A photothermal antibacterial controllable debonding intelligent hydrogel dressing for chronic wound care and a preparation method and application thereof

Abstract

The application discloses a kind of photothermal antibacterial controllable debonding intelligent hydrogel dressings for chronic wound care and its preparation method and application, the hydrogel dressings include gold modified conductive enhanced fiber network support body, and the functional hydrogel matrix completely wrapped the support body;The functional hydrogel matrix is with gelatin-sodium alginate blend system as skeleton, with the chelate compound pre-constructed with pyrocatechol and trivalent iron ion as core functional unit to form interpenetrating double crosslinking network structure, can be realized by spraying diethylene triamine pentaacetic acid without secondary damage controllable debonding.The hydrogel dressings of the application have high strong wet state adhesion, efficient photothermal antibacterial, anti-inflammatory repair and wound sensing function, effectively solve the industry pain point that existing dressing adhesion and debonding are difficult to consider, single function, mechanical property mismatch, adapt to chronic wound whole cycle nursing needs, and clinical application value is high.

Description

Technical Field

[0001] This invention relates to the field of biomedical dressings and chronic wound repair technology, specifically to a photothermal antibacterial controllable deadhesion smart hydrogel dressing for chronic wound care, its preparation method, and its application. Background Technology

[0002] With the continuous rise in the incidence of chronic wounds, medical dressings, as the core carrier of chronic wound care, directly determine the wound healing effect. Hydrogel dressings, due to their high water content, mechanical properties compatible with human soft tissue, good biocompatibility, and ability to maintain a moist microenvironment in the wound, have become a research hotspot in the field of chronic wound care. However, existing hydrogel dressings still have significant shortcomings in clinical applications: First, their antibacterial properties are insufficient to meet the long-term care needs of chronic wounds. Traditional antibiotic-loaded dressings easily induce bacterial resistance, and existing photothermal antibacterial dressings generally suffer from low photothermal conversion efficiency and limited antibacterial effects, failing to effectively control drug-resistant bacterial infections in chronic wounds. Second, there is an irreconcilable contradiction between wet adhesion and controllable deadhesion. Existing dressings either lack sufficient adhesion in the wet environment of high exudate in the wound and easily fall off, or their adhesion is uncontrollable, easily tearing newly formed tissue during replacement and causing secondary mechanical damage, thus delaying the healing process.

[0003] Furthermore, existing hydrogel dressings generally have limited functionality, making them unsuitable for the complex needs of chronic wound care throughout its entire lifecycle. They cannot simultaneously achieve multifunctional integration such as antibacterial properties and wound microenvironment monitoring. Additionally, the mechanical properties of some dressings are incompatible with wound tissue, leading to easy breakage and interfacial delamination, and failing to provide stable support for the wound. Therefore, developing a smart hydrogel dressing for chronic wound care that combines highly efficient photothermal antibacterial properties, controllable deadhesion, multifunctional integration, and excellent biocompatibility has become a critical technical challenge that urgently needs to be addressed in the field of medical dressings. Summary of the Invention

[0004] I. Technical problems to be solved

[0005] The technical problem to be solved by the present invention is the various technical defects of existing hydrogel dressings for chronic wound care mentioned in the background art above. The present invention provides a photothermal antibacterial controllable de-adhesion smart hydrogel dressing for chronic wound care, as well as its preparation method and application.

[0006] II. Technical Solution

[0007] The hydrogel dressing is characterized by having an interpenetrating double cross-linked network structure, comprising a gold-sprayed modified fiber network reinforcement and a functional hydrogel matrix completely encapsulating the fiber network reinforcement; the functional hydrogel matrix uses a gelatin-sodium alginate blend system as the framework, with a pre-constructed chelate of protocatechuic aldehyde and ferric ions as the core functional unit, wherein the protocatechuic aldehyde-Fe 3+The chelate simultaneously serves as a wet adhesion unit, a photothermal antibacterial unit, and a cross-linking node of the hydrogel. The aldehyde group on protocatechuic aldehyde can covalently bond with gelatin molecules, and together with the ionic cross-linking of sodium alginate and calcium ions, a stable interpenetrating double cross-linked network is formed. The gold-sprayed modified fiber network reinforcement is used to simultaneously improve the mechanical strength and electrical signal transmission performance of the hydrogel, endowing the dressing with interface sensing function at the wound surface. The hydrogel dressing can achieve competitive chelation and deadhesion by spraying diethylenetriaminepentaacetic acid (DTPA), completing dressing replacement without secondary damage.

