Non-invasive controllable flexible bio-electronic patch for treatment of diabetic erectile dysfunction

Abstract

The present application belongs to the technical field of biological medicine, and particularly relates to a non-invasive controllable flexible bioelectronic patch for treating diabetic erectile dysfunction. Diabetic-related erectile dysfunction is difficult to recover due to long-term damage to the microenvironment of the corpus cavernosum. Traditional oral or corpus cavernosum injection treatment has poor targeting, uneven distribution and complication risks, and it is difficult to achieve long-term efficacy. The present application proposes a flexible and attachable bioelectronic patch for non-invasive and painless controllable adjustment of the microenvironment of erectile tissue. The device promotes the expression of local vasoactive factors and endothelial repair through mild electrical stimulation, while achieving uniform transdermal delivery of drug molecules, showing high delivery efficiency and cell viability, and significantly improving corpus cavernosum blood flow and cell function. In the in vitro cell model and diabetic animal model, the device shows better vascular regeneration and functional recovery effect than traditional drug or injection treatment.

Description

[0001] Priority application This application claims priority to Chinese invention patent application filed on December 15, 2025, [202511891706.6], entitled "Non-invasive, controllable, flexible bioelectronic patch for the treatment of diabetic erectile dysfunction," which is incorporated herein by reference in its entirety. Technical Field

[0002] This invention belongs to the field of biomedical technology, specifically relating to a non-invasive flexible patch for treating diabetic erectile dysfunction. Background Technology

[0003] Diabetic erectile dysfunction (ED) is a common and difficult-to-treat complication in men with diabetes. Its pathological mechanism primarily stems from impaired endothelial function of the corpora cavernosa, leading to insufficient eNOS production and inducing oxidative stress, thereby disrupting smooth muscle relaxation and blood flow regulation in the corpora cavernosa. Current clinical treatment mainly relies on oral inhibitors and intracavernosal injections. However, these methods have limitations in terms of efficiency, safety, and controllability. For example, oral medications rely on systemic circulation for delivery to penile tissue, resulting in poor targeting, which limits efficiency and / or controllability, while increasing the risk of systemic side effects. Intracavernosal injections, while acting directly on the lesion and restoring erectile function in the short term, only diffuse locally after single-point injection into the corpora cavernosa. Uneven drug distribution not only reduces overall efficacy but may also lead to local drug overdose, causing persistent or priapism, and with long-term repeated injections, can induce fibrosis, nodules, and penile curvature of the corpora cavernosa. Developing a non-invasive, painless, uniform, controllable, and highly efficient transdermal drug delivery strategy remains a long-term challenge.

[0004] The patent with publication number CN103550860A, entitled "A Male Sexual Function Therapy Device with Seven Electrostimulation Therapeutic Effects," discloses a method of treating sexual dysfunction by applying electrical pulse signals to acupoints. However, this treatment method requires large equipment, and applying the electrical pulse device to the correct acupoints often requires professional operation, which reduces patient compliance.

[0005] In summary, there is an urgent need for a new strategy that can be conveniently and directly applied to the affected area, is easy to use, and has a high therapeutic effect. Summary of the Invention

[0006] The purpose of this invention is to provide a novel medical device that partially solves or alleviates the above-mentioned deficiencies in the prior art. The invention specifically adopts the following technical solution.

[0007] A non-invasive flexible electrical stimulation patch, comprising two functional modules: (1) an electrical stimulation drug delivery module and (2) a wireless transmission power supply module; The electrostimulation drug delivery module is composed of a substrate layer, a microelectrode array layer, a gel layer, and a nanoporous membrane layer. The base layer is a biodegradable flexible material used for support and encapsulation; The microelectrode array layer is composed of multiple layers of electrodes. The microelectrode array layer includes multiple microelectrode sheets with the same shape and arranged regularly. The microelectrode sheets are connected by serpentine electrode lines. The serpentine electrode lines have at least two S-shaped structures. Each microelectrode sheet has at least two serpentine electrode lines. The gel layer comprises a viscous gel matrix with hydroxyl and / or amino groups and a drug to be delivered electrically; the microelectrode array layer is embedded in the gel layer; The nanoporous membrane layer is made of an ester group that can form hydrogen bonds with the hydroxyl or amino groups of the gel matrix; the nanoporous membrane layer has a thickness of 10-50 μm and a pore size structure of 500-1000 nm on its surface. The wireless transmission power supply module is connected to the microelectrode array layer via leads to supply power to the electrostimulation drug delivery module.

[0008] Furthermore, the number of leads is two.

[0009] In some embodiments, the biodegradable flexible material is a biodegradable plastic.

[0010] In some embodiments, the thickness of the nanoporous membrane layer is 10-20 μm.

[0011] Furthermore, the serpentine electrode wire is made of the same material as the conductor.

[0012] Furthermore, the serpentine electrode wire is made of silver; or, the lead wire is made of silver.

[0013] Furthermore, the microelectrode array layer is composed of Cr-Ag-Cr composite; the thickness of the Ag layer is 15 to 30 times the total thickness of the Cr layer (i.e., the thickness of the two Cr layers stacked together).

[0014] Furthermore, the shape of the microelectrode sheet includes triangles, quadrilaterals, polygons, or circles; the polygon is a planar figure composed of four or more line segments that are not on the same straight line, connected end to end in sequence, including pentagons, hexagons, and others.

[0015] Furthermore, the material of the gel matrix includes GelMA-chitosan, which is a composite of methacrylamide gelatin and chitosan; or, the material of the nanoporous membrane layer includes a polycarbonate membrane or polyethylene terephthalate (PET). In some preferred embodiments, the mass ratio of methacrylamide gelatin to chitosan is 3:1, but this is not a limitation.

[0016] In embodiments of the present invention, the drug to be electrically delivered includes, but is not limited to, drugs for treating erectile dysfunction. The non-invasive flexible electrical stimulation patch of the present invention may also contain other drugs suitable for localized transdermal drug delivery for treating diseases.

