A self-powered electrostimulator wound dressing and methods of making and using the same

Abstract

The self-powered electric stimulator wound dressing, preparation method and application thereof disclosed by the application relate to the technical field of medical materials, solve the technical problem of slow recovery of existing composite wound recovery, and adopt the scheme of providing a self-powered electric stimulator wound dressing, which comprises: from bottom to top, a sodium alginate hydrogel, a polyvinylidene fluoride electrospun film, a silica gel ring, and an ethyl cellulose electrospun film loaded with nano-silver are stacked in sequence; the self-powered electric stimulator wound dressing can convert the deformation generated by the oral cavity during pronunciation, mastication and movement of the maxillofacial part into a voltage, and output the voltage to the skin of the oral cavity, and the output voltage range is between 150 mV and 210 mV. The scheme does not need an external power supply, and can realize self-power supply through maxillofacial movement, thereby solving the portability problem of traditional electric stimulation devices; the scheme is multifunctional, can provide electric stimulation, and can also maintain a moist environment on a wound surface through a barrier effect.

Description

Technical Field

[0001] This invention relates to the field of medical materials technology, and in particular to a self-powered electrical stimulator wound dressing, its preparation method, and its application. Background Technology

[0002] Combined radiation and wound injury (CRWI) refers to a combination of radiation damage and trauma, which typically occurs in patients undergoing nuclear explosions, nuclear accidents, radiological terrorist attacks, and clinical surgery and radiotherapy.

[0003] Radiation-induced combined injuries, a special type of trauma, often occur in extreme scenarios such as nuclear accidents, nuclear attacks, and radiological terrorist attacks. A review of the cases of victims after the Hiroshima atomic bombing reveals that approximately 65% ​​of radiation victims also suffered from traumatic injuries. The unique characteristic of this type of injury is the synergistic effect between radiation damage and mechanical trauma. This effect significantly delays wound healing and greatly increases the probability of complications. Clinical observations show that the wound healing time for these patients is 2-3 times longer than that of patients with ordinary trauma, the risk of infection is increased by more than 50%, and they often experience systemic complications such as hematopoietic dysfunction and immunosuppression. It is important to note that even if the wound eventually heals, the quality of the scar and the functional recovery are significantly worse than those of patients with ordinary trauma, which can have serious adverse effects on the patient's long-term quality of life and social functioning.

[0004] Therefore, the most prominent characteristic of combined radiation and wound injury is that, in addition to the presence of traumatic factors, the wound surface is also affected by radiation, significantly aggravating the injury and ultimately resulting in delayed wound healing. Compared to simple skin trauma, the wound healing process of CRWI is more complex and takes longer.

[0005] Therefore, CRWI has become a key and challenging issue in current trauma medicine research, with the hope of developing a medical material to address the shortcomings of existing technologies. Summary of the Invention

[0006] To address the technical problem of slow recovery of complex wounds in existing technologies, the purpose of this invention is to provide a triboelectric piezoelectric nano-dressing, its preparation method, and its application.

[0007] To address the aforementioned technical problems, in a first aspect, according to some embodiments, the present invention provides a self-powered electrical stimulator wound dressing, the dressing comprising:

[0008] The layers are stacked sequentially from bottom to top: sodium alginate hydrogel, polyvinylidene fluoride electrospun film, silicone gasket, and ethyl cellulose electrospun film loaded with silver nanoparticles.

[0009] The sodium alginate hydrogel is doped with polydopamine, and the sodium alginate hydrogel adheres closely to the surface of the oral skin; the addition of polydopamine is to increase the adhesion between the hydrogel electrode and the wound.

[0010] The self-powered electrical stimulator wound dressing is used when the oral cavity is in the maxillofacial movement of speech, chewing and movement. The dressing converts the deformation generated by the oral cavity movement into voltage and outputs it to the oral skin. The output voltage range is between 150mV and 210mV.

[0011] The oral cavity skin surface has radio-induced combined injuries.

[0012] Optionally, as one embodiment, the thickness ratio of the polyvinylidene fluoride electrospun film to the ethyl cellulose electrospun film loaded with silver nanoparticles is between 4:1 and 1:1.

[0013] Optionally, as one embodiment, the thickness ratio of the polyvinylidene fluoride electrospun film to the ethyl cellulose electrospun film loaded with silver nanoparticles is 3:1.

[0014] Optionally, as one embodiment, the thickness of the ethyl cellulose electrospun film loaded with silver nanoparticles is 600 μm-900 μm.

[0015] Optionally, as one embodiment, the thickness of the polyvinylidene fluoride electrospun film is from 800 μm to 2500 μm.

[0016] Optionally, as one embodiment, the residual polarization intensity of the dressing is less than 0.01370 C / m. 2 ;

[0017] The residual polarization intensity is the polarization intensity of the hysteresis loop when the external electric field is 0.

[0018] Optionally, as one embodiment, the tangent of the dielectric loss angle of the dressing is not greater than 0.005.

[0019] Optionally, as one embodiment, the absolute value of the surface potential of the ethyl cellulose electrospun film loaded with silver nanoparticles is not less than 750mV.

[0020] In a second aspect, embodiments of the present invention provide a method for preparing a self-powered electrical stimulator wound dressing, used in any of the methods described in the first aspect above, wherein the polyvinylidene fluoride electrospun film is prepared by the following method:

[0021] Preparation of the first electrospinning solution: Weigh a certain amount of polyvinylidene fluoride nanofiber powder, add N,N-dimethylformamide, and stir with a magnetic stirrer at 1000 rpm for 6 hours under a 70℃ water bath. After standing to room temperature, add acetone and continue stirring with a magnetic stirrer at 1000 rpm for 4 hours at room temperature to obtain an electrospinning solution with a mass fraction of 11%-13%. Let stand for 24 hours to eliminate bubbles and store under light-protected conditions.

[0022] Preparation of polyvinylidene fluoride electrospun film: The prepared first electrospinning solution is transferred into a special syringe and assembled with the electrospinning system by a micro-injection pump; the spinning nozzle is connected to a positive high voltage power supply, the receiving device is a roller collector covered with aluminum foil, the distance between the nozzle and the collector is 230-270 mm, the spinning solution propulsion rate is 1.0-1.3, and the single spinning cycle lasts at least 2.8 hours and no more than 3.5 hours;

[0023] Post-processing of electrospun nanofilms: The collected polyvinylidene fluoride electrospun films were peeled off from the surface of the roller and placed in a vacuum drying oven for heat treatment to obtain polyvinylidene fluoride electrospun films.

[0024] And / or,

[0025] The ethyl cellulose electrospun film loaded with silver nanoparticles was prepared by the following method:

[0026] Preparation of the second electrospinning solution: Take a certain mass of ethyl cellulose electrospinning film powder loaded with silver nanoparticles, add N,N-dimethylformamide, stir at 1000 rpm for 4 hours at room temperature using a magnetic stirrer, add acetone, and continue stirring at 1000 rpm for 2 hours at room temperature to obtain an ethyl cellulose solution with a mass fraction of 25%. Add silver nanoparticles to the solution, disperse by ultrasonication, and continue stirring at 1000 rpm for 2 hours at room temperature to obtain the electrospinning solution of ethyl cellulose electrospinning film loaded with silver nanoparticles. Let stand for 24 hours to eliminate bubbles and store under light-protected conditions.