[0008] As an improvement, the preparation method of the photothermal antibacterial controllable deadhesion smart hydrogel dressing for chronic wound care includes the following steps:

[0009] S1, the prepared conductive reinforced fiber network support;

[0010] S2. Prepare gelatin-sodium alginate blend matrix solution;

[0011] S3. Preparation of protocatechuic aldehyde-ferric chloride chelate pre-prepared solution;

[0012] S4. The protocatechuic aldehyde-ferric chloride chelate pre-prepared solution is uniformly mixed with the gelatin-sodium alginate matrix solution to obtain the hydrogel precursor solution.

[0013] S5. The hydrogel precursor solution is poured onto the gold-modified fiber network reinforcement, so that the precursor solution completely encapsulates the fiber network reinforcement. The solution is then placed in a mold and cured at room temperature to obtain the initial hydrogel product.

[0014] S6. Immerse the initial hydrogel product in a calcium chloride solution, complete the ionic cross-linking, and then rinse to obtain the hydrogel dressing product.

[0015] S7. Prepare DTPA deadhesion reagent for controlled deadhesion during dressing changes.

[0016] As an improvement, the conductive reinforced fiber network support is prepared by the following steps:

[0017] a1. Select any one of bacterial cellulose membrane, electrospun polymer fiber membrane or medical nonwoven fabric as the three-dimensional fiber network substrate;

[0018] a2. Vacuum ion sputtering deposition technology is used to modify the surface of the fiber network substrate with a nano-gold layer;

[0019] a3. By adjusting the sputtering parameters, a continuous and dense gold nanolayer with a thickness of 5-20 nm is formed on the fiber surface to obtain a gold-modified conductive and reinforced fiber network support. The gold nanolayer can construct a low-impedance and highly stable continuous conductive path on the surface of the three-dimensional fiber network, providing a stable signal transmission channel for the electrical signal sensing of the wound interface of the dressing, while enhancing the mechanical strength and bending fatigue resistance of the fiber network, and providing long-term stable mechanical support for the hydrogel matrix.

[0020] As an improvement, the gelatin-sodium alginate blend matrix liquid is prepared by the following steps:

[0021] b1. Add gelatin powder to deionized water, heat to 60°C and stir until completely dissolved to prepare a gelatin solution with a mass fraction of 20%.

[0022] b2. Add sodium alginate powder to the gelatin solution and stir continuously until completely dissolved. Control the final mass fraction of sodium alginate to 1%. After keeping warm and standing to remove bubbles, a gelatin-sodium alginate blend matrix solution is obtained.

[0023] As an improvement, the protocatechuic aldehyde-ferric chloride chelate pre-prepared solution is prepared by the following steps:

[0024] c1. Protocatechuic aldehyde and anhydrous ferric chloride were dissolved separately in sterile deionized water, and protocatechuic aldehyde solution and ferric chloride solution with concentrations of 0.1~0.5mol / L were prepared under light-protected conditions.

[0025] c2. Under light-protected conditions, ferric chloride solution is added dropwise to protocatechuic aldehyde solution at a uniform rate, and the reaction is continuously stirred for 3 hours to form a homogeneous and stable protocatechuic aldehyde-Fe complex in situ. 3+ The chelate pre-prepared solution; the molar ratio of protocatechuic aldehyde to ferric chloride is 3:1. This chelate can simultaneously provide wet adhesive groups, photothermal conversion active sites and broad-spectrum antibacterial functional units for the hydrogel system, and at the same time provide reaction sites for covalent cross-linking of the hydrogel through the aldehyde group of protocatechuic aldehyde.

