A force-responsive adaptive hydrogel and a preparation method and application thereof

Abstract

The application discloses a force response adaptive hydrogel and a preparation method and application thereof. The hydrogel is composed of acrylamide, a protein with copper ion binding capacity, copper ions, a polymer component containing an azide group and a polymer component containing an alkyne group. Under the action of an external force, the protein conformation changes and releases copper ions, the released copper ions catalyze the click reaction between the azide group and the alkyne group in the system, and a new covalent crosslinking network is generated in situ in the material, so that the mechanical properties are continuously enhanced. The material has the characteristics of mechanical self-adaptation, fatigue resistance, self-reinforcement and structural stability, and can be widely applied to the fields of tissue repair, dynamic sealing, flexible devices and mechanical response functional materials.

Description

Technical Field

[0001] This invention relates to the fields of functional polymer materials and biomaterials, and in particular to a force-responsive adaptive hydrogel based on mechanical stimulation-induced metal ion release and triggering in-situ crosslinking reaction. Background Technology

[0002] Hydrogels have wide applications in tissue engineering, flexible electronics, and wearable devices due to their high water content, softness, and good biocompatibility. However, traditional hydrogels generally suffer from problems such as low mechanical strength, susceptibility to structural fatigue under cyclic deformation conditions, and insufficient long-term stability.

[0003] Current strategies for improving the mechanical properties of hydrogels mainly include dual-network structures, physicochemical synergistic crosslinking, and dynamic reversible bond design. While these methods can improve toughness or achieve energy dissipation, most are passive regulatory mechanisms and are difficult to form new network structures under external mechanical stimulation, thus failing to achieve sustained performance enhancement.

[0004] Click chemistry reactions offer advantages such as high efficiency, strong selectivity, and mild reaction conditions. Among them, the copper-catalyzed azide-alkyne cycloaddition reaction can rapidly form stable covalent bonds in an aqueous environment. If a controllable copper ion reservoir can be constructed within the hydrogel, and the copper ions can be released in a controlled manner through mechanical stimulation, it is expected that new crosslinking reactions can be triggered during the material's stress process, thereby achieving active enhancement of mechanical properties.

[0005] Therefore, it is of great significance to develop a hydrogel system that can generate new covalent networks in situ under mechanical action and achieve mechanical self-reinforcement. Summary of the Invention

[0006] To address the shortcomings of the existing technologies, this invention proposes a new technical solution to overcome the deficiencies of existing protein hydrogels, such as insufficient structural stability under complex mechanical environments, limited long-term load-bearing capacity, and limited functionality. The solution mainly involves a protein composite hydrogel system constructed based on multiple covalent cross-linking to obtain a mechanically adaptive copper storage protein hydrogel with mechanical self-adaptive properties, high stability, tunable degradation, and functional response characteristics, along with its preparation method and applications.

[0007] To solve the above problems, the technical solution adopted by the present invention is as follows: A mechanically adaptive copper storage protein hydrogel is composed of acrylamide, SpyTag-peptide, copper storage protein, copper ions, a polymer containing azide groups, and a polymer containing alkyne groups; wherein the SpyTag-peptide is modified with acrylic acid groups, the copper storage protein is modified with SpyCatcher domains, and the polymers containing azide groups and alkyne groups are modified with unsaturated bonds.

[0008] The main hydrogel network is composed of acrylamide and SpyTag-peptides modified with acrylic acid groups; copper storage protein is covalently linked to SpyTag through SpyCatcher domains; copper ions are stored in the copper storage protein and can be released under external mechanical action to catalyze the click reaction between azide and alkynyl groups; polymers containing azide groups and polymers containing alkynyl groups participate in the polymerization of the main hydrogel network through unsaturated bonds.

[0009] Among them, the SpyTag-peptide is preferably modified with an acrylic acid group, SpyTag-AA, and the copper storage protein is preferably modified with a SpyCatcher domain, SC-Csp1-SC.