[0017] In some embodiments, the nanopore size of the nanoporous membrane layer ranges from 600 to 800 μm. Drugs contained in the gel matrix can be delivered electrochemically through the nanopores of the nanoporous membrane layer to reach the skin of the target organ.

[0018] Furthermore, the wireless transmission power supply module includes a coil antenna and a rectification and regulation circuit block.

[0019] Furthermore, the wireless transmission power supply module also includes a flexible packaging structure.

[0020] Furthermore, the rectification and regulation circuit adopts an NFC receiver structure, including a rectification module, a voltage regulator module, and an energy storage capacitor.

[0021] In some specific implementations, the coil antenna is a copper or metal wire fabricated on a flexible substrate, which can be made into a spiral or planar winding structure as needed; the rectification and regulation circuit adopts a standard NFC receiver structure, including a rectification module, a voltage regulator module, and an energy storage capacitor; and the flexible packaging (optional) can be packaged using common biocompatible materials such as Parylene, PDMS, or PI, but the module functionality does not depend on specific materials.

[0022] In another aspect, the present invention also provides a method for preparing the above-mentioned non-invasive flexible electrical stimulation patch (device), comprising the following steps: S110: Fabrication of an electrically stimulated drug delivery module; S111: A biodegradable flexible material is coated onto a clean substrate to form a wet film, which is then cured at high temperature; S112: Coat the cured flexible material with photoresist and dry it appropriately; S113: Ultraviolet exposure is performed using a pre-designed mask to pattern the photoresist, followed by nitrogen drying; S114: Place the sample treated in S113 into a magnetron sputtering instrument, evacuate to the base pressure, then introduce argon gas to maintain the working pressure at 0.5 Pa. Apply a sputtering voltage of 120 V to sputter the silver target while the substrate is rotating. S115: After sputtering is completed, the sample is removed from the chamber, the silver-plated flexible material film is peeled off from the substrate, and then a drug-containing hydrogel and nanoporous membrane are coated on it. S120: A wireless transmission power supply module is fabricated on transparent polyethylene terephthalate using flexible printed circuit technology; S130: Assemble the electrostimulation drug delivery module and the wireless transmission power supply module to form the non-invasive flexible electrostimulation patch.

[0023] Beneficial technical effects: This invention provides a novel non-invasive flexible bioelectronic patch—the FlexiStim patch—that enables non-invasive, painless, uniform, and controllable drug delivery to target organs. The patch is flexible, wirelessly powered, and composed of thin, biocompatible layered materials, including an Ecoflex substrate, a serpentine interconnected silver microelectrode array, and a drug-loaded hydrogel. The hydrogel layer forms a mechanical interlock with the electrode layer and nanofilm layer, and intermolecular interactions ensure strong bonding between the layers. The hydrogel also neutralizes the modulus between the tissue and the material, acting as a buffer layer to protect the tissue and device from damage. The core design of the entire device is a "nanopore-drug reservoir-microelectrode" structure, operating under low-amplitude pulses (<20V) to achieve safe, efficient, and uniform transdermal delivery of micro-drugs. Experiments show a delivery efficiency of up to 95% and good cell viability. In a mouse model of DMED, FlexiStim achieved erectile function improvement comparable to intracavernosal injection at a much lower dose than injectable medication. Simultaneously, it activated erection-related signaling pathways (EP2 / PKA / CREB) and inhibited the TGF-β / Smad pathway, thereby significantly alleviating corpus cavernosum fibrosis. As a programmable nanomedicine delivery platform, FlexiStim is not only suitable for drug delivery therapy in DMED, but can also be expanded to gene editing, protein delivery, and multi-drug synergistic delivery in the future, providing new strategies for precision treatment of complex diseases with multiple concurrent mechanisms. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale. Obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0025] Figure 1 This is a schematic diagram of a wearable, non-invasive, painless, wireless drug delivery FlexiStim patch for the treatment of erectile dysfunction, according to one embodiment of the present invention. Figure 2 This is a diagram showing the results of FlexiStim patch delivery of PGE1 in one embodiment of the present invention, which alleviates high glucose-induced smooth muscle and endothelial cell damage and improves cell function. Figure 3 This is a diagram showing the results of FlexiStim patch delivery of PGE1 promoting the repair of cavernous tissue and improving erectile function in DMED mice in one embodiment of the present invention. Figure 4 This is a diagram showing the results of FlexiStim patch delivery of PGE1 upregulating the expression of erectile function-related proteins in the corpus cavernosum tissue of DMED mice in one embodiment of the present invention. Figure 5 This is the result of downregulating the expression of genes and proteins related to fibrosis in the corpus cavernosum compared to FlexiStim-PGE1 and ICI-PGE1 in one embodiment of the present invention; Figure 6 This is a schematic diagram illustrating the fabrication process of the FlexiStim patch delivery module and the wireless power supply module in one embodiment of the present invention. Figure 7 This is a schematic diagram of the wireless transmission power supply module circuit and related modules of the FlexiStim patch in one embodiment of the present invention; Figure 8 This is a diagram showing the results of FlexiStim patch delivery of PGE1 in one embodiment of the present invention, which alleviates high glucose-induced smooth muscle and endothelial cell damage and improves cell function. Figure 9 This is a diagram showing the results of FlexiStim-PGE1 downregulating the expression of genes related to fibrosis in the corpus cavernosum compared to ICI-PGE1 in one embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] In this document, "and / or" includes any and all combinations of one or more of the listed related items.

[0028] In this article, "multiple" means two or more, that is, it includes two, three, four, five, etc.

[0029] As used in this specification, the term "about" typically means + / -5% of the value, more typically + / -4% of the value, more typically + / -3% of the value, more typically + / -2% of the value, even more typically + / -1% of the value, and even more typically + / -0.5% of the value.