[0027] Preparation of ethyl cellulose electrospun nanofilm loaded with silver nanoparticles: The prepared second spinning solution was transferred into a special syringe and assembled with an electrospinning system by a micro-injection pump. The assembly included: a stainless steel needle as a spinning nozzle, which was connected to a positive high voltage power supply; a receiving device was a roller collector with an aluminum foil coating and a rotation speed of 700-1000 rpm; the distance between the spinning nozzle and the collector was 150 mm; the transmitting voltage was 27 kV; the receiving voltage was -2 kV; the spinning solution propulsion rate was 2 mL / h; and the single spinning cycle lasted for 2 hours.

[0028] Post-processing of the silver-loaded ethyl cellulose electrospun film: The collected silver-loaded ethyl cellulose electrospun film was peeled off from the surface of the roller and placed in a vacuum drying oven for heat treatment; the non-uniform area around the obtained film was removed to obtain the ethyl cellulose nanofilm.

[0029] Thirdly, embodiments of the present invention provide a self-powered electrical stimulator wound dressing according to any one of the first aspects above, and / or the self-powered electrical stimulator wound dressing obtained based on the preparation method of the second aspect above, for use in wound repair materials and medical materials.

[0030] Fourthly, according to embodiments of the present invention, a self-powered electrical stimulator wound dressing according to any one of the first aspects described above, and / or the self-powered electrical stimulator wound dressing obtained based on the preparation method of the second aspect described above, is used in skin repair or radiation-induced complex wounds.

[0031] The above-described technical solution of the present invention has at least the following beneficial technical effects:

[0032] This application combines triboelectric generation and piezoelectric effects to construct a highly efficient triboelectric-piezoelectric composite nanogenerator as a wound dressing for a self-powered electrical stimulator. The dressing consists of, from bottom to top, layers of sodium alginate hydrogel, polyvinylidene fluoride electrospun film, silicone gasket, and ethyl cellulose electrospun film loaded with silver nanoparticles. The sodium alginate hydrogel adheres tightly to the oral skin surface. During oral movements such as pronunciation, chewing, and facial motor activity, the dressing converts the deformation generated by these movements into voltage, which is then output to the oral skin. This wound dressing can accelerate the healing of skin with combined radioactive and non-radioactive wounds. The ethyl cellulose electrospun film loaded with silver nanoparticles serves as the positive electrode of the triboelectric layer. The excellent film-forming properties, biocompatibility, and easy electron loss of the ethyl cellulose electrospun film, combined with the significant difference in electron gain and loss capabilities of the polyvinylidene fluoride electrospun film, serve as the triboelectric substrate material. This dressing is based on the following principle: an ethyl cellulose electrospun film loaded with silver nanoparticles serves as the positive electrode, while a polyvinylidene fluoride electrospun film forms the negative electrode. A contact-separation process occurs, generating triboelectric charges. These charges are transferred to the dressing surface through polarization, creating a potential difference. During the compression process after contact, the polyvinylidene fluoride electrospun film generates piezoelectric charges through the strong dipole moment density change characteristic of β-phase crystals. The synergistic effect of both significantly improves energy output efficiency. In practical applications on the maxillofacial region, it can effectively respond to maxillofacial movements, including speech and chewing, and convert them into voltage for output. The output voltage range is between 150mV and 210mV, close to the required electrical stimulation parameters. This ensures therapeutic efficacy without causing secondary damage to the skin surface of facial radiotherapy wounds, effectively promoting wound healing. Furthermore, compared to existing treatment methods, this application also incorporates a passive design, requiring no external power source and achieving self-powered operation through maxillofacial movements, thus solving the portability problem of traditional electrical stimulation devices. Its targeted regulation method precisely reverses radiation damage pathways by activating voltage-gated calcium ion channels and the calcium signal axis, superior to the non-specific nutritional support of traditional dressings. Its multifunctional integration not only provides electrical stimulation but also maintains a moist wound environment through the barrier effect of the dressing, achieving dual effects of physical protection and biological regulation. These characteristics make it uniquely promising for the treatment of combined radiotherapy and radiation-induced injuries in the maxillofacial region, especially suitable for long-term care of skin wounds after radiotherapy for maxillofacial tumors. The output voltage range of this application is between 150mV and 210mV. Under these parameters, the proliferation rate of irradiated fibroblasts is increased compared to the irradiated group, the proportion of dead cells is significantly reduced, and the 24-hour scratch healing rate increases from 19.51% to 42.3%, with no significant cytotoxicity. This ensures parameter consistency between "in vitro mechanism research and in vivo device application," effectively solving the problem of the disconnect between traditional electrical stimulation parameters and devices. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or in the conventional art, the drawings used in the embodiments 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.

[0034] Figure 1 This is a schematic diagram of the structure of a self-powered electrical stimulator wound dressing provided in an embodiment of the present invention.

[0035] Figure 2 This is a diagram of an external electrical stimulation model device provided in an embodiment of the present invention.

[0036] Figure 3 This invention provides the proliferation capacity of L929 fibroblasts under different electrical stimulation conditions.

[0037] Figure 4 This invention provides a test of the in vivo power generation capacity of a self-powered electrical stimulator wound dressing.

[0038] Figure 5 The above are the calcium ion staining results of L929 fibroblasts under different treatment conditions provided in the embodiments of the present invention.

[0039] Figure 6 The results provided in this embodiment of the invention represent the detection results of L929 fibroblast migration ability under different treatment conditions.

[0040] Figure 7 The results provided in this embodiment of the invention represent the detection results of apoptosis levels in L929 fibroblasts under different treatment conditions.

[0041] Figure 8 This invention provides the expression and analysis results of PI3K / AKT signaling pathway-related proteins in L929 fibroblasts under different groupings.

[0042] Figure 9 This invention provides the expression and analysis results of MEK-ERK signaling pathway-related proteins in L929 fibroblasts under different groupings.

[0043] Figure 10 This is an embodiment of the present invention, showing the expression and analysis results of proteins related to proliferation and apoptosis in different groups of L929 fibroblasts.

[0044] Figure 11 These are the XRD and FTIR detection results of PVDF electrospun films with different concentrations provided in the embodiments of the present invention.

[0045] Figure 12 The AFM test results provided in this embodiment of the invention represent electrospun films of different concentrations of PVDF.

[0046] Figure 13 These are SEM detection results of PVDF electrospun films with different concentrations provided in the embodiments of the present invention.

[0047] Figure 14 The results provided in this embodiment of the invention represent the piezoelectric coefficient test results of electrospun films with different concentrations of PVDF.

[0048] Figure 15 This is a characterization of the conductivity of EC@Ag NPs nanofiber films with different AgNPs doping ratios provided in the embodiments of the present invention.

