode films have been widely used to regulate biological tissue activities, such as photoelectric excitation or inhibition of neural activity (Y. Huang, et al, Nature Biomedical Engineering, 2023, 7(4), 486–498.), activation of sciatic nerve (P. Sun, et al, Nature Communications, 2024, 15(1), 4721.) and neural activity in the cerebral cortex (Y. Jiang, et al, Nature Biomedical Engineering, 2018, 2(7), 508–521.).

[0005] However, the inventors of this application have discovered that the above technology has at least the following technical problems: At present, the preparation of flexible crystalline silicon photodiode films for neural regulation generally requires a high-temperature ion implantation process for doping to achieve photoelectric properties, and requires expensive SOI wafers to facilitate the release and transfer of the flexible silicon film, resulting in complex processes and high costs.

[0006] Therefore, there is an urgent need to develop a low-cost flexible silicon-based optoelectronic patch. Summary of the invention

[0007] The present application solves the technical defects of complex process and high cost in the prior art by providing a preparation method and application of a flexible photoelectric patch for accelerating skin tissue repair, and achieves the technical effects of simple process, low cost and more convenient application. Clinical trials have shown that it can be used for photoelectric stimulation to accelerate skin tissue repair.

[0008] The embodiment of the present application provides a flexible photoelectric skin patch, which is characterized by being composed of a vertical amorphous silicon radial junction PIN structure photoelectric unit and an ultra-thin, ultra-flexible, transparent substrate.

[0009] Preferably, the thickness of the substrate ranges from 5 to 500 microns.

[0010] The present invention also discloses a method for preparing a flexible photoelectric skin patch, which is characterized by comprising the following steps: In the first step, the silicon oxide wafer sample is cleaned and placed in a plasma enhanced chemical vapor deposition system, where Sn is used as a catalyst to grow radial junction nanowires at low temperature through a VLS growth mechanism. In the second step, the PMMA solution was spin-coated on the surface of the sample obtained in the first step and baked at 185 °C to form a PMMA film; The third step is to immerse the sample obtained in the second step in a hydrofluoric acid solution to etch the silicon oxide layer on the substrate, and the radial junction nanowire film coated with the PMMA film is released from the substrate; In the fourth step, the floating PMMA film is picked up with a flexible transparent substrate, and after drying, the PMMA film on the surface is removed with an acetone solution and a layer of conductive material is evaporated.

[0011] Preferably, in the fourth step, the flexible transparent substrate is a polydimethylsiloxane film, a polyethylene terephthalate film or a polyimide film.

[0012] Preferably, in the fourth step, the conductive material is gold, platinum, molybdenum, aluminum or magnesium.

[0013] The present invention also discloses an application of the above-mentioned flexible photoelectric skin patch, characterized in that the application method comprises: A) Stick the conductive surface of the flexible transparent photoelectric patch directly on the damaged skin surface and fix it directly by using the adhesion of surface body fluids without additional suturing; B) Through sunlight or white LED light, the light is irradiated through the transparent flexible substrate to the radial junction nanowire film in the flexible amorphous silicon photovoltaic patch; C) A built-in electric field is generated inside the radial junction under the action of the photovoltaic effect. The n-type amorphous silicon layer on the surface of the film accumulates electrons, and the cations in the body fluid accumulate at the n-type amorphous silicon-skin tissue interface, causing cell depolarization and stimulating the action potential of nerve tissue, thereby stimulating and accelerating skin tissue repair.

[0014] The technical solution provided by this application has at least the following technical effects or advantages: 1. Through the photovoltaic effect, under light, the surface of the photoelectric patch accumulates electrons, promoting the aggregation of cations at the body fluid / photoelectric patch interface, leading to cell depolarization and stimulating the action potential of nerve tissue, accelerating the repair of damaged skin, without the need for additional large power supply devices and complex circuits, and avoiding the inflammatory response caused by transcutaneous wires when stimulated by external power supply.

