Anti-infection scar-free healing promoting tissue repair material as well as preparation method and application thereof

Abstract

The invention discloses an anti-infection scar-free healing promoting tissue repair material as well as a preparation method and application thereof. The tissue repair material can recover endogenous potential of a wound to the maximum extent, a suitable microenvironment is provided for cell migration and epithelial regeneration, in-vitro experiments verify that a micro electric field generated by the tissue repair material effectively kills bacteria and promotes reprogramming of macrophages, and the tissue repair material shows excellent antibacterial performance and immune regulation performance. In addition, various infectious skin wound animal models all show that the traditional Chinese medicine composition can effectively promote scar-free wound healing through the ways of resisting bacteria, relieving inflammation, promoting collagen regeneration and angiogenesis and the like.

Description

Technical Field

[0001] This invention belongs to the field of regenerative medicine technology, and in particular relates to an anti-infection, scar-free tissue repair material, its preparation method, and its application. Background Technology

[0002] Skin defects (such as infected skin defects) are difficult to heal and easily lead to scarring after repair, accompanied by itching, functional limitations, and psychological burden. The core mechanism lies in the imbalance of the microenvironment at each stage of wound healing (inflammation, proliferation, and remodeling). Bacterial infection triggers a vicious cycle of reactive oxygen species (ROS) and inflammation, with excessive inflammation leading to abnormal collagen deposition. Current skin repair methods mainly include dressings and antibiotics, but these are prone to drug resistance and have limited dynamic regulation of wound healing. Specifically, current treatment options have the following shortcomings: (1) Problems such as low drug utilization, increased bacterial resistance, and reduced clinical treatment and treatment effect for patients; (2) Lack of multi-stage regulation: Existing materials mostly focus on a single function (such as anti-inflammatory and angiogenesis), which cannot meet the dynamic needs of wound healing - antibacterial and anti-inflammatory treatment is needed during the inflammatory phase, angiogenesis is needed during the proliferation phase, and fibrosis is needed during the remodeling phase, resulting in the inability to resolve the contradiction between "repair and scar". (3) Limited signal triggering methods: piezoelectric hydrogels require continuous mechanical stimulation (such as ultrasound, wound compression), and have poor compatibility with fragile tissues such as chronic wounds and deep wounds; magnetic response materials can only achieve drug delivery, cannot construct a biomimetic EF (endogenous potential of wound) microenvironment, and are difficult to regulate cell polarity and differentiation; (4) Weak scar repair capability: Existing materials can only accelerate wound closure, but do not regulate the core scar targets such as collagen ratio (COL-I / COL-III), and cannot achieve dual repair of "structure and function".

[0003] Therefore, developing biomaterials with antibacterial properties, multi-stage microenvironment adaptation capabilities, and scarless repair functions is an urgent need in the field of regenerative medicine. Summary of the Invention

[0004] To address at least some of the technical problems in existing technologies, this invention designs a tissue repair material with magneto-electric coupling therapeutic function. The electrical signals generated by this material exhibit good antibacterial effects in infected skin wounds. Simultaneously, this electrical signal can modulate the transformation of macrophages from the M1 pro-inflammatory phenotype to the M2 repair phenotype under inflammatory conditions. The constructed repair immune microenvironment can promote angiogenesis, facilitate spontaneous wound closure without the need for additional drugs, and can be removed as needed during treatment without causing tissue adhesion. Research results show that the tissue repair material of this invention effectively heals open wounds infected with Staphylococcus aureus in a mouse model within 8 days, reduces inflammation, promotes re-epithelialization and angiogenesis, and significantly reduces scar area and scar indicators after 20 days. Simultaneous experiments in New Zealand rabbits and miniature Bama pigs further validated its ability to promote scarless healing of infected wounds, providing evidence for its clinical translation. Specifically, this invention includes the following:

[0005] In a first aspect, the present invention provides an anti-infection, scar-free tissue repair material, comprising a polymer material having a three-dimensional network structure, magnetoelectric nanoparticles and conductive fillers filled in the polymer material, wherein the magnetoelectric nanoparticles comprise a shell structure having piezoelectric properties and a core structure having magnetoelectric response properties, wherein the shell structure is prepared from raw materials including inorganic piezoelectric materials and / or organic piezoelectric materials, and the core structure is prepared from a magnetoelectric material.

[0006] In some embodiments, the anti-infection, scar-free tissue repair material according to the present invention includes polymeric materials of natural origin and / or synthetic origin.

[0007] In some embodiments, the anti-infection, scar-free tissue repair material according to the present invention comprises at least one of alginate, chitosan, hyaluronic acid, collagen, fibroin, silk fibroin, polyacrylates, acrylamides, polycaprolactone / polylactic acid hydrogels, gelatin, and polypeptide self-assembled hydrogels.

[0008] In some embodiments, the anti-infection, scar-free tissue repair material according to the present invention, wherein the conductive filler comprises at least one of graphene, reduced graphene oxide, carbon nanotubes, and gold nanomaterials.

[0009] In some embodiments, the anti-infection, scar-free tissue repair material according to the present invention, wherein the inorganic piezoelectric material is selected from at least one of ferric acid, niobic acid, titanic acid, silicate, and aluminic acid materials; and the organic piezoelectric material is selected from at least one of polyvinylidene fluoride, polyester, polymethyl methacrylate, nylon, polyvinyl chloride, polylactic acid, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), vinylidene fluoride / trifluoroethylene copolymer, vinylidene fluoride / tetrafluoroethylene copolymer, polyvinylidene fluoride-hexafluoropropylene, and polydimethylsiloxane materials.

[0010] In some embodiments, the anti-infection, scar-free tissue repair material according to the present invention, wherein the ferric acid material has the following structure: M x Fe 3-x O y M includes at least one of Bi, Ca, Ba, Mg and Ba, x is a number from 0.25 to 1.5, and y is 4.

[0011] In some embodiments, the anti-infection, scar-free tissue repair material according to the present invention, wherein the magnetoelectric material has the following structure: N a Fe 1-a O b N includes at least one of Co, Mn, Zn and Ni, a is a number from 0.25 to 0.75, and b is 3.

[0012] In some embodiments, the anti-infection, scar-free tissue repair material according to the present invention, wherein the magnetoelectric nanoparticles are cobalt ferrite-bismuth ferrite nanoparticles.

[0013] In some embodiments, the anti-infection, scar-free tissue repair material according to the present invention, wherein the cobalt ferrite-bismuth ferrite nanoparticles have a particle size of 100-500 nm.

[0014] A second aspect of the present invention provides a method for preparing an anti-infection, scar-free tissue repair material, comprising the following steps: (1) Prepare magnetoelectric nanoparticles comprising a shell structure with piezoelectric properties and a core structure with magnetoelectric response properties, wherein the shell structure is prepared from raw materials including inorganic piezoelectric materials and / or organic piezoelectric materials, and the core structure is prepared from magnetoelectric materials; (2) The magnetoelectric nanoparticles and conductive fillers are filled into a polymer material with a three-dimensional network structure to obtain the repair material.

[0015] In some embodiments, the method for preparing an anti-infection, scar-free tissue repair material according to the present invention further includes: (3) a step of treating the repair material with a magnetic field having a magnetic field strength of 0.01-300 mT.

[0016] A third aspect of the invention provides the use of the repair material described in the first aspect in the preparation of products for repairing skin damage.

[0017] This invention successfully prepared a tissue repair material with antibacterial properties doped with magnetoelectric nanoparticles, which in some embodiments is a composite hydrogel. The tissue repair material of this invention promotes scarless healing of Staphylococcus aureus-infected wounds through the magnetostrictive piezoelectric effect. Since the magnetoelectric nanoparticles can generate electrical signals, and the conductive filler can reduce the attenuation of these signals, the porous microstructure of the hydrogel material forms a conductive network, which can maximize the restoration of the wound's endogenous potential, providing a suitable microenvironment for cell migration and epithelial regeneration. In in vitro experiments, the micro-electric field generated by the tissue repair material of this invention can effectively kill Staphylococcus aureus and promote macrophage reprogramming, exhibiting excellent antibacterial and immunomodulatory properties. Furthermore, the feasibility of applying magnetoelectric hydrogel therapy to mouse full-thickness infected skin wound models, New Zealand rabbit ear infected skin wound models, and miniature Bama pig infected skin wound models has been demonstrated, showing that it can effectively promote scarless wound healing through antibacterial, anti-inflammatory, collagen regeneration-promoting, and angiogenesis pathways. More importantly, safe magnetoelectric therapy can maximize antibacterial and tissue repair functions without the addition of topical medications, thus having broad application prospects in the biomedical engineering industry. Attached Figure Description

[0018] Figure 1 Characterization of the prepared CFO@BFO nanoparticles. (A) Preparation process of CFO-BFO NP using hydrothermal and sol-gel synthesis. (B) TEM, HRTEM and (C) EDS results of CFO-BFO NP. Scale bars represent 100 nm, 20 nm and 100 nm, respectively. (D) XRD pattern of CFO-BFO NP. (E) XPS pattern of CFO-BFO NP. (F) Phase diagram of CFO-BFO NP. (G) Piezoelectric response amplitude curve and (H) phase curve of CFO-BFO NP. (I) •O2 trapped by DMPO under magnetic field. - EPR spectra of CFO and •OH. (J) COMSOL simulations of single CFO-BFO nanoparticles under a 1.5 mT magnetic field.

[0019] Figure 2Preparation and characterization of GelMA / C@B / rGO magnetoelectric hydrogels. (A) Schematic diagram of the GelMA / C@B / rGO manufacturing process. (B) Different states of different hydrogels before and after gelation, injectability and in-situ gelation of C@B / rGO magnetoelectric hydrogels, and tissue adhesion of GelMA / C@B / rGO hydrogels. (C) Water contact angles of different hydrogels. (D) SEM images of different hydrogels. (E) EDS images and analysis of GelMA / C@B / rGO hydrogels. (F) FTIR spectra of different hydrogels. (G) Mechanical properties of different hydrogels. (H) Residual weight ratio of different hydrogels during in vitro degradation (n=3). (I) Swelling curves of different hydrogels immersed in PBS at 37°C and pH 7.4. (J) Schematic diagram of the device for generating RMF. (K) Voltage changes of magnetoelectric hydrogels with or without rGO added to RMF. (L) Voltage variation of magnetoelectric hydrogels with or without rGO content in RMF.