[0049] Figure 16 This is an example of SEM analysis of EC@Ag NPs nanofiber membranes with different AgNPs doping ratios, provided by an embodiment of the present invention.

[0050] Figure 17 This is a COMSOL simulation calculation provided by an embodiment of the present invention to represent the power generation capacity of a self-powered electrical stimulator wound dressing under different triboelectric layer thickness ratios.

[0051] Figure 18 This is the open-circuit voltage of PVDF-EC@AgNPs with different triboelectric layer thickness ratios provided in the embodiments of the present invention.

[0052] Figure 19 This invention provides KPFM detection of EC@Ag NPs nanofiber membranes with different AgNPs doping ratios.

[0053] Figure 20 These are the hysteresis loop detection results of PVDF-EC@AgNPs with different triboelectric layer thickness ratios provided in the embodiments of the present invention.

[0054] Figure 21 The dielectric loss test results of the self-powered electrical stimulator wound dressing under different triboelectric layer thickness ratios provided in the embodiments of the present invention are as follows.

[0055] Figure 22 This is the stability test result of the PVDF-EC@AgNPs PTNG provided in the embodiments of the present invention. Detailed Implementation

[0056] 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 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.

[0057] Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the present invention.

[0058] It should be noted that the sequence number mentioned in this application does not necessarily mean that the execution must be strictly in the correct order in the actual implementation process. The sequence number is used to distinguish each step, facilitate explanation, and prevent confusion.

[0059] The accompanying drawings illustrate a layer structure according to an embodiment of the present invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0060] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0061] The following explains the English terms that may be used in this application.

[0062] VGCC (Voltage-gated calcium ion channel)

[0063] AgNPs (Silver nanoparticles)

[0064] PVDF (Polyvinylidene fluoride)

[0065] PTNG Piezoelectric-triboelectric composite nanogenerator / self-powered electrical stimulator wound dressing;

[0066] TENG Triboelectric Nanogenerator

[0067] CRWI (Combined Radiation and Wound Injury)

[0068] EC@Ag NPs-loaded silver nanoparticle-supported ethyl cellulose electrospun fibers

[0069] PVDF-EC@Ag NPs are polyvinylidene fluoride-loaded silver nanoparticle-ethyl cellulose composite nanogenerators, or simply composite nanogenerators.

[0070] CRWI (Combined Radiation and Wound Injury) refers to a special type of trauma that often occurs in extreme scenarios such as nuclear accidents, nuclear attacks, and radiological terrorist attacks. Furthermore, patients receiving clinical radiotherapy may also exhibit similar pathological characteristics. Ionizing radiation not only directly damages the DNA molecular structure but also indirectly causes irreversible damage to tissue cells by generating reactive oxygen species. Trauma further exacerbates the disruption of the local microenvironment, forming a unique "secondary attack" pathological pattern.

[0071] The regulatory role of bioelectric fields in tissue repair is receiving increasing attention. The endogenous electric field in the human body manifests as a potential difference of approximately 23 mV between the skin surface and the dermis. This potential gradient changes significantly during skin formation, driving current flow from surrounding tissues to the wound surface. This phenomenon provides a new theoretical basis for treatment strategies for combined radiation and radiotherapy wounds.

[0072] Electrical stimulation therapy can significantly promote angiogenesis through multi-level molecular regulatory mechanisms. Previous studies have shown that electrical stimulation can upregulate the expression level of vascular endothelial growth factor (VEGF), directly stimulating endothelial cell proliferation and migration. The oral and maxillofacial region, compared to other parts of the body, undertakes a series of regular motor functions such as speech, chewing, and facial expressions. Capturing the mechanical energy generated during these movements and converting it into electrical stimulation is a potentially advantageous treatment strategy.

[0073] Based on the above theory, this application proposes a self-powered electrical stimulator wound dressing, which works by synergistically utilizing the piezoelectric effect and the triboelectric effect to achieve efficient conversion of mechanical energy into electrical energy.

[0074] This application innovatively designs an EC electrospun film doped with Ag NPs as the positive electrode of the triboelectric layer, based on the PVDF piezoelectric layer. Ethyl cellulose electrospun films loaded with silver nanoparticles were selected as the triboelectric substrate material due to their excellent film-forming properties, biocompatibility, and easy electron loss characteristics, exhibiting a significant difference in electron gain and loss capabilities compared to PVDF. Based on Maxwell's displacement current theory, the power density (P) of the TENG is positively correlated with the square of the surface charge density (σ) of the triboelectric material (P∝σ²). Therefore, effectively increasing the surface charge density becomes the core strategy for optimizing the TENG's output performance.

[0075] The triboelectric effect is based on the contact electrification phenomenon between different materials and the principle of electrostatic induction. When two materials with different chemical properties and physical structures come into contact, rub against each other, and then separate, the inherent differences in their ability to bind electrons result in equal amounts of opposite charges being distributed at the contact surface. Subsequently, with the relative movement of the two materials, a directional current flows in the external circuit connecting them through electrostatic induction, realizing the conversion of mechanical energy into electrical energy.

[0076] The novel wound dressing with a self-powered electrical stimulator disclosed in this application can fit closely to the wound site. During actual use, the biodynamic energy generated by the patient's daily activities and the triboelectric effect play a role in the relative movement between the body and the dressing surface and between different materials inside the dressing. The electrical energy generated by the synergy of these two effects continuously provides stable electrical stimulation to the wound without the need for an external power source, greatly improving the convenience of treatment and patient compliance.

[0077] like Figure 1 As shown, a self-powered electrical stimulator wound dressing includes:

[0078] The following layers are stacked sequentially from bottom to top: sodium alginate hydrogel 1, polyvinylidene fluoride electrospun film 2, silicone gasket 3, and ethyl cellulose electrospun film loaded with nano-silver 4.

[0079] The sodium alginate hydrogel 1 is doped with polydopamine. The sodium alginate hydrogel 1 adheres tightly to the surface of the oral skin, so that when the oral cavity is in the process of pronunciation, chewing and facial movement, the dressing converts the deformation generated by the oral activity into voltage and outputs it to the oral skin. The output voltage range is between 150mV and 210mV.

[0080] The oral cavity skin surface has radio-induced combined injuries.

[0081] The sodium alginate hydrogel 1 has a thickness ranging from 0.9mm to 1.1mm and adheres closely to the facial skin. It is used for wound care, absorbing exudate, maintaining a moist environment in the wound, and promoting healing. The silicone gasket 3 has a thickness ranging from 0.1mm to 1.1mm and is used to form an electrical circuit. It can also effectively disperse pressure, maintain a stable position, and prevent nerve damage.

[0082] Polyvinylidene fluoride electrospun film 2 serves as the positive electrode of the self-powered electrical stimulator wound dressing, while ethyl cellulose electrospun film 4 loaded with silver nanoparticles serves as the negative electrode. The normal range of human mouth opening is generally 3.7cm-4.5cm. During chewing, a complete chewing cycle is approximately 0.875s, and the mandibular movement trajectory is typically teardrop-shaped. This characteristic provides an objective basis for the self-powered electrical stimulator wound dressing.