[0030] In this specification, certain embodiments may be disclosed in a range-bound format. It should be understood that this "range-bound" description is merely for convenience and brevity and should not be construed as a rigid limitation on the disclosed range. Therefore, the description of a range should be considered as having specifically disclosed all possible subranges and the individual numerical values ​​within those ranges. For example, a description of the range 1-6 should be considered as having specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and the individual numbers within those ranges, such as 1, 2, 3, 4, 5, and 6. This rule applies regardless of the breadth of the range.

[0031] Detailed description of the attached images: Figure 1 (a) A comparison of traditional intracavernosal injection and FlexiStim patch and their respective effects on related signal pathways; (b) A schematic diagram of the layered structure of the device; (c) A schematic diagram of the layered structure of the wireless transmission power supply module; (d) A schematic diagram of the delivery module of the device; (e) Optical images of the delivery module under natural conditions and simulated application scenarios under bending and twisting conditions; (f) Finite element analysis stress / strain simulation results under the corresponding optical images; (g) Resistance change test of FlexiStim patch after 1000 bending at 180°; (h) A comparison of the performance of several commonly used treatment methods in terms of non-invasiveness, treatment effect, treatment time, duration of action, local adverse reactions, and systemic adverse reactions.

[0032] Figure 2 (a) Representative images of PGE1 FITC expression in smooth muscle cells from the normal control group, PGE1 treatment group, and FlexiStim patch group; (b) Representative images of AM / PI staining in smooth muscle cells from each experimental group (green: live cells; red: dead cells), scale bar 100µm; (c) Smooth muscle cell viability detected by CCK-8 assay (n=3); (d) Real-time monitoring of smooth muscle cell proliferation curves from 0-48 h in the normal control group, HG group, HG-PGE1 treatment group, and HG-FlexiStim group using the IncuCyte live cell imaging system (n=3); (e) Representative scatter plot of smooth muscle cell apoptosis detected by flow cytometry (Q1: necrotic cells; Q2: late apoptotic cells; Q3: early apoptotic cells; Q4: normal cells); (f) Statistical analysis of apoptosis rate of smooth muscle cells in each group (n=3); (g) Ca2+ expression of smooth muscle cells. 2+ Quantitative analysis of probe fluorescence intensity (n=3); (h) Schematic diagram of smooth muscle and endothelial cells damaged by hyperglycemia; (i) Representative immunofluorescence staining images of angiogenesis capacity of endothelial cells in each group (scale bar: 100 μm); (j) Quantitative analysis of angiogenesis capacity (n=3); (k) Quantitative analysis of eNOs probe fluorescence intensity of endothelial cells in each group (n=3). Statistical analysis: Data are expressed as mean ± standard error; n=3 independent experiments; one-way ANOVA was used for comparisons between groups.

[0033] Figure 3 (a) Schematic diagram of the establishment and treatment process of the DMED mouse model; (b) Physical display of PGE1 delivered by FlexiStim patch; (c) Distribution of FITC-labeled PGE1 in the control group, ICI treatment group and FlexiStim patch treatment group at 0 h, 3 h and 6 h using a small animal in vivo imaging system (green fluorescence); (d) Immunofluorescence staining images of penile cavernous tissue sections of mice in each group under a confocal microscope (blue: DAPI staining nuclei; green: FITC-labeled PGE1); (e) Representative images of penile erection state of mice in each group after electrical stimulation of cavernous nerves (scale bar: 5 mm). Experimental groups: normal control group (Control), DMED model group (DMED), DMED+ICI treatment group (DMED-ICI), and DMED+FlexiStim treatment group (DMED-FlexiStim); (f) Quantitative analysis of penile erection angle in mice after electrical stimulation (n=6); (g) Typical real-time change curves of intracavernosal pressure (ICP) in mice in each group under electrical stimulation; (h) Statistical analysis of maximum intracavernosal pressure (ICPmax) in mice in each group (n=6); Statistical analysis: Data are expressed as mean ± standard error (n=6); One-way ANOVA was used for comparisons between groups.

[0034] Figure 4 (a) Representative image of penile cavernous body endothelial cells stained with immunofluorescence double labeling (green: eNOS; red: vWF); scale bar: 30 μm; (b) (c) Quantitative analysis of SMA fluorescence intensity (n=6); (d) Representative images of smooth muscle cells from the corpus cavernosum tissue stained with immunofluorescence double labeling (green: α-SMA; red: Desmin). Scale bar: 30 μm; (e) Quantitative analysis of eNOS fluorescence intensity (n=6); (f) Quantitative analysis of vWF fluorescence intensity (n=6); (g) Western blot results of key erectile function proteins (eNOS, α-SMA); (h) Relative quantitative analysis of eNOS protein expression (n=6); (i) - Relative quantitative density of SMA (n=6); (j) Western blot results of PGE1 downstream signaling pathway proteins (EP2, PKA, CREB); (km) Relative quantitative analysis of EP2, PKA and CREB protein expression (as shown in the figure). -Tubulin was used as an internal reference, mean ± standard error, n=6); (n) Representative images of the corpus cavernosum tissue stained with Masson's trichrome (blue: collagen fibers; red: smooth muscle), overall structural scale bar: 500 μm; local magnified image scale bar: 50 μm; (o) Quantitative analysis of the smooth muscle / collagen ratio in the corpus cavernosum of each group to assess the degree of tissue fibrosis. Statistical analysis: All data are expressed as mean ± standard error (n=6); one-way ANOVA was used for comparisons between groups.

