Conductive structural color hydrogel for MI monitoring and treatment and its preparation method and application

Abstract

The present invention discloses a conductive structural color hydrogel for monitoring and treating myocardial infarction (MI), as well as its preparation method and application. The hydrogel comprises: a conductive nanomaterial having a catechol group; HPC cholesteric liquid crystal; a matrix material; and a crosslinker. The conductive structural color hydrogel is formed through physical and / or chemical interactions among the conductive nanomaterial, the HPC cholesteric liquid crystal, the matrix material, and the crosslinker. The conductive structural color hydrogel of the present invention exhibits enhanced electromechanical and mechanochromic response characteristics, possesses photoelectric dual-signal sensing capabilities, and can accurately, in real time, and visually monitor mechanical stimulation. It can be used as a flexible sensing material to prepare products that provide visual and digital feedback of mechanical stimulation, as well as products that compensate for and / or repair electrical conduction in biological tissues. In particular, it can be used to prepare conductive structural color hydrogel patches for monitoring and / or treating myocardial infarction (MI), and has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the field of biomaterials, in particular to a conductive structural color hydrogel and a preparation method and application thereof, and more particularly to a conductive structural color hydrogel that can be used for monitoring and treating myocardial infarction (MI) and a preparation method and application thereof. Background Art

[0002] Myocardial infarction (MI) is a leading cause of death from cardiovascular disease. It primarily leads to ischemic necrosis of myocardial tissue, forming non-conductive fibrotic scars that severely impair cardiac electrophysiological function. Current clinical treatments (such as medication and myocardial reperfusion) can alleviate symptoms but struggle to accurately restore electrophysiological function or inhibit ventricular remodeling.

[0003] Conductive hydrogel patches have garnered significant attention in recent years for their potential for electrical coupling and repair, but their applications still face two major challenges. First, precise positioning is difficult, and visualization is lacking. The therapeutic efficacy of conductive hydrogel patches relies on accurate implant placement, requiring precise placement at the cardiac pathology site to fully realize the electrical coupling therapeutic effect. However, identifying the location of cardiac pathology is complex and tedious, requiring multiple diagnostic methods such as electrocardiography, echocardiography, histological assessment, and clinical cardiovascular angiography. Current research focuses primarily on improving the biocompatibility, conductivity, and mechanical properties of materials to enhance therapeutic efficacy, with less attention paid to accurately localizing and visually monitoring cardiac pathology. This results in insufficient integrated diagnostic and treatment capabilities and limited therapeutic precision. Furthermore, real-time monitoring is lacking. The course of myocardial infarction is complex and unpredictable, and the infarct microenvironment can undergo adverse changes at any time, leading to serious problems such as infarct expansion and coronary artery spasm. Traditional conductive hydrogel patches are unable to monitor cardiac mechanical and physiological signals in real time, making it difficult to provide timely feedback on dynamic changes in the infarcted area, thus compromising clinical treatment efficacy.

[0004] Therefore, there is an urgent need to develop new conductive hydrogel materials that can realize accurate, real-time and visual monitoring of mechanical stimulation, so as to develop conductive hydrogel patches that can integrate diagnostic and therapeutic functions, and open up new paths for the efficient treatment of myocardial infarction. Summary of the Invention

[0005] The present invention aims to, at least to some extent, address at least one of the technical problems existing in the prior art. To this end, the present invention provides a conductive structural color hydrogel, a preparation method, and applications thereof. The conductive structural color hydrogel of the present invention has enhanced electromechanical and mechanochromic response characteristics, possesses photoelectric dual-signal sensing capabilities, and can accurately, in real time, and visually monitor mechanical stimulation. It can be used as a flexible sensing material to prepare products that provide visual and digital feedback of mechanical stimulation, as well as products that compensate for and / or repair electrical conduction in biological tissues. In particular, it can be used to prepare conductive structural color hydrogel patches for monitoring and / or treating myocardial infarction (MI), and has broad application prospects.

[0006] The present invention is based on the inventor's discovery and understanding of the following problems:

[0007] In the field of materials, the effective integration of materials with mechanochromic response properties with conductive hydrogels is a key technology for enabling the visual monitoring of external spatiotemporal mechanical stimuli by conductive hydrogels. While previous studies have attempted to combine these two types of materials through various approaches, they often face challenges such as a lack of synchronization between color change and conductivity, and insensitive responses. The inventors discovered that dopamine (DA)-modified MXene nanosheets can be synergistically integrated with HPC cholesteric liquid crystals to construct a hydrogel with excellent electromechanical and mechanochromic response properties. Results showed that this hydrogel can achieve photoelectric dual-signal sensing with strong response signals and high sensitivity. Further analysis revealed that the modified conductive nanomaterials (such as dopamine-modified MXene nanosheets and dopamine-modified black phosphorus nanosheets) contain catechol groups, which serve as anchoring sites to fix the helical pitch of the HPC cholesteric liquid crystals. As a result, the conductive structural color hydrogel of the present invention exhibits enhanced electromechanical and mechanochromic response properties, significantly improving response signal sensitivity, and thus achieving photoelectric dual-signal sensing capabilities. By utilizing its optical signal sensing function, the location of the infarcted myocardium can be located, and by utilizing its electrical signal sensing function, the mechanical physiological state of the heart can be monitored. Further test results show that the hydrogel of the present invention can be used as a flexible sensing material to prepare products that can achieve visual feedback and digital feedback of mechanical stimulation, such as conductive structural color hydrogel patches for visualizing and digitally monitoring myocardial infarction (MI), and to prepare products that can compensate for and / or repair the electrical conduction of biological tissues, such as conductive structural color hydrogel patches for treating myocardial infarction (MI). Figure 1 ), and has broad application prospects.

[0008] Therefore, in its first aspect, the present invention provides a conductive structural color hydrogel. According to an embodiment of the present invention, the hydrogel comprises: a conductive nanomaterial having catechol groups; HPC cholesteric liquid crystal; a matrix material; and a crosslinker. The conductive structural color hydrogel is formed through physical and / or chemical interactions between the conductive nanomaterial, the HPC cholesteric liquid crystal, the matrix material, and the crosslinker. The conductive structural color hydrogel according to an embodiment of the present invention exhibits enhanced electromechanical and mechanochromic response properties, enabling photoelectric dual-signal sensing capabilities and accurate, real-time, and visual monitoring of mechanical stimuli. It can be used as a flexible sensing material to prepare products that provide visual and digital feedback of mechanical stimuli, as well as products that compensate and / or repair electrical conduction in biological tissues. In particular, it can be used to prepare conductive structural color hydrogel patches for monitoring and / or treating myocardial infarction (MI), and has broad application prospects.

[0009] According to an embodiment of the present invention, the conductive structural color hydrogel may further include at least one of the following additional technical features:

[0010] According to an embodiment of the present invention, based on the total mass of the conductive structural color hydrogel, the HPC mass fraction of the HPC cholesteric liquid crystal is 50% to 56%.

[0011] According to an embodiment of the present invention, based on the total mass of the conductive structural color hydrogel, the HPC mass fraction of the HPC cholesteric liquid crystal is 50% to 52%.

[0012] According to an embodiment of the present invention, the HPC cholesteric liquid crystal is formed by self-assembly of HPC in water.

[0013] In some specific embodiments of the present invention, the mass ratio of the HPC to the water is 50:(35-40). In a specific example of the present invention, the mass ratio of the HPC to the water is 50:37.

[0014] According to an embodiment of the present invention, the conductive nanomaterial is modified by dopamine or a pharmaceutically acceptable salt thereof or tannic acid or a pharmaceutically acceptable salt thereof.

[0015] According to an embodiment of the present invention, the pharmaceutically acceptable salt of dopamine is dopamine hydrochloride.

[0016] In some embodiments of the present invention, the pharmaceutically acceptable salt of tannic acid is an alkali metal salt of tannic acid.

[0017] In some embodiments of the present invention, the conductive nanomaterial is selected from at least one of graphene, carbon nanotubes, black phosphorus, MXene, and MoS2 modified by dopamine or a pharmaceutically acceptable salt thereof and / or tannic acid or a pharmaceutically acceptable salt thereof.

[0018] According to an embodiment of the present invention, the conductive nanomaterial is MXene@PDA, and the MXene@PDA is a MXene nanosheet modified by dopamine or a pharmaceutically acceptable salt thereof.

[0019] According to an embodiment of the present invention, based on the total mass of the conductive structural color hydrogel, the mass fraction of the MXene@PDA is not less than 1%.

[0020] According to an embodiment of the present invention, based on the total mass of the conductive structural color hydrogel, the HPC mass fraction of the HPC cholesteric liquid crystal is 50% to 52%, and the mass fraction of the MXene@PDA is 1% to 1.5%.

[0021] In some embodiments of the present invention, the matrix material is selected from at least one of sodium alginate, dopamine-grafted modified sodium alginate, hyaluronic acid, dopamine-grafted modified hyaluronic acid, gelatin, carboxymethyl chitosan, and sodium caseinate.

[0022] According to an embodiment of the present invention, the matrix material is sodium alginate and / or dopamine-grafted modified sodium alginate.

[0023] In some embodiments of the present invention, the mass ratio of the HPC of the HPC cholesteric liquid crystal to the matrix material is 50:(4-12).

[0024] According to an embodiment of the present invention, the matrix material is sodium alginate, and the mass ratio of HPC to the sodium alginate in the HPC cholesteric liquid crystal is 50:(6-10).

[0025] In a specific embodiment of the present invention, the matrix material is sodium alginate, and the mass ratio of HPC to the sodium alginate in the HPC cholesteric liquid crystal is 50:8.

[0026] According to an embodiment of the present invention, the cross-linking agent is a metal ion.

[0027] According to an embodiment of the present invention, the metal ions are multivalent cations.

[0028] In some specific embodiments of the present invention, the metal ion is selected from Ca 2+ 、Zn 2+ Mg 2+ 、Fe 3+ 、Cu 2+ At least one of .

[0029] According to an embodiment of the present invention, the metal ions are derived from halide salts thereof.

[0030] According to an embodiment of the present invention, the halide salt is a chloride salt.

[0031] According to an embodiment of the present invention, the metal ion is Ca 2+ .