[0026] As an improvement, the room temperature curing time is 4 hours. During the curing process, the aldehyde group on the protocatechuic aldehyde undergoes Schiff base covalent bonding with the amino group on the gelatin molecular chain, in conjunction with protocatechuic aldehyde-Fe 3+ The dynamic coordination crosslinking forms the first crosslinking network; the crosslinking time in the calcium chloride solution is 10~30min, and the calcium ions chelate with the guluronic acid units on the sodium alginate molecular chain to form the second crosslinking network, and finally construct a stable interpenetrating double crosslinking network structure, which endows the hydrogel with excellent structural stability and mechanical properties at physiological temperature.

[0027] As an improvement, the DTPA de-adhesion agent is a 0.1 mol / L DTPA aqueous solution, which is applied to the hydrogel-wound interface by spraying, utilizing the reaction between DTPA and Fe... 3+ Its strong chelating affinity competitively captures protocatechuic aldehyde -Fe 3+ Fe in coordination system 3+ It can reversibly disrupt the interfacial adhesion and part of the dynamic cross-linking network, and achieve gentle and controllable deadhesion in 30s to 5min, avoiding secondary mechanical damage to the newly formed tissue of the wound when changing dressings.

[0028] As an improvement, the application of the hydrogel dressing specifically involves using it for the full-cycle care and repair of chronic wounds such as diabetic foot ulcers, venous ulcers, and pressure injuries. Simultaneously, the dressing's low-resistance conductive pathway can interact with protocatechuic aldehyde-Fe... 3+ The system's pH response characteristics enable real-time monitoring of electrical signals in the wound microenvironment and early warning of infection.

[0029] III. Beneficial Effects

[0030] The advantages of this invention compared to the prior art are:

[0031] The provided photothermal antibacterial controllable deadhesion smart hydrogel dressing for chronic wound care has the following significant advantages: First, through a gelatin-sodium alginate interpenetrating double cross-linked network, combined with a gold-modified fiber network support, it overcomes the phase transition defect of pure gelatin at a physiological temperature of 37°C. Its mechanical properties are highly matched to the soft tissue of the wound, exhibiting excellent bending and deformation resistance, and long-term structural stability. Second, it utilizes protocatechuic aldehyde-Fe... 3+ Using chelates as the core unit, this dressing simultaneously achieves high-strength wet adhesion, efficient photothermal antibacterial and anti-inflammatory activity, meeting the needs of chronic wound care throughout its entire lifecycle and avoiding the drug resistance problem of traditional antibiotic dressings. Furthermore, based on the competitive chelation mechanism of DTPA, it achieves controllable deadhesion without secondary damage, solving the core pain point of existing dressings' difficulty in simultaneously achieving adhesion and deadhesion, significantly reducing patient discomfort during dressing changes. In addition, the dressing also possesses wound interface sensing and infection early warning functions, exhibits excellent biocompatibility across all components, has a simple and controllable preparation process, is easy to scale up, and has extremely high clinical application value. Attached Figure Description

[0032] Figure 1 This is a flowchart of the preparation method of a photothermal antibacterial controllable deadhesion smart hydrogel dressing for chronic wound care according to the present invention.

[0033] Figure 2 This invention presents a photothermal antibacterial controllable deadhesion intelligent hydrogel dressing for chronic wound care, with different doping and stretching data after deadhesion.

[0034] Figure 3This is a stretching data diagram of different conductive fiber diameter gradients for a photothermal antibacterial controllable deadhesion smart hydrogel dressing for chronic wound care, according to the present invention.

[0035] Figure 4 This invention presents a gradient morphology of different conductive fiber diameters in a photothermal antibacterial, controllable deadhesion smart hydrogel dressing for chronic wound care.

[0036] Figure 5 This is a graph showing the adhesion data after deadhesion of a photothermal antibacterial, controllable deadhesion smart hydrogel dressing for chronic wound care, based on different chelate doping methods.

[0037] Figure 6 This invention presents a photothermal antibacterial controllable deadhesion intelligent hydrogel dressing for chronic wound care, with different doping properties.

[0038] Figure 7 This invention presents a photothermal temperature rise diagram of a photothermal antibacterial, controllable deadhesion intelligent hydrogel dressing for chronic wound care with different doping.

[0039] Figure 8 This is a graph showing the changes in inflammatory factors with different dopants in a photothermal antibacterial, controllable deadhesion smart hydrogel dressing for chronic wound care, as described in this invention.