[0015] 2. The main structure of the flexible optoelectronic patch, the amorphous silicon radial junction, is made of traditional semiconductor silicon material, has good biocompatibility, has no toxic side effects on the body, and has very good biocompatibility.

[0016] 3. The optoelectronic patch is transferred to a flexible organic material substrate by transfer, has very good flexibility, and can form conformal contact with the skin surface.

[0017] 4. Amorphous silicon has excellent weak light response characteristics, which enables the flexible optoelectronic patch to have a very good electrical response under sunlight or LED white light conditions, accelerating the repair of skin tissue.

[0018] 5. The preparation method of the present invention relies on a low-temperature and low-cost VLS growth process and a transfer process. The flexible optoelectronic patch is low-cost, simple to prepare, and the prominent three-dimensional structure gives the device excellent flexibility.

[0019] 6. The present invention grows amorphous silicon radial junction nanowires on a substrate through a vapor-liquid-solid (VLS) mechanism, and then transfers the entire nanowire to a flexible and transparent substrate surface, thereby obtaining a flexible optoelectronic patch that can be conformally attached to the surface of the skin, thereby accelerating the repair of skin wounds under light. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a flow chart of the preparation of the flexible optoelectronic patch in Example 1 and Example 2; Figure 2The morphology of the nanowires on the surface of the flexible optoelectronic patch obtained in Example 1 and Example 2 of the present invention; Figure 3 Schematic diagram of the photo of the flexible optoelectronic patch obtained in Example 1 and Example 2 of the present invention; Figure 4 This is a diagram showing the effect of the flexible photoelectric patch in Examples 1 and 2 of the present invention being applied to skin repair. DETAILED DESCRIPTION

[0021] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. Example

[0022] This embodiment provides a flexible amorphous silicon photovoltaic patch, which is composed of a vertical amorphous silicon radial junction PIN structure photovoltaic unit and an ultra-thin, ultra-flexible, transparent substrate, such as Figure 3 shown.

[0023] This embodiment also provides a method for preparing the above-mentioned flexible optoelectronic patch, such as Figure 1 In Figure 1 a- Figure 1 As shown in g, the specific steps include: In the first step, the silicon oxide wafer is cleaned, a 4-nanometer-thick Sn is evaporated on the surface, and then placed in a plasma-enhanced chemical vapor deposition system to grow radial junction nanowire films at low temperature through the VLS growth mechanism, such as Figure 1 As shown in a~1b.

[0024] In the second step, the PMMA solution was spin-coated on the sample surface obtained in the first step and baked at 185 °C for 10 min to form a thin film. Figure 1 As shown in c.

[0025] In the third step, the sample is immersed in a 10% HF solution to etch the silicon oxide layer on the substrate, and the radial junction nanowire film coated with the PMMA film is released from the substrate. Figure 1 As shown in d.

[0026] In the fourth step, the floating film was picked up with a PDMS substrate, and after drying, the PMMA film on the surface was removed with an acetone solution. The obtained sample was placed in an EBE system, and a 5 nm thick Au was evaporated on the surface, such as Figure 1 As shown in e~1g.

[0027] This embodiment also provides an application of the above-mentioned flexible optoelectronic patch, wherein the method is: The above-obtained flexible photoelectric patch is directly attached to the cleaned wound surface of the patient and fixed directly by the surface body fluid adhesion. Through LED white light irradiation, the radial junction film surface of the photoelectric patch can accumulate electrons, and the cations on the interface of the flexible photoelectric patch / body fluid can be aggregated, resulting in cell depolarization and stimulating the action potential of nerve tissue, thus accelerating the repair of skin wounds. Figure 4 shown.