[0083] The proposed solution can effectively respond to maxillofacial movements, including speech and chewing, and convert them into voltage for output, with the overall output voltage ranging from 150mV to 210mV.

[0084] To better illustrate the parameters of this application, such as Figure 2 As shown, Figure 2 This diagram shows the setup for an in vitro electrical stimulation model. Cell viability was assessed under different electrical stimulation parameters by detecting the effects of electrical stimulation at different intensities (0 mV / mm, 50 mV / mm, 100 mV / mm, 200 mV / mm, 300 mV / mm, and 400 mV / mm) on the in vitro radiation model. Specifically, the electrical stimulation voltage parameters were set to 0 mV, 50 mV, 100 mV, 200 mV, 300 mV, and 400 mV, with a frequency of 5 Hz and a pulse width of 5 ms.

[0085] Previous studies have shown that applying direct current stimulation to cells can increase cell proliferation, but excessively high voltages can inhibit cell activity and proliferation due to electrochemical side reactions and electrothermal effects. This experiment used an electrostimulation cell culture system to simulate the pulse voltage waveform generated by the PVDF-EC@Ag NPs film and detected the activity of L929 fibroblasts under different electrostimulation conditions. The results are as follows: Figure 3 As shown, Figure 3 In the table, A: 6h; B: 12h; C: 24h; different letters represent statistical differences between groups (P<0.01).

[0086] As can be seen, at 6h, 12h, and 24h, the cell proliferation rates of the 100mV / mm, 200mV / mm, and 300mV / mm groups all showed significant increases (P<0.01), with the 200mV / mm group showing the most significant increase, reaching a relative cell proliferation rate of 181.48% after 24 hours of electrical stimulation. Compared to the control group, the 50mV / mm group only showed an increase after 24 hours of electrical stimulation (116.77%), while the 400mV / mm group showed decreased activity at 6h (73.31%) compared to the control group, increased activity at 12h (123.21%), and showed no significant difference in cell activity between the two groups until 24h. This suggests that L929 fibroblasts exhibit the highest cell activity under electrical stimulation at 200mV / mm.

[0087] Experiments have demonstrated that electrical stimulation has the optimal effect on an in vitro model of combined radiotherapy and radiation-induced injury. At this parameter, in vitro electrical stimulation significantly increases intracellular calcium ion concentration by activating VGCC, promoting cell migration (increasing the 24-hour scratch healing rate from 19.51% to 42.3%) and inhibiting apoptosis (reducing the proportion of dead cells to 6.8%). Molecular experiments have confirmed that it activates the PI3K-AKT and MEK-ERK pathways, upregulates proliferation and migration-related genes and proteins, and downregulates apoptosis-related molecules.

[0088] Therefore, the output voltage of this application is generally between 150mV and 210mV, which is close to the electrical stimulation parameters required to promote wound healing, thus achieving better results.

[0089] Therefore, in the design of this application, the voltage range is set at around 200mV. Since the wound dressing powered by the electrical stimulator in this application is affected by oral movement, converting the mechanical energy of oral movement into electrical energy, the designed voltage range is between 150mV and 210mV. Further, 180mV-210mV or 190mV-210mV are also acceptable. Considering the changes in the proportion of dead cells under different electrical stimulation parameters, the changes in cell migration ability under different electrical stimulation parameters, the activation of VGCC-mediated calcium ion influx by electrical stimulation, the reversal of the migration ability of irradiated fibroblasts by electrical stimulation through VGCC activation, and the reversal of the apoptosis level of irradiated fibroblasts by electrical stimulation through VGCC activation, it is determined that setting the output voltage between 150mV and 210mV is more prudent.

[0090] The application showed that the proliferation rate of radiated fibroblasts was higher than that of the radiated group, the proportion of dead cells was significantly reduced, the 24-hour scratch healing rate increased from 19.51% to 42.3%, and there was no obvious cytotoxicity. This ensured the consistency of parameters between "in vitro mechanism research and in vivo device application" and effectively solved the problem of the disconnect between traditional electrical stimulation parameters and devices.

[0091] To further illustrate the scheme of this application, this application experimentally verified the macroscopic output capability of PVDF-EC@AgNPs under different triboelectric layer thickness ratios.

[0092] The power generation capability of the proposed solution was tested. By fabricating the device, the power generation of the self-powered electrical stimulation wound dressing under different motion states was tested. The results showed that: Figure 4 As shown, Figure 4 In the image, A: Practical application example of PVDF-EC@AgNPs PTNG; B: Power generation of PTNG during chewing; C: Power generation of PTNG during speaking. It can be seen that the self-powered electrical stimulation wound dressing can effectively respond to maxillofacial movements, including speech and chewing, and convert them into voltage for output. The overall output voltage is between 150mV and 210mV, which meets the requirements.

[0093] The following explains the possible grouping situations that may be involved in this application.

[0094] Rad group: i.e., the radiation group, receiving a total dose of 6 Gy at a rate of 2.92 Gy / min; Rad+ES group: Radiation + electrical stimulation group, with electrical stimulation applied on the basis of Rad group; Inhibitor group: Based on the Rad+ES group, 10 μmol L-1 of Nifedipine was added to inhibit voltage-gated calcium channels (VGCC). Con group: that is, control group, blank control group, no treatment is given.

[0095] The inhibitor group was established to demonstrate that the wound-healing-promoting effect is induced by the activation of calcium ion channels (VGCCs) through electrical stimulation. This group contained the VGCC inhibitor nifedipine. Electrical stimulation can activate VGCCs, but the presence of the inhibitor eliminated this activation effect. Therefore, the experiment showed that although electrical stimulation was applied, it did not promote healing, thus proving that the wound-healing-promoting effect of electrical stimulation is induced by the activation of VGCCs.

[0096] To illustrate the scheme of this application, the following experimental description is provided, for reference. Figure 5 As shown, Figure 5 The results of calcium ion staining in L929 fibroblasts under different treatment conditions are shown. Different letters represent statistical differences between groups (P<0.01).

[0097] Activation of voltage-gated calcium channels induces calcium ion influx, which in turn activates a series of downstream pathways, including the MAPK and PI3K-AKT signaling pathways, thereby enhancing cell proliferation and migration, and reducing apoptosis. To investigate the effect of exogenous electrical stimulation on calcium levels in a CRWI in vitro model, this study stained L929 fibroblasts in different groups. Results showed that compared to the Con group, calcium levels in the Rad group decreased. After exogenous electrical stimulation, intracellular calcium levels significantly increased (P<0.05). The addition of the L-type calcium channel inhibitor Nifedipine eliminated the increase in intracellular calcium levels after electrical stimulation, suggesting that exogenous electrical stimulation-induced calcium ion influx is mediated by L-type voltage-gated calcium channels on the cell surface.