[0035] Figure 5(a) Schematic diagram of transcriptome sequencing analysis of corpus cavernosum tissue in each group; (b) Principal component analysis (PCA) of corpus cavernosum tissue in each group (closer distances indicate higher similarity between samples; the horizontal axis represents the first principal component, and the vertical axis represents the second principal component. Different colors indicate different groups). (c) Heatmap of differentially expressed genes in each group (the horizontal axis represents genes, each column represents one sample; red indicates highly expressed genes, and blue indicates low-expressed genes). (d) Volcano plot of differentially expressed genes between the DMED-ICI and DMED-FlexiStim groups (x-axis: log2FC (DMED-ICI VS DMED-FlexiStim), y-axis: -log10 (pvalue). The two dashed lines represent 2-fold difference in expression; the horizontal dashed line represents the pvalue 0.05. Red dots indicate upregulated genes, blue dots indicate downregulated genes, and gray dots indicate genes with no significant differential expression. (e) GO functional enrichment analysis of upregulated genes in the DMED-ICI group (top 5, bp, biological process, cc, cellular component, MF, molecular function); (f) GSEA enrichment analysis of the upregulated TGF-β signaling pathway in the DMED-ICI group; (g) Representative immunohistochemical staining images of Col1a1, Col3a1, and TGF-β in corpus cavernosum tissue (brown: positive signal); scale bar: 100. μm; (hj) Quantitative analysis of the proportion of immunohistochemically positive regions (n=6); (k) Western blot results of fibrosis-related proteins (Col1a1, Col3a1, TGF-β, MMP2, Smad5); (lp) Relative quantitative analysis of protein expression (with α-Tubulin as an internal reference, n=6); Statistical analysis: All data are expressed as mean ± standard error (n=6); One-way ANOVA was used for intergroup comparisons.

[0036] Figure 6 Electrical delivery module: The designed pattern is transferred to Eco-Flex by photolithography, and a layer of silver is covered on the microelectrode area by magnetron sputtering. Then the non-electrode area is cleaned to form a microelectrode array. Wireless transmission power supply module: The three-layer composite sheet formed by PET with copper foil on both sides is cut into a circle and deep holes are drilled by laser. Then, copper is filled into the deep holes by electroplating. The copper foil is used to form coils and stimulation electrodes by wet etching technology.

[0037] Figure 7 (a) Hardware components of a radio stimulation device; (b) Schematic diagram of the top and bottom layers of a flexible printed circuit board (FPCB) for radio stimulation; (c) Voltage waveforms acting on tissues under different spacings of transmitting and receiving coils; (d) Variations in stimulation voltage amplitude under different coil spacings.

[0038] Figure 8 (a) Representative images of PGE1 FITC expression in endothelial cells of the normal control group, PGE1 treatment group, and FlexiStim patch group; (b) Quantitative analysis of AM / PI staining fluorescence intensity in smooth muscle cells (n=3); (c) Representative scatter plots of endothelial cell apoptosis detected by flow cytometry in the normal control group, PGE1 treatment group, and FlexiStim patch group; (d) Ca2+ expression in smooth muscle cells of the normal control group, HG group, HG-PGE1 treatment group, and HG-FlexiStim group. 2+ Representative images of probe staining; (e) flow cytometry analysis of ROS probe fluorescence intensity in each group; (f) representative images of endothelial cell scratch assay in each group (scale bar: 100 μm); (g) quantitative analysis of endothelial cell scratch assay in each group (n=3); (h) quantitative analysis of eNOs probe fluorescence intensity in endothelial cells in each group (n=3); (i) quantitative analysis of NO levels in endothelial cells in each group (n=3). Statistical analysis: data are expressed as mean ± standard error; n=3 independent experiments; one-way ANOVA was used for comparisons between groups.

[0039] Figure 9 (a) Venn diagram showing the differentially expressed genes and their intersections between each group; (b) Heatmap of fibrosis-related genes (genes are represented horizontally, each column is a sample, red indicates high-expression genes, and blue indicates low-expression genes); (c) Heatmap of inflammation-related genes (genes are represented horizontally, each column is a sample, red indicates high-expression genes, and blue indicates low-expression genes).

[0040] Example 1 This embodiment provides the design and working principle of a non-invasive flexible electrical stimulation patch (hereinafter referred to as FlexiStim patch), such as... Figure 1 As shown.

[0041] Unlike the commonly used intracavernosal injection therapy, FlexiStim patches not only promote erectile function recovery by activating the EP2 / PKA / CREB pathway, but also inhibit the TGF-β1 / Smad signaling pathway, thereby significantly reducing the progression of fibrosis caused by physical acupuncture of the corpora cavernosa (e.g., Figure 1 (as shown in a). The FlexiStim patch consists of two functional modules: (1) an electrostimulation drug delivery module and (2) a wireless power supply module for providing electrotransfection. Figure 1b). The delivery module comprises a four-layer structure. From the perspective of the structure in contact with the target organ's skin, the outermost layer is a biodegradable plastic (Ecoflex) layer, serving as a flexible substrate and device encapsulation, which can extend the lifespan of the FlexiStim patch; the second layer is a microelectrode array layer, comprising multiple uniformly shaped, regularly arranged microelectrode sheets connected by serpentine electrode wires made of silver, each serpentine electrode wire having at least two S-shaped structures; each microelectrode sheet has at least two serpentine electrode wires (the microelectrode array layer is a composite material: Cr / Ag / Cr, thickness: 5 μm / 150 μm / 5 μm, with Cr as an adhesion layer); the third layer is GelMA-chitosan hydrogel (100 The numerous hydrogen bonds formed between the hydroxyl and amino groups of chitosan and the ester groups of Ecoflex (22 μm thick) ensure sufficient toughness at the hydrogel-Ecoflex interface, preventing the inherent adhesive failure of FlexiStim. Its porous structure serves as a medium for storing payloads, such as prostaglandins (PGE1), in liquid form. In this embodiment, the GelMA-chitosan hydrogel is prepared by mixing 15% GelMA (methacrylamide gelatin, replacing 55%-65%) and 1.5% chitosan (200-600 mPa·s) at a 3:1 mass ratio. The innermost layer is a thin polycarbonate film (22 μm thick) with nanopores (800 nm in diameter) that can directly contact the target organ. These nanopores enhance the external electric field in the nanopore-tissue juxtaposition configuration, thereby achieving efficient, safe, and controllable drug delivery.