[0020] Figure 3Magnetoelectric hydrogels inhibit Staphylococcus aureus and its biofilm. (A) Schematic diagram of the antibacterial experimental procedure. (B) Representative colony-forming units (CFU) images of Staphylococcus aureus after 24 h of different treatments. (C) Quantitative statistical results. (n=3, mean ± standard error; *Compared with the Control group, #: compared with the Mag+ group, &: compared with the Mag+C@B group; ns indicates no significant difference, P>0.05; ***P<0.0001, ####P<0.0001, &&P=0.0011; one-way ANOVA was used). (D) Live-dead staining images of Staphylococcus aureus after treatment with PBS (Ctrl), Magnetic, Mag+C@B, and Mag+C@B / rGO. (E) Antibacterial rate analysis based on red / (red+green) fluorescence intensity. Scale bar: 20 μm. (n=3, mean ± standard error; *Compared with the Control group, #: compared with the Mag+ group, &: compared with the Mag+C@B group; ns indicates no significant difference, P>0.05; ***P<0.0001, ####P<0.0001, &&&&P<0.0001; one-way ANOVA was used). (F) Representative scanning electron microscope (SEM) images of Staphylococcus aureus after 24 h of different treatments; green arrows indicate bacterial cell membrane rupture. Scale bar: 1 μm. (G) Mean cell size of Staphylococcus aureus after treatment with PBS (Ctrl), Magnetic, Mag+C@B and Mag+C@B / rGO. (n=3, mean ± standard error; * compared with the Control group, # compared with the Mag+ group, & compared with the Mag+C@B group; ns indicates no significant difference, P>0.05; **P=0.0013, ##P=0.0031, ***P<0.0001, ####P<0.0001, &P=0.0273; one-way ANOVA was used). (H) Representative reactive oxygen species (ROS) staining images of Staphylococcus aureus after 30 min of different treatments. Scale bar: 10 μm. (I) Quantitative analysis results of reactive oxygen species levels. (n=3, mean ± standard error; * compared with the Control group, # compared with the Mag+ group, & compared with the Mag+C@B group; ns indicates no significant difference, P>0.05; ***P<0.0001, ####P<0.0001, &P=0.0386; one-way ANOVA was used). (J) Representative viable-dead bacteria staining images of Staphylococcus aureus biofilm after 24 h of different treatments. Scale bar: 100 μm. (K) Analysis of anti-biofilm efficacy based on viable / dead bacteria fluorescence intensity ratio.(n=3, mean ± standard error; *Compared with the Control group, #: compared with the Mag+ group, &: compared with the Mag+C@B group; ns indicates no significant difference, P>0.05; ***P<0.0001, ####P<0.0001, &&&&P<0.0001; one-way ANOVA was used). (L) Crystal violet staining images of Staphylococcus aureus biofilm after 24 h of different treatments. Scale bar: 100 μm. (M) Absorbance (OD) at 590 nm was detected using an ELISA reader. 590 (n=3, mean ± standard error; * compared with the Control group, # compared with the Mag+ group, & compared with the Mag+C@B group; ns indicates no significant difference, P>0.05; ***P<0.0001, ####P<0.0001, &&&&P<0.0001; one-way ANOVA was used).

[0021] Figure 4 Magnetoelectric hydrogels create a regenerative immune environment. (A) Schematic diagram of the Transwell co-culture system of magnetoelectric hydrogels and macrophages: the hydrogel is placed in the upper chamber and the macrophages are placed in the lower chamber. (B) Flow cytometry results of CD86 (FITC-labeled) and CD206 (APC-labeled) and (C) quantitative statistical analysis. (n=3, mean ± standard error; P=0.0014, *P=0.0002; two-tailed unpaired t-test was used). (D) Representative images of CD86 immunofluorescence staining in bone marrow-derived macrophages (BMDMs) after 24 h of different treatments. Scale bar: 100 μm. (E) Three-dimensional surface map of CD86 immunofluorescence intensity. (F) Representative images of CD206 immunofluorescence staining in BMDMs after 24 h of different treatments. Scale bar: 100 μm. (G) Three-dimensional surface map of CD206 immunofluorescence intensity. (HK) Macrophage RNA sequencing (RNA-seq) and pathway enrichment analysis. Volcano plots show differentially expressed genes between the Con group and the C@B / rGO group.

[0022] Figure 5Mechanism of macrophage-mediated wound healing regulated by magnetic field-responsive magnetoelectric C@B / rGO hydrogel. (A) Seahorse XF energy metabolism assay of macrophages: Oxygen consumption rate (OCR, an indicator of oxidative phosphorylation (OXPHOS)) curve; mitochondrial inhibitors (oligomycin, FCCP, rotenone / antimycin A) injected sequentially (dashed lines). (B) Quantitative analysis of OCR-derived parameters (basal respiration, maximal respiration, reserve respiration capacity, ATP production). (n=3, data are expressed as mean ± standard error; *p=0.0112, p<0.01; two-tailed unpaired t-test used). (C) Extracellular acidification rate (ECAR, an indicator of glycolysis) curve. (D) Quantitative analysis of glycolysis-related parameters (glycolytic capacity, actual glycolysis level). (n=3, data are expressed as mean ± standard error; *p=0.0342, *p=0.0060; two-tailed unpaired t-test was used). (E) Untargeted metabolomics analysis of macrophages. Volcano plot shows differentially expressed metabolites between the Con group and the C@B / rGO group (screening criteria: |log2 (fold change)|>1, p<0.05; red: upregulated metabolites, blue: downregulated metabolites). (F) Metabolite pathway enrichment scatter plot; the intensity of the color of the dot indicates the p-value (the darker the color, the higher the significance), and the size of the dot indicates the degree of influence of the pathway (the larger the dot, the higher the influence). (G) Heatmap of differentially expressed metabolites involved in the OXPHOS pathway. (H) Immunofluorescence staining of JC-1 aggregates (red, an indicator of high mitochondrial membrane potential) and MitoTracker (green, a mitochondrial marker); scale bar = 20 μm. (I) Transmission electron microscopy (TEM) images of macrophage mitochondria (7x and 20x magnification); black arrows indicate intact mitochondrial cristae; scale bar = 1 μm (7x) and 500 nm (20x). (J) Western blot analysis of OXPHOS complex subunits: expression levels of OXPHOS complex proteins (CV-ATP5A, CIII-UQCRC2, CIV-MTCO1, CI-NDUFB8) in the Con group, C@B / rGO group, and C@B / rGO + PI3K-AKT inhibitor** group; β-actin was used as an internal control.

[0023] Figure 6Magnetoelectric hydrogels can construct regenerative immune microenvironments and promote angiogenesis. (A) Representative images of human umbilical vein endothelial cells (HUVECs) treated with different conditioned medium (CM): 0 h (initial state) and 24 h (after migration). Migrating cells were stained with crystal violet; scale bar = 100 μm. (B) Representative images of two-dimensional tube formation experiments of HUVECs treated with different CM groups; scale bar = 200 μm. (C) Quantitative analysis of migration rate and tube formation-related parameters, including (D) number of nodes, (E) number of segments, (F) number of mesh structures, and (G) vessel length (n=3, data are expressed as mean ± standard error; ns: no significant difference, ***p<0.001, ****p<0.0001, &&&p<0.001; one-way ANOVA was used). (H) Representative immunofluorescence staining images of CD31 (green, vascular endothelial marker), VEGF (red, pro-angiogenic factor), and DAPI (blue, nuclear marker) in HUVECs after different CM group treatments; scale bar = 25 μm. (I) Quantitative analysis of mean fluorescence intensity (MFI) of CD31 and (J) mean fluorescence intensity of VEGF (n=3, mean ± standard error; ns: no significant difference, *p=0.0196, #p=0.0122, **p=0.0030, ##p=0.0030, ****p<0.0001, ####p<0.0001, &&&&p<0.0001; one-way ANOVA combined with Dunnett's multiple comparison test). (KM) Relative mRNA expression levels of angiogenesis-related genes in HUVECs treated with different CM groups, as detected by real-time quantitative PCR (RT-qPCR): (K) ANG1, (L) CD31, (M) VEGF (Data are expressed as mean ± standard error; ns: no significant difference, ****p<0.0001, #####p<0.0001, &&&&p<0.0001; one-way ANOVA combined with Dunnett's multiple comparison test was used).

[0024] Figure 7 Magnetoelectric hydrogels promote the healing of infected wounds. (A) Staphylococcus aureus ( S.aureus(A) Schematic diagram of the treatment process for a mouse model of full-thickness skin defects infected with Staphylococcus aureus. (B) Representative photographs of bacterial colonies in infected skin wounds on day 3 after different treatments. All tissue homogenates were diluted with PBS at the specified ratio and then plated. (C) Photographs of Staphylococcus aureus-infected skin wounds at different time points. Scale bar = 1 mm. (D) Quantitative analysis of wound healing rate (n=3, mean ± standard error; *: compared with the Control group, #: compared with the Mag+ group, &: compared with the Mag+C@B group; ns: no significant difference, P>0.05; *P<0.05, **P<0.01, ****P<0.0001, #P<0.05, ##P<0.01, ####P<0.0001, &&P<0.01; one-way ANOVA was used). (E) Representative images of hematoxylin-eosin (H&E) staining on day 10. (F) Quantitative statistics of inflammatory cell count on day 10 (n=5, mean ± standard error; *: compared with the Control group, #: compared with the Mag+ group, &: compared with the Mag+C@B group; ns: no significant difference, P>0.05; ****P<0.0001, ###P<0.001, ####P<0.0001, &&&P<0.001, &&&&P<0.0001; one-way ANOVA was used). (G) Masson staining results on day 10. Double red arrows indicate the width of granulation tissue. Scale bar = 500 μm and 200 μm. (H) Quantitative statistics of collagen deposition (n=5, mean ± standard error; *: compared with the Control group, #: compared with the Mag+ group, &: compared with the Mag+C@B group; ns: no significant difference, P>0.05; ****P<0.0001, ###P<0.001, ####P<0.0001, &&&P<0.001, &&&&P<0.0001; one-way ANOVA was used). (I) Representative images of co-immunofluorescence staining of iNOS (red, M1 pro-inflammatory marker), KRT5 (purple, epithelial marker), and CD31 (green, vascular endothelial marker) in infected skin wounds on day 10. DAPI staining labeled cell nuclei (blue). (J) Quantitative statistics of three-dimensional interactive surface maps of iNOS, CD31, and KRT5 immunofluorescence intensity.