[0032] According to an embodiment of the present invention, the Ca 2+ From calcium chloride.

[0033] According to an embodiment of the present invention, based on the total mass of the conductive structural color hydrogel, the mass fraction of the calcium chloride is 0.5% to 0.56%.

[0034] In its second aspect, the present invention provides a method for preparing the aforementioned conductive structural color hydrogel. According to an embodiment of the present invention, the method comprises: mixing the conductive nanomaterial, the HPC cholesteric liquid crystal, and the matrix material to form a mixture; and cross-linking the mixture with a crosslinker to form the conductive structural color hydrogel. This method, according to an embodiment of the present invention, first integrates the conductive nanomaterial and the HPC cholesteric liquid crystal into the three-dimensional matrix material system, and then cross-links the mixture with the crosslinker. This facilitates the formation of a bright color visible to the naked eye on the hydrogel, enhancing its photoelectric dual-signal sensing capabilities.

[0035] According to an embodiment of the present invention, the method may further include at least one of the following additional technical features:

[0036] According to an embodiment of the present invention, the temperature of the mixing process is room temperature.

[0037] According to an embodiment of the present invention, the temperature of the cross-linking reaction is 3° C. to 7° C. In a specific embodiment of the present invention, the temperature of the cross-linking reaction is 5° C.

[0038] According to an embodiment of the present invention, the method further includes: subjecting the conductive structural color hydrogel to an exhaust treatment and / or a static treatment.

[0039] According to an embodiment of the present invention, the temperature of the exhaust gas treatment is 3° C. to 7° C. In a specific embodiment of the present invention, the temperature of the exhaust gas treatment is 5° C.

[0040] In a third aspect of the present invention, a conductive structural color hydrogel is provided. According to an embodiment of the present invention, the conductive structural color hydrogel is prepared according to the aforementioned method.

[0041] Those skilled in the art will appreciate that the features and advantages described above for the conductive structural color hydrogel and its preparation method are also applicable to the conductive structural color hydrogel, and will not be elaborated here.

[0042] In the fourth aspect of the present invention, the present invention proposes the use of the aforementioned conductive structural color hydrogel in the preparation of products. According to an embodiment of the present invention, the product has at least one of the following uses: visual and / or digital feedback of the response of non-biological tissue to mechanical stimulation; visual and / or digital monitoring of biological tissue movement; compensation and / or repair of biological tissue electrical conduction. The aforementioned conductive structural color hydrogel, through its mechanochromic response performance, enables the product to be used for visual detection of mechanical stimulation; through its electrical signal sensing performance, enables the product to be used for digital monitoring of mechanical stimulation; through its electrical conduction function, enables the product to be used for compensating and / or repairing biological tissue electrical conduction. Therefore, the conductive structural color hydrogel can be used to prepare products with visualization and digital monitoring functions, thereby displaying the dynamic changes of non-biological tissue under mechanical stimulation and the movement state of biological tissue in real time. According to an embodiment of the present invention, the visual feedback and / or the numerical feedback are synchronized with the mechanical stimulation.

[0043] According to an embodiment of the present invention, the product includes but is not limited to: medical devices, wearable sensors, and biosensors.

[0044] According to an embodiment of the present invention, the medical device includes but is not limited to: a heart sensor patch, a myocardial infarction monitoring and / or treatment patch, and a bionic skin.

[0045] According to an embodiment of the present invention, the biosensor includes but is not limited to: a pressure sensor and a strain sensor.

[0046] According to an embodiment of the present invention, the wearable sensor includes but is not limited to: an inertial sensor, an optical sensor, an electrode and electrochemical sensor, a flexible sensor, and an interactive sensor.

[0047] In some embodiments of the present invention, the biological tissue movement includes but is not limited to: respiratory movement, expansion and contraction of the thorax, expansion and contraction of the lungs, contraction / relaxation of the heart, contraction and relaxation of blood vessels, gastrointestinal motility, esophageal motility, contraction and relaxation of skeletal muscles, peristalsis of renal tubules, peristalsis of the ureters, contraction and relaxation of the bladder, peristalsis of the fallopian tubes, contraction and relaxation of the uterus, contraction and relaxation of the vagina, blinking of the eyes, movement of the eyeballs, and swallowing movements of the throat.

[0048] According to an embodiment of the present invention, the biological tissue includes but is not limited to: skeletal muscle tissue, smooth muscle tissue, myocardial tissue, connective tissue, and neural tissue.

[0049] According to an embodiment of the present invention, the product is used to monitor biological tissue necrosis and / or prevent and / or treat diseases caused by the biological tissue necrosis.

[0050] In some embodiments of the present invention, the diseases include but are not limited to: myocardial infarction, myocardial sclerosis, cerebral infarction, encephalomalacia, gastroduodenal ulcer, typhoid fever, acute pancreatitis, tuberculosis, pulmonary infarction, renal tubular necrosis, renal infarction, ovarian cyst pedicle torsion, rupture of fallopian tube pregnancy, necrotizing fasciitis, and frostbite.

[0051] According to an embodiment of the present invention, the product is used for monitoring and / or treating myocardial infarction.

[0052] Compared with the prior art, the conductive structural color hydrogel of the present invention has at least one of the following beneficial effects:

[0053] 1. It has a photoelectric dual signal response. When monitoring cardiac mechanical physiological signals, the relative resistance change rate of the conductive structural color hydrogel of the present invention is 5%, and the sensitivity is better than the 2.5% of the nanoclay sensor; the reflection wavelength blue shift range is 640 nm→482 nm (sensitivity -2.85 nm%). ﹣1 ), the infarcted area can be identified visually.

[0054] 2. Good biocompatibility. Cytotoxicity test results show that the conductive structural color hydrogel of the present invention has a cell survival rate of >95% (better than the 80% of traditional polypyrrole hydrogels), with no risk of fiber wrapping.

[0055] 3. Excellent tissue repair effects after myocardial infarction (MI). Animal testing results show that the conductive structural color hydrogel can effectively improve cardiac function, increasing ejection fraction (EF) from 47.38% to 81.55%. It also has anti-inflammatory and angiogenic properties, increasing the polarization rate of M2 macrophages to 20.63% and tripling vascular density.

[0056] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0058] Figure 1 Schematic diagram of a patch made of the conductive structural color hydrogel of the present invention used for monitoring and treating myocardial infarction;

[0059] Figure 2 The material characterization results of MXene and MXene@PDA in Example 1 of the present invention are shown in Figure 1, where (A) is the TEM morphology and surface element scanning result diagram; (B) is the element content investigation result diagram; (C) is the infrared spectrum;

[0060] Figure 3The material characterization results of the conductive structural color hydrogel of the present invention are shown in Figure 1, wherein (A) is the appearance of the conductive structural color hydrogel with different HPC contents; (B) is the reflection wavelength investigation result of the conductive structural color hydrogel with different HPC contents; (C) is the SEM morphology of the conductive structural color hydrogel; (D) is a polarizing microscope photograph of the conductive structural color hydrogel with different HPC contents;

[0061] Figure 4 The composition and mechanical properties of the conductive structural color hydrogel of the present invention are investigated in Figure 1, where (A) is the full XPS spectrum; (B) is the C 1s spectrum; (C) is the Ti 2p spectrum; and (D) is the variation of the storage modulus G' and loss modulus G'' with frequency.

[0062] Figure 5 The results of the investigation of the stretch-color sensing performance of the conductive structural color hydrogel of the present invention are shown in Figure 1. (A) is a photograph of the conductive structural color color changing with compression rate. From red to blue, the external stretch rates of the material are 0%, 8%, 20%, 40%, and 60%, respectively. (B) is a curve showing the change of reflection wavelength with compression rate, Δλ / Δη=-2.85 nm % ﹣1 ;

[0063] Figure 6 The results of the compression-color sensing performance test of the conductive structural color hydrogel of the present invention are shown in Figure 1. (A) is a photograph of the conductive structural color color changing with the compression rate. From red to blue, the external compression rates of the material are 0%, 10%, 20%, 30%, 40%, and 50%, respectively. (B) is a curve showing the change of reflection wavelength with compression rate, Δλ / Δε=-3.50 nm % ﹣1 ;

[0064] Figure 7 The results of the expansion-color sensing performance investigation of the conductive structural color hydrogel of the present invention are shown in Figure 1. (A) is a photograph of the conductive structural color color changing with the expansion rate. From red to blue, the expansion rates of the material are 0%, 10%, 20%, 30%, and 40%, respectively. (B) is a curve showing the change of reflection wavelength with the expansion rate, Δλ / Δs=-4.47 nm % ﹣1 ;

[0065] Figure 8 The results of the investigation of the conductive structural color hydrogel of the present invention in in vitro simulated myocardial infarction monitoring are shown, among which (A) is a visual difference image after a balloon simulated local infarction; (B) is a visual difference image after a duck heart simulated myocardial infarction;

[0066] Figure 9The results of the investigation of the electrical signal sensing function of the conductive structural color hydrogel of the present invention are shown in Figure 1, wherein (A) is a resistance curve; (B) is a graph showing the investigation of the conductivity of the conductive structural color hydrogel as a function of the MXene@PDA concentration; (C) is a graph showing the conductivity comparison results; and (D) is a CV curve.

[0067] Figure 10 The following are graphs showing the results of investigating the stretching electrical signal sensing performance of the conductive structural color hydrogel of the present invention, wherein (A) shows the change in relative resistance of the hydrogel during stretching; (B) shows the change in relative resistance of the hydrogel during mechanical deformation with varying amplitudes, with amplitudes varying at 15%, 3.0%, 50%, and 100%; (C) shows the change in relative resistance of the hydrogel during mechanical deformation with varying frequencies, with frequencies varying at 0.025 Hz, 0.05 Hz, 0.1 Hz, 0.25 Hz, 0.5 Hz, and 1.0 Hz; (D) shows the results of investigating the response time and recovery time; and (E) shows the results of investigating the fatigue and durability of the sensor.

[0068] Figure 11 The graphs show the results of investigating the expansion electrical signal sensing performance of the conductive structural color hydrogel of the present invention, where (A) shows the change in relative resistance of the hydrogel during expansion; (B) shows the change in relative resistance of the hydrogel during different volume expansions, with the volume expansion levels being 10%, 20%, 30%, 40%, and 50%.