[0098] like Figure 6 As shown, the results of L929 fibroblast migration ability detection under different treatment conditions are presented. Different letters represent statistical differences between groups (P<0.05).

[0099] To further investigate the effect of in vitro electrical stimulation on the migration ability of the CRWI in vitro model, this experiment performed scratch assays on L929 fibroblasts treated with different methods. The results are as follows: Figure 6 As shown, the Rad group exhibited inhibited migration ability compared to the Con group; at all time points, the Rad+ES group showed higher migration levels compared to other groups, suggesting that in vitro electrical stimulation can reverse radiation-induced inhibition of fibroblast migration ability; compared to the Rad group, the Inhibitor group did not show significant changes in migration ability, suggesting that inhibiting voltage-gated calcium ion channels can eliminate the enhancing effect of electrical stimulation on fibroblast migration ability.

[0100] like Figure 7 As shown, Figure 7 The results show the apoptosis levels of L929 fibroblasts under different treatment conditions. In this paper, A represents Calcein-AM / PI staining of L929 fibroblasts under different treatment conditions; B represents statistical analysis, with different letters indicating statistical differences between groups (P<0.05).

[0101] To investigate whether in vitro electrical stimulation could reverse the increased apoptosis rate in L929 fibroblasts induced by radiation, this experiment involved Calcein-AM / PI staining of cells under different treatment conditions. The results are as follows: Figure 7As shown: Compared with the Con group, the Rad group exhibited a higher proportion of dead cells, which was statistically significant (P<0.05); after in vitro electrical stimulation of irradiated cells, the proportion of apoptotic Rad+ES cells was significantly reduced compared with the Rad group, suggesting that in vitro electrical stimulation can reverse the increased apoptosis level of fibroblasts caused by radiation; compared with the Rad group, the apoptosis level in the Inhibitor group did not change significantly, suggesting that inhibiting voltage-gated calcium ion channels can eliminate the mitigating effect of electrical stimulation on fibroblast apoptosis.

[0102] like Figure 8 As shown, Figure 8 The expression of proteins related to the PI3K / AKT signaling pathway in L929 fibroblasts under different groups and the analysis results are shown. Different letters represent significant differences between groups (P<0.05).

[0103] To further confirm the inhibition of PI3K / AKT and MEK / ERK signaling pathways induced by electrical stimulation reversal radiation, and to verify the possible molecular mechanism of radiation-induced fibroblast inhibition, this experiment performed Western blot analysis on signaling pathway-related proteins in Con, Rad, Rad+ES, and Inhibitor groups. Combined with transcriptome sequencing results, the PI3K / AKT and MEK / ERK signaling pathways were detected, respectively.

[0104] The detection results of the PI3K / AKT pathway are as follows: Figure 8 As shown, in the PI3K / AKT signaling pathway, compared with the Con group, the phosphorylation levels of PI3K and AKT in the Rad group were significantly decreased and statistically significant.

[0105] Compared with the Rad group, the Rad+ES group showed significantly increased phosphorylation levels of PI3K and AKT. The phosphorylation level of PI3K was higher than that of the Con group, while the phosphorylation level of AKT returned to the same level as that of the Con group, suggesting that in vitro electrical stimulation can reverse the inhibition of the PI3K / AKT signaling pathway caused by radiation.

[0106] Compared to the Rad+ES group, the phosphorylation levels of PI3K and AKT in the Inhibitor group were significantly reduced, returning to the same level as the Rad group. This demonstrates that calcium channel inhibitors can eliminate the reversal effect of external electrical stimulation on the radiation-induced inhibition of the PI3K / AKT signaling pathway, suggesting that the effect of external electrical stimulation on the PI3K / AKT signaling pathway may be mediated by calcium channels.

[0107] like Figure 9As shown, the expression and analysis results of MEK-ERK signaling pathway-related proteins in L929 fibroblasts under different groups are presented. Different letters represent significant differences between groups (P<0.05).

[0108] The detection results of the MEK / ERK pathway are as follows Figure 9 As shown, in the MEK / ERK signaling pathway, compared with the Con group, the phosphorylation levels of MEK and ERK in the Rad group were significantly decreased and statistically significant.

[0109] Compared to the Rad group, the Rad+ES group showed significantly higher levels of MEK and ERK phosphorylation, and both showed higher phosphorylation levels than the Con group, suggesting that in vitro electrical stimulation can reverse radiation-induced inhibition of the MEK / ERK signaling pathway.

[0110] Compared to the Rad+ES group, the phosphorylation levels of MEK and ERK in the Inhibitor group decreased significantly, returning to the same level as the Rad group. This demonstrates that calcium channel inhibitors can eliminate the reversal effect of in vitro electrical stimulation on the radiation-induced inhibition of the MEK-ERK signaling pathway, suggesting that the effect of in vitro electrical stimulation on the MEK-ERK signaling pathway may be mediated by calcium channels.

[0111] like Figure 10 As shown, Figure 10 The expression and analysis results of proliferation and apoptosis-related proteins in L929 fibroblasts from different groups are shown. Different letters represent significant differences between groups (P<0.05).

[0112] To further verify the effects of electrical stimulation on fibroblasts under radiation conditions, this experiment continued to verify the expression levels of proteins related to cell proliferation and apoptosis. Cyclin D1 is a key protein regulating the cell cycle and can reflect cell proliferation status; its detection results are as follows: Figure 10 As shown in Figures AB: Compared to the Rad group and the Inhibitor group, the expression level of Cyclin D1 in the Rad+ES group was significantly increased, and this was statistically significant. Results of apoptosis-related protein detection are as follows... Figure 10As shown in A and CH: the anti-apoptotic protein Bcl-2 was significantly decreased in both the Rad and Inhibitor groups compared to the Con group, but its expression level returned to the Con group level in the Rad+ES group; the apoptosis-related proteins Bax, Caspase9, and Cleaved Caspase9 were significantly increased in both the Rad and Inhibitor groups compared to the Con group, but their expression levels returned to the Con group level in the Rad+ES group; however, the detection results of Caspase3 and Cleaved Caspase3 showed downregulation in both the Rad+ES group and the Inhibitor group compared to the Rad group, which is speculated to be due to the existence of other response pathways of fibroblasts to electrical stimulation, and will be further explored in future studies.

[0113] In summary, the four treatment groups showed similar trends in the detection of cell proliferation and apoptosis-related proteins: the Rad and Inhibitor groups exhibited inhibition of proliferation and increased apoptosis, while the Rad+ES group showed recovery of proliferation and decreased apoptosis. Based on these results, this experiment further validated the following hypothesis at the cellular protein expression level: in vitro electrical stimulation activates VGCC, thereby inducing calcium ion influx, which further reverses the inhibition of the PI3K-AKT and MEK-ERK signaling pathways caused by radiation, thus promoting the recovery of cell proliferation and migration, and reducing apoptosis.

[0114] like Figure 11 As shown, Figure 11 The XRD and FTIR results of PVDF electrospun films with different concentrations are shown.