[0025] Figure 8Magnetoelectric hydrogels inhibit scar formation in mice. (A) Schematic diagram of the potential mechanism by which magnetoelectric hydrogels promote scarless wound healing through four major effects: antibacterial, anti-inflammatory, pro-angiogenic, and anti-fibrotic. (B) Optical photographs and simulations of scar area changes from day 15 to day 20. (C) Analysis of scar change curves in scar tissues of each treatment group (n=3, biologically independent samples). (D) Immunofluorescence staining images of COLI (red), α-SMA (green), TGF-β (purple), and DAPI (blue) in wound tissue on day 20, and quantitative analysis of three-dimensional interactive surface maps of COLIII, α-SMA, and TGF-β immunofluorescence intensity. (E) Quantitative analysis of mRNA expression levels of COLIII, α-SMA, and TGF-β on day 20 (n=3, mean ± standard error; p<0.001, ****p<0.0001, ###p<0.001, ####p<0.0001, &&&p<0.001, &&&&p<0.0001; one-way ANOVA was used). (F) Detection results of vascular density and oxygen content in scar tissue of each treatment group.

[0026] Figure 9 Magnetoelectric hydrogels promote scarless wound healing in a New Zealand rabbit model. (A) Staphylococcus aureus ( S.aureus(A) Schematic diagram of the treatment process for an infected rabbit ear skin defect model. (B) Optical photographs of wound healing changes from day 0 to 21. (C) Schematic diagram of assessment indicators related to rabbit ear scarring effect. (D) Scar thickness in different groups on day 21. (E) Scar elevation index (SEI) in different groups on day 21. (n=5, mean ± standard error; *: compared with the Control group, #: compared with the Mag+ group, &: compared with the Mag+C@B group; ns: no significant difference, P>0.05; ****P<0.0001, ####P<0.0001, &&P<0.01, &&&&P<0.0001; one-way ANOVA was used). (F) Schematic diagram of the transilluminance experiment used to analyze the inflammatory response and observation of gross erythema in rabbit ear scar tissue. Scale bar: 2 mm. (G) Quantitative analysis of erythema area in different groups on day 21. (n=5, mean ± standard error; *: compared with Control group, #: compared with Mag+ group, &: compared with Mag+C@B group; ns: no significant difference, P>0.05; ****P<0.0001, ####P<0.0001, &&&P<0.001, &&&&P<0.0001; one-way ANOVA was used). (H) Ultrasound images of scar tissue. Red lines represent scar boundaries. Scale bar: 2 mm. (I) Quantitative analysis of scar elevation angles in different groups on day 21. (J) H&E staining of scar tissue in each treatment group on day 21. Scale bar: 2 mm (low magnification) and 500 μm (high magnification). (K) Quantitative analysis of the number of inflammatory cells in different groups on day 21. (n=5, mean ± standard error; *: compared with Control group, #: compared with Mag+ group, &: compared with Mag+C@B group; ns: no significant difference, P>0.05; *P<0.05, ***P<0.001, #P<0.05, ###P<0.001, &&P<0.01; one-way ANOVA was used). (L) Masson's trichrome staining of scar tissue in each treatment group on day 21. Scale bar: 2 mm (low magnification) and 500 μm (high magnification). (M) Quantitative analysis of collagen deposition in different groups on day 21. (n=5, mean ± standard error; *: compared with the Control group, #: compared with the Mag+ group, &: compared with the Mag+C@B group; ns: no significant difference, P>0.05; ****P<0.0001, ####P<0.0001, &&&&P<0.0001; one-way ANOVA was used).

[0027] Figure 10Magnetoelectric hydrogels promote scarless wound healing in a miniature pig model. (A) Schematic diagram of the treatment process for a full-thickness skin defect model in miniature Bama pigs. (B) Photographs of skin wounds in miniature pigs from different treatment groups at different time points. Scale bar = 5 mm. (C) Representative H&E staining images of wound tissue on day 21. Scale bar = 2 mm (low magnification) and 500 μm (high magnification). (D) Quantitative analysis of epidermal thickness in different groups. (n=4, mean ± standard error; *: compared with the control group, #: compared with the Beifuji group; ***P<0.0001, ####P<0.001; one-way ANOVA was used). (E) Representative Masson's trichrome staining images of wound tissue on day 21. Scale bar = 2 mm (low magnification) and 500 μm (high magnification). (F) Quantitative analysis of collagen deposition in different groups. (n=4, mean ± standard error; *: compared with the Control group, #: compared with the Beifuji group; ns: no significant difference, P>0.05; ***P<0.0001, ####P<0.001; one-way ANOVA was used). (G) Representative Sirius red staining images of wound tissue on day 21. Scale bar = 100 μm. (H) Quantitative analysis of type I / III collagen ratio in different groups. (n=4, mean ± standard error; *: compared with the Control group, #: compared with the Beifuji group; **P=0.0038, ***P<0.0001, ##P=0.0039; one-way ANOVA was used). (I) Representative immunohistochemical staining images of wound tissue on day 21. Scale bar = 100 μm. (J) Quantitative analysis of mRNA expression levels of α-SMA, TGF-β and MMP-1 on day 21. (n=3, mean ± standard error; *: compared with the control group, #: compared with the Beifuji group; **P=0.0039, ****P<0.0001, ##P<0.01, ###P=0.0004; one-way ANOVA was used). Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that the upper and lower limits of the range and each intermediate value between them are specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0030] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention.

[0031] Anti-infection and scar-free tissue repair materials One aspect of this invention provides an anti-infection, scar-free healing tissue repair material (sometimes referred to herein as a composite material), comprising a polymer material with a three-dimensional network structure, magnetoelectric nanoparticles and conductive fillers filled in the polymer material, wherein the magnetoelectric nanoparticles comprise a shell structure with piezoelectric properties and a core structure with magnetoelectric responsive properties, the shell structure being prepared from raw materials including inorganic piezoelectric materials and / or organic piezoelectric materials, and the core structure being prepared from magnetoelectric materials. Addressing the core defects of existing skin repair materials—"easy to develop drug resistance, strong signal modulation invasiveness, poor multi-stage adaptability, and low scar-free repair efficiency"—in some embodiments, this invention provides a non-invasive magnetoelectric responsive hydrogel that stabilizes the endogenous potential output of the wound through magnetic field triggering, avoiding secondary damage to the wound surface from thermal or mechanical stimulation, achieving multi-stage dynamic regulation of the wound microenvironment, providing antibacterial and anti-inflammatory effects during the inflammatory phase, promoting angiogenesis during the proliferative phase, and inhibiting fibrosis during the remodeling phase, synergistically blocking scar formation.

[0032] In this invention, when the core structure of the magnetoelectric nanoparticle is magnetized in a magnetic field, it can be displaced (elongated or shortened) along the magnetization direction, and the shell structure with piezoelectric properties can convert the mechanical energy brought by the core structure into an output voltage (endogenous potential of the wound).

[0033] In a preferred embodiment, the composite material is a magnetoelectrically treated composite material. The magnetoelectric treatment includes treating the composite material with a magnetic field strength of 0.01-300 mT and a frequency of 0.1-100 kHz for a treatment time of 0.1-500 min. The magnetic field strength is also preferably 0.1-200 mT, more preferably 0.5-100 mT, more preferably 0.5-50 mT, and most preferably 0.5-10 mT, for example, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10 mT. The frequency is also preferably 0.5-50 kHz, more preferably 0.5-10 kHz, and more preferably 0.5-5 kHz, for example, 0.5, 1, 2, 3, 4, 5 kHz.

[0034] In this invention, the shell structure with piezoelectric properties is prepared from inorganic piezoelectric materials and / or organic piezoelectric materials. In a preferred embodiment, the shell structure with piezoelectric properties is prepared from an inorganic piezoelectric material. In a more preferred embodiment, the inorganic piezoelectric material is selected from at least one of ferrite, niobate, titanate, silicate, and aluminate. In a most preferred embodiment, the shell structure with piezoelectric properties is prepared from a ferrite material. In this invention, the ferrite material has the following structure: M x Fe 3-x O y M includes at least one of Bi, Ca, Ba, Mg and Ba, where x is a number from 0.25 to 1.5 and y is 4.

[0035] In this invention, the core structure with magnetoelectric response properties is prepared from a magnetoelectric material, wherein the magnetoelectric material has the following structure: N a Fe 1-a O b Wherein, N includes at least one of Co, Mn, Zn and Ni, a is a number from 0.25 to 0.75, and b is 3.

[0036] It is understood that the magnetoelectric nanoparticles of the present invention may or may not contain doping elements. When doping elements are present, the elements include, but are not limited to, at least one of carbon, nitrogen, phosphorus, sulfur, silicon, aluminum, iron, titanium, nickel, manganese, copper, silver, and zinc, thereby further improving the piezoelectric properties and / or magnetoelectric response properties of the magnetoelectric nanoparticles.

[0037] In one specific embodiment, the magnetoelectric nanoparticles are cobalt ferrite-bismuth ferrite nanoparticles. In this invention, the average particle size of the cobalt ferrite-bismuth ferrite nanoparticles is 100-500 nm, preferably 200-400 nm, even more preferably 200-300 nm, further preferably 220-260 nm, and most preferably 220-240 nm, for example 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, and 240 nm.