[0042] The wireless power supply module is connected to one side of the silver microelectrode array and consists of an antenna coil and a rectifier circuit. Figure 1 c). The inductive coupling between the transmitting and receiving coils allows the modulated and amplified signal from the transmitting end to be converted into a pulse voltage at the receiving end. Figure 7 The electrical pulses generated between the working electrodes can be adjusted via a rectifier circuit, according to the requirements of in vitro or in vivo delivery, to provide specific amplitude (e.g., 17V), frequency (e.g., 10 Hz), and duration (e.g., 5 ms). Figure 7 With a built-in Zener diode for voltage regulation, and adjustment of the transmitter input power, the output voltage can be maintained at a predetermined level under various conditions that may attenuate radio frequency (RF) power transmission, such as device bending and increased distance between transmitter and receiver antennas. During treatment, the FlexiStim patch delivers PGE1 percutaneously, painlessly, and uniformly into the corpus cavernosum by applying a pulsed electric field. Figure 1d). The entire FlexiStim patch is made of a soft material with a thin geometry, which allows it to achieve a flexible, non-irritating, and close contact with the skin through a principle similar to that of epidermal electronics.

[0043] The strain / stress distribution simulates the deformation of the FlexiStim patch on the organ (penis) surface under different mechanical deformations, as shown by the finite element analysis (FEA) results corresponding to the optical images of representative devices. Figure 1 e, f). The maximum principal strain in the metal wire does not exceed 3%. Note that the strain in most trace regions is much lower (<0.5%) compared to the maximum strain. The FlexiStim patch can also withstand extreme deformation and has high mechanical durability. The ΔR / R of the FlexiStim patch remains constant after approximately 1000 bending cycles. Figure 1 g).

[0044] To further illustrate the main advantages of the FlexiStim patch, this experiment compared several existing treatment methods: Intracavernosal injection (ICI), Oral PDE5 inhibitors, and Li-ESWT (low-intensity extracorporeal shock wave therapy). In the comparison of performance in terms of non-invasiveness, efficacy, onset time, duration of action, local adverse reactions, and systemic adverse reactions, the FlexiStim patch of this invention showed superiority. Figure 1 h).

[0045] This embodiment also provides a specific example of a method for preparing a FlexiStim patch (see manufacturing details). Figure 6 ).

[0046] Fabrication of the wireless power supply module: The wireless power supply module is manufactured using flexible printed circuit (FPC) technology on a transparent polyethylene terephthalate (PET) film (100 μm thick). A double-sided copper-clad PET film (12 μm thick copper) is fabricated with receiving coils (6 turns) and two serpentine wires (15 mm long) on ​​each side. The ends of the serpentine wires are connected to a pair of square electrodes for applying pulsed electrical stimulation via a drug delivery device. Gold plating (200 nm thickness; magnetron sputtering, TRP450) is applied to these square electrodes. Specifically, the copper-clad PET substrate film is first cleaned with deionized water and ethanol. The substrate film is then cut into the shape of the wireless power supply module, and through-holes (100 μm diameter) are formed using laser drilling. Copper foil on both sides is connected via through-hole copper plating. Subsequently, the substrate film is laminated by heated roll pressing, exposed to ultraviolet light, and treated with a developer (sodium carbonate). The bare copper foil on the PET is etched into coils and serpentine stimulation electrodes using APS 100 copper etching solution. The remaining dry film was stripped using an alkaline solution (such as NaOH). Finally, holes were laser-drilled in the pad mask layer (i.e., the cover film) to ensure exposed surfaces for adding electronic components and outputting pulsed voltages via stimulation electrodes. The cover film (12.5 μm thick) was then thermo-pressed onto the double-sided patterned circuit as an insulating layer. Two Schottky diodes (NSR02301MX4T5G), one Zener diode (GRM022D80G104ME15L), and three capacitors (180 pF, 4 pF, 0.1 uF) were added to the circuit using silver paste for final use.

[0047] Preparation of the drug delivery module: First, the A and B phases of the Eco-flex material were weighed and mixed in a 1:1 mass ratio. After thorough stirring until homogeneous, the mixture was spin-coated onto a clean glass substrate at 4600 rpm to form a wet film approximately 20 μm thick. The film was then cured on an 80°C hot stage for 30 minutes. Next, photoresist was spin-coated onto the cured Eco-flex substrate at 1000 rpm and soft-baked at 90°C for 1 minute. Then, UV exposure was performed through a pre-designed mask to pattern the photoresist. After exposure, the sample was immersed in developer for 20 seconds, rinsed with deionized water, and dried with nitrogen. Subsequently, the sample was placed in a magnetron sputtering instrument. After evacuating to the base pressure, argon gas was introduced at a flow rate of 30 sccm to maintain a working pressure of 0.5 Pa. Silver target sputtering was performed with a sputtering voltage of 120 V while the substrate rotated at 5 rpm for 3 minutes. After sputtering, the sample is removed from the chamber, and the silver-plated Eco-flex film is gently peeled off from the glass plate. It is then immersed in a resist remover and subjected to 40 W ultrasonic treatment for 20 minutes to remove the photoresist and silver film covering the non-electrode areas, ultimately forming a precise silver electrode pattern on the Eco-flex surface. Furthermore, a drug-containing hydrogel and nanoporous membrane are coated on top. After electrode fabrication, the electrodes are cleaned with deionized water and dried with nitrogen, ready for electrical connection to the wireless power supply module and assembly into a complete device.