[0010] A method for preparing a mechanically adaptive copper-storing protein hydrogel, which employs photoinitiated free radical polymerization and pre-designed click reaction to synergistically construct a network structure, is as follows: Preparation of the first precursor solution: The copper storage protein modified with the SpyCatcher domain, the SpyTag-peptide modified with the acrylic acid group, and acrylamide were dissolved in deionized water and mixed evenly to obtain the first precursor solution. SpyTag and SpyCatcher can undergo specific covalent binding, which can be used to construct protein cross-linking nodes.

[0011] Preparation of the second precursor solution: The polymer containing azide groups and the polymer containing alkynyl groups are dissolved in deionized water and mixed evenly to obtain the second precursor solution. The polymers containing azide groups and the polymers containing alkynyl groups are modified with unsaturated bonds, which can participate in the bulk polymerization of hydrogels through the unsaturated bonds. The polymers containing azide groups and the polymers containing alkynyl groups can form a covalent cross-linked structure by using the copper ions released by the copper storage protein to catalyze the azide-alkynyl click reaction.

[0012] Construction of cross-linked network: The first precursor solution and the second precursor solution were mixed, and the photoinitiator LAP was added to make the final concentration 0.01-5 mg·mL⁻¹. The mixture was irradiated under ultraviolet or visible light with a wavelength of 320-405 nm for 1-30 min to carry out free radical polymerization. At the same time, the polymer containing azide groups and the polymer containing alkynyl groups participated in the polymerization reaction through unsaturated bonds to form a multi-covalent cross-linked network structure, thus obtaining a mechanically adaptive copper storage protein hydrogel.

[0013] The copper-storing protein is a natural or recombinant protein with the ability to bind copper ions, and it serves as a dynamic metal ion reservoir and a mechanical response unit.

[0014] The total concentration of azide and alkynyl groups is preferably 0–9 mM. The hydrogel of the present invention can release copper ions through mechanical action, thereby initiating a click reaction and enhancing structural strength. The mechanical action includes stretching, compression, shearing, or cyclic deformation, with deformation reaching 100%–500% and the number of cycles reaching 1–50.

[0015] An application of a mechanically adaptive copper storage protein hydrogel, which applies the mechanically adaptive copper storage protein to biomedical materials, tissue repair materials, tissue sealing materials, flexible electronic devices, wearable sensors, soft robots, or mechanically responsive functional materials.

[0016] The technical advantages of this invention are as follows: By synergistically constructing a multi-crosslinked network through photo-initiated free radical polymerization, SpyTag–SpyCatcher specific covalent bonding, and azide-acetylene click reaction, a mechanically adaptive copper storage protein hydrogel with high toughness, strong stress dissipation capacity, structural stability, and functionalizability is provided. This hydrogel can maintain its structural integrity under repeated deformation conditions and is suitable for fields such as biomedicine, tissue engineering, and functional materials.

[0017] The hydrogel of this invention uses the copper storage protein SC-Csp1-SC, modified with the SpyCatcher domain, as the functional protein component, combined with the acrylic acid-modified polypeptide SpyTag-AA, acrylamide monomer, and polymer components containing azide and alkyne groups to construct a network structure. By rationally designing the proportions of each component and the cross-linking method, the hydrogel can achieve stress relaxation and energy dissipation under applied stress through local conformational changes in the protein structure and the dynamic breakage and recombination at multiple points in the network, thereby maintaining overall structural stability under tensile conditions.

[0018] The hydrogel of this invention utilizes specific covalent isopeptide bonds formed between SpyTag and SpyCatcher as stable cross-linking nodes, significantly improving the structural integrity of the network. The main network formed by acrylamide free radical polymerization provides basic mechanical support. Click reactions between azide and alkyne groups further construct a second cross-linking structure, achieving synergistic enhancement of multiple covalent networks. Therefore, the hydrogel of this invention maintains excellent strength while retaining toughness and exhibits good mechanical self-adaptive properties.