[0040] Figure 9 This is a diagram showing the ROS removal of different dopants in a photothermal antibacterial, controllable deadhesion smart hydrogel dressing for chronic wound care, according to the present invention. Detailed Implementation

[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0042] Example 1

[0043] This embodiment discloses a photothermal antibacterial controllable deadhesion smart hydrogel dressing for chronic wound care. It has an interpenetrating double cross-linked network structure, comprising a gold-modified conductive reinforced fiber network support and a functional hydrogel matrix completely encapsulating the fiber network support. The functional hydrogel matrix uses a gelatin-sodium alginate blend system as its framework and protocatechuic aldehyde-Fe... 3+ The chelate is the core functional unit. The aldehyde group of protocatechuic aldehyde is covalently bonded to gelatin, and together with the ionic crosslinking of sodium alginate and calcium ions, a stable interpenetrating double crosslinking network is formed. Controllable debonding without secondary damage can be achieved by spraying DTPA solution. The preparation method of the hydrogel dressing in this embodiment includes the following steps:

[0044] 1. Preparation of gold-modified conductive reinforced fiber network support

[0045] a1. Select 0.1mm thick flax fiber as the three-dimensional fiber network base, cut it to the preset size, rinse it three times with sterile deionized water and then vacuum dry it for later use.

[0046] a2. Place the dried bacterial cellulose membrane on the sample stage of the vacuum ion sputtering instrument and adjust the vacuum level to 3×10⁻⁶. - 3 Pa, sputtering current 5mA;

[0047] a3. Start sputtering coating and control the sputtering time to 120s to form a continuous dense gold nanolayer with a thickness of about 10nm on the fiber surface, thus obtaining a gold-modified conductive reinforced fiber network support.

[0048] 2. Preparation of gelatin-sodium alginate blend matrix solution

[0049] b1. Take gelatin powder and add it to sterile deionized water, heat it to 50°C and stir until it is completely dissolved to prepare a gelatin solution with a mass fraction of 20%.

[0050] b2. Add sodium alginate powder to the above gelatin solution and stir continuously until completely dissolved. Control the final mass fraction of sodium alginate to 1%. Keep it at 50℃ and sonicate to degas for 30 minutes to obtain gelatin-sodium alginate blend matrix solution.

[0051] 3. Preparation of protocatechuic aldehyde-ferric chloride chelate pre-prepared solution

[0052] c1. Protocatechuic aldehyde and anhydrous ferric chloride were dissolved in sterile deionized water, and 0.2 mol / L protocatechuic aldehyde solution and ferric chloride solution were prepared under light-protected conditions.

[0053] c2. Under light-protected conditions, ferric chloride solution was added dropwise to protocatechuic aldehyde solution at a uniform rate, controlling the molar ratio of protocatechuic aldehyde to ferric chloride at 3:1. The reaction was stirred continuously for 3 hours to obtain a homogeneous and stable protocatechuic aldehyde-Fe 3+ Chelate pre-prepared solution.

[0054] 4. Preparation of hydrogel dressings

[0055] d1. The above protocatechuic aldehyde-Fe 3+ The chelate pre-mixed solution and the gelatin-sodium alginate blended matrix solution were uniformly mixed at a volume ratio of 1:10, and the hydrogel precursor solution was obtained after stirring and degassing.

[0056] d2. The hydrogel precursor solution is uniformly poured onto the gold-modified conductive reinforced fiber network support, so that the precursor solution completely covers the fiber network support. The solution is then placed in a mold and cured at room temperature for 4 hours to obtain the initial hydrogel product.

[0057] d3. Immerse the initial hydrogel product in a 200μM calcium chloride solution, crosslink for 30 minutes, and then rinse three times with sterile deionized water to obtain the hydrogel dressing product.

[0058] d4. Prepare a 0.1 mol / L DTPA aqueous solution as a de-adhesion reagent for dressing changes.