[0048] Example 2 Flexible electrical stimulation patch for in vitro drug delivery After the wireless power supply module is activated, the FlexiStim patch delivers its contained drug to cells. To evaluate the ability of the FlexiStim patch to deliver the FITC-labeled PGE1 to smooth muscle cells (SMCs) and endothelial cells (ECs), the intracellular FITC fluorescence intensity was measured. FITC Similar to the negative control group, the direct treatment group showed almost no detectable fluorescence within cells; while FlexiStim-PGE1... FITC The treatment group exhibited significant green fluorescence in both cell types, confirming that the FlexiStim patch successfully delivered FITC-labeled PGE1 intracellularly. Figure 2 a). Further, SMCs were stained for live / dead cells using calcein-AM (green-labeled live cells) and propidium iodide (PI, red-labeled dead cells). Confocal microscopy imaging showed that both the PGE1 direct treatment group and the FlexiStim-PGE1 treatment group maintained normal SMC morphology, comparable to the control group, mainly characterized by very little PI signal, thus demonstrating the high safety of the FlexiStim-PGE1 treatment group. Figure 2b). Furthermore, the cytotoxic effect of FlexiStim-PGE1 was quantitatively assessed using the Cell Counting Kit-8 (CCK-8) method. Statistical analysis showed that FlexiStim did not exhibit significant cytotoxicity to SMCs compared to the control group (p>0.05). Figure 2 c), further confirming its biocompatibility. Furthermore, flow cytometry was used to further evaluate the toxicity of FlexiStim to endothelial cells (ECs), and the results showed that it did not produce significant toxic effects on ECs. Figure 8 c).

[0049] Establishment of a high glucose (HG) cell model: Cells were placed in normal glucose (NG) at 7 mmol / L and high glucose (HG) at 32 mmol / L, respectively, and incubated at 37°C for 48 h. Incubation in high glucose medium simulated diabetic cell damage.

[0050] Real-time proliferation analysis using the Incucyte live cell analysis system showed that, compared with the high glucose (HG) group, both direct PGE1 treatment and FlexiStim-PGE1 treatment significantly promoted SMC proliferation. Figure 2 d). Further analysis using Annexin V / PI double staining flow cytometry revealed that the apoptosis rate of smooth muscle cells in the high glucose group was significantly higher than that in the other three groups (p<0.05), while the apoptosis rates of PGE1 and FlexiStim-PGE1 treatment groups under high glucose conditions were significantly lower than those in the high glucose group (p<0.05). Figure 2 ef). Further analysis of intracellular Ca²⁺ in smooth muscle cells was performed. + Concentration. The results showed that the Ca²⁺ concentration in the high-sugar group was higher. + Levels were significantly elevated (p<0.05 compared to the control group); while direct PGE1 treatment and FlexiStim-PGE1 treatment significantly reduced Ca²⁺ levels. + Level (p<0.05 compared to the high glucose group) Figure 2 g, Figure 8 d).

[0051] In a high-glucose environment, the formation of capillary-like structures was significantly reduced compared to the NG group, while both PGE1 and FlexiStim-PGE1 treatments could restore these angiogenesis-related parameters to near-normal levels. Figure 2 ik). Scratch assay results indicate that high glucose conditions also impair the migration ability of endothelial cells (IK). Figure 8f,g), and FlexiStim-PGE1 treatment significantly alleviated this high glucose-induced migration inhibition. Further flow cytometry analysis of ROS fluorescent probe intensity showed that endothelial cell ROS expression levels were significantly increased in the HG-treated group, and both PGE1 and FlexiStim-PGE1 treatments alleviated this change, with FlexiStim-PGE1 treatment showing significantly better efficacy. Figure 8 e). Further analysis of the expression levels of eNOS and nitrite (NaNO2, a stable metabolite of NO) in ECs revealed that the fluorescence intensity of DAF-FM DA was significantly reduced in ECs treated with high glucose. Figure 2 j, p<0.05; In addition, high glucose significantly inhibited NaNO2 production in ECs (p<0.05 compared with the control group), while PGE1 and FlexiStim-PGE1 treatment could restore these key factors to near normal levels (j, p<0.05); Figure 8 i).

[0052] Example 3 A mouse model was established by treating mice with FlexiStim patches. Before model induction, there were no significant differences in body weight and fasting blood glucose among the groups. Seven-week-old male c57BL / 6J mice were purchased, acclimatized for one week, and marked. Their fasting blood glucose was measured. Before modeling, the mice were fasted for 16 hours. A 1% solution of streptozotocin (STZ) was prepared using citrate buffer (prepared immediately) and injected intraperitoneally at a dose of 120 mg / kg (i.e., 12 mL / kg). After injection, the mice were observed for 30 minutes, and then given sufficient food and a 10% sucrose solution once (to prevent death from hypoglycemia in mice that had just been injected with STZ). Blood samples were collected from the tail at 24 h, 72 h, and 1 week after intraperitoneal injection to measure body weight and random blood glucose. If all three blood glucose levels were above 16.7 mmol / L and accompanied by the "three highs and one low" symptoms (polyuria, polydipsia, polyphagia, and weight loss), the mouse diabetic model was considered successfully established and the mice were included in the experiment. Mice with uncontrolled blood glucose levels were excluded from the experiment.

[0053] (2) The control group mice were injected intraperitoneally with the corresponding volume of citrate buffer and fed with normal feed.

[0054] (3) Screening of DMED mice using the APO test: After the successful establishment of the diabetic mouse model, ED mice were screened by subcutaneous injection of apomorphine (100 μg / kg) and included in the experiment. Erection was observed within 30 minutes after apomorphine injection in the control group; no erection was observed within 30 minutes after apomorphine injection in the diabetic group. Twenty-eight days after successful modeling, fasting blood glucose levels in the modeling groups (DMED group, DMED-PGE1 group, and DMED-FlexiStim group) were significantly increased (p<0.05), accompanied by a decrease in body weight. The trend of blood glucose index changes persisted after 28 days of treatment with PGE1 and FlexiStim.