[0019] The precursor system of the mechanically adaptive copper storage protein hydrogel of this invention includes copper storage protein SC-Csp1-SC, SpyTag-AA, acrylamide, and a polymer component containing functional groups. The preferred concentration ranges for each component are: copper storage protein 40–120 mg·mL⁻¹, SpyTag-AA 3–15 mg·mL⁻¹, acrylamide 10–250 mg·mL⁻¹, and azide- or alkyne-containing polymer 5–100 mg·mL⁻¹. By adjusting the concentrations and ratios of these components, hydrogel systems with different mechanical properties, network densities, and degradation rates can be obtained to meet various application requirements.

[0020] In this invention, copper-storing proteins are introduced into the network as functional structural units. While maintaining the stability of the protein structure, they provide metal binding sites, enabling the hydrogel to bind and store metal ions. By adjusting the concentration and binding state of copper ions, the functional properties of the material can be enhanced without affecting the overall network structural stability.

[0021] Compared to traditional protein hydrogels, the mechanically adaptive copper-storing protein hydrogel of this invention achieves excellent stress relaxation and energy dissipation capabilities through the synergistic effect of multiple covalent cross-linked networks. These multiple covalent cross-linked networks include: (1) a basic polymer network formed by photo-initiated free radical polymerization of acrylamide and components containing unsaturated double bonds, providing overall structural support; (2) a protein cross-linked network formed by the specific covalent binding of SpyTag and SpyCatcher, serving as a mechanical response unit that can undergo conformational changes and dissipate mechanical energy under external force; and (3) a click chemical cross-linked network formed by the cycloaddition reaction between azide and alkyne groups catalyzed by copper ions, which can dynamically generate new covalent cross-linking points under external force. During repeated deformation, the protein cross-linked network preferentially undergoes conformational unfolding to dissipate energy, thereby effectively alleviating local stress concentration; simultaneously, the released copper ions further catalyze the formation of new click cross-linked structures, providing in-situ reinforcement and repair to damaged areas; while the basic polymer network maintains the overall structural integrity. The synergistic effect of these multiple networks significantly improves the fatigue resistance and long-term stability of the material under cyclic loading conditions.

[0022] Compared to hydrogels with a single cross-linked structure, the present invention constructs a multi-scale network structure through SpyTag–SpyCatcher specific binding, free radical polymerization, and click reaction, which significantly improves the strength and toughness of the material and makes the network structure more stable, less prone to structural damage or performance degradation.

[0023] Compared to traditional functional hydrogels, the mechanically adaptive copper storage protein hydrogel of this invention, through the introduction of functional proteins, enables the material to possess both structural support and functional regulation capabilities, and can be further expanded into application systems such as metal ion regulation, catalytic reactions, or functional responses as needed.

[0024] The mechanically adaptive copper storage protein hydrogel of this invention has good biocompatibility and structural tunability, and can be widely used in the fields of biomedicine and engineering, including but not limited to tissue engineering scaffolds, cell culture substrates, drug or functional molecular carriers, and soft tissue repair materials.

[0025] The mechanically adaptive copper storage protein hydrogel of this invention can also be prepared into bulk, thin film, coating or three-dimensional structure form according to the use requirements. It can maintain structural stability in the in vivo or in vitro environment for a long time, and can gradually undergo structural changes or degradation according to environmental conditions. It is suitable for a variety of long-term or medium-term use scenarios.

[0026] Compared with the prior art, the present invention has the following advantages: 1. New covalent crosslinks are generated in situ under mechanical stimulation, resulting in continuous enhancement of mechanical properties.

[0027] 2. The protein conformational changes are reversible, giving the material good fatigue resistance.

[0028] 3. The click reaction conditions are mild and suitable for aqueous and physiological environments.

[0029] 4. Performance can be adjusted by regulating the concentration of metal ions and the ratio of functional groups.