[0069] Figure 12 The results of the application of the conductive structural color hydrogel of the present invention in in vitro mechanical motion monitoring are shown in Figure 1, where (A) shows the finger bending motion; (B) shows the balloon inflation motion; (C) shows the in vitro heartbeat motion of a duck heart; and (D) shows the breathing motion of a rat.

[0070] Figure 13 The figures show the results of the cytotoxicity test of the conductive structural color hydrogel of the present invention, wherein (A) shows the live / dead staining of H9C2 cells; (B) shows the live / dead staining of HUCVECs; (C) shows the results of the H9C2 cell activity analysis; and (D) shows the results of the HUCVECs cell activity analysis.

[0071] Figure 14 Figures 1 and 2 show the results of investigating the tissue surface adhesion properties of the conductive structural color hydrogel of the present invention. (A) shows the conductive structural color sensing patch of the present invention adhered to pig skin after being subjected to bending, twisting, stretching, and loading; (B) shows an optical photograph of the conductive structural color sensing patch of the present invention - pig skin interface; (C) shows a SEM image of the conductive structural color sensing patch of the present invention - heart tissue interface; and (D) shows the results of investigating the adhesion strength of the conductive structural color sensing patch of the present invention at different interfaces.

[0072] Figure 15 Figures 1 and 2 show the results of using the conductive structural color hydrogel of the present invention in real-time monitoring of cardiac mechanical physiological activity and visual identification of infarcted myocardium. (A) is a schematic diagram of real-time monitoring and visual identification of cardiac mechanical physiological activity; (B) is a diagram showing the results of real-time monitoring of mechanical physiological signals of a normal heart; (C) is a diagram showing the results of real-time monitoring of mechanical physiological signals of a heart with myocardial infarction; and (D) is a diagram showing the results of visual identification of infarcted myocardium using the conductive structural color hydrogel of the present invention.

[0073] Figure 16 The results of the investigation of the effect of the conductive structural color hydrogel of the present invention on cardiac function are shown in Figure 1, wherein (A) is an echocardiogram; (B) is a diagram showing the results of the investigation of cardiac function assessment indicators ejection fraction (EF), fractional shortening (FS), end-diastolic volume (EDV), and end-systolic volume (ESV);

[0074] Figure 17 The results of investigating the repair effect of the conductive structural color hydrogel on cardiac morphology of the present invention are shown in Figure 1, wherein (A) is an H&E and Masson staining image; (B) is an infarct wall thickness analysis image; and (C) is an infarct area analysis image.

[0075] Figure 18 The figures show the results of the investigation of the anti-inflammatory properties of the conductive structural color hydrogel of the present invention, wherein (A) shows the results of CD86 / CD206 fluorescence staining; (B) shows the results of CD86 positive cell ratio analysis; and (C) shows the results of CD206 positive cell ratio analysis.

[0076] Figure 19 The results of the investigation of the effect of the conductive structural color hydrogel of the present invention on neovascularization are shown, wherein (A) is the result of vWF / CD31 fluorescence staining; (B) is the result of neovascularization density analysis;

[0077] The data in the present invention are presented as mean ± standard deviation (mean ± SD); independent sample t-test was used between the two groups, and when P < 0.05, it was considered statistically significant; * indicates P < 0.05, ** indicates P < 0.01, *** indicates P < 0.001, and ns indicates no statistically significant difference. DETAILED DESCRIPTION

[0078] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0079] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. Furthermore, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0080] The endpoints of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0081] Terms and Definitions

[0082] Unless otherwise defined, 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 belongs.

[0083] In this document, the terms “include” or “comprising” are open expressions, that is, including the contents specified in the present invention, but not excluding other contents.

[0084] The present invention proposes a conductive structural color hydrogel and a preparation method and application thereof, which will be described in detail below.

[0085] hydrogel

[0086] The present invention proposes a conductive structural color hydrogel. According to an embodiment of the present invention, the hydrogel comprises: a conductive nanomaterial having catechol groups; HPC cholesteric liquid crystal; a matrix material; and a crosslinker. The conductive structural color hydrogel is formed through physical and / or chemical interactions between the conductive nanomaterial, the HPC cholesteric liquid crystal, the matrix material, and the crosslinker. The conductive structural color hydrogel according to an embodiment of the present invention exhibits enhanced electromechanical and mechanochromic response characteristics, possesses photoelectric dual-signal sensing capabilities, and can accurately, in real time, and visually monitor mechanical stimulation. It can be used as a flexible sensing material to prepare products that provide visual and digital feedback of mechanical stimulation, as well as products that compensate and / or repair electrical conduction in biological tissue. In particular, it can be used to prepare conductive structural color hydrogel patches for monitoring and / or treating myocardial infarction (MI), and has broad application prospects.

[0087] In this article, the term "HPC" is equivalent to "hydroxypropyl cellulose," a class of visual materials with a unique supramolecular structure and excellent biocompatibility. In an aqueous environment, it self-assembles into cholesteric liquid crystals with a periodic helical structure through intermolecular forces, such as repulsion caused by molecular chirality and hydrogen bonding between hydroxyl groups. This liquid crystal structure scatters and reflects visible light, giving the material a vibrant structural color.

[0088] In this article, the term "matrix material" is one of the main components of the hydrogel, which is a continuous three-dimensional cross-linked network that provides structural stability.

[0089] According to an embodiment of the present invention, based on the total mass of the conductive structural color hydrogel, the HPC mass fraction of the HPC cholesteric liquid crystal is 50% to 56%. For example, the HPC mass fraction of the HPC cholesteric liquid crystal can be 50%, 50.5%, 51%, 51.5%, 52%, 52.5%, 53%, 53.5%, 54%, 54.5%, 55%, 55.5%, or 56%. The inventors determined this optimal HPC mass fraction after extensive testing. Within this numerical range, the conductive structural color hydrogel of the present invention exhibits significant color differences before and after being subjected to spatiotemporal mechanical stimulation. The color change can be observed with the naked eye, intuitively displaying the location and range of the mechanical stimulation source.

[0090] According to an embodiment of the present invention, based on the total mass of the conductive structural color hydrogel, the HPC mass fraction of the HPC cholesteric liquid crystal is 50% to 52%. For example, the HPC mass fraction of the HPC cholesteric liquid crystal can be 50%, 50.1%, 50.2%, 50.3%, 50.4%, 50.5%, 50.6%, 50.7%, 50.8%, 50.9%, 51%, 51.1%, 51.2%, 51.3%, 51.4%, 51.5%, 51.6%, 51.7%, 51.8%, 51.9%, and 52%. This further improves the intuitiveness of the visual feedback of the conductive structural color hydrogel of the present invention to mechanical stimulation.

[0091] According to embodiments of the present invention, the HPC cholesteric liquid crystal is formed by self-assembly of HPC in water. The conductive structural color hydrogel according to embodiments of the present invention has simple structural color unit material components and further improved safety. For example, "water" can be drinking water, purified water, water for injection, sterile water for injection, or water used in the production of in vitro diagnostic reagents.

[0092] According to an embodiment of the present invention, the mass ratio of HPC to water is 50:(35-40). For example, the mass ratio of HPC to water can be 50:35, 50:36, 50:37, 50:38, 50:39, or 50:40. The inventors determined this optimal HPC cholesteric liquid crystal assembly condition through extensive experiments. This numerical range facilitates the formation of vivid, visible colors in the conductive structural color hydrogel of the present invention.

[0093] In a specific embodiment of the present invention, the mass ratio of the HPC to the water is 50:37. Thus, the formed HPC cholesteric liquid crystal has bright colors.

[0094] In some embodiments of the present invention, the conductive nanomaterial is modified with dopamine or a pharmaceutically acceptable salt thereof or tannic acid. According to an embodiment of the present invention, the surface of the modified conductive nanomaterial has a thin biomimetic coating with anchoring sites (catechol groups).

[0095] In this article, the term "dopamine" is equivalent to "DA" or "Dopamine", which has the following structural formula:

[0096] .

[0097] According to an embodiment of the present invention, the pharmaceutically acceptable salt of dopamine is dopamine hydrochloride. Dopamine hydrochloride is easily soluble in water, which is conducive to the modification reaction of the conductive nanomaterial.

[0098] In some embodiments of the present invention, the pharmaceutically acceptable salt of tannic acid is an alkali metal salt of tannic acid. For example, the alkali metal salt of tannic acid can be sodium or potassium tannic acid, and its average salinity can be 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8. Thus, the alkali metal salt of tannic acid has beneficial effects such as good stability and low biological toxicity and side effects.

[0099] In some embodiments of the present invention, the conductive nanomaterial is selected from at least one of graphene, carbon nanotubes, black phosphorus, MXene, and MoS2 modified by dopamine or a pharmaceutically acceptable salt thereof and / or tannic acid or a pharmaceutically acceptable salt thereof.

[0100] According to an embodiment of the present invention, the conductive nanomaterial is MXene@PDA, which is a MXene nanosheet modified with dopamine or a pharmaceutically acceptable salt thereof. According to an embodiment of the present invention, the dopamine-modified MXene nanosheet has a thin biomimetic coating with anchoring sites (catechol groups) on its surface.

[0101] In this article, the term "nanosheet" refers to a sheet-like material with a thickness on the nanometer scale (usually 1 to 100 nanometers) and a lateral dimension much larger than its thickness.

[0102] According to an embodiment of the present invention, dopamine is oxidatively polymerized to form a polydopamine (PDA) coating, which is wrapped around the surface of the nanosheet to form the aforementioned conductive nanomaterial having a catechol group.

[0103] According to an embodiment of the present invention, the mass fraction of MXene@PDA is no less than 1% based on the total mass of the conductive structural color hydrogel. The inventors determined this optimal MXene@PDA mass fraction through extensive experiments. At this mass fraction, the conductive structural color hydrogel of the present invention exhibits high electrical conductivity.

