High-toughness konjac-based biological polysaccharide composite film and preparation method and application thereof

Abstract

The present application relates to the technical field of high polymer materials, in particular to a high-strength and high-toughness konjac-based biological polysaccharide composite film and a preparation method and application thereof. First, a konjac-based hydrogel composite film is prepared by a one-pot method, and then water is volatilized in a hydrophilic environment to obtain a high-strength and high-toughness konjac-based biological polysaccharide composite film with controllable wet interface adhesion. The prepared high-strength and high-toughness konjac-based biological polysaccharide composite film realizes controllable and rapid adhesion at the wet interface, has the characteristics of self-healing, repeated bonding and recycling, and also shows excellent biological adaptability, good antibacterial property at the wet tissue interface, and can realize efficient regeneration and repair of damaged tissue with controllable time sequence. The preparation process of the present application is simple and easy to operate, and the product has excellent performance, which can be applied to the fields of biological tissue engineering and wet bonding engineering materials.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a high-strength and tough konjac-based biopolysaccharide composite membrane, its preparation method, and its application. Background Technology

[0002] Konjac glucomannan (KGM) is a natural neutral polysaccharide rich in hydroxyl groups extracted from konjac. It possesses excellent film-forming, water-retention, gelling, biocompatibility, and biodegradability properties, and is commonly used to prepare bulk or polymeric membrane materials with wide applications in biomedicine, hydrophilic foods, and cosmetics. However, the highly hydrophilic molecular structure of KGM generally significantly weakens its mechanical and interfacial adhesion properties under service conditions, making it particularly difficult to use in humid or underwater environments, severely limiting its practical applications.

[0003] To address the issue of weak mechanical strength, Zhang Liqiong et al. made a preliminary attempt to prepare an edible packaging composite film by combining KGM and carrageenan (KC) under certain conditions (Zhang Liqiong, et al. Study on the performance effects of konjac glucomannan-carrageenan edible packaging composite film, Food Industry Technology, 2013, 16: 114-116.). The prepared composite film showed a certain improvement in mechanical strength (the optimal tensile breaking strength was about 25 MPa), but it exhibited relatively brittle mechanical properties and poor interfacial adhesion.

[0004] To improve the interfacial adhesion properties of KGM-based materials, Wei et al. prepared hydrogel membranes using a Schiff base reaction of modified carboxyethyl chitosan and oxidized konjac glucomannan (XYWei, et al, "Injectable hydrogel based on dodecyl-modified N-carboxyethyl chitosan / oxidized konjac glucomannan effectively prevents bleeding and postoperative adhesions after partial hepatectomy", International Journal of Biological Macromolecules, 2022, 199:401-412.). This KGM-based polysaccharide hydrogel membrane exhibited some adhesion to porcine skin tissue (adhesion strength 20.4 kPa), but its mechanical properties were weak and the preparation process was complex. Summary of the Invention

[0005] To simultaneously improve the mechanical and interfacial adhesion properties of KGM-based biopolysaccharide membrane materials, this invention first prepares a konjac polysaccharide / carrageenan / tannic acid dual-network hydrogel composite membrane (konjac-based hydrogel composite membrane) using a one-pot method. Then, under the induction of a hydrophilic environment, water is evaporated in situ from the surface. During the water evaporation process, the polar groups inside the composite membrane tend to migrate and accumulate on the surface, ultimately resulting in a high-strength and tough konjac-based biopolysaccharide composite membrane with controllable wetted interfacial adhesion. The dual-network structure, strong hydrogen bonding between molecular chains, and this evaporation and concentration process of the prepared high-strength and tough konjac-based biopolysaccharide composite membrane significantly enhance its cohesive force. The polar groups induced to accumulate on its surface can further enhance its interfacial adhesion by absorbing an appropriate amount of interfacial water molecules, thereby effectively regulating its "cohesion-adhesion" balance and achieving controllable and rapid adhesion at wetted interfaces. The prepared high-strength and tough konjac-based biopolysaccharide composite membrane possesses self-healing, reusable, and recyclable properties. Furthermore, it exhibits good antibacterial properties and excellent biocompatibility at moist tissue interfaces. The preparation process of this invention is not only simple to operate, but also produces a product with excellent performance, making it applicable to fields such as tissue engineering and moist bonding engineering materials.