[0038] This invention does not particularly limit the preparation of magnetoelectric nanoparticles. Methods known in the art can be used to prepare a shell structure with piezoelectric properties and a core structure with magnetoelectric response properties, which are then mixed and calcined to obtain composite nanoparticles with a core-shell structure. It is understood that arbitrary doping elements or other layered structures may be present between the shell and core structures, in the outer layer of the shell structure, and within the core structure to improve the piezoelectric properties and / or magnetoelectric response properties of the nanoparticles.

[0039] In this invention, the specific type of polymeric material with a three-dimensional network structure is not particularly limited. It can be a polymeric material of natural origin and / or artificial synthesis, and examples include, but are not limited to, at least one of: alginate, chitosan, hyaluronic acid, collagen, fibroin, silk fibroin, polyacrylates, acrylamides, polycaprolactone / polylactic acid hydrogels, gelatin, and polypeptide self-assembled hydrogels. In a preferred embodiment, the polymeric material is gelatin, more preferably methacrylamide gelatin.

[0040] In this invention, the conductive filler can be any material with good biocompatibility and conductivity, as long as it can enhance the intrinsic potential conduction efficiency and reduce charge loss. Examples of the conductive filler include, but are not limited to, at least one of graphene, reduced graphene oxide, carbon nanotubes, and gold nanomaterials.

[0041] In this invention, the composite material comprises 0.1-50 parts by weight of polymer material, 0.1-50 parts by weight of magnetoelectric nanoparticles and 0.01-50 parts by weight of conductive filler. Preferably, the composite material comprises 1-10 parts by weight of polymer material, 0.1-10 parts by weight of magnetoelectric nanoparticles and 0.05-5 parts by weight of conductive filler.

[0042] In the composite material of the present invention, the mass ratio of polymer material to magnetoelectric nanoparticles is 1-50:1, preferably 1-20:1, and even more preferably 1-10:1, for example 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1.

[0043] In the composite material of the present invention, the mass ratio of magnetoelectric nanoparticles to conductive fillers is 1-100:1, preferably 1-80:1, even more preferably 1-60:1, and further preferably 1-50:1, for example 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1.

[0044] Preparation method One aspect of the present invention provides a method for preparing an anti-infection, scar-free tissue repair material, comprising: (1) Prepare magnetoelectric nanoparticles comprising a shell structure with piezoelectric properties and a core structure with magnetoelectric response properties, wherein the shell structure is prepared from raw materials including inorganic piezoelectric materials and / or organic piezoelectric materials, and the core structure is prepared from magnetoelectric materials; (2) The magnetoelectric nanoparticles and conductive fillers are filled into a polymer material with a three-dimensional network structure to obtain the tissue repair material.

[0045] In a preferred embodiment, the preparation method of the present invention includes: (1) CoFe2O4 precursor was synthesized by hydrothermal method and BiFeO3 precursor was prepared by sol-gel synthesis method. CoFe2O4 precursor and BiFeO3 precursor were mixed and heated at 80-200°C (preferably 80-150°C, more preferably 100-120°C) for 0.5-5 hours (preferably 1-5 hours, more preferably 1-3 hours), and then calcined at 200-800°C (preferably 400-800°C, more preferably 500-700°C) until core-shell structured magnetoelectric nanoparticles were formed. (2) The magnetoelectric nanoparticles and conductive fillers are dispersed in a solution of a polymer material with a three-dimensional network structure, a photoinitiator is added to obtain a precursor solution, and the precursor solution is cured to obtain the tissue repair material.

[0046] In a preferred embodiment, the method of the present invention further includes: (3) treating the tissue repair material with a magnetic field having a magnetic field strength of 0.01-300 mT.

[0047] In this invention, the photoinitiator is selected from at least one of lithium phenyl(2,4,6-trimethylbenzoyl)phosphate (LAP), ethyl 2,4,6-trimethylbenzoyl-phenylphosphonate (TPO-L), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure 819), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (Irgacure 2959), and camphorquinone (CQ). When photocuring the precursor solution, a suitable wavelength can be selected according to the chosen photoinitiator. The wavelength range is preferably 250-500 nm, more preferably 380-500 nm, and even more preferably 380-455 nm. The irradiation time is 5-300 s, preferably 5-200 s, even more preferably 5-100 s, and even more preferably 5-80 s.

[0048] application One aspect of the present invention provides the use of the repair material in the preparation of products for skin damage repair. The specific type of product is not particularly limited and may be an ointment, cream, lotion, gel, paste, etc., or the product for repair may be a dressing, microneedle array / patch, or tissue engineering scaffold. Alternatively, the product may also be a medical device for skin repair, such as, but not limited to, a magnetic field therapy device and / or a phototherapy device comprising the composite material of the present invention, wherein the magnetic field therapy device is provided with a magnetic field generating unit configured to generate a magnetic field with a magnetic field strength of 0.01-300 mT and a frequency of 0.1-100 kHz; and the phototherapy device is provided with a light generating unit configured to generate therapeutic light with a wavelength in the range of 250 nm to 1200 nm and an intensity in the range of 1 mW / cm² to 500 mW / cm².

[0049] In this invention, the repair effect can be confirmed by indicators including but not limited to wound healing rate, healing time, wound size, scar size or scar index, epidermal regeneration, angiogenesis, and inflammatory response, or by molecular biological indicators such as growth factor expression level, collagen synthesis-related genes, and inflammatory factor level. Corresponding measurement methods are well known in the art.

[0050] In this invention, the wound healing rate is defined as: Wound healing rate = (initial area - current area) / initial area × 100%.

[0051] In this invention, the scar index is defined as: SEI = H / H0. Where H represents the length from the highest point of the scar tissue to the cartilage surface, and H0 represents the length from the stratum corneum of normal skin to the cartilage surface before surgery. SEI = 1 indicates that the height of the scar is equal to the thickness of the surrounding undamaged skin, and SEI > 1 indicates scar tissue hyperplasia.

[0052] Methods to promote macrophage reprogramming One aspect of the present invention provides a method for promoting macrophage reprogramming, the method comprising the step of indirectly contacting and culturing macrophages in vitro using the tissue repair material (magnetoelectric hydrogel) described in this invention. In some embodiments, the method of the present invention is used for non-disease diagnostic and therapeutic purposes.

[0053] In a preferred embodiment, promoting macrophage reprogramming refers to promoting the conversion of the M1 pro-inflammatory phenotype to the repair phenotype M2.

[0054] Example I. Experimental Methods 1. Preparation and performance testing of magnetoelectric nanoparticles (CFO-BFO) (1) Synthesis method CoFe₂O₄ nanoparticles were synthesized using a hydrothermal method. First, a mixed solution containing 0.2 M FeCl₃·6H₂O, 0.01 M CoCl₂·6H₂O, 0.19 M C₆H₅O₇Na₃, and 1.25 M C₂H₃O₂Na was added to a mixed solvent of diethylene glycol and ethylene glycol. The homogeneous solution was then heated at 200°C for 10 hours. After cooling, the black precipitate was thoroughly washed with deionized water and ethanol, and then dried at 60°C for 2 hours. Simultaneously, piezoelectric BiFeO₃ was prepared using a sol-gel synthesis method. A mixture of 0.2 M Bi(NO₃)₃·5H₂O and 0.2 M Fe(NO₃)₃·9H₂O was dissolved in a mixture of ethylene glycol and glacial acetic acid. The solution was continuously stirred and heated for 6 hours to form the BiFeO₃ precursor. Subsequently, 0.94 g of the prepared CoFe2O4 nanoparticles were mixed with 40 mL of BiFeO3 precursor and heated at 110°C for 2 hours. The composite powder was then calcined overnight at 600°C to form core-shell structured CoFe2O4-BiFeO3 nanoparticles.

[0055] (2) Performance testing The morphology and size of the materials were observed using electron microscopy. Elemental analysis of the nanoparticles was performed using energy dispersive spectroscopy (EDS). X-ray diffraction (XRD) patterns of CFO NPs, BFO NPs, and CFO-BFO NPs were recorded on a Bruker-AXS D8 Advance powder diffractometer. X-ray photoelectron spectroscopy (XPS) was performed on a spectrometer. The hysteresis loop modes of CFO NPs and CFO-BFO NPs were measured using a vibrating sample magnetometer. Piezoelectric response force microscopy (PFM) measurements were recorded. Electron paramagnetic resonance (EPR) spectra were detected using a Bruker EMX-10 / 12 spectrometer. Absorption spectra were determined using a spectrophotometer.

[0056] 2. Design, construction, and performance testing of the magneto-electrically coupled hydrogel GelMA / C@B / rGO. (1) Synthesis method Hydrogel matrix: Taking biocompatible polymer methacrylamide gelatin (GelMA) as an example, it can provide a three-dimensional network structure and cell adhesion sites, accounting for 5% by mass; Magnetoelectric nanoparticles: CFO-BFO core-shell structure, the core CFO responds to the magnetic field to generate mechanical deformation, and the shell BFO ​​converts the deformation into EF, accounting for 1%-5% by mass; Conductive filler: Reduced graphene oxide (rGO) is used to enhance EF conduction efficiency and reduce charge loss, accounting for 0.1%-1% by mass; GelMA is dissolved in PBS, heated to 50℃ and stirred for 30 min until completely dissolved; rGO and CFO-BFO nanoparticles are added sequentially, and ultrasonically dispersed for 30 min; 0.25% (w / v) lithium phenyl (2,4,6-trimethylbenzoyl)phosphate (LAP) photoinitiator is added, and stirred in the dark for 30 min to obtain the precursor solution; The precursor solution is injected into a mold, irradiated with blue light (wavelength 405 nm) for 60 s to cure, to obtain a magneto-electric coupled hydrogel. Figure 2 A).

[0057] (2) Magnetic field loading The magnetic field strength was 1.5 mT, the frequency was 1 kHz, and the duration was 30 min.