[0030] 5. The structure remains stable even under cyclic loading conditions.

[0031] 6. It has good application scalability. Attached Figure Description

[0032] Figure 1 A schematic diagram of the construction of a mechanically responsive self-reinforcing hydrogel.

[0033] Figure 2 Results of cyclic tensile mechanical property tests on hydrogel.

[0034] Figure 3 Copper ion release behavior and click reaction verification results.

[0035] Figure 4 Mechanical enhancement effect under different concentration conditions.

[0036] Figure 5 Analysis of the self-growth mechanism through mechanically induced CuAAC reaction.

[0037] Figure 6 Experiments to induce protein unfolding and release Cu(I) by mechanical deformation.

[0038] Figure 7 In vitro biocompatibility experiments of hydrogels.

[0039] Figure 8 Experiments on the mechanical strength and copper storage capacity of hydrogels. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings.

[0041] like Figure 1 As shown, a mechanically adaptive copper storage protein hydrogel is prepared as follows: The copper storage protein SC-Csp1-SC, modified with a SpyCatcher domain, is dissolved in deionized water to prepare a solution with a mass concentration of 240 mg·mL⁻¹; the polypeptide SpyTag-AA, modified with acrylic acid groups, is dissolved in deionized water to prepare a solution with a mass concentration of 30 mg·mL⁻¹; and acrylamide is dissolved in deionized water to prepare a monomer solution with a mass concentration of 500 mg·mL⁻¹. The three solutions are then mixed and thoroughly stirred to obtain a homogeneous first precursor solution. Further, the polymer component containing azide groups and the polymer component containing alkyne groups are dissolved in deionized water to prepare solutions with mass concentrations of 1.8 and 45 mg·mL⁻¹, respectively, and then mixed in equal volumes to obtain a homogeneous second precursor solution.

[0042] The first and second precursor solutions were mixed at a volume ratio of 1:1, and the photoinitiator LAP was added to a final concentration of 2.5 mg·mL⁻¹. After thorough mixing, the mixture was poured into a mold and irradiated under ultraviolet light at a wavelength of 365 nm for approximately 15 min to complete the free radical polymerization reaction. Simultaneously, the azide and alkyne groups underwent a click reaction, forming protein cross-linking nodes through the specific covalent binding between SpyTag and SpyCatcher, thereby constructing a multivalent covalent cross-linked network structure. After the reaction, the resulting hydrogel was washed multiple times with deionized water and equilibrated to obtain a mechanically adaptive copper storage protein hydrogel, which was used for the following performance tests.

[0043] The following are examples of performance tests for various aspects of the present invention.

[0044] Example 1: Reversible release and recovery of Cu(I) during protein defolding-refolding process To verify the conformational response behavior of copper-storing proteins under external force and their reversible ability to regulate Cu(I) ions, single-molecule force spectroscopy was performed on the mechanotropic unfolding behavior of the Csp1 protein. Figure 2 As shown in Figure a, the fusion protein was immobilized on the substrate using a specific linkage method, and tensile measurements were performed using functionalized probes. Typical serrated force-elongation curves were obtained during the tensile process, as shown in Figure a. Figure 2As shown in b, a distinct characteristic unfolding peak appears. Statistical results indicate that the unfolding force of Csp1 is approximately 120 pN, accompanied by an increase in profile length of approximately 42 nm, as shown in Figure b. Figure 2 c and Figure 2 As shown in d, this demonstrates that the protein can undergo stable and reproducible force-induced unfolding under network stress conditions.