[0028] Scanning electron microscopy of surface morphology, such as Figure 2 The results show that the diameter of a single radial junction nanowire on the surface of the flexible optoelectronic patch is about 300 nanometers. Figure 3 The photos show that the photoelectric patch is very flexible and can form conformal contact with the skin. When the flexible photoelectric patch is attached to the surface of the skin wound, compared with the blank control group (no treatment), the patch surface generates electrical stimulation under light, and the effect of accelerating the healing of the skin wound is obvious from the third day, and the wound is basically healed after 7 days. Example

[0029] This embodiment provides a method for preparing a flexible optoelectronic patch. The preparation method is similar to that of Embodiment 1, and the specific steps include: In the first step, the silicon oxide wafer is cleaned, 2 nanometers thick Sn is evaporated on the surface, and then placed in a plasma enhanced chemical vapor deposition system to grow radial junction nanowire films at low temperature through the VLS growth mechanism.

[0030] In the second step, the PMMA solution was spin-coated on the surface of the sample obtained in the first step and baked at 150 °C for 15 min to form a thin film.

[0031] In the third step, the sample is immersed in BOE solution to etch the silicon oxide layer on the substrate, and the radial junction nanowire film coated with PMMA film is released from the substrate.

[0032] In the fourth step, the floating film was picked up with a PET substrate, and after drying, the PMMA film on the surface was removed with an acetone solution; the sample was then placed in a magnetron sputtering system, and 10 nm thick Mo was sputtered on the surface.

[0033] This embodiment also provides an application of the above-mentioned flexible optoelectronic patch, wherein the method is: The flexible photovoltaic patch obtained by the above preparation method is directly attached to the cleaned wound surface of the patient and fixed directly by the surface body fluid adhesion. Through sunlight irradiation, under the action of the photovoltaic effect, the radial junction film surface of the photovoltaic patch accumulates electrons, and the cations at the photovoltaic patch / body fluid interface gather, resulting in cell depolarization and stimulation of the action potential of the nerve tissue, accelerating the repair of the skin wound.

[0034] The above description is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements without departing from the principle of the present invention. These improvements should also be regarded as within the scope of protection of the present invention.

Claims

1. A flexible photoelectric skin patch, characterized in that: It consists of a vertical amorphous silicon radial junction PIN structure photoelectric unit and a flexible transparent substrate.

2. The flexible optoelectronic skin patch according to claim 1, characterized in that: The thickness of the substrate ranges from 5 to 500 microns.

3. A method for preparing a flexible photoelectric skin patch, characterized in that: The steps include: In the first step, the silicon oxide wafer sample is cleaned and placed in a plasma enhanced chemical vapor deposition system, where Sn is used as a catalyst to grow radial junction nanowires at low temperature through a VLS growth mechanism. In the second step, the PMMA solution was spin-coated on the surface of the sample obtained in the first step and baked at 185 °C to form a PMMA film; The third step is to immerse the sample obtained in the second step in a hydrofluoric acid solution to etch the silicon oxide layer on the substrate, and the radial junction nanowire film coated with the PMMA film is released from the substrate; In the fourth step, the floating PMMA film is picked up with a flexible transparent substrate, and after drying, the PMMA film on the surface is removed with an acetone solution and a layer of conductive material is evaporated.

4. The method for preparing the flexible optoelectronic skin patch according to claim 3, characterized in that: In the fourth step, the flexible transparent substrate is a polydimethylsiloxane film, a polyethylene terephthalate film or a polyimide film.

5. The method for preparing the flexible optoelectronic skin patch according to claim 3, characterized in that: In the fourth step, the conductive material is gold, platinum, molybdenum, aluminum or magnesium.

6. An application of the flexible optoelectronic skin patch according to any one of claims 1 to 5, characterized in that: Application methods include: A) Stick the conductive surface of the flexible transparent photoelectric patch directly on the damaged skin surface and fix it directly by using the adhesion of surface body fluids without additional suturing; B) Through sunlight or white LED light, the light is irradiated through the transparent flexible substrate to the radial junction nanowire film in the flexible amorphous silicon photovoltaic patch; C) A built-in electric field is generated inside the radial junction under the action of the photovoltaic effect. The n-type amorphous silicon layer on the surface of the film accumulates electrons, and the cations in the body fluid accumulate at the n-type amorphous silicon-skin tissue interface, causing cell depolarization and stimulating the action potential of nerve tissue, thereby stimulating and accelerating skin tissue repair.

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