[0055] FlexiStim-PGE1 promotes the repair of cavernous tissue and improves erectile function. In vivo imaging results in small animals showed that FITC-labeled PGE1 was significantly retained in penile tissue at 0, 3, and 6 hours after radio stimulation, with effects similar to those of ICI. Figure 3 c). Furthermore, immunofluorescence analysis showed that FITC-labeled PGE1 was successfully delivered to the mouse corpus cavernosum tissue after transdermal administration of FlexiStim. FlexiStim-mediated transdermal delivery resulted in uniform distribution of FITC-labeled PGE1 throughout the corpus cavernosum tissue. In contrast, after ICI injection, FITC-labeled PGE1 was mainly distributed at the injection site, with fluorescence intensity gradually decreasing outwards. This demonstrates that transdermal administration via the FlexiStim patch can deliver drugs more uniformly into the target organ. Figure 3 d). Furthermore, the safety of FlexiStim was assessed one month after in vivo delivery. Hematoxylin-eosin (H&E) histological staining of major organs, including the heart, liver, spleen, lungs, and kidneys, showed no significant pathological changes in the FlexiStim-PGE1 group.

[0056] Further evaluation was conducted on their therapeutic potential for corpus cavernosum tissue repair in a DMED mouse model. Results showed that both DMED-ICI and DMED-FlexiStim administration significantly increased the erectile angle compared to the DMED group (both P < 0.05), reaching values ​​similar to the healthy control group. However, the erectile angle in the DMED-FlexiStim administration group was closer to that of the healthy control group. Figure 3 Furthermore, erectile function tests showed that, compared with the control group, the erectile function of mice in the DMED group was significantly impaired (P<0.05). Both ICI and FlexiStim treatments significantly increased ICPmax in DMED mice (ef). Figure 3 gh), and there was no statistically significant difference between the two treatment methods (P>0.05).

[0057] Immunofluorescence staining results showed that the expression levels of α-SMA and Desmin were significantly decreased in the DMED group (p<0.001), while the expression levels of α-SMA and Desmin were significantly increased in the DMED-ICI and DMED-FlexiStim groups, approaching the control group levels. Figure 4 ac). With DMED group (eNOS) + Compared to the DMED group (where cell counts were significantly reduced), both the DMED-ICI and DMED-FlexiStim groups showed significant upregulation of eNOS, reaching near-normal levels. Notably, compared to the DMED group, FlexiStim treatment showed a significant increase in the fluorescence intensity of eNOS and vWF (p<0.001). Figure 4 df). Furthermore, Western blot analysis showed that, compared to the DMED group, the protein expression of eNOS and α-SMA in the corpora cavernosa of both the DMED-ICI and DMED-FlexiStim groups was significantly increased. Figure 4 These results indicate that, compared to the DMED group, FlexiStim treatment restored the expression of smooth muscle markers α-smooth muscle actin (α-SMA) and desmin to near-healthy levels, with distribution and fluorescence intensity comparable to ICI treatment, suggesting that FlexiStim treatment can effectively improve corpus cavernosum smooth muscle damage. Regarding endothelial markers, FlexiStim treatment significantly increased eNOS expression, and the fluorescence intensity of vWF was approximately 1.34 times greater than in the DMED group, indicating that this drug delivery system can partially reverse endothelial dysfunction caused by hyperglycemia and promote angiogenesis and endothelial activity recovery.

[0058] Furthermore, Western blot analysis showed that, compared with the DMED group, the protein expression of EP2, PKA, and CREB in the corpus cavernosum of both the ICI-PGE1 group and the FlexiStim-PGE1 group was significantly increased, suggesting that ICI and FlexiStim treatment may improve erectile function in DMED mice through the EP2 / PKA / CREB pathway. Figure 4 jm).

[0059] The degree of corpus cavernosum fibrosis was assessed. Results showed that, compared to the control group, the smooth muscle (red) / collagen (blue) ratio was significantly lower in the DMED group (P<0.05), indicating that corpus cavernosum fibrosis was more severe in the DMED group. Compared to the DMED group, there was no statistically significant difference in the smooth muscle (red) / collagen (blue) ratio in the DMED-ICI group; however, the smooth muscle (red) / collagen (blue) ratio was significantly higher in the DMED-FlexiStim treatment group. Figure 4 no).

[0060] Further, transcriptome sequencing and analysis were performed on the corpus cavernosum tissue of mice from the DMED, DMED-ICI, and DMED-FlexiStim groups. Figure 5 a). First, principal component analysis was performed on the three groups of samples, and significant cluster differences were found among the three groups ( Figure 5 b); Differential gene analysis results showed that there were 2608 differentially expressed genes between the DMED-ICI group and the DMED-FlexiStim group, 351 differentially expressed genes between the DMED-FlexiStim group and the DMED group, and 2685 differentially expressed genes between the DMED-ICI group and the DMED group. Figure 9 a). Further cluster analysis of differentially expressed genes revealed significant differences in gene expression among the groups; compared with the DMED group and the DMED-FlexiStim group, the DMED-ICI group showed significantly upregulated fibrosis and inflammation-related genes, indicating that local injection is more likely to cause inflammation and tissue fibrosis. Figure 9 a,b).

[0061] To further clarify the differences in treatment efficacy between ICI-PGE1 and FlexiStim-PGE1, this study analyzed differentially expressed genes between the DMED-ICI and DMED-FlexiStim groups. The results showed that ICI-PGE1 treatment upregulated fibrosis-related genes such as MMP2, Col1a1, Col3a1, MMP9, Timp1, and Tgfbβ1. Figure 5 d). GO functional enrichment analysis showed that, compared to the ICI-PGE1 group, the genes downregulated by FlexiStim-PGE1 treatment were enriched in functional categories such as "collagen fibril organization" and "inflammatory response." Furthermore, KEGG pathway enrichment analysis revealed the "TGF-beta signaling pathway" (transforming growth factor-β signaling pathway). Figure 5 f) Pathways closely related to fibrosis and inflammation, such as the "TNF signaling pathway," were activated in the DMED-ICI group.