[0045] Furthermore, ultrasound was used as a macroscopic mechanical perturbation method to simulate the protein unfolding behavior induced by external force. Detection was performed using the hydrophobic fluorescent probe ANS. The results showed a significant increase in fluorescence intensity after treatment, indicating that the internal hydrophobic structure of the protein was exposed and partial unfolding occurred, such as... Figure 2 As shown in eg. Simultaneously, the release of Cu(I) was detected by the BCA colorimetric method. The treated solution gradually turned purple, indicating that the protein released approximately 30% of Cu(I) ions during the development process. Figure 2 As shown in the diagram, after the external force was stopped, the solution color gradually weakened, indicating that the protein could recapture the released Cu(I) ions during the refolding process, achieving a reversible release and recovery process of ions. This endows the system with good metal ion recycling capabilities, reduces the risk of metal loss, and helps maintain the long-term stability of the material's structure and function. Figure 2 jk).

[0046] Example 2 Construction of copper-storing protein hydrogel A PAAm / Csp1 hydrogel with copper storage protein as crosslinking nodes was constructed by copolymerizing SC–Csp1–SC with an acrylamide system. The structural diagram is shown below. Figure 3 As shown in figure a, the mechanical properties of the hydrogel under different protein concentrations were tested. The results showed that the fracture strain of the hydrogel could exceed 600%, and the maximum fracture stress could reach approximately 173 kPa. Figure 3 As shown in b, a significant hysteresis loop can be observed in the cyclic tensile test, indicating that the system exhibits significant energy dissipation behavior during deformation, such as... Figure 3 As shown in c, the hysteresis area gradually increases with increasing strain amplitude, indicating that the degree of protein unfolding increases with increasing strain. Figure 3 As shown in d. In multiple cyclic tests, the curves of each cycle basically overlapped, and the changes in maximum stress and residual strain were relatively small, as shown in... Figure 3 As shown in e, the copper-storing protein can refold during the unloading process, and the hydrogel has good structural recovery ability and fatigue resistance.

[0047] Under the aforementioned cyclic loading conditions, the effects of different strain amplitudes, protein concentrations, and loading times on Cu(I) release behavior were further investigated. The results showed that the amount of Cu(I) released increased with increasing cycle number, strain amplitude, and stretching holding time, and the release was more significant at higher Csp1 concentrations. Figure 3 f~ Figure 3 As shown in h. Simultaneously, analysis of the Cu(I) recovery process revealed that the recovery efficiency decreased with increasing strain, but extending the relaxation time significantly improved the ion recapture ability. Different protein concentrations had little effect on the recovery behavior, such as... Figure 3 i~ Figure 3 As shown in k. The above results indicate that the Cu(I) release and recovery process in the system is synergistically regulated by mechanical loading and time parameters, exhibiting good mechanical response reversibility.

[0048] Example 3: Mechanical Adaptive Self-Growth Behavior By further introducing equimolar proportions of azide groups and alkynyl groups into the above system, a PAAm / Csp1 / AA hydrogel was constructed, the structure of which is shown in the figure below. Figure 4 As shown in Figure a, the hydrogel underwent cyclic tensile training with an input strain of approximately 400%. The results show that with increasing cycle number, the loading force and elastic modulus of the material gradually increase, such as... Figure 4 As shown in b, after 16 cycles, the Young's modulus increased by more than 400%, indicating that the system exhibited significant mechanical self-growth behavior. Comparing the changes in mechanical properties under different functional group concentrations reveals that as the azide / alkynyl group concentration increased from 3 mM to 9 mM, the stress-strain curve shifted upwards overall after cycling, indicating a significant increase in material strength, while the fracture strain remained essentially unchanged. Figure 4 As shown in c.

[0049] Further research into the effects of loading time and recovery time on the enhancement process revealed that extending the loading hold time accelerates the enhancement rate, while increasing the recovery time weakens the enhancement effect. Figure 4 d and Figure 4 As shown in e, the self-growth process is regulated by protein unfolding-renaturation kinetics. After multiple training cycles, the hydrogel can gradually withstand larger external loads, and the reinforcement tends to stabilize after reaching mechanical equilibrium; when the external load is further increased, the material is reinforced again, exhibiting a stepwise adaptive reinforcement behavior, such as... Figure 4 f and Figure 4 As shown in g.