[0115] This experiment used X-ray diffraction (XRD) patterns to characterize the phase composition of PVDF films and commercial powders prepared by electrospinning. The commercial PVDF powder exhibited predominantly (020), (110), and (021) crystal orientations (e.g., ...). Figure 11As shown in Figure A). The (020) crystal plane is the characteristic crystal plane of the α phase, and the (110) crystal plane is the characteristic crystal plane of the β phase. Compared to other spinning solutions, the highest relative diffraction intensity of the (110) diffraction peak was obtained when the PVDF concentration in the spinning solution was 12%. After Gaussian fitting peak division calculation, the (110) diffraction peak accounted for 53.2% of the overall peak area formed with the (020) peak, exceeding the (110) peak area ratio (39.9%) of commercial PVDF powder samples. To further clarify whether the β phase ratio changed in the electrospun film, Fourier transform infrared (FTIR) spectroscopy was used to characterize the PVDF film prepared by electrospinning technology. Figure 11 As shown in B, 763cm⁻¹ (in-CH₂- plane or oscillating) and 976cm -1 The characteristic peak at (-CH2- torsional vibration) corresponds to the α phase of PVDF; located at 840 cm⁻¹ -1 (-CH2- swaying and -CF2- asymmetric stretching) and 1276cm -1 (CF tensile vibration) corresponds to the β phase. FTIR results show that the content of the non-piezoelectric α phase of PVDF first decreases and then slightly increases with the increase of spinning solution concentration, which is consistent with the conclusions of XRD.

[0116] like Figure 12 As shown, Figure 12 The AFM test results are shown for electrospun films of different concentrations of PVDF.

[0117] The microstructure of PVDF films prepared by electrospinning was observed using atomic force microscopy (AFM). At a spinning solution concentration of 8 wt%, the film exhibited a disordered fibrous structure with radially uneven thickness. With increasing spinning solution concentration, the fiber diameter gradually increased and became more uniform, while the disorder of fiber distribution decreased. It was found that when the spinning solution concentration exceeded 12 wt%, the density of the PVDF film decreased significantly, which may inhibit its piezoelectric properties. Consistent results were clearly observed in the corresponding phase and amplitude diagrams of the AFM.

[0118] like Figure 13 The figure shows the SEM detection results of PVDF electrospun films with different concentrations, where AD: magnification 2kX; EH: magnification 5kX.

[0119] Scanning electron microscopy (SEM) was used to further observe the morphology of the PVDF films prepared by electrospinning. In Figures 13A and 13E, a distinct beaded structure was clearly observed in the PVDF fibers prepared at a spinning solution concentration of 8 wt%. The formation of the beaded structure was attributed to the adhesion and uneven precipitation of fibers caused by solvent evaporation, and the imbalance between surface tension and electric field, leading to jet instability due to insufficient spinning solution viscosity. Under suitable spinning solution concentration conditions, the PVDF fibers exhibited a more uniform morphology and fewer defect structures, promoting electron extraction and increasing power generation potential. When the spinning solution concentration was too low (8%) or exceeded the optimal concentration (14%), the PVDF fibers showed insufficient density, and the ordered arrangement of the PVDF molecular chains was disrupted.

[0120] like Figure 14 As shown, Figure 14 The piezoelectric coefficient test results of PVDF electrospun films with different concentrations are shown in the figure. Different letters in the figure represent statistical differences between groups, P<0.05.

[0121] Figure 14 In the PVDF piezoelectric performance test, the PVDF powder group was set up to demonstrate that this experimental group has a better piezoelectric effect than commercially available PVDF powder.

[0122] Under normal circumstances, the electromotive force generated by piezoelectric materials conforms to the following inequality:

[0123]

[0124] Where d is the piezoelectric constant, ε is the dielectric constant, Y is Young's modulus, S is strain, and t is the thickness of the piezoelectric layer. As the electromechanical conversion coefficient of piezoelectric materials such as PVDF, d... 33 The calculation of d is of great significance for assessing power generation expectations. As shown in Figure 14, the d of PVDF films prepared under different electrospinning conditions was experimentally tested. 33 All were higher than those of commercial PVDF powder. When the spinning solution concentration increased from 8 wt% to 12 wt%, d 33 The concentration increased from 19.1 pC / N to 25.87 pC / N. Furthermore, even when the optimal spinning solution concentration was exceeded, d 33 The value decreased slightly. The piezoelectric coefficient results are consistent with the previous characterization results of phase and morphology. The high β phase ratio and uniform and dense fiber distribution bring about better piezoelectric properties.

[0125] like Figure 15 As shown, Figure 15The conductivity of EC@Ag NPs nanofilms with different AgNPs doping ratios is characterized.

[0126] In this experiment, EC@AgNPs were subsequently used as the negative electrode for the wound dressing of the self-powered electrical stimulator. Adjusting the EC film fabrication process is crucial for the output performance of the triboelectric nanogenerator. This experiment optimized the EC layer using Ag NPs doping. Figure 15 shows the EC@Ag NPs at 10... 2 -10 6 Conductivity tests were conducted in the Hz range, with the conductivity value at 1 kHz being representative of the conductive properties of the EC film. After Ag NPs doping, the conductivity of EC continuously increased with the increase of Ag NPs doping concentration, from the initial 2.43 × 10⁻⁶. -9 S / m increased to 1.49×10 -9 S / m (doping concentration of 4 wt%). Within a suitable range, the good conductivity allows the charge generated during the contact-separation process to be transferred directly to the positive and negative electrodes through the material itself very efficiently, which can improve the maximum output power of the TENG.

[0127] like Figure 16 As shown, Figure 16 The values ​​represent SEM measurements of EC@Ag NPs nanofilms with different AgNPs doping ratios, where AD represents a magnification of 2kX and EH represents a magnification of 5kX.

[0128] like Figure 16 As shown, SEM was used to observe the morphology of EC films doped with Ag NPs prepared by electrospinning. At 2kX and 5kX magnification, it was observed that without Ag NPs, the EC fibers themselves exhibited very poor uniformity and inconsistent fiber sizes. With gradually increasing the mass fraction of Ag NPs doping, the EC fibers tended to become more uniform in size, with the most uniform microstructure and largest diameter observed at 2 wt%.

[0129] Optionally, as one embodiment, the thickness ratio of the polyvinylidene fluoride electrospun film to the ethyl cellulose electrospun film loaded with silver nanoparticles is between 4:1 and 1:1.

[0130] Optionally, as one embodiment, the thickness ratio of the polyvinylidene fluoride electrospun film to the ethyl cellulose electrospun film loaded with silver nanoparticles is 3:1.

[0131] The following is an explanation through specific examples.