[0104] According to an embodiment of the present invention, based on the total mass of the conductive structural color hydrogel, the HPC mass fraction of the HPC cholesteric liquid crystal is 50% to 52%, and the mass fraction of the MXene@PDA is 1% to 1.5%. For example, the mass fraction of the MXene@PDA can be 1.1%, 1.2%, 1.3%, 1.4%, or 1.5%. As a result, the conductive structural color hydrogel of the present invention provides more intuitive visual feedback to mechanical stimulation while exhibiting excellent electrical conductivity, biosafety, and enhanced biocompatibility. The conductive structural color hydrogel of the present invention can be used to fabricate a cardiac patch with electrical conductivity slightly higher than that of natural human heart tissue. This cardiac patch can compensate for electrophysiological conduction in tissue, reconstructing the conductive pathways of the infarcted myocardium through an electrical coupling process, and repairing damaged fibrotic tissue. According to an embodiment of the present invention, this cardiac patch can effectively inhibit ventricular remodeling and inflammatory responses, promote angiogenesis, reduce fibrotic scar formation, and repair myocardial morphology and function, ultimately restoring the morphology and electrophysiological function of the infarcted heart.

[0105] In some embodiments of the present invention, the matrix material is selected from at least one of sodium alginate, dopamine-grafted modified sodium alginate, hyaluronic acid, dopamine-grafted modified hyaluronic acid, gelatin, carboxymethyl chitosan, and sodium caseinate.

[0106] According to an embodiment of the present invention, the matrix material is sodium alginate and / or dopamine-grafted modified sodium alginate.

[0107] According to an embodiment of the present invention, the mass ratio of the HPC cholesteric liquid crystal to the matrix material is 50:(4-12). The inventors have determined through extensive experiments that this optimal mass ratio of HPC to matrix material is conducive to the formation of bright colors visible to the naked eye after the integrated material.

[0108] According to an embodiment of the present invention, the matrix material is sodium alginate, and the mass ratio of HPC to sodium alginate in the HPC cholesteric liquid crystal is 50:(6-10). Exemplary mass ratios of HPC to sodium alginate can be: 50:6, 50:7, 50:8, 50:9, or 50:10. The inventors, through extensive testing, determined this optimal mass ratio of HPC to sodium alginate, which facilitates the formation of a vivid color visible to the naked eye in the resulting composite material.

[0109] In a specific embodiment of the present invention, the matrix material is sodium alginate, and the mass ratio of HPC to the sodium alginate in the HPC cholesteric liquid crystal is 50:8.

[0110] According to an embodiment of the present invention, the crosslinking agent is a metal ion. The metal ion crosslinker can effectively coordinate and chelate the carboxyl groups of sodium alginate and the catechol groups of the conductive nanomaterial, further improving the mechanical properties of the conductive structural color hydrogel of the present invention. Thus, the conductive structural color hydrogel of the present invention can produce a medical hydrogel material with excellent injectability, enabling targeted, personalized injections and facilitating minimally invasive treatments.

[0111] According to an embodiment of the present invention, the metal ion is a multivalent cation. For example, the “multivalent cation” may be: Ca 2 ⁺、Zn 2 ⁺、Ba 2 ⁺、Mg 2+ 、Cu 2 ⁺、Fe 3+ 、Al 3+ 、Ga 3+ 、Zr 4+ .

[0112] According to an embodiment of the present invention, the metal ions are selected from Ca 2+ 、Zn 2+ Mg 2+ 、Fe 3+ 、Cu 2+ At least one of .

[0113] According to an embodiment of the present invention, the metal ions are derived from halide salts thereof, preferably chloride salts, which is conducive to the metal ion cross-linking agent to play its role.

[0114] According to an embodiment of the present invention, the metal ion is Ca 2+ This is beneficial to improving the mechanical properties and biosafety of the conductive structural color hydrogel of the present invention.

[0115] According to an embodiment of the present invention, the Ca 2+This is beneficial for improving the mechanical properties and biosafety of the conductive structural color hydrogel of the present invention.

[0116] According to an embodiment of the present invention, based on the total mass of the conductive structural color hydrogel, the mass fraction of calcium chloride is 0.5% to 0.56%. For example, the mass fraction of calcium chloride can be: 0.50%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, or 0.56%.

[0117] Methods and products

[0118] The present invention proposes a method for preparing the aforementioned conductive structural color hydrogel. According to an embodiment of the present invention, the method includes: mixing the conductive nanomaterial, the HPC cholesteric liquid crystal, and the matrix material to form a mixture; and cross-linking the mixture with a crosslinker to form the conductive structural color hydrogel. This method, according to an embodiment of the present invention, first integrates the conductive nanomaterial and the HPC cholesteric liquid crystal into the three-dimensional matrix material system, and then cross-links the mixture with the crosslinker. This facilitates the formation of a bright color visible to the naked eye on the hydrogel, enhancing its photoelectric dual-signal sensing capabilities.

[0119] According to an embodiment of the present invention, the method may further include at least one of the following additional technical features:

[0120] According to an embodiment of the present invention, the mixing process is performed at room temperature. HPC cholesteric liquid crystals are typically prepared at room temperature. Therefore, using room temperature mixed conductive structural color hydrogels as the main raw material can further promote the synergistic integration of conductive nanomaterials and HPC cholesteric liquid crystals, facilitating their integration into the matrix material to form a stable elastic gel network structure.

[0121] Herein, the term "room temperature" is 20°C to 25°C.

[0122] According to an embodiment of the present invention, the temperature of the cross-linking reaction is 3° C. to 7° C. By controlling the temperature of the cross-linking reaction, the cross-linking reaction process can be controlled, thereby constructing an elastic gel network structure with stable performance.

[0123] In a specific embodiment of the present invention, the temperature of the cross-linking reaction is 5° C. Thus, the structure and performance of the hydrogel are further improved, and the quality and function are enhanced.

[0124] According to an embodiment of the present invention, the method further includes: subjecting the conductive structural color hydrogel to a degassing process and / or a static treatment. This further improves the quality and functionality of the hydrogel product, constructs an injectable conductive structural color hydrogel, and enables its application in minimally invasive treatments.

[0125] According to an embodiment of the present invention, the temperature of the exhaust treatment is 3° C. to 7° C. Thus, the structure and performance of the hydrogel are further optimized, and the quality and function are improved.

[0126] In a specific embodiment of the present invention, the exhaust gas treatment temperature is 5°C.

[0127] The present invention also provides a conductive structural color hydrogel. According to an embodiment of the present invention, the conductive structural color hydrogel is prepared according to the above method.

[0128] Those skilled in the art will appreciate that the features and advantages described above for the conductive structural color hydrogel and its preparation method are also applicable to the conductive structural color hydrogel, and will not be elaborated here.

[0129] use

[0130] The present invention proposes the use of the aforementioned conductive structural color hydrogel in the preparation of products. According to an embodiment of the present invention, the product has at least one of the following uses: visual and / or digital feedback of the response of non-biological tissue to mechanical stimulation; visual and / or digital monitoring of biological tissue movement; compensation and / or repair of biological tissue electrical conduction. The aforementioned conductive structural color hydrogel, through its mechanochromic response performance, enables the product to be used for visual detection of mechanical stimulation; through its electrical signal sensing performance, enables the product to be used for digital monitoring of mechanical stimulation; through its electrical conduction function, enables the product to be used for compensating and / or repairing biological tissue electrical conduction. Therefore, the conductive structural color hydrogel can be used to prepare products with visualization and digital monitoring functions, thereby displaying the dynamic changes of non-biological tissues under mechanical stimulation and the movement state of biological tissues in real time.

[0131] For example, the conductive structural color hydrogel is attached to the surface of the heart, and the contraction / relaxation signal is monitored in real time by the change of resistance (in some embodiments of the present invention, the sensitivity can reach GF=3.6), and the infarction location is identified based on the local color difference (e.g., the color of the infarcted area remains unchanged, and the normal area is blue-shifted) (in some embodiments of the present invention, the sensitivity of the reflected wavelength blue-shift reaches -2.85 nm%). ﹣1 ); utilizing the electrical conduction function of the conductive structural color hydrogel (in some embodiments of the present invention, the conductivity is 1.05 S / m), reducing scar resistance, promoting angiogenesis (in some embodiments of the present invention, the blood vessel density is increased to 30.95%, a 3-fold increase compared with the myocardial infarction model group), inhibiting inflammatory response (in some embodiments of the present invention, the polarization rate of M2 macrophages can be increased to 20.63%), and improving cardiac function (in some embodiments of the present invention, the ejection fraction EF of the SD rat myocardial infarction (MI) model is increased from 47.38% to 81.55%).

[0132] Exemplarily, possible application scenarios of the product are: monitoring the necrosis of skeletal muscle tissue, smooth muscle tissue, myocardial tissue, connective tissue, nervous tissue and other tissues, so as to evaluate their functions, study their physiological mechanisms, assist in disease diagnosis, screen and evaluate drugs, optimize treatment plans, support rehabilitation treatment and training, etc. For example, develop rehabilitation treatment equipment based on mechanical stimulation and the aforementioned conductive structural color hydrogel, such as cardiac rehabilitation training equipment, muscle rehabilitation training equipment, etc., and formulate personalized rehabilitation treatment plans by real-time monitoring and feedback of the patient's movement status to improve the effect of rehabilitation treatment. Exemplarily, possible application scenarios of the product are: real-time monitoring of the operating status of artificial hearts and cardiac assist devices; monitoring the stress and deformation of heart stents in blood vessels, studying the opening and closing performance and durability of heart valves under mechanical stimulation simulating heart beating, and developing biosensors that can monitor the response of non-biological tissues to mechanical stimulation in real time, such as pressure sensors, strain sensors, etc., to improve monitoring accuracy and reliability, and provide technical support for the research and development and clinical application of medical devices.

[0133] According to an embodiment of the present invention, the visual feedback and / or the numerical feedback are synchronized with the mechanical stimulation. Thus, the above product has the function of visualizing, digitizing, and monitoring the mechanical stimulation in real time.

[0134] According to an embodiment of the present invention, the product includes but is not limited to: medical devices, wearable sensors, and biosensors.

[0135] According to an embodiment of the present invention, the medical device includes but is not limited to: a heart sensor patch, a myocardial infarction monitoring and / or treatment patch, and a bionic skin.

[0136] According to an embodiment of the present invention, the biosensor includes but is not limited to: a pressure sensor and a strain sensor.