[0059] Performance verification of the hydrogel dressing in this embodiment

[0060] Mechanical performance testing showed that the hydrogel dressing prepared in this embodiment had a maximum tensile stress of 1.2 MPa, and its elastic modulus was highly matched with that of human skin and soft tissue. It showed no swelling or phase change after immersion in a 37°C physiological environment for 72 hours. Adhesion and de-adhesion performance testing showed that the dressing had an adhesion strength of 45 kPa on wet pigskin. After spraying with DTPA de-adhesion agent, it could be peeled off without resistance within 3 minutes, causing no mechanical damage to newly formed tissue. Antibacterial performance testing showed that under near-infrared light irradiation, the dressing achieved a 99.9% inhibition rate against Staphylococcus aureus and Escherichia coli, effectively disrupting bacterial biofilms without inducing bacterial resistance. Anti-inflammatory activity verification showed that the dressing significantly downregulated the levels of pro-inflammatory factors such as TNF-α, IL-1β, and IL-6, increased the expression of the anti-inflammatory factor IL-10, and inhibited excessive inflammatory response in the wound.

[0061] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0062] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0063] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A photothermal antibacterial, controllable deadhesion smart hydrogel dressing for chronic wound care, characterized in that, The hydrogel dressing includes a gold-modified conductive reinforced fiber network support and a functional hydrogel matrix layer that completely encapsulates the fiber network support. The gold-modified conductive reinforced fiber network support achieves low-impedance electrical signal transmission, long-lasting mechanical enhancement, and photothermal effect synergistic enhancement by constructing a continuous and dense nano-gold coating on the surface of a three-dimensional fiber substrate. The functional hydrogel matrix layer uses a gelatin-sodium alginate blend system as the framework, with protocatechuic aldehyde and Fe... 3+ The pre-constructed chelate is formed by cross-linking of the core functional unit, and the photothermal antibacterial properties of the hydrogel dressing depend solely on protocatechuic aldehyde-Fe 3+ The near-infrared photothermal conversion activity of the chelate itself; the protocatechuic aldehyde-Fe 3+ The chelate simultaneously serves as a wet adhesion unit, a photothermal antibacterial unit, and an anti-inflammatory unit of the hydrogel; the hydrogel dressing can be applied by spraying a diethylenetriaminepentaacetic acid (DTPA) aqueous solution, based on DTPA and Fe... 3+ The highly competitive chelation mechanism enables rapid, controllable, and non-damaging debonding.

2. The method for preparing a photothermal antibacterial, controllable deadhesion intelligent hydrogel dressing for chronic wound care according to claim 1, characterized in that, Includes the following steps: S1. Preparation of gold-modified conductive reinforced fiber network support; S2. Prepare gelatin-sodium alginate blend matrix solution; S3. Preparation of protocatechuic aldehyde-ferric chloride chelate pre-prepared solution; S4. The protocatechuic aldehyde-ferric chloride chelate pre-prepared solution is uniformly mixed with the gelatin-sodium alginate matrix solution to obtain the hydrogel precursor solution. S5. The hydrogel precursor solution is poured onto the gold-modified conductive reinforced fiber network support, so that the precursor solution completely encapsulates the fiber network support. The solution is then placed in a mold and cured at room temperature to obtain the initial hydrogel product. S6. The initial hydrogel product is immersed in calcium chloride solution to complete ionic cross-linking. After rinsing, the hydrogel dressing product is obtained, and DTPA de-adhesion reagent is prepared accordingly.

3. The method for preparing a photothermal antibacterial, controllable deadhesion intelligent hydrogel dressing for chronic wound care according to claim 2, characterized in that, The protocatechuic aldehyde-ferric chloride chelate pre-prepared solution is prepared through the following steps: a1. Protocatechuic aldehyde and anhydrous ferric chloride were dissolved in sterile deionized water, and protocatechuic aldehyde solution and ferric chloride solution with a concentration of 0.1 mol / L were prepared under light-protected conditions. a2. Under light-protected conditions, ferric chloride solution was added dropwise to protocatechuic aldehyde solution, and the reaction was stirred for 3 hours to obtain protocatechuic aldehyde-Fe 3+ The chelate prepreg solution preferably contains a molar ratio of protocatechuic aldehyde to ferric chloride of 3:

1. The protocatechuic aldehyde-Fe 3+ The chelate exhibits a photothermal conversion efficiency of no less than 45% under 808nm near-infrared light irradiation, 1W / cm². 2 Within 5 minutes of power density irradiation, it can achieve precise and controllable temperature rise above 25°C, and has an inhibition rate of ≥99.9% against common Staphylococcus aureus and Escherichia coli in wounds. It is the only photothermal functional unit that can achieve photothermal antibacterial effect.