[0058] (3) Performance testing Each group of GelMA / C@B / rGO was prepared into 1 cm diameter samples. The porous structure of the hydrogel was observed using a scanning electron microscope to detect the dispersion of CFO@BFO and rGO particles in the GelMA hydrogel. Fourier transform infrared spectroscopy was used to detect the absorption peaks of the chemical groups, confirming successful loading of CFO@BFO and rGO particles. The hydrogel's adhesion was tested by applying different weights and bending fingers. Surface wettability was measured using a water contact angle meter. The hydrogel's swelling properties were tested by weighing it at different time points after immersion in PBS (pH 7.4). Its degradability was also tested by weighing the hydrogel at different time points. Tensile strength and Young's modulus were measured using a universal testing machine. The magnetoelectric output signal and conductivity of the hydrogel were detected using an electrometer and a universal electrochemical workstation.

[0059] 3. In vitro antibacterial study of magneto-electrically coupled hydrogels Staphylococcus aureus was used as a representative bacterium to evaluate the antibacterial effect. Magnetoelectric hydrogels and bacterial suspensions were co-cultured. After magnetic field loading, bacteria were fixed with glutaraldehyde for 4 h, dehydrated with graded ethanol, and sputter-coated with gold for scanning electron microscopy and transmission electron microscopy imaging to observe bacterial structure and assess the damage to bacterial morphology caused by the magnetoelectric effect. To further evaluate the antibacterial activity of the magnetoelectric hydrogel, bacteria were stained with SYTO9 and propidium iodide (PI) fluorescent dyes and scanned using a laser scanning confocal microscope. Green fluorescence indicated viable bacteria, and red fluorescence indicated dead bacteria. Bacteria were co-cultured in 12-well plates for 3 days. Viable / dead bacterial staining was performed using a laser scanning confocal microscope to detect bacterial biofilm formation. Simultaneously, crystal violet solution was stained for 20 min, and the stained biofilm was eluted with acetic acid solution. The absorbance was measured at 595 nm. To further investigate the mechanism of the magnetoelectric effect in killing bacteria, a ROS (reactive oxygen species) staining kit was used. Preliminary results showed that the magnetoelectric effect can induce an increase in intracellular ROS levels, leading to bacterial cell wall damage and leakage of contents, thereby killing the bacteria.

[0060] 4. In vitro regulation of macrophage reprogramming using magneto-electrically coupled hydrogels Bone marrow-derived macrophages (BMDMs) were used at a rate of 1 × 10⁶ cells per well. 5 Cells were cultured at specific densities. First, bone marrow-derived macrophage membrane markers (BMDMs) were treated with *E. coli* lipopolysaccharide for 24 hours to construct an inflammatory cell model. Subsequently, they were cultured in Transwell chambers (magnetoelectric hydrogel in the upper chamber, BMDMs in the lower chamber) for 24 hours to investigate their immunomodulatory effects. Immunofluorescence staining was performed using anti-CD86 (pro-inflammatory) and anti-CD206 (anti-inflammatory) primary antibodies, and images were acquired using a laser confocal microscope. Macrophage surface markers (CD86, CD206) were assessed by flow cytometry to determine macrophage phenotype.

[0061] 5. Study on the effect of magneto-electrically coupled hydrogel on scarless healing of full-thickness skin defects in mice To investigate the effect of magneto-electric coupling hydrogel on promoting scarless healing of infected wounds under alternating magnetic field stimulation, a mouse model of full-thickness dermal wound infection was established. Eight-week-old male C57BL / 6J mice were completely anesthetized, and two circular full-thickness skin wounds were created on their backs. =6 mm), and 20 μL of Staphylococcus aureus suspension was applied to the wound. An infected wound was successfully established in mice using a 3M dressing for 24 h. Subsequently, the infected skin wound was covered with hydrogel, and magnetic field therapy was administered daily. Wound size was measured and recorded on days 2, 6, and 8, and scar tissue was measured and recorded on days 15 and 20. The wound healing rate and scar area were calculated using ImageJ software. Mice were sacrificed on days 10 and 20, and infected and scar tissues around the wounds were collected from each group. These tissue samples were subjected to hematoxylin-eosin (HE) staining, Masson's trichrome staining, immunofluorescence staining, and qPCR detection to evaluate wound healing and scar index, thus assessing the scarless healing effect of the magnetoelectric hydrogel. On day 20, in vivo photoacoustic imaging was performed on the backs of mice to assess blood flow and oxygenation levels in the defective skin.

[0062] 6. Study on the effect of magneto-electric coupling hydrogel on scarless healing of infected skin defects in New Zealand rabbit ears To investigate the effect of magneto-electric coupling hydrogel on promoting scarless healing of infected wounds under alternating magnetic field stimulation, a rabbit ear skin wound infection model was established. Three-month-old male New Zealand rabbits were completely anesthetized, and six circular skin wounds were created on the ear. =10 mm), and 60 μL of Staphylococcus aureus suspension was applied to the wound surface. A rabbit ear infection wound was successfully established by fixing it with a 3M dressing for 24 h. Subsequently, the infected skin wound was covered with hydrogel, and magnetic field therapy was administered daily. Wound and scar sizes were measured and recorded on days 5, 14, and 21, and the wound healing rate and scar area were calculated using ImageJ software. New Zealand rabbits were euthanized on day 21, and infected and scarred skin tissues around the wounds were collected from each group. These tissue samples were stained with hematoxylin-eosin (HE) and Masson's trichrome to evaluate wound healing and scar index, assessing the scarless healing effect of the magnetoelectric hydrogel. On day 21, live acoustic imaging was performed on the ears of New Zealand rabbits to assess the scar index. On day 21, a darkroom transillumination test was performed on the ears of New Zealand rabbits to assess the extent of redness and swelling of the ear skin defect and determine the degree of inflammation.

[0063] 7. Study on the effect of magneto-electrically coupled hydrogels on scarless healing of infected skin defects in miniature Bama pigs To investigate the effect of magneto-electric coupling hydrogel on promoting scarless healing of infected wounds under alternating magnetic field stimulation, a full-thickness skin wound infection model was established in miniature Bama pigs. Male miniature Bama pigs weighing 5 kg were completely anesthetized, and six circular skin wounds were created on their backs. = 20 mm), and 100 μL of Staphylococcus aureus suspension was applied to the wound surface. An infected wound was successfully established using a 3M dressing for 24 h. Subsequently, the infected skin wound was covered with hydrogel, and magnetic field therapy was administered daily. Wound and scar sizes were measured and recorded on days 5, 14, and 21, and the wound healing rate and scar area were calculated using ImageJ software. Miniature Bama pigs were euthanized on day 21, and infected and scarred skin tissues around the wounds were collected from each group. These tissue samples were subjected to hematoxylin-eosin (HE) staining, Masson's trichrome staining, Siris red staining, immunohistochemical staining, and qPCR detection to evaluate wound healing and scar index, thus assessing the scarless healing effect of the magnetoelectric hydrogel.

[0064] II. Experimental Results Previous experimental studies have shown that bacterial infection and macrophage phenotype dysregulation lead to delayed wound healing and scar formation. Chronic infected wounds are characterized by an dysregulated immune metabolic microenvironment, which perpetuates inflammation and impairs tissue regeneration, resulting in inevitable scarring. Preliminary pathological verification showed that compared with uninfected controls, Staphylococcus aureus infection reduced wound closure rate by 40% on day 8, accompanied by extensive inflammatory cell infiltration and disordered collagen deposition, which are hallmarks of impaired healing and early scar formation. Immunofluorescence staining results showed that infected wounds exhibited strong CD86 (M1 marker) expression, while KRT5 (epithelial marker) was reduced, confirming that bacterial infection locks macrophages into a pro-inflammatory M1 state. Therefore, precise regulation of macrophage phenotype is a potential target for treating infected wounds and preventing scarring.

[0065] 1. Preparation and characterization of magnetoelectric CFO-BFO NPs This embodiment first synthesizes CFO core-shell nanoparticles by hydrothermal synthesis of CFO core and sol-gel coating of BFO shell. Figure 1 A). TEM images confirm that the CFO-BFO NP exhibits a clear core-shell morphology with a total diameter of approximately 100 nm. High-resolution TEM (HRTEM) images show the lattice spacing of BFO (110) and CFO (220). Figure 1 B). The EDS spectrum showed a uniform distribution of Co, Fe, Bi, and O elements, confirming the successful integration of CFO and BFO. Figure 1 C). The XRD pattern of CFO-BFO NP shows that its diffraction peaks match those of CFO (JCPDS No. 03-0864, ​​spinel structure) and BFO (JCPDS No. 71-2494, perovskite structure), and there are no impurity peaks, indicating that its purity is high. Figure 1 D). XPS measurements confirmed the presence of Co, Fe, Bi, O, and C, while high-resolution spectroscopy verified the chemical states of key elements. Figure 1 E). The magnetic properties of CFO-BFO NP were evaluated using a vibrating sample magnetometer (VSM). Initial magnetization and magnetic saturation indicate that CFO-BFO NP exhibits excellent response to alternating magnetic fields. Figure 1 F). The magnetoelectric conversion properties of CFO-BFO nanoparticles were investigated using piezoelectric force microscopy (PFM). PFM measurements revealed piezoelectric hysteresis loops, confirming the piezoelectric effect in the core-shell CFO-BFO NPs. Under magnetic field stimulation, EPR spectra showed DMPO-•O2. - The characteristic peaks of DMPO-•OH indicate that ROS is generated through magneto-electrocatalysis, a fact further verified over time by RHB degradation experiments. Figure 1 GJ).

[0066] In summary, these results confirm the successful fabrication of magnetoelectric CFO-BFO NPs, in which the synergistic magnetostrictive piezoelectric coupling effect between the CFO core and BFO shell is fully realized. This not only validates the rational design of magnetoelectric nanocomposites but also provides a key functional material basis for the subsequent synthesis of magnetoelectric hydrogels, thus laying the foundation for developing non-invasive treatment strategies to achieve scarless healing of infected wounds.