[0050] Example 4: Mechanical Adaptive Self-Growing Spatial Confinement Behavior To verify whether the mechanically adaptive self-growth of the copper-storing protein hydrogel of this invention possesses spatial controllability, its network reinforcement behavior under localized stress conditions was tested. First, a rigid mold with a specific pattern was used to locally compress the PAAm / Csp1 / AA hydrogel, causing large local strain only in the compressed region. This induced conformational unfolding of the copper-storing protein and the release of Cu(I) ions, which then catalyzed an azide-alkynyl cycloaddition reaction in the localized region. Figure 5As shown in Figure a, this method can realize a patterned mechanically induced reaction process based on external force. After treatment, the hydrogel was immersed in a solution of the fluorescent probe 3-azido-7-hydroxycoumarin to label the unreacted azide groups. The results showed that the overall appearance of the samples was not significantly different under bright field conditions, but obvious pattern contrasts could be observed under ultraviolet excitation. The fluorescence of the compressed areas was significantly weakened, while the uncompressed areas maintained a strong fluorescence signal, such as... Figure 5 As shown in b. This indicates that azide groups in the locally stressed region have participated extensively in the CuAAC reaction, proving that the mechanical self-growth process has significant spatial selectivity.

[0051] Further atomic force microscopy nanoindentation tests were used to assess the local mechanical properties of different regions. The results showed that the Young's modulus of the compressed region was significantly higher than that of the uncompressed region, as illustrated in the statistical results below. Figure 5 As shown in Figure c, this indicates that a higher density of covalently cross-linked structures has formed in local areas. The above results demonstrate that the mechanically adaptive self-growth of the hydrogel of this invention can not only be strengthened by external forces, but also be locally controlled through spatial force distribution, resulting in spatially differentiated distributions of network cross-linking density and mechanical properties. This enables programmable regional strengthening functions, making it suitable for applications requiring local enhancement or patterned structural control.

[0052] Example 5: Mechanical Adaptive Self-Growing Spatial Confinement Behavior To verify that the aforementioned self-growth mechanism originates from the Cu(I)-catalyzed azide-alkynyl reaction, the reaction process was systematically characterized. For example... Figure 6 As shown in Figure a, mechanical deformation induces protein unfolding and releases Cu(I), thereby catalyzing cycloaddition reactions within the network. Reacting the extracts obtained after different cycles with fluorescent probes showed that the fluorescence intensity gradually increased with increasing cycle number, indicating that the released Cu(I) possesses good catalytic activity. Figure 6 b and Figure 6 As shown in c. Further analysis of the degree of reaction within the hydrogel revealed that the fluorescence signal gradually weakened with increasing cycle number, indicating that the azide and alkynyl groups were gradually consumed, such as... Figure 6 d~ Figure 6 As shown in f.

[0053] Infrared spectroscopy results show that the characteristic absorption peaks of azide and alkynyl groups gradually weaken and triazole structural characteristic peaks appear, such as... Figure 6 As shown in g; scanning electron microscopy revealed that the pore size of the hydrogel decreased significantly with increasing cycle number, and the network structure gradually became denser, as shown in g. Figure 6 As shown in h. Simultaneously, the birefringence signal is significantly enhanced under polarized light, indicating an increased degree of molecular chain orientation and the formation of a new stress-transfer structure, such as... Figure 6 i and Figure 6As shown in j. The above results indicate that the mechanical self-growth of the hydrogel of the present invention originates from the unfolding and release of Cu(I) by the copper storage protein induced by external force, which triggers the formation of new covalent crosslinks by the azide-alkynyl reaction within the network, thereby achieving tunable mechanical adaptive reinforcement.