[0006] One of the objectives of this invention is to provide a method for preparing a high-strength and tough konjac-based biopolysaccharide composite membrane that is simple in process, easy to control, uses readily available raw materials, and has a short preparation cycle.

[0007] The solution adopted by the present invention to achieve the above objectives is as follows:

[0008] A method for preparing a high-strength and tough konjac-based biopolysaccharide composite membrane includes the following steps:

[0009] 1) Dissolve the crosslinking agent in water to prepare a solution, and add konjac powder (KGM), carrageenan (KC), and tannic acid (TA) in sequence, and stir at a certain temperature until a uniform mixture is formed;

[0010] 2) Centrifuge the homogeneous mixture from step 1) under certain conditions to remove bubbles for a certain time to obtain a homogeneous mixed solution without bubbles;

[0011] 3) The uniformly mixed solution after degassing in step 2) is injected into a glass mold, molded under certain pressure conditions, and annealed for a certain time. Then, the mold is opened and cooled to form a konjac-based hydrogel composite film.

[0012] 4) Place the konjac-based hydrogel composite membrane obtained in step 3) on a hydrophilic glass substrate and dry it in situ under certain ambient temperature and humidity conditions to obtain a high-strength and tough konjac-based biopolysaccharide composite membrane. This polysaccharide composite membrane has controllable wetting interface adhesion ability.

[0013] Furthermore, in step 4), the controllable wetting interface is a liquid with a surface density of 30–80 g / m³. 2 The interface (preferably 50g / m) 2 The liquid is water or an aqueous solution of a soluble metal salt; the soluble metal salt is Li. + Na + K + Ag + Mg 2+ Ca 2+ Zn 2+ Cu 2+ Al 3+ Fe 3+ or Zr 4+ An aqueous solution of one or more of the soluble salts (preferably K) + The concentration of the aqueous solution is 0.005-0.2 mol / L (preferably 0.15 mol / L).

[0014] Furthermore, in the preparation method, a metal coordination ion compound is added to the homogeneous mixture in step 1) to prepare a high-strength and tough konjac-based biopolysaccharide composite membrane with underwater interfacial adhesion ability. The metal coordination ion is Ag. + Mg 2+ Ca 2+ Zn 2+ Al 3+ Fe 3+ Zr 4+ One or more of the following, the concentration of metal coordination ions in the homogeneous mixture is 0.005 to 0.02 mol / L.

[0015] Furthermore, the crosslinking agent in step 1) is one or more of sodium tetraborate, sodium trimetaphosphate, epichlorohydrin, and glutaraldehyde (preferably sodium tetraborate).

[0016] Furthermore, in step 1), the mass ratio of konjac powder to crosslinking agent is 30:(0.5-1.5) (preferably 30:1); the mass ratio of konjac powder to carrageenan is 30:(2-6) (preferably 30:5); and the mass ratio of konjac powder to tannic acid is 30:(2-10) (preferably 30:8).

[0017] Further, in step 1), the stirring temperature is 70–95°C (preferably 70°C), and the stirring time is 30–60 minutes (preferably 30 minutes); in step 2), the centrifugation degassing conditions are a temperature of 70–95°C (preferably 70°C), a rotation speed of 8000–10000 rpm (preferably 10000 rpm), and a degassing time of 10–30 minutes (preferably 10 minutes); and / or

[0018] Step 3) describes the molding conditions as follows: molding pressure 1 MPa, molding time 5 minutes, annealing temperature at room temperature, and time 24 to 48 hours (preferably 24 hours).

[0019] Furthermore, the in-situ drying conditions described in step 4) are a temperature of 10–40°C (preferably 25°C) and an ambient relative humidity of 60–90% (preferably 80%).

[0020] The second objective of this invention is to provide a high-strength and tough konjac-based biopolysaccharide composite membrane with controllable wetting interface adhesion capability, which is obtained by the above-mentioned preparation method of the high-strength and tough konjac-based biopolysaccharide composite membrane with controllable wetting interface adhesion capability.

[0021] The third objective of this invention is to provide a high-strength and tough konjac-based biopolysaccharide composite membrane with underwater interfacial adhesion capability, obtained by the above-mentioned preparation method of the high-strength and tough konjac-based biopolysaccharide composite membrane with underwater interfacial adhesion capability.