[0067] 2. Preparation and characterization of magnetoelectric gel GelMA / C@B / rGO hydrogel Digital imaging revealed that the precursor solution was injectable and formed a stable gel upon UV irradiation. The C@B / rGO hydrogel exhibited excellent injectability and compliance, confirming its suitability for irregular wound sites in clinical applications. Figure 2 B). The wetting angle (a key indicator of material hydrophilicity / hydrophobicity) of each material group was tested: pure GelMA showed a moderate wetting angle of approximately 60°, while the wetting angle of GelMA / C@B / rGO was significantly reduced (~30°). A smaller wetting angle indicates stronger hydrophilicity, confirming that the introduction of rGO enhances the hydrophilicity of the hydrogel. Figure 2 C). Figure 2 The SEM images shown in Figure D reveal that pure GelMA has a loose porous structure (a); C@B ​​shows the nanocomposite material aggregated in the pores (b); C@B / rGO maintains a uniform porous structure (pore size ~50-100 μm) and is well dispersed (c). This porous structure of CFO@BFO / rGO facilitates nutrient exchange, cell penetration, and waste removal in the wound environment. Figure 2 D). Fe (CFO core), Co (BFO shell), and Bi (BFO component) are uniformly distributed in the C@B / rGO hydrogel (without local aggregation), confirming the uniform integration of the magnetoelectric nanocomposite material—crucial for stable magnetoelectric properties. Figure 2E). FTIR spectra show GelMA (e.g., amide I) at ~1650 cm⁻¹. -1 CFO@BFO (metal-oxygen bond at ~500 cm⁻¹) -1 (location) and rGO (C=C~1580 cm) -1 All peaks at the specified locations are present in C@B / rGO, and no new peaks indicate non-covalent (physical) integration—avoiding the loss of biocompatibility caused by chemical modification. Figure 2 F). The storage modulus (G') of C@B / rGO is ~1000 Pa (much greater than the loss modulus G'), confirming a stable gel state; compared to pure GelMA, C@B / rGO exhibits enhanced mechanical strength, sufficient to withstand shear forces in wound dressing applications. Figure 2 G). In vitro degradation assays showed that the hydrogel retained 20% of its weight after 48 hours, matching the skin healing timeline, while the swelling rate reached 50% within 72 hours, demonstrating effective absorption of exudate. Figure 2 H, I). Under magnetic field stimulation, the hydrogel produced a stable output voltage of 1.5 V, confirming reliable magnetoelectric conversion—a key mechanism for regulating cell behavior through endogenous electro-electro-like signals (H, I). Figure 2 J, K). The images visually demonstrate the conductivity of the C@B / rGO hydrogel, and the lamp with the closed circuit disconnected was relit by connecting it with C@B / rGO. Conductivity measurements show that rGO significantly enhances electron transfer: conductivity increases with increasing rGO concentration, reaching 3 S / m at 0.5 mg / mL rGO. Figure 2 L).

[0068] 3. Magnetoelectric hydrogels kill Staphylococcus aureus and inhibit its biofilm by generating ROS. Staphylococcus aureus ( S.aureus Bacteria are a major cause of infected wounds and delayed healing. Reactive oxygen species (ROS) can mediate antibacterial activity by oxidizing bacterial cell membrane lipids and intracellular biomolecules, disrupting cell membrane structural integrity, or directly damaging key cellular components. Thanks to the excellent electroactive properties of magnetoelectric hydrogels, they can efficiently generate ROS through reactions with water molecules and oxygen under magnetic field stimulation, offering significant potential for inhibiting infections caused by pathogenic bacteria. Figure 3 A). Colony forming unit (CFU) count results showed that the bacterial count in the Mag+C@B / rGO group was 1.23 × 10⁻⁶. 8 CFU / mL was significantly lower than that of the control group (PBS treatment, 1.5 × 10⁻⁶). 9 CFU / mL), Mag+ group (1.53×10) 9 CFU / mL) and Mag+C@B group (4.5×10 9 CFU / mL)( Figure 3 B, C). Live / dead bacteria staining experiments confirmed that a large number of bacteria died (red fluorescence) in the Mag+C@B / rGO group, while the Control group was dominated by live bacteria (green fluorescence), with an antibacterial rate exceeding 92%. Figure 3 D, E). Scanning electron microscopy (SEM) images further revealed that bacteria in the Mag+C@B / rGO group exhibited cell membrane rupture, cytoplasmic leakage, and morphological deformation—consistent with ROS-mediated damage characteristics; simultaneously, the average cell size of Staphylococcus aureus in the Mag+C@B / rGO group decreased by 70%. Figure 3 F, G). Dichlorofluorescein diacetate (DCFH-DA) staining results confirmed that the intracellular ROS level of bacteria in the Mag+C@B / rGO group was significantly increased, which verified that its antibacterial activity originated from the ROS generated by cobalt ferrite-bismuth ferrite (CFO-BFO) through magnetoelectric catalysis, and the electron transfer process enhanced by reduced graphene oxide (rGO). Figure 3 H, I). Biofilm formation is a key obstacle to the healing of infected wounds. Figure 3 The results of biofilm live / dead bacteria staining in J and K are compared with Figure 3 Consistent with D, the Mag+C@B / rGO group exhibited the highest anti-biofilm efficacy. Crystal violet staining and live / dead bacteria staining results showed that the Mag+C@B / rGO group almost completely eliminated biofilm formation, while the Control group formed a dense and complete biofilm, confirming that this material can effectively inhibit the formation of Staphylococcus aureus biofilm. Figure 3 In summary, these findings highlight the powerful antibacterial properties of magnetoelectric hydrogels, which can be attributed to magnetoelectric-induced ROS generation.

[0069] 4. Magnetoelectric hydrogels induce macrophage reprogramming to construct a regenerative immune microenvironment. Macrophage polarization (M1→M2) is a key step in alleviating inflammation and initiating tissue repair. To simulate the inflammatory microenvironment of infected wounds, bone marrow-derived macrophages (BMDMs) were treated with lipopolysaccharide (LPS) for 24 hours. To verify the immunomodulatory effect of the magnetoelectric hydrogel, BMDMs were collected using a Transwell chamber system for subsequent analysis: the hydrogel was placed in the upper chamber, and the BMDMs were placed in the lower chamber. Figure 4 A). Flow cytometry quantification results showed that CD206 + The cell percentage increased from 20% (Control group) to 60%, while CD86 + The cell percentage decreased from 18% to 5%. Figure 4B, C). Immunofluorescence staining results showed that, compared with the Control group, the Mag+C@B / rGO group had significantly higher fluorescence intensity of CD206 (M2 macrophage marker) and significantly lower fluorescence intensity of CD86 (M1 macrophage marker). Figure 4 DG).

[0070] To elucidate the molecular mechanism by which magnetoelectric hydrogels induce functional shifts in macrophages, this embodiment integrates transcriptome sequencing, energy metabolism assays, non-targeted metabolomics, and pathway inhibition experiments, focusing on the core association between signaling pathways and metabolic reprogramming. First, RNA sequencing (RNA-seq) was performed on LPS-stimulated macrophages treated with / without Mag+C@B / rGO hydrogels (groups: Gel group vs. SC group). Volcano plot analysis ( Figure 4 H) identified 511 upregulated differentially expressed genes (DEGs) and 1039 downregulated differentially expressed genes (screening criteria: |log2FC|>0.585, p<0.05), among which genes related to metabolic pathways showed obvious clustering. KEGG enrichment scatter plot showed that differentially expressed genes were significantly enriched in the PI3K-AKT signaling pathway and metabolic pathway, especially the oxidative phosphorylation (OXPHOS) pathway (both p*<0.001, enrichment factor>1.2), suggesting that these two pathways are the core of hydrogel-induced macrophage reprogramming. Figure 4 I). Gene set enrichment analysis (GSEA) further confirmed that the tricarboxylic acid cycle (TCA cycle) and OXPHOS pathway were significantly activated and upregulated in the Gel group. Figure 4 J). The enrichment scores (RES) of both pathways showed positive deviations from baseline, with core enriched genes (such as Akt1, Ndufb8, and Atp5f1a) showing synergistic upregulation. Figure 4 These transcriptomic data directly demonstrate that the magnetoelectric hydrogel drives metabolic reprogramming in macrophages by activating the PI3K-AKT signaling pathway and enhancing oxidative phosphorylation.

[0071] 5. Magnetoelectric hydrogels mediate macrophage metabolic reprogramming via mitochondrial oxidative phosphorylation (OXPHOS) metabolic reprogramming. To verify the functional effects of transcriptome changes, the oxygen consumption rate (OCR, an indicator of oxidative phosphorylation (OXPHOS)) and extracellular acidification rate (ECAR, an indicator of glycolysis) of macrophages were measured using a Seahorse XF analyzer. OCR curves showed that the OCR level in the Mag+C@B / rGO group was significantly increased; compared with the control group, its basal respiration, maximal respiration, ATP-coupled respiration, and reserve respiration capacity (OXPHOS core parameters) were increased by approximately 1.8, 2.1, 1.9, and 2.3 times, respectively. Figure 5A, B). Conversely, the ECAR curves, glycolytic capacity, and quantitative analysis results of glycolytic reserve in the Mag+C@B / rGO group were all reduced by approximately 50%. Figure 5 (C, D). These results directly confirm that the hydrogel can reverse the LPS-induced "glycolysis-dominated" metabolic phenotype of macrophages, switching their energy metabolism mode to OXPHOS-, consistent with the enrichment results of the OXPHOS pathway in transcriptomics. To supplement the transcriptomics and functional experimental data, this embodiment performed non-targeted metabolomics detection on the same macrophage group ( Figure 5 E). KEGG enrichment analysis of the metabolite set showed that metabolites involved in OXPHOS were significantly accumulated in the Mag+C@B / rGO group, while the expression of glycolysis-related metabolites was downregulated (E). Figure 5 F, G). This change in metabolic level is completely consistent with the results of transcriptomics (upregulation of the OXPHOS pathway) and functional experiments (increased OCR), further confirming that OXPHOS is a key metabolic switch driving macrophage reprogramming under the regulation of magnetoelectric hydrogel.