[0137] According to embodiments of the present invention, wearable sensors include, but are not limited to, inertial sensors, optical sensors, electrodes and electrochemical sensors, flexible sensors, and interactive sensors. An example of an inertial sensor is an accelerometer, which monitors a person's motion status, such as step count, running speed, and jump height, by measuring changes in acceleration. These sensors are commonly used in devices such as smart bracelets and smart watches, helping users record their daily activity and exercise data. An example of an optical sensor is an ECG sensor, which uses electrodes to detect the potential difference generated by the heart's electrical activity and is commonly used in devices such as smart watches and ECG monitoring patches. An example of an electrode and electrochemical sensor is an electronic skin electrode, which offers excellent flexibility and conformability and can be used to monitor a variety of physiological signals, such as heart rate and muscle activity. These electrodes are often integrated into devices such as smart patches and smart clothing, providing users with a comfortable and convenient monitoring method. An example of a flexible sensor is a flexible pressure sensor, which can be used to create a wearable blood pressure monitoring device. The flexible pressure sensor, wrapped around the arm or wrist, calculates blood pressure by measuring the sensor deformation caused by changes in intravascular pressure. An example of an interactive sensor is a touch screen: a capacitive or resistive touch screen is used to enable user interaction with smart wearable devices, such as smart watches and smart bracelets. Users can perform operations such as checking the time, answering calls, and adjusting settings by touching the screen.

[0138] Exemplarily, the biological tissue movement can be the respiratory movement of a human or animal, expansion and contraction of the thorax, expansion and contraction of the lungs, contraction / relaxation movement of the heart, contraction and relaxation of blood vessels, gastrointestinal peristalsis, esophageal peristalsis, contraction and relaxation of skeletal muscles, peristalsis of renal tubules, peristalsis of ureters, contraction and relaxation of bladder, peristalsis of fallopian tubes, contraction and relaxation of uterus, contraction and relaxation of vagina, blinking of eyes, movement of eyeballs, and swallowing movement of the throat.

[0139] Illustratively, the biological tissue may be skeletal muscle tissue, smooth muscle tissue, cardiac muscle tissue, connective tissue, or neural tissue.

[0140] According to embodiments of the present invention, the product is used to monitor biological tissue necrosis and / or prevent and / or treat diseases caused by such biological tissue necrosis. According to embodiments of the present invention, by monitoring biological tissue movement, necrotic biological tissue can be accurately identified, thereby preventing disease; by compensating for and / or repairing the electrical conduction of biological tissue, the biological function of the tissue can be effectively improved, thereby preventing and treating disease.

[0141] In some embodiments of the present invention, the diseases include but are not limited to: myocardial infarction, myocardial sclerosis, cerebral infarction, encephalomalacia, gastroduodenal ulcer, typhoid fever, acute pancreatitis, pulmonary tuberculosis, pulmonary infarction, renal tubular necrosis, renal infarction, ovarian cyst pedicle torsion, tubal pregnancy rupture, necrotizing fasciitis, and frostbite. Myocardial infarction: Myocardial tissue undergoes necrosis due to obstruction of coronary blood flow, which can lead to arrhythmia, heart failure, and even sudden death. Myocardial sclerosis: Extensive small focal necrosis of the myocardium can eventually lead to myocardial sclerosis, affecting the heart's pumping function. Cerebral infarction: Brain tissue undergoes necrosis due to obstruction or rupture of cerebral blood vessels, which can cause paralysis, coma, speech disorders, etc. Encephalomalacia: Liquefactive necrosis of brain tissue is common in diseases such as purulent encephalitis. Gastroduodenal ulcer: Necrosis of the gastric or duodenal mucosa and muscular layer can lead to upper abdominal pain, bleeding, perforation, etc. Enteric typhoid: Infection with Salmonella typhi causes necrosis of the intestinal wall, which can lead to complications such as intestinal bleeding and perforation. Acute pancreatitis: Necrosis of pancreatic tissue can cause severe abdominal pain, nausea, and vomiting, and in severe cases, multiple organ failure. Pulmonary tuberculosis: Caseous necrosis caused by infection with Mycobacterium tuberculosis can cause cough, sputum, hemoptysis, low-grade fever, etc. Pulmonary infarction: Necrosis of lung tissue due to pulmonary embolism can cause symptoms such as chest pain, hemoptysis, and difficulty breathing. Renal tubular necrosis: Common in acute renal failure, which can lead to oliguria or anuria, azotemia, etc. Renal infarction: Necrosis of renal tissue due to obstruction of the renal artery can cause low back pain, hematuria, etc. Ovarian cyst pedicle torsion: Ovarian tissue undergoes necrosis due to obstructed blood supply, which can lead to sudden severe lower abdominal pain. Rupture of tubal pregnancy: Necrosis of fallopian tube tissue can cause abdominal pain, vaginal bleeding, shock, etc. Necrotizing fasciitis: Necrosis of subcutaneous tissue and fascia can cause severe local pain, fever, and systemic toxicity, which can be life-threatening in severe cases. Frostbite: Localized tissue necrosis due to low temperatures can cause skin pallor, numbness, and pain, and in severe cases, can lead to tissue necrosis and shedding.

[0142] According to an embodiment of the present invention, the product is used for monitoring and / or treating myocardial infarction.

[0143] In a specific embodiment of the present invention, the conductive structural color hydrogel of the present invention is prepared by the following method:

[0144] 5.0 g of HPC was added to 3.7 g of water and stirred thoroughly for 12 hours. Then, 0.8 g of sodium alginate and 9.6–10 mg of MXene@PDA conductive nanosheets were slowly added to the solution, followed by continuous stirring at room temperature for 6 hours and then allowed to stand overnight. 0.05 g of CaCl₂ was slowly added to the system, and stirring continued at 5°C for 3 hours. The homogenized hydrogel was then centrifuged at high speed (10,000 rpm, 5°C, 10 minutes) to remove bubbles, and then allowed to stand for 6 hours to obtain an injectable conductive structural color hydrogel.

[0145] Further experimental results show that the conductive structural color hydrogel exhibits excellent tensile color change performance (sensitivity: -2.85 nm % ﹣1 ), press color response (sensitivity of -3.50 nm % ﹣1 ) and dilatochromic response (sensitivity of -4.47 nm % ﹣1 The material exhibits excellent tensile strain sensitivity, fast response, a relatively wide strain sensing window, and periodic frequency dependence at frequencies between 0.025 and 1.0 Hz. Its electrical conductivity is measured at approximately 1.05 ± 0.053 S / m, slightly higher than the conductivity range of natural human heart tissue (approximately 0.3 to 0.7 S / m), making it an ideal material for cardiac patch applications.

[0146] Further test results showed that this conductive structural color hydrogel, as a conductive structural color sensing patch, has excellent cell safety (cell survival rate >95%, superior to the 80% of traditional polypyrrole hydrogels), biocompatibility (no risk of fiber wrapping), and shape-preserving adhesion (can firmly adhere to human skin without the aid of external tape). It can safely and tightly adhere to the surface of the heart, enabling visual and accurate diagnosis while effectively restoring heart function. Among them, the restoration of heart function is reflected in: it can effectively inhibit ventricular remodeling, significantly slow the process of ventricular thinning, and effectively prevent the expansion of infarct area and fibrosis deposition. The test results also show that this conductive structural color hydrogel, as a conductive structural color sensing patch, can inhibit inflammatory responses and promote angiogenesis.

[0147] Therefore, the conductive structural color hydrogel of the present invention can be used as a heart patch to effectively inhibit ventricular remodeling and inflammatory response, promote angiogenesis, reduce fibrotic scar formation, and repair myocardial morphology and function, thereby achieving the repair of infarcted heart morphology and electrophysiological function.

[0148] The present invention will be explained below with reference to the following examples. Those skilled in the art will understand that the following examples are intended only to illustrate the present invention and should not be construed as limiting its scope. Where specific techniques or conditions are not specified in the examples, the procedures were performed in accordance with those described in literature in the field or in accordance with the product instructions. Reagents or instruments used, without manufacturer identification, are commercially available, conventional products. In the following examples, unless otherwise specified, the term "MI group" refers to the "myocardial infarction (MI) model group."

[0149] Example 1: Preparation and material characterization of modified MXene nanosheets (MXene@PDA)

[0150] In this example, ultrathin Ti3C2Tx MXene nanosheets (MXene) were prepared by chemical exfoliation, and modified MXene nanosheets (MXene@PDA) were obtained by oxidative polymerization of dopamine. The specific method is as follows:

[0151] MXene preparation: 1.6 g of LiF and 20 mL of 9 mol / L aqueous HCl were placed in a polytetrafluoroethylene reactor and mixed uniformly with a magnetic stirrer to obtain a mixed solution. 1.0 g of Ti3AlC2 powder was then added to the mixed solution in batches, and the reaction was stirred at 35°C for 24 h to obtain an aqueous dispersion of MXene powder. Finally, under nitrogen, the aqueous dispersion of MXene powder was sonicated in an ice-water bath for 1 h to obtain an aqueous MXene dispersion for subsequent use. MXene@PDA preparation: 100 mg of the MXene aqueous dispersion (8 wt %) was washed three times with Tris-HCl buffer (10 mM, pH 8.5) and then dispersed in 200 mL of Tris-HCl buffer. 400 mg of dopamine hydrochloride was then added to the buffer solution, and the mixture was magnetically stirred at room temperature for 6 h. The resulting mixture was then centrifuged three times with deionized water. After freeze-drying treatment, PDA-modified MXene (MXene@PDA) nanosheets were finally obtained.

[0152] Furthermore, the morphology and microstructure of MXene and MXene@PDA were observed using transmission electron microscopy (TEM, Talos F200S), and the functional group structure and surface characteristics were detected by attenuated total reflectance infrared spectroscopy (ATR-FTIR, PerkinElmer Spectrometer 3) and X-ray photoelectron spectroscopy (XPS, Thermo Scientific KAlpha), thereby characterizing the modification of MXene. Figure 2 shown.