[0022] The fourth objective of this invention is to provide the application of the above-mentioned high-strength and tough konjac-based biopolysaccharide composite membrane with controllable wetting interface adhesion or with underwater interface adhesion, wherein the application is to prepare wound dressings or tissue surface adhesion substitutes.

[0023] This invention first prepares a konjac-based hydrogel composite membrane with a dual-network structure of konjac polysaccharide / carrageenan / tannic acid using a one-pot method. Then, under the induction of a hydrophilic environment, water evaporates in situ from the surface. During this evaporation process, polar groups within the composite membrane tend to migrate and accumulate on the surface, ultimately resulting in a high-strength, tough konjac-based biopolysaccharide composite membrane with controllable wetting interface adhesion. In the constructed dual-network composite structure, the first KGM network is mainly achieved through the introduction of appropriate amounts of dynamic borate ester bonds for cross-linking. The second, more rigid KC network is mainly achieved through intermolecular hydrogen bonding during cooling annealing, leading to the formation of a double-helix structure. Simultaneously, the introduced TA molecules contain a large number of phenolic hydroxyl groups, which can form effective hydrogen bonds with the first and second KGM and KC networks. After water evaporates in situ from the newly formed polysaccharide gel composite membrane surface, the dual-network structure, strong intermolecular hydrogen bonding, and this evaporation and concentration process significantly enhance the cohesiveness of the resulting polysaccharide composite membrane. Simultaneously, during the in-situ evaporation of water from the polysaccharide composite membrane surface to form a film, the hydrophilicity of the substrate and the environment effectively induces polar groups in the dual-network composite structure to migrate and accumulate on the polysaccharide composite membrane surface. Therefore, during use, the polysaccharide composite membrane can "activate" the surface polar groups by absorbing an appropriate amount of interfacial water molecules, thereby forming a large number of hydrogen bonds with the adhered polar substrate, effectively enhancing its interfacial adhesion and effectively regulating the "cohesion-adhesion" balance of the dual-network composite structure, successfully achieving controllable, rapid, and high adhesion of the high-strength and tough polysaccharide composite membrane at a wet interface. Furthermore, by introducing coordinating metal ions in situ into the aforementioned high-strength and tough konjac-based biopolysaccharide composite membrane, effective metal coordination bonds can be formed with the anionic groups on the second KC network and TA, enhancing the polysaccharide composite membrane's resistance to dissolution and swelling during underwater use, thereby achieving its long-lasting high adhesion in an underwater environment. Meanwhile, the prepared konjac-based polysaccharide composite membrane also possesses advantages such as self-healing, reusability, recyclability, and wound repair and regeneration. Furthermore, it features one-pot feeding, one-time reaction, high strength, high toughness, and strong adhesion. This will become a new method for producing high-strength and tough konjac-based biopolysaccharide composite membranes with controllable wetting interface adhesion capabilities.

[0024] Compared with the prior art, the present invention has the following advantages and significant progress:

[0025] 1) The preparation process of this invention is extremely simple, with a short production cycle, simple process conditions, low production cost, and readily available raw materials.

[0026] 2) In this invention, by introducing a relatively rigid KC network and TA molecules containing a large number of phenolic hydroxyl groups into the KGM network, and through in-situ volatilization and drying under controlled conditions, the dual-network structure and strong hydrogen bonding between molecular chains of the prepared high-strength and tough konjac-based biopolysaccharide composite membrane significantly improve the mechanical properties of the polysaccharide composite membrane. Simultaneously, the polar groups that migrate and accumulate on the membrane surface during in-situ drying of the high-strength and tough konjac-based biopolysaccharide composite membrane can be "activated" by an appropriate amount of interfacial water, thereby forming a large number of hydrogen bonds with the polar substrate, significantly improving its adhesion performance at wetted interfaces. When the mass ratio of KGM, KC, and TA is 3:0.5:0.8, its tensile breaking strength is 161.50 MPa, Young's modulus is 4048.90 MPa, and tensile toughness is 12.77 MJ / m. 3 The elongation at break is 10.05%, and the adhesive strength is 146.38 kPa.