[0062] Immunohistochemical analysis showed that, compared with the Control group, the expression of COL1A1 and TGF-β in the corpus cavernosum tissue of the DMED group was increased, but the difference was not statistically significant. The expression of COL1A1 was significantly increased in the ICI-PGE1 group, while there was no significant difference between the FlexiStim-PGE1 group and the Control group. Meanwhile, the protein expression of COL3A1 increased in the DMED group, and the difference was statistically significant; the protein expression of COL3A1 was significantly increased in the ICI-PGE1 group, while there was no statistically significant difference between the FlexiStim-PGE1 group and the Control group. Furthermore, Western blot results also showed that, compared with the Control group, the protein expression of COL3A1, COL1A1, MMP2, TGF-β1, and SMAD5 increased in the DMED group, and the difference was statistically significant. In addition, compared with the Control group, the protein expression of COL3A1, COL1A1, MMP2, TGF-β1, and SMAD5 in the corpus cavernosum tissue of the ICI-PGE1 group was significantly increased. The expression of the above indicators in the DMED-FlexiStim group was significantly lower than that in the DMED-ICI group, and was closer to that in the Control group.

[0063] The combined results of transcriptomic and protein level experiments suggest that diabetic erectile dysfunction causes tissue fibrosis, and intracavernosal injection of PGE1 exacerbates the degree of fibrosis, possibly due to the activation of the TGF-β1 / SMAD pathway. Compared with the ICI-PGE1 group, the activity of this pathway was significantly downregulated in the FlexiStim-PGE1 group, which is the key reason why FlexiStim-PGE1 has a better therapeutic effect.

[0064] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0065] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A non-invasive flexible electrical stimulation patch, characterized in that, The non-invasive flexible electrical stimulation patch includes: (1) an electrical stimulation drug delivery module and (2) a wireless transmission power supply module; The electrostimulation drug delivery module is composed of a substrate layer, a microelectrode array layer, a gel layer, and a nanoporous membrane layer. The base layer is a biodegradable flexible material used for support and encapsulation; The microelectrode array layer is composed of multiple layers of electrodes. The microelectrode array layer includes multiple microelectrode sheets with the same shape and arranged regularly. The microelectrode sheets are connected by serpentine electrode lines. The serpentine electrode lines have at least two S-shaped structures. Each microelectrode sheet has at least two serpentine electrode lines. The gel layer comprises a viscous gel matrix with hydroxyl and / or amino groups and a drug to be delivered electrically; the microelectrode array layer is embedded in the gel layer; The nanoporous membrane layer is made of an ester group that can form hydrogen bonds with the hydroxyl or amino groups of the gel matrix; the nanoporous membrane layer has a thickness of 10-50 μm and a pore size structure of 500-1000 nm on its surface. The wireless transmission power supply module is connected to the microelectrode array layer via leads to supply power to the electrostimulation drug delivery module.

2. The non-invasive flexible electrical stimulation patch as described in claim 1, characterized in that, The serpentine electrode wire is made of silver; or, the lead wire is made of silver.

3. The non-invasive flexible electrical stimulation patch as described in claim 1, characterized in that, The microelectrode array layer is composed of Cr-Ag-Cr composite; the thickness of the Ag layer is 15 to 30 times the total thickness of the Cr layer.

4. The non-invasive flexible electrical stimulation patch as described in claim 1, characterized in that, The shape of the microelectrode sheet includes triangle, quadrilateral, polygon, or circle.

5. The non-invasive flexible electrical stimulation patch as described in claim 1, characterized in that, The material of the gel matrix includes GelMA-chitosan, which is a complex of methacrylamide gelatin and chitosan; or, the material of the nanoporous membrane layer includes polycarbonate membrane or polyethylene terephthalate.

6. The non-invasive flexible electrical stimulation patch as described in claim 1, characterized in that, The drug to be delivered electrically includes drugs for treating erectile dysfunction.

7. The non-invasive flexible electrical stimulation patch as described in claim 6, characterized in that, The nanopore size of the nanoporous membrane is in the range of 600-800 μm.

8. The non-invasive flexible electrical stimulation patch as described in claim 1, characterized in that, The wireless transmission power supply module includes a coil antenna and a rectification and regulation circuit block.

9. The non-invasive flexible electrical stimulation patch as described in claim 8, characterized in that, The wireless transmission power supply module further includes a flexible packaging structure; or, the rectification and regulation circuit adopts an NFC receiver structure, including a rectification module, a voltage regulator module, and an energy storage capacitor.

10. The method for preparing the non-invasive flexible electrical stimulation patch according to any one of claims 1-9, characterized in that, Includes the following steps: S110: Fabrication of an electrically stimulated drug delivery module; S111: A biodegradable flexible material is coated onto a clean substrate to form a wet film, which is then cured at high temperature; S112: Coat the cured flexible material with photoresist and dry it appropriately; S113: Ultraviolet exposure is performed using a pre-designed mask to pattern the photoresist, followed by nitrogen drying; S114: Place the sample treated in S113 into a magnetron sputtering instrument, evacuate to the base pressure, then introduce argon gas to maintain the working pressure at 0.5 Pa. Apply a sputtering voltage of 120 V to sputter the silver target while the substrate is rotating. S115: After sputtering is completed, the sample is removed from the chamber, the silver-plated flexible material film is peeled off from the substrate, and then a drug-containing hydrogel and nanoporous membrane are coated on it. S120: A wireless transmission power supply module is fabricated on transparent polyethylene terephthalate using flexible printed circuit technology; S130: Assemble the electrostimulation drug delivery module and the wireless transmission power supply module to form the non-invasive flexible electrostimulation patch.

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