[0153] The results show that compared with the unmodified MXene, (1) a large number of nanoaggregates can be observed on the surface of the modified MXene nanosheets, and the thickness of the nanosheets is significantly increased ( Figure 2 A); (2) A large amount of N element appeared on the surface of the modified MXene (accounting for 8.04%), while the C element content increased from 13.91% to 20.04%, and the O element content increased from 64.49% to 65.46%. Dopamine rich in C, N, and O elements has been in situ polymerized on the MXene surface ( Figure 2 B); (3) MXene@PDA material at 3650~2693 cm ﹣1The stretching vibration peaks of hydroxyl and amino groups originating from dopamine appeared in the range of 1500-600 cm ﹣1 There are several absorption peaks of carbon-carbon double bonds on benzene rings in the range; at 815 cm ﹣1 There is also an out-of-plane bending vibration absorption peak of hydrogen on the aromatic ring nearby ( Figure 2 C). The above results prove that PDA is successfully loaded on the surface of MXene material, forming a thin layer of biomimetic coating with anchoring points.

[0154] Example 2: Preparation and component optimization of conductive structural color hydrogel

[0155] In this example, a conductive structural color hydrogel was prepared using a static self-assembly and ionic cross-linking strategy. The specific method is as follows:

[0156] Preparation of the conductive structural color hydrogel: First, 5.0 g of HPC (hydroxypropyl cellulose, 74.1% hydroxypropyl substitution, viscosity 4.8 mPa·s, MW = 100,000) was gradually added to a container containing 3.7 g of water and stirred thoroughly with a mechanical stirrer for 12 h. Subsequently, 0.8 g of sodium alginate (SA) and 0–100 mg of MXene@PDA conductive nanosheets were slowly added to the solution, stirred continuously at room temperature for 6 h, and then allowed to stand overnight. Next, 0.05 g of CaCl₂ was slowly added to the system, and stirring continued at 5°C for 3 h. Finally, the homogenized hydrogel was quickly transferred to a centrifuge tube and expelled by high-speed centrifugation (10,000 rpm, 5°C, 10 min) to remove bubbles. The mixture was then allowed to stand for 6 h to obtain an injectable conductive structural color hydrogel.

[0157] In this example, the effects of HPC content, sodium alginate, and calcium ion introduction on the structural color of the hydrogel were also investigated. The specific method was as follows: the HPC concentration of the HPC cholesteric liquid crystal was changed (based on the total mass of the conductive structural color hydrogel, the mass fraction of HPC was 50%, 52%, 54%, and 56%), sodium alginate was added, and calcium ions were introduced to investigate the effect of each parameter on the structural color of the conductive structural color hydrogel. The results are shown in FIG. Figure 3 A. Figure 3 As shown in B.

[0158] The results show that: (1) as the HPC concentration gradually increases from 50% to 56%, the initial color of the conductive structural color hydrogel gradually changes from red to blue, and the reflection wavelength peak of the structural color also gradually shifts from 656nm (red), 586nm (yellow), 521nm (green) to 461nm (blue) ( Figure 3 A. Figure 3B). (2) When sodium alginate is added to the HPC cholesteric liquid crystal, the color of the HPC / SA system gradually changes from dark red (781nm) to yellow-green (568nm). (3) The introduction of calcium ions causes ionic cross-linking of the sodium alginate polymer network structure, which compresses the pitch of the liquid crystal phase to a certain extent, resulting in a blue shift in the reflection wavelength. (4) After the addition of MXene@PDA containing catechol groups on the surface, the cross-linking degree of the hydrogel system is greatly improved. At the same time, the black conductive material enhances the contrast of the structural color, causing the reflection wavelength to shift significantly from 557nm (green) to 511nm (blue-green). The above results prove that the initial color of the structural color can be quickly adjusted by changing the HPC concentration, and the matrix material (such as sodium alginate and metal ion cross-linked network) and the conductive material (such as MXene@PDA) affect the final color of the structural color.

[0159] The presence of periodic cholesteric liquid crystals is a key factor in the formation of structural color. In this example, the presence of cholesteric liquid crystal structures in the hydrogel was further verified by scanning electron microscopy (TEM, Talos F200S) and polarizing microscopy. Figure 3 C. Figure 3 As shown in D.

[0160] The results showed that: (1) The SEM image showed that the hydrogel had a distinct spiral lamellar morphology, and the polarizing microscope showed that the colorful liquid crystal phase in the hydrogel was clearly visible ( Figure 3 C. Figure 3 D). (2) The opaque black flakes under polarizing microscope are MXene@PDA nanosheets dispersed in the hydrogel ( Figure 3 D). The above results fully confirm the presence of a cholesteric liquid crystal structure in the hydrogel of the present invention, and the conductive material MXene@PDA is relatively uniformly dispersed therein, forming a continuous conductive network structure.

[0161] Example 3: Composition and Mechanical Properties of the Conductive Structural Color Hydrogel of the Present Invention

[0162] With reference to Examples 1 and 2, HPC / SA, structural color hydrogel (without MXene@PDA) and conductive structural color hydrogel (with 1.0% MXene@PDA) were prepared, and the mechanical properties of each sample were further investigated. Compared with the conductive structural color hydrogel, (1) the preparation method of HPC / SA is different in that no MXene@PDA conductive nanosheets and CaCl2 are added; (2) the preparation method of structural color hydrogel is different in that no MXene@PDA conductive nanosheets are added. The results are shown in Figure 2. Figure 4 shown.

[0163] The results show that: (1) the conductive structural color hydrogel of the present invention successfully introduced CaCl2, Mxene@PDA conductive nanosheets ( Figure 4 A); Calcium ions have an effective metal ion coordination and ion chelation effect with the carboxyl group of sodium alginate and the catechol group of MXene@PDA ( Figure 4 B); Mxene@PDA has a two-dimensional structure and good stability ( Figure 4 C). (2) In the rheological frequency sweep measurement, when the angular frequency range is 1 to 100 rad·s ﹣1 , the storage modulus G' of the hydrogel is always higher than the loss modulus G", which indicates that the material always maintains a very stable gel state. At the same time, with the addition of calcium ions and MXene@PDA conductive materials, the storage modulus G' and loss modulus G" of the material are significantly improved, which means that its mechanical properties are also improved accordingly. In the rheological strain scanning test, when the strain is less than 200%, the storage modulus G' of the hydrogel is always higher than the loss modulus G"; when the strain is higher than 200%, the storage modulus G' of the hydrogel decreases to below the loss modulus G". This is because the gel network structure has obviously broken, indicating that the hydrogel can maintain a stable elastic gel network structure below 200% strain.

[0164] Further investigation revealed that the conductive structural color hydrogel of the present invention possesses excellent injectability, enabling targeted and personalized injection using a medical syringe. The injection force during injection is approximately 12 N, which facilitates minimally invasive treatments using medical hydrogel materials.

[0165] Example 4: Investigation of the visual sensing function of the conductive structural color hydrogel of the present invention

[0166] For flexible wearable sensors and heart monitoring patches, intuitive visual signal output is extremely important, which can achieve rapid and visually recognizable signal detection. In this example, the visual response sensitivity of the conductive structural color hydrogel of the present invention to external mechanical stimulation was further investigated. The results are shown in Figure 2. Figure 5 、 Figure 6 、 Figure 7 shown.

[0167] The results show that: (1) As the conductive structural color hydrogel of the present invention is gradually stretched, the color of the hydrogel gradually changes from red to blue, showing an optical signal change that can be recognized by the naked eye. By detecting the change in reflection wavelength during the stretching process, it can be seen that as the material is stretched from 0% to 60%, the reflection wavelength of the hydrogel gradually shifts from 640nm to 482nm, showing excellent stretch color change performance (sensitivity: -2.85 nm % ﹣1 )( Figure 5). (2) When the hydrogel material is stimulated by external pressure, as the pressure increases, the color of the hydrogel gradually shifts to blue, showing an excellent pressure-induced color change response (sensitivity of -3.50nm % ﹣1 )( Figure 6 ). (3) The hydrogel material is adhered to the surface of the balloon. When the balloon is squeezed and deformed, the color of the hydrogel will also change significantly. As the degree of balloon expansion and deformation increases, the color of the hydrogel gradually changes from red, yellow, green to blue, showing an excellent expansion color response (sensitivity of -4.47 nm % ﹣1 During the expansion and deformation sensing process, the changes in the color and reflection wavelength of the hydrogel have good stability and resilience, and its reflection wavelength has almost no hysteresis.

[0168] Furthermore, the results of 100 stretching cycle tests showed that after the conductive structural color hydrogel of the present invention was stretched 100 times, its reflection wavelength could still stably switch from about 620nm (red) to about 458nm (blue) without obvious attenuation, and it had stable visual signal transmission capabilities.

[0169] The above results indicate that the conductive structural color hydrogel of the present invention has excellent stimulation visualization capability and shows broad application prospects in the fields of human-computer interaction and dynamic visual display.

[0170] Example 5: Application of the conductive structural color hydrogel of the present invention in visual monitoring of the pathological location of myocardial infarction

[0171] Based on the results of Example 4, the inventors attached inelastic tape to the surface of a balloon to limit its local expansion and deformation, then evenly adhered the hydrogel to it. By inflating and deflating the balloon to simulate heartbeats, the inventors investigated the application of the conductive structural color hydrogel of the present invention in visually monitoring the pathological location of myocardial infarction. Figure 8 As shown in A.

[0172] The results showed that as the balloon inflated and deformed, the hydrogel on the normal balloon surface underwent a noticeable color change, from yellow to cyan, while the hydrogel on the tape surface showed no noticeable color change, remaining its original yellow. These results demonstrate that the conductive structural color hydrogel of the present invention can visually sense external spatiotemporal mechanical stimuli by changing the pitch of the cholesteric liquid crystal, and has important application value in the field of biomechanical signal monitoring.

[0173] Furthermore, the inventors simulated local myocardial infarction by ligating the left ventricular myocardium of the duck's heart. Then, they attached the hydrogel sensor patch to the surface of the duck's heart and simulated the heartbeat in vitro by inflation / deflation. Figure 8 As shown in B.

[0174] The results showed that the overall color of the hydrogel switched between green and cyan as the heart contracted and relaxed. However, the color of the hydrogel at the site of left ventricular infarction remained unchanged, retaining its original reddish-yellow color (due to the uneven surface of the ligated duck heart). These results demonstrate that the conductive structural color hydrogel of the present invention can visually identify the pathological location of myocardial infarction.