[0027] 3) Further, in situ coordination metal ions are introduced into the high-strength and tough konjac-based biopolysaccharide composite membrane, which can form effective metal coordination bonds with the second KC network and the anionic groups on TA, thereby enhancing the polysaccharide composite membrane's ability to resist dissolution and swelling during underwater use, thus achieving its long-lasting high adhesion in the underwater environment.

[0028] 4) The high-strength and tough konjac-based biopolysaccharide composite membrane obtained by the method of the present invention has the advantages of self-healing, repeated bonding, recyclability and reusability, and wound repair and regeneration. It also exhibits good antibacterial properties and excellent biocompatibility at the interface of moist tissue. Attached Figure Description

[0029] Figure 1 The diagram shows the design principle and preparation of the high-strength and tough konjac-based biopolysaccharide composite membrane (KGM / KC / TA polysaccharide composite membrane) with controllable wetting interface adhesion of the present invention. a is the design principle diagram, b is the main molecular formula, cross-linking reaction and intermolecular interaction of the KGM / KC / TA polysaccharide composite membrane, c is the main preparation steps of the KGM / KC / TA polysaccharide composite membrane, and d is the prepared KGM / KC / TA polysaccharide composite membrane.

[0030] Figure 2 Examples 1-21 and Comparative Examples 1-8 are methods for evaluating the adhesion performance of polysaccharide composite films prepared in these examples. Method a is a method for controlling the surface water density of the substrate, and method b is a method for testing the overlap-shear adhesion performance.

[0031] Figure 3 The graphs show the mechanical and adhesive properties of several polysaccharide composite films with different formulations prepared in Examples 1 and Comparative Examples 3-5. a) is a tensile stress-strain curve, and b) is an overlap-shear force-displacement curve.

[0032] Figure 4Tensile stress-strain curves of polysaccharide composite films with different carrageenan contents prepared in Examples 1-5;

[0033] Figure 5 The diagram shows the overlap-shear force-displacement curves of polysaccharide composite membranes with different tannic acid contents prepared in Examples 1, 6-10.

[0034] Figure 6 The graphs show the overlap-shear force-displacement curves of polysaccharide composite films prepared under different in-situ drying temperatures in Examples 1, 11-14, and Comparative Example 6.

[0035] Figure 7 The graphs show the overlap-shear force-displacement curves of the polysaccharide composite films prepared in Examples 1, 15-18 under different in-situ drying environments and humidity.

[0036] Figure 8 The graphs show the overlap-shear force-displacement curves of the polysaccharide composite films prepared in Examples 1, 19-21 and Comparative Examples 1, 7-8 on glass slide substrates with different water areal densities.

[0037] Figure 9 The images show the adhesion of the polysaccharide composite film prepared in this invention to different substrates (including glass, aluminum plate, polyester film, silicone rubber, pig liver, pig myocardium, and pig skin).

[0038] Figure 10 This is a schematic diagram of the bonding method of the polysaccharide composite membranes prepared in Examples 22-29 during the underwater overlap-shear adhesion performance test;

[0039] Figure 11 The different coordinated metal ions (including Mg) prepared in Examples 22-25 2+ Zn 2+ Ca 2+ Al 3+ The mechanical and adhesive properties of the hybrid polysaccharide composite membrane are shown in the following figures: a is the tensile stress-strain curve, and b is the overlap-shear force-displacement curve.

[0040] Figure 12 The graphs show the mechanical and adhesive properties of polysaccharide composite films with different concentrations of aluminum ions prepared in Examples 24, 26-29. a is the tensile stress-strain curve, and b is the underwater overlap-shear force-displacement curve.

[0041] Figure 13 To demonstrate the self-healing properties of the polysaccharide composite membrane prepared in Example 1, a is a physical image of the self-healing process of the sample, b is a tensile stress-strain curve, and c is an overlap-shear force-displacement curve.

[0042] Figure 14The polysaccharide composite membrane prepared in Example 1 has repeatable adhesion characteristics. a is a graph of the sample after 5 repeated overlaps, shear force and displacement, and b is a bar graph of the adhesion strength after 5 times.

[0043] Figure 15 To demonstrate the recyclability of the polysaccharide composite membrane prepared in Example 1, a is the tensile stress-strain curve of the original (KGM / KC / TA polysaccharide composite membrane in Example 1) and the recycled and reshaped sample, and b is the overlap-shear force-displacement curve.