[0072] To clarify the role of the PI3K-AKT pathway in hydrogel-induced metabolic reprogramming, this study evaluated mitochondrial structure / function and conducted pathway inhibition experiments. Immunofluorescence staining results showed that, compared with the control group, the Mag+C@B / rGO group had more abundant and more evenly distributed mitochondria (green, MitoTracker labeled). Figure 5 H). Furthermore, transmission electron microscopy (TEM) images revealed that the mitochondrial cristae structure of macrophages in the Mag+C@B / rGO group was intact, and the mitochondrial density was increased, while the mitochondria in macrophages of the control group were swollen and the cristae structure was damaged. Figure 5 I). Western blot analysis confirmed a significant upregulation of OXPHOS complex subunits (such as CI-NDUFB8 and CIV-MTCO1) in the Mag+C@B / rGO group. Figure 5 (J). Crucially, pretreatment with the PI3K-AKT inhibitor (LY294002) reversed the above effects: mitochondrial structure was damaged again, and OXPHOS complex expression was downregulated to control levels. These results directly indicate that the PI3K-AKT pathway is an upstream regulator mediating the restoration of macrophage mitochondrial function and enhancement of OXPHOS induced by magnetoelectric hydrogel.

[0073] This multi-omics and functional experimental research chain constructed a complete mechanism of action: Mag+C@B / rGO magnetoelectric hydrogel activates the PI3K-AKT signaling pathway in macrophages, thereby promoting mitochondrial biogenesis, repairing mitochondrial cristae structure, and enhancing the expression of OXPHOS complex subunits—ultimately driving the macrophage's energy metabolism to switch from glycolysis to OXPHOS. This metabolic reprogramming is the core driving force of macrophage M2 polarization: OXPHOS not only provides sustained energy for the synthesis of anti-inflammatory cytokines (such as IL-10), but also restores redox homeostasis, preventing excessive accumulation of glycolysis-related reactive oxygen species (ROS). This mechanism also explains why the magnetoelectric hydrogel performs better than traditional immunomodulatory materials: most materials can only induce phenotypic changes in macrophages, while the hydrogel in this embodiment targets the metabolic root of macrophage polarization—by restoring OXPHOS, achieving a stable and sustained M2 phenotype, rather than a transient functional shift. This metabolic regulation strategy provides a new paradigm for designing immunomodulatory biomaterials for scarless wound healing.

[0074] 6. Magnetoelectric hydrogels induce macrophage metabolic reprogramming, generating paracrine signals that promote angiogenesis. To verify the role of macrophage-secreted factors in angiogenesis—a crucial biological event in wound healing—this embodiment added different conditioned media of bone marrow-derived macrophages (BMDMs) to human umbilical vein endothelial cells (HUVECs). To clarify the paracrine regulatory effect of magnetoelectric hydrogel-reprogrammed macrophages on angiogenesis (a core component of scarless healing), conditioned media of macrophages treated with different groups (Control group: LPS treatment; Mag+ group: LPS + simple magnetic field stimulation; Mag+C@B group: LPS + magnetic field stimulation + C@B hydrogel; Mag+C@B / rGO group: LPS + magnetic field stimulation + GelMA / C@B / rGO hydrogel) were collected and co-cultured with HUVECs to assess vascular-related functions. Scratch assay results showed ( Figure 6 A) After 24 h of culture, the migration area of ​​HUVECs in the Mag+C@B / rGO group was significantly larger than that in other groups, while the migration of cells in the Control group, Mag+ group, and Mag+C@B group was sparse. In the two-dimensional tube formation experiment ( Figure 6 In group B), HUVECs in the Mag+C@B / rGO group formed a denser and more complete vascular-like network. Quantitative analysis showed that the cell migration rate, vessel length, number of nodes, number of segments, and number of mesh structures in this group were significantly higher than those in other groups. Figure 6 Immunofluorescence results showed that the fluorescence intensity of CD31 (a vascular endothelial marker) and VEGF (angiogenic factor) in HUVECs of the Mag+C@B / rGO group was significantly higher than that of other groups. Figure 6 Quantitative analysis confirmed that the average fluorescence intensity of these two molecules was approximately 3-fold and 2.8-fold higher than that of the Control group, respectively, directly reflecting the upregulation of angiogenesis-related protein levels. Figure 6 I, J). Real-time quantitative PCR (RT-qPCR) results ( Figure 6 D) Further verification showed that the relative mRNA expression levels of angiogenesis-related genes (ANG1, CD31, VEGF) in HUVECs of the Mag+C@B / rGO group were significantly upregulated. Figure 6 KM).

[0075] Angiogenesis is a key prerequisite for scarless healing: a fully functional and adequate vascular network can improve local oxygen supply and nutrient delivery, breaking the vicious cycle of "infection-hypoxia-inflammation." Simultaneously, orderly angiogenesis can guide the directional migration of fibroblasts and the orderly deposition of collagen, avoiding collagen disorder and excessive scar formation caused by hypoxia or nutrient deficiency. Intergroup comparisons showed that simple magnetic field stimulation (Mag+ group) or pure magnetoelectric nanoparticles (Mag+C@B group) could not effectively activate this paracrine effect—this is attributed to the synergistic design of the magnetoelectric hydrogel: the enhanced conductivity of reduced graphene oxide (rGO) stabilizes the magnetic field-induced electrical signal, prolonging the regulatory duration of macrophage metabolic reprogramming, thereby continuously secreting pro-angiogenic factors. This finding further refines the action chain of "magnetoelectric hydrogel → macrophage metabolic reprogramming → angiogenesis paracrine regulation → scarless healing," providing vascular-level mechanistic support for the application of magnetoelectric hydrogels in the repair of infected wounds.

[0076] 8. Magnetoelectric hydrogels promote scarless wound healing in a mouse model of infected full-thickness skin defects. In Staphylococcus aureus ( S.aureus In a mouse model of full-thickness skin defects infected with ) Figure 7 A) Colony forming unit (CFU) plate count results showed that the Mag+C@B / rGO group achieved almost complete bacterial clearance by day 2, while the Control group, Mag+ group, and Mag+C@B group still had a large number of Staphylococcus aureus colonies. Figure 7 B). Gross observation and quantitative analysis of wound healing rate showed that the wound healing rate of the Mag+C@B / rGO group reached ~95% on day 8, significantly higher than the ~65% of the Control group. Figure 7 C, D). Hematoxylin-eosin (H&E) staining results showed that by day 8, the Mag+C@B / rGO group had very little inflammatory cell infiltration. Figure 7 E and F), and the epidermal-dermal junction was intact; Masson staining showed that its collagen fibers were arranged in parallel, dense patterns—a stark contrast to the loose, disordered collagen structures in other groups. Figure 7 G, H). Immunofluorescence and three-dimensional quantitative analysis further confirmed that the fluorescence intensity of inducible nitric oxide synthase (iNOS, an M1-type pro-inflammatory marker) was significantly reduced in the Mag+C@B / rGO group, while the fluorescence intensity of CD31 (a vascular endothelial marker) and keratin 5 (KRT5, an epithelial marker) was approximately 3-fold and 2.8-fold higher, respectively, compared to the Control group. Figure 7 I, J).

[0077] The highly efficient early wound healing achieved by Mag+C@B / rGO magnetoelectric hydrogel stems from its synergistic regulatory effect of "antibacterial-anti-inflammatory-promoting regeneration." First, the hydrogel eliminates Staphylococcus aureus by generating reactive oxygen species (ROS) through magnetoelectric triggering, thus eliminating the core inducing factor of infectious inflammation. Second, it drives macrophage metabolic reprogramming, promoting M2 polarization. This process not only inhibits iNOS-mediated inflammatory cascade responses but also induces M2 macrophages to secrete pro-angiogenic factors (such as VEGF) and enhance CD31... + Angiogenesis improves local oxygen supply and nutrient delivery. Simultaneously, it accelerates KRT5. + The re-epithelialization process can rapidly cover the wound. This early control of inflammation and orderly tissue regeneration avoids the "chronic inflammation → collagen disorder" cascade that initiates scar formation, laying the structural and microenvironmental foundation for scarless repair in the subsequent remodeling stage.

[0078] Furthermore, the timeline of stage-specific treatment with magnetoelectric hydrogel in Staphylococcus aureus-infected mouse wounds was investigated, clearly linking early wound healing with late scarless outcomes. Figure 8 A). This diagram integrates the pathological progression of the wound (from Staphylococcus aureus inoculation on day 0 to remodeling on day 20, and the matching function of the hydrogel). During the wound remodeling phase, gross observations showed that the Mag+C@B / rGO group formed a smooth, flat wound surface, while other groups exhibited raised, uneven scar tissue. Figure 8 B). Quantitative analysis of scar area confirmed that on day 20, the scar area in the Mag+C@B / rGO group was approximately 70% smaller than that in the Control group. Figure 8 C). Immunofluorescence staining and real-time quantitative PCR (q-PCR) results showed that the expression intensity of profibrotic markers (COL-I, αOL-I, TGF-β) was significantly reduced. Figure 8 DE). Ultrasound examination further showed that the Mag+C@B / rGO group had higher vascular density and oxygen content in the wound area - consistent with the early pro-angiogenic effect of this hydrogel. Figure 8F). Notably, this effect is closely associated with early improvements in angiogenesis and oxygenation: adequate vascular supply maintains fibroblast metabolic homeostasis and prevents hypoxia-induced fibrosis activation.

[0079] In summary, these findings confirm that the hydrogel achieves functional scarless healing by coordinating early infection control, mid-term regeneration regulation, and late-stage matrix remodeling—overcoming the multi-stage pathological bottleneck driving scar formation in infected wounds.