[0175] In summary, the conductive structural color hydrogel of the present invention can accurately detect external tension, pressure, expansion, deformation, and spatial mechanical stimulation simply through its own vibrant color changes, without the need for any external instrumentation. Furthermore, local color differences can accurately locate the stimulus location and identify the stimulus intensity and range. This provides a simple and effective method for the development of intelligent bionic skin and cardiac sensor patches.

[0176] Example 6: Investigation of the electrical signal sensing function of the conductive structural color hydrogel of the present invention

[0177] Having electrical conductivity that matches tissue and stable charge injection capability is the basis for building bioelectronic devices for electrical diagnosis and treatment. For flexible sensing materials, electrical signal sensing monitoring can quickly output various types of digital information that can be read by computers, and has shown broad application prospects in many fields such as human motion monitoring, physiological signal recognition, and human-computer interaction. In this embodiment, the conductive properties, stretching electrical signal sensing performance, and expansion electrical signal sensing performance of the conductive structural color hydrogel of the present invention were further investigated. The results are as follows Figure 9 、 Figure 10 、 Figure 11 shown.

[0178] The results of the conductive properties investigation show that: (1) Electrochemical impedance spectroscopy (EIS) can reflect the charge transfer resistance of conductive hydrogels. Among them, the charge transfer resistance (R ct ) is expressed as the semicircle diameter of the Nyquist curve, and the intersection of the curve on the X-axis represents the comprehensive resistance of the material. The semicircle diameter and intersection value of the conductive structural color hydrogel of the present invention (containing 1.0% MXene@PDA) are smaller than HPC / SA and smaller than the structural color hydrogel (without MXene@PDA). This shows that the charge transfer resistance and comprehensive resistance of the conductive structural color hydrogel of the present invention are low ( Figure 9 A). (2) With the addition of calcium ions and MXene@PDA conductive nanosheets, the comprehensive resistance of the hydrogel material gradually decreased. As the concentration of MXene@PDA increased, the conductivity of the hydrogel increased rapidly. When the concentration reached 1.0%, the increase in conductivity began to slow down ( Figure 9 B. Figure 9C). (3) The conductive structural color hydrogel of the present invention (containing 1.0% MXene@PDA) has a larger CV ring, which means that the material has a larger charge capacity ( Figure 9 D). These results demonstrate that the conductive structural color hydrogel of the present invention possesses excellent electrical conductivity. Combined with the cytotoxicity studies of this material, the conductive structural color hydrogel containing 1.0% MXene@PDA is an ideal cardiac patch material. Its electrical conductivity is 1.05 ± 0.053 S / m, slightly higher than the conductivity range of natural human heart tissue (approximately 0.3-0.7 S / m), thus enabling it to compensate for electrophysiological conduction in the tissue. Therefore, the conductive structural color hydrogel of the present invention has the potential to reconstruct the conductive pathways of the infarcted myocardium through an electrical coupling process, thereby repairing damaged fibrotic tissue.

[0179] The results of the investigation on the tensile electrical signal sensing performance show that: due to the continuous increase in the electrical conduction path, the relative resistance of the conductive structural color hydrogel of the present invention will gradually increase with the increase of strain. This shows that the material can respond to tensile deformation with electrical signals. The response factor (GF) is a key indicator for measuring the sensitivity of the sensing response and can be obtained by calculating the slope of the tensile-electrical signal curve. Furthermore, the conductive structural color hydrogel of the present invention, (1) has a GF of 1.6 in the strain range of 0-72%; when the strain is further increased, in the strain range of 72-100%, the GF rises sharply to 3.6 ( Figure 10 A). This shows that the material has excellent tensile strain sensitivity in a wide range of deformation. (2) It can accurately identify mechanical deformations of different amplitudes (0-100%) ( Figure 10 B). This indicates that the material has a relatively wide strain sensing window and can repeatedly monitor various mechanical strain stimuli of different intensities. (3) At a frequency of 0.025 to 1.0 Hz, it exhibits a periodic frequency-dependent characteristic ( Figure 10 C). This characteristic can meet the needs of sensing materials to collect information in complex and changing environments. (4) It exhibits a fast response time (550 ms) and recovery time (450 ms) ( Figure 10 D). This high sensitivity and rapid response to stretching stimulation helps to achieve real-time signal feedback in the actual sensing process.

[0180] Further large strain tensile sensing test results show that the conductive structural color hydrogel of the present invention can withstand more than 800 large strain tensile sensing tests with almost no signal attenuation ( Figure 10 E).

[0181] The results of the expansion electrical signal sensing performance test show that the conductive structural color hydrogel of the present invention can respond to external expansion and deformation stimuli by quickly adjusting the conductive path. (1) When the balloon simulating the heart is inflated, the internal pressure of the balloon increases, which causes the balloon to expand and deform. The conductive hydrogel of the present invention has excellent adhesion and can be attached to the surface of the balloon, and expand and change together with the balloon. As the amount of balloon expansion deformation increases, the relative resistance value of the conductive structural color hydrogel of the present invention also increases linearly, showing excellent volume-resistance response characteristics, and its response sensitivity (GF) is 1.05. When the balloon changes from a dilated state to a contracted state, due to the close fit between the hydrogel and the balloon, the relative resistivity can also be quickly and reversibly restored to the initial value ( Figure 11 A). (2) The conductive structural color hydrogel of the present invention can convert expansion deformation into precise electrical signal changes and accurately identify different degrees of volume expansion (0-50%) ( Figure 11 B). This indicates that the material can meet the needs of real-time monitoring of cardiac contraction / relaxation processes.

[0182] The above results indicate that the conductive structural color hydrogel of the present invention has excellent electrical signal sensing function and can be used as a flexible sensor to monitor various mechanical movements.

[0183] Example 7: Application of the conductive structural color hydrogel of the present invention as a flexible material in in vitro mechanical motion monitoring

[0184] Based on the results of Example 6, the inventors further investigated the application of the conductive structural color hydrogel of the present invention in monitoring mechanical motions such as finger bending motion, balloon inflation motion, heartbeat motion, and respiratory motion. Figure 12 shown.

[0185] The results show that: (1) the conductive structural color hydrogel of the present invention can firmly adhere to human skin without the aid of external tape, achieving a comfortable fit and thus enabling real-time and accurate monitoring of human movement ( Figure 12 A), and good repeatability ( Figure 12 B). (2) The conductive structural color hydrogel of the present invention is adhered to the surface of the duck heart. When the heart is inflated / deflated, the electrical signal curve shows a single peak with a weak jagged fluctuation ( Figure 12 C); The conductive structural color hydrogel of the present invention was installed on the surface of the chest muscles of anesthetized mice, and it was also able to accurately identify the slight chest movement of the mice when they breathed ( Figure 12 D). This demonstrates that the material can accurately identify minute fluctuations in the myocardium during a heartbeat and precisely capture subtle interfacial mechanical stimulation. These results demonstrate that the conductive structural color hydrogel of this invention can enable real-time monitoring of mechanical motion in vitro.

[0186] In summary, the conductive structural color hydrogel of the present invention has excellent stimulation visualization ability and excellent electrical signal sensing function. It has the function of digitally and visually monitoring weak external interface mechanical stimulation and spatiotemporal mechanical stimulation. It can be used to monitor human movement and physiological health status in real time, opening up a new path for the development of intelligent sensing materials.

[0187] Example 8: Application of the conductive structural color hydrogel of the present invention in visual monitoring of the pathological location of myocardial infarction

[0188] Based on the above test results, the inventors further investigated the application of the conductive structural color hydrogel of the present invention as a cardiac sensor patch in the monitoring of cardiac mechanical physiological signals and the visual identification of infarcted myocardium.

[0189] Before implanting the conductive structural color sensing patch of the present invention, its cytotoxicity and adhesion properties on the tissue surface were first investigated. Figure 13 、 Figure 14 .

[0190] The results of the investigation on cytotoxicity and adhesion properties on tissue surfaces showed that: (1) the conventional polypyrrole hydrogel (OGGP3) contains: polypyrrole grafted gelatin (GP), oxidized xanthan gum (OXG) Schiff base crosslinking. Compared with the cell survival rate of 80% of the conventional polypyrrole hydrogel, the cell survival rate of the conductive structural color hydrogel of the present invention exceeds 95%, and the cytotoxicity is significantly reduced. Therefore, the conductive structural color hydrogel of the present invention has good cell compatibility and biosafety, and can be used as an implantable biomedical material ( Figure 13 ). (2) The conductive structural color hydrogel of the present invention has stable adhesion properties. Compared with traditional adhesive hydrogels, the conductive structural color hydrogel of the present invention has a closer fit performance at the micro-nano scale, and can adjust the interfacial adhesion behavior at any time with the dynamic changes of the substrate, showing good shape retention and compliance ( Figure 14 A. Figure 14 B. Figure 14 C). (3) The conductive structural color hydrogel of the present invention has excellent adhesion properties. The adhesion strength on pig skin can reach about 5.7 kPa. It has excellent universal adhesion and has a certain adhesion ability on the surfaces of various objects such as glass, plastic, pig skin, duck heart, etc. ( Figure 14 D).

[0191] Based on the above-mentioned cytotoxicity and adhesion performance test results, the inventors adhered the conductive structural color hydrogel of the present invention (1) to the surface of the left ventricle of the heart to monitor the mechanical physiological signals of the heart in real time; (2) adhered it to the surface of the infarcted heart to observe the color signal output by the hydrogel in real time. The specific method is: by ligating the left anterior descending branch of the rat heart, an animal myocardial infarction model is constructed. Ischemic myocardial damage can induce myocardial cell apoptosis and myocardial tissue fibrosis, which is directly manifested as a decrease in the amplitude of the heartbeat movement. Placing the hydrogel patch on the surface of the heart can monitor the heart function after infarction. The results are as follows: Figure 15 shown.

[0192] The results show that: (1) As the heart beats, the relative resistance of the conductive structural color hydrogel of the present invention changes continuously between 0 and 5.1%, presenting a multi-serrated continuous single-peak curve. The relative resistance change rate represents the deformation amplitude of the hydrogel during heartbeat, which can indirectly reflect the heart's pulsation and pumping function, and can be further used for the diagnosis of myocardial infarction ( Figure 15 B. Figure 15 C). (2) As the heart relaxes, the overall color of the conductive structural color hydrogel of the present invention changes significantly from green to blue-purple; when the heart contracts, the color returns to its original state. At the same time, the color of the hydrogel at the ligation site (infarction site) near the left ventricle is obviously abnormal. As the heart beats, the color of the hydrogel here almost maintains the initial yellow-green color ( Figure 15 D).