[0054] Example 6 Biocompatibility Verification The in vitro biocompatibility of the hydrogel of this invention was evaluated. B16F10 cells were co-cultured with the hydrogel extract for 1, 3, and 7 days, and the results were analyzed by live / dead staining and cell viability assays. Figure 7 The results showed that the cells at each time point were predominantly live cells, and the cell survival rate was not significantly different from that of the control group.

[0055] Example 7: Evaluation of Mechanical Stability and Long-Term Service Performance The hydrogel was immersed at 37 °C for an extended period, and mechanical tests were performed periodically. The results showed that after 18 days of immersion, the hydrogel maintained similar mechanical strength and copper storage capacity as the freshly prepared gel. Figure 8 ).

Claims

1. A mechanically adaptive copper-storing protein hydrogel, characterized in that, The hydrogel is composed of acrylamide, SpyTag-peptide, copper storage protein, copper ions, polymers containing azide groups, and polymers containing alkynyl groups; the SpyTag-peptide is modified with acrylic acid groups, the copper storage protein is modified with SpyCatcher domains, and the polymers containing azide groups and alkynyl groups are modified with unsaturated bonds.

2. The mechanically adaptive copper-storing protein hydrogel according to claim 1, characterized in that, The main hydrogel network is composed of acrylamide and SpyTag-peptides modified with acrylic acid groups; copper storage protein is covalently linked to SpyTag through SpyCatcher domains; copper ions are stored in the copper storage protein and can be released under external mechanical action to catalyze the click reaction between azide and alkynyl groups; polymers containing azide groups and polymers containing alkynyl groups participate in the polymerization of the main hydrogel network through unsaturated bonds.

3. A method for preparing a mechanically adaptive copper-storing protein hydrogel, characterized in that, The network structure was constructed by synergistic construction of photoinitiated radical polymerization and pre-designed click reaction, and the preparation method is as follows: Preparation of the first precursor solution: Dissolve the copper storage protein modified with the SpyCatcher domain, the SpyTag-peptide modified with the acrylic acid group, and acrylamide in deionized water and mix them evenly to obtain the first precursor solution. SpyTag and SpyCatcher can undergo specific covalent binding, which can be used to construct protein cross-linking nodes. Preparation of the second precursor solution: The polymer containing azide groups and the polymer containing acetylene groups are dissolved in deionized water and mixed evenly to obtain the second precursor solution. The polymers containing azide groups and the polymers containing acetylene groups are modified with unsaturated bonds, which can participate in the bulk polymerization of hydrogels through the unsaturated bonds. The polymers containing azide groups and the polymers containing acetylene groups can form a covalent cross-linked structure by using copper ions released from copper storage protein to catalyze the azide-acetylene click reaction. Construction of cross-linked network: The first precursor solution and the second precursor solution are mixed, and the photoinitiator LAP is added. Under ultraviolet or visible light conditions with a wavelength of 320-405 nm, a free radical polymerization reaction is carried out. At the same time, the polymer containing azide groups and the polymer containing alkynyl groups participate in the polymerization reaction through unsaturated bonds to form a multi-covalent cross-linked network structure, thus obtaining a mechanically adaptive copper storage protein hydrogel.

4. The hydrogel according to claim 1, characterized in that, The copper-storing protein is a natural or recombinant protein with copper ion binding capacity, and serves as a dynamic metal ion reservoir and mechanical response unit.

5. The mechanically adaptive copper-storing protein hydrogel according to claim 1, characterized in that, The total concentration of azide and alkynyl groups is 0–9 mM.

6. The mechanically adaptive copper-storing protein hydrogel according to claim 1, characterized in that, The mechanical action is tension, compression, shearing or cyclic deformation, with a deformation of 100% to 500% and a cycle of 1 to 50 times.

7. The application of the mechanically adaptive copper-storing protein hydrogel according to claim 1, characterized in that, Mechanically adaptive copper storage proteins can be applied to biomedical materials, tissue repair materials, tissue sealing materials, flexible electronic devices, wearable sensors, soft robots, or mechanically responsive functional materials.

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