[0132] like Figure 17As shown, when the thickness of the polyvinylidene fluoride (PVDF) electrospun film no longer changes, the output voltage generated by the piezoelectric component can be considered to remain constant. Here, only the electromotive force generated by the triboelectric nanogenerator formed by the PVDF electrospun film and the ethyl cellulose electrospun film loaded with silver nanoparticles as a whole is simulated. As the thickness ratio of the positive to negative electrode decreases from 1:1 to 1:4, the triboelectric electromotive force shows an increasing trend, reaching its maximum value (3.0 V / cm) at a thickness ratio of 1:3. 2 However, as the thickness ratio continues to decrease, the electromotive force decreases slightly. At this point, the thickness of EC is insufficient to form enough polarization, and a large amount of charge cannot be accumulated on the material surface.

[0133] Therefore, the best effect is achieved when the thickness ratio of polyvinylidene fluoride electrospun film to the ethyl cellulose electrospun film loaded with silver nanoparticles is 3:1. From the process of the thickness ratio from 4:1 to 1:1, it can be seen that the self-powered electrical stimulator wound dressing also has a certain effect, but it is weaker than the effect of 3:1.

[0134] Optionally, as one embodiment, the thickness of the polyvinylidene fluoride electrospun film is 600μm-900μm.

[0135] Optionally, as one embodiment, the thickness of the ethyl cellulose electrospun film loaded with silver nanoparticles is from 800 μm to 2500 μm.

[0136] To further illustrate the scheme of this application, the macroscopic output capability of PVDF-EC@AgNPs under different triboelectric layer thickness ratios was experimentally verified. (Reference) Figure 18 As shown, the open-circuit voltage of PVDF-EC@AgNPs is obtained under different triboelectric layer thickness ratios.

[0137] This experiment systematically investigated the effect of the thickness ratio of the Ag NPs@EC layer to the PVDF layer in a PTNG device on the output voltage. The experimental data verified the reliability of the previous theoretical simulations. Figure 18The results shown indicate that when the thickness ratio of Ag NPs @ EC to PVDF is 1:3, the device exhibits the best electrical performance, with an open-circuit voltage (Voc) reaching a peak of 17V. When the thickness ratio is 1:1, the excessively thick EC@Ag NPs layer leads to high dielectric loss, causing significant leakage of triboelectric charge during transport and interfering with the polarization process of PVDF, ultimately resulting in a lower Voc value. When the ratio is adjusted to 1:2, the thickness of the EC@Ag NPs layer becomes more reasonable, improving triboelectric efficiency and reducing the suppression of PVDF polarization; the synergistic effect of these two factors significantly increases the output voltage. However, when the ratio is further increased to 1:4, the excessively thin EC@Ag NPs layer reduces the amount of triboelectric charge generated, while the agglomeration of silver nanoparticles exacerbates charge leakage, ultimately causing a decrease in output voltage.

[0138] It should be noted that the 17V peak voltage obtained in this application is the maximum open-circuit voltage obtained under rapid motion stimulation of a mechanized hand without any restriction on its range of motion. This is different from the conditions under which the speed and range of motion of human oral cavity movement are limited in this application. The purpose is to explore what thickness ratio of Ag NPs@EC layer to PVDF layer can obtain a higher voltage output.

[0139] Optionally, as one embodiment, the absolute value of the surface potential of the ethyl cellulose electrospun film loaded with silver nanoparticles is not less than 750mV.

[0140] like Figure 19 The figure shows the KPFM detection results of EC@Ag NPs nanofilms with different AgNPs doping ratios.

[0141] To further observe the impact of Ag NPs introduction on the triboelectric power generation performance of electrochemical reactors (ECs), Kelvin probe force microscopy (KPFM) was used to assess the surface potential of ECs. The surface potential of a material reflects the surface charge density, which is of great significance for triboelectric generation (TENGs). Figure 19 As shown, when the Ag NPs doping concentration increases from 0 wt% to 2 wt%, the overall absolute value of the surface potential increases, and the uniformity of the surface potential also improves significantly. However, when the Ag NPs doping concentration reaches 4 wt%, the surface potential drops sharply. The aggregation of Ag NPs forms current leakage channels, preventing charge accumulation at the interface. Based on the above characterization analysis, this experiment will subsequently employ a 2 wt% Ag NPs-doped EC fabrication process to achieve the best output performance of the piezoelectric-triboelectric nanogenerator.

[0142] from Figure 19As can be seen, when the preparation process of EC doping with 2 wt% Ag NPs is used, the absolute value of the surface potential of the electrospun ethyl cellulose film loaded with silver nanoparticles is not less than 750mV, while other processes cannot achieve this effect. Therefore, the preparation process of EC doping with 2 wt% Ag NPs ensures that the absolute value of the surface potential of the prepared electrospun ethyl cellulose film loaded with silver nanoparticles is not less than 750mV.

[0143] Optionally, as one embodiment, the residual polarization intensity of the dressing is less than -0.01372 C / m, wherein the residual polarization intensity is the polarization intensity of the hysteresis loop when the external electric field is 0.

[0144] like Figure 20 As shown, Figure 20 The figures show the hysteresis loop detection results of ethyl cellulose electrospun films loaded with silver nanoparticles under different triboelectric layer thickness ratios (hysteresis loop detection results of PVDF-EC@AgNPs under different triboelectric layer thickness ratios). The polarization intensity induced by the external electric field exhibits a near-periodic variation. The polarization intensity of the hysteresis loop when the external electric field is 0 is called the remanent polarization intensity. In the figure, the remanent polarization intensity of the entire device is the highest (-0.01372 C / m) when the thickness ratio is 1:3. 2 This is more favorable for the output performance of polyvinylidene fluoride (PVDF) electrospun film as a piezoelectric fiber layer. PVDF electrospun film is a common ferroelectric material; however, the hysteresis loop did not close well in the absence of an external electric field. This is presumably because the presence of the ethyl cellulose electrospun film loaded with silver nanoparticles weakened the overall ferroelectric properties exhibited by the device.

[0145] Optionally, as one embodiment, the tangent of the dielectric loss angle of the dressing is not greater than 0.005.

[0146] like Figure 21 As shown, Figure 21 The dielectric loss test results of ethyl cellulose electrospun films loaded with silver nanoparticles under different triboelectric layer thickness ratios are presented (dielectric loss test results of PVDF-EC@AgNPs under different triboelectric layer thickness ratios).

[0147] The dielectric loss tangent reflects the proportion of electrical energy converted into useless heat energy by a material under an alternating electric field. For piezoelectric or triboelectric devices, mechanical energy ultimately needs to be efficiently converted into usable electrical energy output. The characterization of dielectric loss is used to study the impact of the thickness of the positive and negative electrode materials on the energy conversion efficiency and losses of the device. Typically, in the low-frequency region (1~1kHz), dielectric loss is significantly affected by conductivity, making it important for characterizing power generation efficiency. Figure 21As shown, when the thickness ratio is 1:3, the tangent of the dielectric loss angle is the smallest, remaining around 0.005. Under this thickness ratio adjustment, the proportion of the entire device that utilizes mechanical energy to convert into effective electrical energy output is the highest.