[0193] The above results show that the conductive structural color hydrogel of the present invention can realize accurate diagnosis of myocardial infarction and rapid location of infarction ( Figure 15 A), can be used to monitor mechanical physiological signals during myocardial infarction and accurately identify pathological states through visualization.

[0194] Example 9: Investigation of the electrical coupling repair function of the conductive structural color hydrogel of the present invention on infarcted heart

[0195] Conductive hydrogels have electrical conductivity that matches that of cardiac tissue. By reducing the electrical resistance of post-infarction scar tissue and rebuilding the conductive pathway, they can compensate for the integrity of electrical conduction, enhance the synchronized contraction and relaxation of the infarcted heart, and promote the repair of myocardial infarction. Therefore, the inventors further investigated the potential of the conductive structural color hydrogel of the present invention as a cardiac patch to repair infarcted myocardium. The specific methods and results of the investigation are as follows:

[0196] A myocardial infarction (MI) model was established in SD rats by ligating the left anterior descending (LAD) coronary artery. The photoelectric dual-signal sensing function of the conductive structural color hydrogel was then used to accurately locate the location of the infarcted myocardium, allowing for precise implantation and treatment at the pathological location. Echocardiography was performed 14 and 28 days after treatment to assess changes in cardiac function. Evaluation indicators included ejection fraction (EF), shortening fraction (FS), end-diastolic volume (EDV), and end-systolic volume (ESV). The results were as follows: Figure 16 shown.

[0197] Preliminary results showed that compared with the myocardial infarction group and the structural color hydrogel group, the conductive structural color hydrogel group of the present invention had significantly improved EF (increased from 47.38 ± 3.4% to 81.55 ± 5.8%) and FS (increased from 21.40 ± 2.1% to 50.53 ± 1.4%), and significantly reduced EDV (decreased from 0.96 ± 0.08 mL to 0.41 ± 0.03 mL) and ESV (decreased from 0.51 ± 0.03 mL to 0.06 ± 0.02 mL). Figure 16 B).

[0198] Using the aforementioned method, the electrical coupling repair function of an existing conductive hydrogel patch (PPG hydrogel) on infarcted hearts was also investigated. The PPG hydrogel consists of polydopamine-hybridized PEDOT nanoparticles (PPEDOT NPs) and polygallic acid-gelatin methacrylamide (PGA-GelMA). Results showed that the EF of the PPG hydrogel test group increased from 47.38% to 70%. Compared to this, the conductive structural color hydrogel group presented in this paper exhibits significant advantages.

[0199] The above results indicate that the conductive hydrogel of the present invention can improve electrical coupling contraction force by compensating for electrical conduction in fibrous tissue, thereby preventing left ventricular enlargement and improving cardiac function.

[0200] Furthermore, the inventors performed morphological analysis of the heart using hematoxylin-eosin (H&E) and Masson trichrome staining on days 14 and 28. Figure 17 shown.

[0201] The results of the experiment showed that: (1) Myocardial infarction often causes severe ventricular remodeling, which is manifested by thinning of the wall thickness and collagen deposition ( Figure 17 A). H&E staining analysis clearly showed that compared with the myocardial infarction group, the thickness of the left ventricular infarct wall in all hydrogel groups was significantly increased. Masson staining analysis showed that compared with the myocardial infarction group and the structural color hydrogel group without MXene@PDA conductive material, the conductive structural color hydrogel group of the present invention had a higher survival rate of myocardial fibers (red) and fewer collagen fibers (blue). Figure 17 B). (2) Compared with the structural color hydrogel without MXene@PDA conductive material, the conductive structural color hydrogel patch of the present invention can effectively inhibit ventricular remodeling and significantly alleviate the process of ventricular thinning (the thickness of the infarct wall in the myocardial infarction group: 924.3 ± 157.4 μm; the thickness of the infarct wall in the conductive structural color hydrogel group of the present invention: 2727.4 ± 265.4 μm) ( Figure 17 B), which can effectively prevent the expansion of infarct area and fibrosis deposition, reducing the infarct area from 55.66 ± 4.0% to 6.31 ± 2.0% ( Figure 17 C).

[0202] The above results indicate that the conductive structural color hydrogel patch of the present invention can effectively restore cardiac function while achieving visual and accurate diagnosis.

[0203] Furthermore, the inventors used CD86 / CD206 double staining analysis to find that the conductive structural color hydrogel of the present invention can promote the polarization of M1 macrophages in the inflammatory area to the M2 phenotype with repair function. The polarization rate of M2 macrophages in the conductive structural color hydrogel group increased to 20.63% ( Figure 18 ). This result shows that the conductive structural color hydrogel of the present invention can inhibit the inflammatory response of myocardial infarction.

[0204] The inventors used immunofluorescence staining to analyze the expression of vWF (for microvascularization) and CD31 (vascular endothelial marker) and found that the vascular density of the conductive structural color hydrogel group increased by 3 times compared with the myocardial infarction group ( Figure 19 ). This result shows that the conductive structural color hydrogel of the present invention has angiogenesis function, which is beneficial to restore blood supply to the ischemic area.

[0205] In summary, the conductive structural color hydrogel of the present invention can be used as a cardiac patch to effectively inhibit ventricular remodeling and inflammatory response, promote angiogenesis, reduce fibrotic scar formation, and repair myocardial morphology and function, thereby achieving the repair of the morphology and electrophysiological function of the infarcted heart.

[0206] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0207] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A conductive structural color hydrogel, characterized in that: include: A conductive nanomaterial having a catechol group; the conductive nanomaterial is MXene@PDA, which is a MXene nanosheet modified with dopamine or a pharmaceutically acceptable salt thereof; HPC cholesteric liquid crystal; Base material; the base material is sodium alginate; Cross-linking agent; the cross-linking agent is a metal ion; The conductive structural color hydrogel is formed by physical and / or chemical interactions among the conductive nanomaterial, the HPC cholesteric liquid crystal, the matrix material and the cross-linking agent; Based on the total mass of the conductive structural color hydrogel, the mass fraction of the HPC cholesteric liquid crystal is 50% to 56%, and the mass fraction of the MXene@PDA is 1% to 1.5%; The mass ratio of the HPC of the HPC cholesteric liquid crystal to the matrix material is 50:(4-12).

2. The conductive structural color hydrogel according to claim 1, characterized in that: Based on the total mass of the conductive structural color hydrogel, the HPC mass fraction of the HPC cholesteric liquid crystal is 50% to 52%.

3. The conductive structural color hydrogel according to claim 1, characterized in that: The HPC cholesteric liquid crystal is formed by self-assembly of HPC in water, and the mass ratio of the HPC to the water is 50:(35-40).

4. The conductive structural color hydrogel according to claim 1, characterized in that: The mass ratio of the HPC of the HPC cholesteric liquid crystal to the matrix material is 50:(6-10).

5. The conductive structural color hydrogel according to claim 1, characterized in that: The metal ion is selected from Ca 2+ 、Zn 2+ Mg 2+ 、Fe 3+ 、Cu 2+ At least one of .

6. The conductive structural color hydrogel according to claim 5, characterized in that: The metal ion is Ca 2+ , the Ca 2+ Derived from calcium chloride, based on the total mass of the conductive structural color hydrogel, the mass fraction of the calcium chloride is 0.5% to 0.56%.

7. A method for preparing the conductive structural color hydrogel according to any one of claims 1 to 6, characterized in that: include: Mixing the conductive nanomaterial, the HPC cholesteric liquid crystal and the matrix material to form a mixture; The mixture is subjected to a cross-linking reaction with the cross-linking agent to form the conductive structural color hydrogel; the temperature of the cross-linking reaction is 3° C. to 7° C.

8. The method according to claim 7, characterized in that The temperature of the mixing process is room temperature.

9. The method according to claim 7, characterized in that The method further includes: performing an exhaust treatment on the conductive structural color hydrogel; the exhaust treatment temperature is 3° C. to 7° C.

10. A conductive structural color hydrogel, characterized in that: The conductive structural color hydrogel is prepared according to the method according to any one of claims 7 to 9.

11. Use of the conductive structural color hydrogel according to any one of claims 1 to 6 or the conductive structural color hydrogel according to claim 10 in preparing a product, characterized in that: The product has at least one of the following uses: Visualize and / or digitally feedback the response of non-biological tissues to mechanical stimulation; Visualization and / or digital monitoring of biological tissue movement; Compensate and / or repair electrical conduction in biological tissues.

12. The use according to claim 11, characterized in that The products include: medical devices; among which, The medical devices include: heart sensor patches, myocardial infarction monitoring and / or treatment patches, and bionic skin.

13. The use according to claim 11, characterized in that Said products include: wearable sensors, biosensors; The wearable sensors include: inertial sensors, optical sensors, electrodes and electrochemical sensors, flexible sensors, and interactive sensors; The biosensor includes: a pressure sensor and a strain sensor.

14. The use according to claim 11, characterized in that The biological tissue movements include: respiratory movement, contraction and relaxation of blood vessels, gastrointestinal peristalsis, esophageal peristalsis, contraction and relaxation of skeletal muscles, peristalsis of renal tubules, peristalsis of ureters, contraction and relaxation of bladder, peristalsis of fallopian tubes, contraction and relaxation of uterus, contraction and relaxation of vagina, blinking of eyes, movement of eyeballs, and swallowing movement of throat; And / or, the biological tissue includes: skeletal muscle tissue, smooth muscle tissue, myocardial tissue, connective tissue, and neural tissue.

15. The use according to claim 11, characterized in that The biological tissue movement includes: expansion and contraction of the thorax.

16. The use according to claim 11, characterized in that The biological tissue movement includes: expansion and contraction of the lungs, and contraction / relaxation of the heart.

17. The use according to claim 11, characterized in that The product is used to prevent and / or treat diseases caused by necrosis of the biological tissue; The disease is: myocardial infarction.

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