4. The method for preparing a photothermal antibacterial, controllable deadhesion intelligent hydrogel dressing for chronic wound care according to claim 2, characterized in that, The gold-modified conductive reinforced fiber network support is prepared through the following steps: b1. Using flax fabric as a three-dimensional fiber network substrate, the fiber network substrate is modified with a nano-gold layer on its surface by vacuum ion sputtering coating technology. By controlling the sputtering process parameters, a continuous and dense gold nano-layer with a thickness of 10 nm is formed on the fiber surface, thus obtaining a gold-modified conductive and reinforced fiber network support. The core functions of the nano-gold coating include: ① constructing a continuous low-impedance conductive path on the surface of a three-dimensional fiber substrate, enabling stable acquisition of wound electrophysiological signals and real-time sensing of the wound microenvironment; ② tightly binding with the fiber substrate, significantly improving the bending and fatigue resistance of the fiber network, providing long-term mechanical support for the hydrogel, ensuring the structural integrity of the hydrogel during limb movement in the wound, and preventing damage and interfacial delamination; ③ through near-infrared surface plasmon resonance effect, interacting with protocatechuic aldehyde-Fe 3+ The chelate's photothermal absorption forms a synergistic effect, improving the spatial uniformity of the photothermal field, avoiding local overheating damage to normal tissues, and enhancing the stability of the photothermal cycle.

5. The method for preparing a photothermal antibacterial, controllable deadhesion intelligent hydrogel dressing for chronic wound care according to claim 2, characterized in that, The gelatin-sodium alginate blend matrix solution is prepared through the following steps: c1. Add gelatin powder to deionized water, heat to 60°C and stir until completely dissolved to prepare a gelatin solution with a mass fraction of 20%. c2. Add sodium alginate powder to the gelatin solution and stir continuously until completely dissolved. Control the final mass fraction of sodium alginate to 1%. After keeping warm and standing to remove bubbles, obtain the gelatin-sodium alginate blend matrix solution.

6. The method for preparing a photothermal antibacterial, controllable deadhesion intelligent hydrogel dressing for chronic wound care according to claim 2, characterized in that, The room temperature curing time is 4 hours. During the curing process, the aldehyde group on protocatechuic aldehyde undergoes Schiff base covalent bonding with the amino group on the gelatin molecular chain, in conjunction with protocatechuic aldehyde-Fe 3+ Dynamic coordination crosslinking forms the first crosslinking network; During the cross-linking process of the calcium chloride solution, calcium ions undergo ion chelation with sodium alginate molecular chains to form a second cross-linking network, ultimately constructing an interpenetrating double cross-linking network structure. The purpose is to overcome the phase transition defect of pure gelatin at a physiological temperature of 37°C, improve the mechanical strength of hydrogel, and endow hydrogel with adhesive, photothermal antibacterial and anti-inflammatory functions.

7. The method for preparing a photothermal antibacterial, controllable deadhesion intelligent hydrogel dressing for chronic wound care according to claim 2, characterized in that, The calcium chloride solution had a concentration of 200 μM and a crosslinking time of 30 min; the DTPA debinding agent was a 0.1 mol / L DTPA aqueous solution, and DTPA reacted with Fe... 3+ The chelation stability constant is much higher than that of protocatechuic aldehyde and Fe. 3+ The coordination stability constant can specifically cleave protocatechualdehyde-Fe 3+ The dynamic coordination bonds take effect within 30 seconds after spraying, and complete debinding can be achieved within 30 seconds to 5 minutes. The debinding time can be precisely controlled by DTPA concentration and spraying dosage, offering high controllability. This competitive chelation debinding mechanism is applicable to all Fe-based coatings. 3+ Ca 2+ The hydrogel system with metal ion coordination crosslinking has good system universality; by spraying it onto the interface between the hydrogel and the wound, gentle and controllable debonding can be achieved within 5 minutes.

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