[0148] In this experiment, when the thickness ratio of polyvinylidene fluoride electrospun film to ethyl cellulose electrospun film loaded with silver nanoparticles (EC@AgNPs:PVDF) changed from 4:1 to 1:1, the dielectric loss tangent (tanδ) first decreased and then increased. In the 3:1 to 1:1 group, as the thickness ratio of the ethyl cellulose electrospun film loaded with silver nanoparticles (EC@AgNPs) decreased from 50% to 25%, the probability of internal defects / impurities decreased, and the dielectric loss decreased. However, in the 4:1 group, the excessively thin ethyl cellulose electrospun film layer loaded with silver nanoparticles (EC@AgNPs) caused a sharp drop in polarization ability, making it impossible to accumulate sufficient surface charge and increasing energy dissipation. Furthermore, the extremely thin ethyl cellulose electrospun film layer loaded with silver nanoparticles (EC@AgNPs) induced local agglomeration of silver nanoparticles, increasing local conductivity and thus increasing dielectric loss.

[0149] like Figure 22 As shown, Figure 22 The results show the stability test results for PVDF-EC@AgNPs PTNG.

[0150] To further investigate the operational stability of PTNG, this experiment conducted 100,000 contact-separation fatigue tests. Figure 22 As shown, the output of the piezoelectric-triboelectric nanogenerator remains consistently at an AC output voltage of approximately -3 to 17V. Fatigue testing results demonstrate high stability, strong resistance to degradation, and a long service life.

[0151] Optionally, as one embodiment, in the method for preparing a self-powered electrical stimulator wound dressing, the polyvinylidene fluoride electrospun film is prepared by the following method:

[0152] Preparation of the first electrospinning solution: Weigh 2.22g-2.73g of polyvinylidene fluoride nanofiber powder, add 14mL of N,N-dimethylformamide, and stir with a magnetic stirrer at 1000rpm for 6 hours in a 70℃ water bath. After standing to room temperature, add 6mL of acetone and continue stirring with a magnetic stirrer at 1000rpm for 4 hours at room temperature to obtain an electrospinning solution with a mass fraction of 11%-13%. Let stand for 24 hours to eliminate air bubbles and store in the dark.

[0153] Preparation of polyvinylidene fluoride electrospun film: The prepared first electrospinning solution is transferred into a special syringe and assembled with the electrospinning system by a micro-injection pump; the spinning nozzle is connected to a positive high voltage power supply, the receiving device is a roller collector covered with aluminum foil, the distance between the nozzle and the collector is 230-270 mm, the spinning solution propulsion rate is 1.0-1.3, and the single spinning cycle lasts at least 2.8 hours and no more than 3.5 hours;

[0154] Post-processing of electrospun nanofilms: The collected polyvinylidene fluoride electrospun film is peeled off from the surface of the roller and placed in a vacuum drying oven for heat treatment to obtain the polyvinylidene fluoride electrospun film.

[0155] And / or,

[0156] The ethyl cellulose electrospun film loaded with silver nanoparticles was prepared by the following method:

[0157] Preparation of the second electrospinning solution: Take 6.67 g of ethyl cellulose electrospinning film powder loaded with silver nanoparticles, add 15 mL of N,N-dimethylformamide, stir at 1000 rpm for 4 hours at room temperature using a magnetic stirrer, add 5 mL of acetone, and continue stirring at 1000 rpm for 2 hours at room temperature to obtain a 25% ethyl cellulose solution. Add silver nanoparticles to the solution, disperse by ultrasonication, and continue stirring at 1000 rpm for 2 hours at room temperature to obtain the electrospinning solution of ethyl cellulose electrospinning film loaded with silver nanoparticles. Let stand for 24 hours to eliminate bubbles and store under light-protected conditions.

[0158] Preparation of ethyl cellulose electrospun nanofilm loaded with silver nanoparticles: The prepared second spinning solution was transferred into a special syringe and assembled with an electrospinning system by a micro-injection pump. The assembly included: a stainless steel needle as a spinning nozzle, which was connected to a positive high voltage power supply; a receiving device was a roller collector with an aluminum foil coating and a rotation speed of 700-1000 rpm; the distance between the spinning nozzle and the collector was 150 mm; the transmitting voltage was 27 kV; the receiving voltage was -2 kV; the spinning solution propulsion rate was 2 mL / h; and the single spinning cycle lasted for 2 hours.

[0159] Post-processing of the silver-loaded ethyl cellulose electrospun film: The collected silver-loaded ethyl cellulose electrospun film was peeled off from the surface of the roller and placed in a vacuum drying oven for heat treatment; the non-uniform area around the obtained film was removed to obtain the ethyl cellulose nanofilm.

[0160] Specifically, the self-powered electrical stimulator wound dressing of this application has good applications in wound repair materials and medical materials.

[0161] And the application of self-powered electrical stimulator wound dressings in skin repair or radiation-induced complex injuries.

[0162] 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 inventive effort are within the scope of protection of the present invention.

[0163] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A self-powered electrical stimulator wound dressing, characterized in that, The dressing comprises, from bottom to top, a sodium alginate hydrogel, a polyvinylidene fluoride electrospun film, a silicone gasket, and an ethyl cellulose electrospun film loaded with silver nanoparticles; the sodium alginate hydrogel is doped with polydopamine and adheres tightly to the surface of the oral skin; the self-powered electrical stimulator wound dressing is used during maxillofacial movements such as pronunciation, chewing, and motor activities, whereby the dressing converts the deformation generated by oral activity into voltage and outputs it to the oral skin, with the output voltage range between 150mV and 210mV; wherein, the surface of the oral skin has a combined radio-induced wound.

2. The self-powered electrical stimulator wound dressing according to claim 1, characterized in that, The thickness ratio of the polyvinylidene fluoride electrospun film to the ethyl cellulose electrospun film loaded with silver nanoparticles is between 4:1 and 1:

1.

3. The self-powered electrical stimulator wound dressing according to claim 1, characterized in that, The thickness ratio of the polyvinylidene fluoride electrospun film to the ethyl cellulose electrospun film loaded with silver nanoparticles is 3:

1.

4. The self-powered electrical stimulator wound dressing according to claim 1, characterized in that, The thickness of the ethyl cellulose electrospun film loaded with silver nanoparticles is 600 μm-900 μm.

5. The self-powered electrical stimulator wound dressing according to claim 1, characterized in that, The thickness of the polyvinylidene fluoride electrospun film is 800 μm to 2500 μm.

6. The self-powered electrical stimulator wound dressing according to claim 1, characterized in that, The residual polarization intensity of the dressing is less than -0.01370 C / m2; wherein, the residual polarization intensity is the polarization intensity of the hysteresis loop when the external electric field is 0.

7. The self-powered electrical stimulator wound dressing according to claim 1, characterized in that, The tangent of the dielectric loss angle of the dressing is not greater than 0.

005.

8. The self-powered electrical stimulator wound dressing according to claim 1, characterized in that, The absolute value of the surface potential of the ethyl cellulose electrospun film loaded with silver nanoparticles is not less than 750mV.

9. The use of a self-powered electrical stimulator wound dressing according to any one of claims 1-8 in wound repair materials.

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