[0080] 9. Magnetoelectric hydrogel promotes scarless healing in a rabbit ear wound infection model. Rabbit ear skin models are the gold standard for simulating human hypertrophic scars (HS). Their thinner dermis and high tendency for excessive collagen deposition allow for precise replication of the pathological features of human hypertrophic scars. This example uses Staphylococcus aureus (S. aureus) as a model. S.aureus In a rabbit ear wound model infected with Staphylococcus aureus, the anti-scarring efficacy of magnetoelectric hydrogel was evaluated. A full-thickness skin defect model infected with Staphylococcus aureus was constructed in rabbit ears. Patients were then treated with Control (untreated), Mag+, Mag+C@B, and Mag+C@B / rGO groups, respectively. Wound assessments were performed on days 0, 5, 14, and 21. Figure 9 A). On day 0, all groups had the same wound morphology (red, exudative wound). On day 5, the Control group still showed severe exudation and erythema, while the Mag+C@B / rGO group showed reduced exudation and accelerated wound contraction. On day 14, the Mag+C@B / rGO group achieved almost complete reepithelialization, while the Control group remained in an ulcerated state. On day 21, the Control group developed raised, uneven hypertrophic scars, while the Mag+C@B / rGO group had smooth, flat wounds with no significant difference from the surrounding normal skin. Figure 9 B). Quantitative analysis of scar-related indicators (scar area, scar elevation index (SEI), scar thickness, and elevation angle) confirmed the superiority of the Mag+C@B / rGO group: the scar area was reduced by approximately 75% compared to the Control group, the core hypertrophic scar marker SEI decreased from 2.5 in the Control group to 1.2 in the Mag+C@B / rGO group, and the scar thickness was reduced by approximately 60%. Figure 9 CE). On day 21, the Mag+C@B / rGO group showed uniform translucency (orange color), consistent with normal skin; the Control group showed strong red (indicating persistent inflammation / scar congestion), confirming that the inflammation had completely subsided. Figure 9 F, G). Ultrasound images showed that the scar tissue in the Control group was thick and raised (marked by red dotted lines), while the images in the Mag+C@B / rGO group overlapped with normal skin (rightmost panel), confirming that their scar thickness was extremely thin. Figure 9H, I). Hematoxylin-eosin (H&E) staining results showed that the epidermal-dermal structure of the Mag+C@B / rGO group was intact, with very little inflammatory infiltration (consistent with normal skin); the Control group, on the other hand, showed disordered tissue layers and a large number of inflammatory cell aggregates. Figure 9 J, K). Masson staining showed that collagen fibers in the Mag+C@B / rGO group were arranged in a parallel and orderly manner (consistent with normal skin); collagen fibers in the Control group were disordered and clumped together (a typical feature of hypertrophic scars). Figure 9 L, M). Experimental results from the rabbit ear model confirmed that the magnetoelectric hydrogel achieved an anti-scarring effect in a preclinical model with clinical translational significance, filling a key gap between small animal experiments such as mice and human clinical translation. This efficacy is supported by three core mechanisms: (1) Infection-inflammation resolution: The hydrogel clears Staphylococcus aureus through the antibacterial effect mediated by reactive oxygen species (ROS), and at the same time inhibits the secretion of pro-fibrotic cytokines by reprogramming macrophages to M2 polarization. (2) Collagen homeostasis maintenance: M2 macrophages can balance collagen synthesis and degradation, promoting collagen deposition patterns consistent with normal skin. (3) Magnetoelectric synergistic regulation: Compared with the Mag+ group or the Mag+C@B group, the superiority of the Mag+C@B / rGO group stems from the enhanced electrical signal stability of reduced graphene oxide (rGO): This allows macrophages to continuously undergo metabolic reprogramming during the 21-day healing cycle, avoiding the transient M2 polarization (and subsequent reversal to the pro-fibrotic M1 type) that occurred in other groups.

[0081] 10. Magnetoelectric hydrogels outperform clinical growth factor gels (Beifuji) in scarless wound healing in large animals (miniature pig models, clinical translation). Miniature Bama pig skin is highly similar to human skin in terms of thickness, hair follicle density, and extracellular matrix composition, making it a gold standard preclinical model for evaluating the clinical translational potential of wound healing therapies. This study compared the efficacy of magnetoelectric hydrogel (Mag+C@B / rGO group), clinically commonly used recombinant growth factor gel (Beifuji), and an untreated control group in a full-thickness skin defect model caused by Staphylococcus aureus infection in miniature Bama pigs. A Staphylococcus aureus-infected wound model was constructed on the back skin of miniature Bama pigs. Patients were then treated with either the Control group (untreated), the Beifuji group, or the Mag+C@B / rGO group (magnetoelectric hydrogel + magnetic field), and evaluations were conducted on days 0, 5, 14, and 21. Figure 10A). On day 0, all wounds presented as exudative erythematous lesions with no significant differences. On day 5, compared with the Control group (continuous exudation) and the Beifuji group (moderate exudation), the Mag+C@B / rGO group showed faster exudation resolution and more significant wound contraction. On day 14, the Mag+C@B / rGO group achieved near-complete reepithelialization with hair follicle regeneration; the Control group remained ulcerated; and the Beifuji group only showed partial epithelialization. On day 21, the wounds in the Control group had not healed, the Beifuji group formed smooth scars, while the wounds in the magnetoelectric hydrogel group were smooth, with pigmentation consistent with the surrounding normal skin, and accompanied by hair regeneration, showing no significant difference from normal skin. Figure 10 B). H&E staining results showed that the epidermal thickness and dermal structure of the Mag+C@B / rGO group were consistent with normal skin; the epidermal-dermal junction was disordered in the Control group; and the Beifuji group showed epidermal hyperplasia. Figure 10 C, D). Masson staining results showed that collagen fibers in the Mag+C@B / rGO group were arranged in a parallel and orderly manner (consistent with normal skin); collagen fibers in the Control group were clumped and disordered; the degree of disorder in the collagen arrangement in the Beifuji group was between the two. Figure 10 E, F). Sirius red staining can distinguish between type I and type III collagen: the Mag+C@B / rGO group showed a distribution pattern dominated by type III collagen (consistent with normal skin); the Control group had a large amount of type I collagen deposition; the Beifuji group showed a mixed pattern of type I / III collagen (with lower orderliness than the Mag+C@B / rGO group). Figure 10 G, H). Significant differences were observed in the expression of pro-fibrotic markers such as α-SMA, TGF-β, and MMP-1: the Control group showed the strongest staining intensity, the Beifuji group showed moderate staining, and the Mag+C@B / rGO group showed extremely weak staining (consistent with normal skin). Figure 10 I). Furthermore, the relative expression levels of α-SMA and TGF-β in the Mag+C@B / rGO group were lower than those in the Control group and the Beifuji group ( Figure 10J). The epidermal thickness in the Mag+C@B / rGO group was consistent with normal skin, while the Beifuji group showed epidermal hyperplasia; the hair follicle density in the Mag+C@B / rGO group was approximately 3 times higher than that in the Beifuji group. These results indicate that the magnetoelectric hydrogel not only outperforms the untreated control group but also demonstrates functional scarless healing effects surpassing those of clinical growth factor gels (Beifuji) in clinically significant large animal models—addressing a key unmet need in clinical wound care: while growth factor therapy can accelerate healing, it cannot effectively inhibit scar formation. Furthermore, unlike Beifuji, which lacks antibacterial activity, this hydrogel eliminates Staphylococcus aureus through ROS generated by magnetoelectric triggering, eliminating the infection trigger for chronic inflammation. Its ability to support hair follicle regeneration further confirms that this hydrogel achieves functional skin repair, rather than simply epidermal wound closure.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An anti-infective pro-near scarless tissue repair material, characterized in that, The repair material comprises a polymer material with a three-dimensional network structure, magneto-electric nanoparticles filled in the polymer material, and conductive fillers, the magneto-electric nanoparticles comprising a shell structure with piezoelectric properties and a core structure with magneto-electric response properties, the shell structure being prepared from raw materials comprising inorganic piezoelectric materials and / or organic piezoelectric materials, and the core structure being prepared from raw materials comprising magneto-electric materials.

2. The anti-infective pro-scarring tissue repair material of claim 1, wherein, The polymer material comprises natural and / or artificially synthesized polymer materials.

3. The anti-infective pro-scarring tissue repair material of claim 1, wherein, The polymer material comprises at least one of alginate, chitosan, hyaluronic acid, collagen, fibrin, fibroin, polyacrylate, acrylamide, polycaprolactone / polylactic acid-based hydrogel, gelatin, and polypeptide self-assembled hydrogel.

4. The anti-infective pro-scarring tissue repair material of claim 1, wherein, The conductive fillers comprise at least one of graphene, reduced graphene oxide, carbon nanotubes, and gold nanomaterials.

5. The anti-infective pro-scarring tissue repair material of claim 1, wherein, The inorganic piezoelectric materials are selected from at least one of ferrite, niobate, titanate, silicate, and aluminate materials; and the organic piezoelectric materials are selected from at least one of polyvinylidene fluoride, polyester, polymethyl methacrylate, nylon, polyvinyl chloride, poly-L-lactide, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), vinylidene fluoride / trifluoroethylene copolymer, vinylidene fluoride / tetrafluoroethylene copolymer, polyvinylidene fluoride-hexafluoropropylene, and polydimethylsiloxane materials.

6. The anti-infective pro-scarring tissue repair material of claim 5, wherein, The ferrite material has the following structure: M x Fe 3-x O y wherein M includes at least one of Bi, Ca, Ba, Mg, and Ba, x is a number from 0.25 to 1.5, and y is 4. Preferably, the magnetoelectric material has the following structure: N a Fe 1-a O b , N includes at least one of Co, Mn, Zn, and Ni, a is a number from 0.25 to 0.75, and b is 3.

7. The anti-infective pro-scarring tissue repair material of claim 1, wherein, The magneto-electric nanoparticles are cobalt ferrite-bismuth ferrite nanoparticles. Preferably, the particle size of the cobalt ferrite-bismuth ferrite nanoparticles is 100-500 nm.

8. A method of making an anti-infective pro-Scar-free healing tissue repair material, characterized in that, The method comprises: (1) preparing magneto-electric nanoparticles comprising a shell structure with piezoelectric properties and a core structure with magneto-electric response properties, the shell structure being prepared from raw materials comprising inorganic piezoelectric materials and / or organic piezoelectric materials, and the core structure being prepared from magneto-electric materials; (2) filling the magneto-electric nanoparticles and conductive fillers in a polymer material with a three-dimensional network structure to obtain the repair material.

9. The method of claim 8, wherein the anti-infective pro-near scarless tissue repair material is prepared by, Further comprising: (3) a step of treating the repair material using a magnetic field with a magnetic field strength of 0.01-300 mT.

10. Use of the repair material according to any one of claims 1-7 in the preparation of a product for skin damage repair.

Images