[0044] Figure 16 The results of the wound repair and regeneration experiment of the polysaccharide composite membrane prepared in Example 1 are shown in the following figures: a) is a bar graph of CCK8 detection results after 1 day and 3 days of co-culture of the cell line of the sample; b) is a macroscopic view of the sample 24 hours after inoculation in a culture dish containing Staphylococcus aureus; c) is a Calcein / PI staining result 24 hours after L929 was directly inoculated into the sample.

[0045] Figure 17 The adhesion properties of the polysaccharide composite membrane prepared in Example 1 at different solution interfaces. Detailed Implementation

[0046] To better understand the present invention, the following embodiments are further illustrations of the present invention, but the content of the present invention is not limited to the following embodiments.

[0047] Unless otherwise specified, all materials and reagents used in this invention are commercially available conventional materials and reagents.

[0048] In the examples and comparative examples: konjac powder (CAS No.: 37220-17-0; purity: ≥95%; molecular weight: 820kDa); carrageenan (CAS No.: 11114-20-8; purity: ≥99%; molecular weight: 780kDa). Room temperature was 20–25°C.

[0049] Example 1: Preparation method of high-strength and tough konjac-based biopolysaccharide composite membrane with controllable wetting interface adhesion.

[0050] 1) Weigh 0.1g of sodium tetraborate at room temperature and completely dissolve it in a certain amount of pure water to prepare a sodium tetraborate solution (keeping the total mass at 100g). Then weigh 3.0g of konjac powder, 0.5g of carrageenan and 0.8g of tannic acid and add them to the solution in sequence. Stir in an 80℃ water bath for 30 minutes until a uniform mixture is formed.

[0051] 2) Centrifuge the well-stirred mixture from step 1) at 80°C and 10,000 rpm for 10 minutes to remove bubbles;

[0052] 3) The mixture after centrifugation and degassing in step 2) is injected into a glass film forming mold with a sandwich structure. After annealing at room temperature for 24 hours, the mold is opened and cooled to obtain a konjac-based hydrogel composite film with a double network structure.

[0053] 4) Remove one side of the glass plate of the molding mold used to prepare the composite gel membrane in step 3), and place the composite gel membrane together with the other side of the glass plate in an environment with a temperature of 25°C and a relative humidity of 80% until it is completely dried in situ, to obtain a high-strength and tough konjac-based biopolysaccharide composite membrane (KGM / KC / TA polysaccharide composite membrane) with controllable wetting interface adhesion.

[0054] The samples were cut into dumbbell-shaped strips with an effective size of 12×2mm for tensile testing. Based on the obtained stress-strain curves, the tensile fracture work (i.e., tensile toughness) of the polysaccharide composite membrane was accurately calculated using the following formula (W). b ):

[0055]

[0056] Where σ and ε are tensile stress and strain, respectively, and ε b This refers to the elongation at break of the sample. The experimentally measured tensile strength of the obtained polysaccharide composite membrane was 161.50 MPa, Young's modulus was 4048.90 MPa, and tensile breaking energy was 12.77 MJ / m. 3 The elongation at break was 10.05%.

[0057] 5) Cut the polysaccharide composite membrane obtained in step 4) into a rectangular sample with dimensions of 25×20×0.03mm, and attach one side of it to a wetted glass slide (75×25mm). The surface density of water on the surface of the glass slide is 50g / m³. 2 (The surface density of the water is precisely controlled by spraying deionized water using a spray method. See [link to specific control method] for details.) Figure 2 ), and at the same time according to Figure 2 The method involves attaching another glass slide to the sample surface, applying pressure (2N) at room temperature and holding it for at least 3 minutes, and then performing an lap-shear adhesion test using a tensile testing machine. The test results are as follows: Figure 3 As shown, the adhesion strength (τ) of the polysaccharide composite membrane was accurately calculated using the following formula:

[0058]

[0059] Where F max is the average force in the steady-state region during shearing; for samples without a steady state, the maximum shear force is selected; h is the overlap length of the membrane sample; b is the width of the membrane sample. It can be seen that the adhesive strength of the obtained polysaccharide composite membrane is 146.38 kPa.

[0060] Effects of different KC contents on high-strength and tough konjac-based biopolysaccharide composite membranes in Examples 2-5

[0061] The preparation and testing steps 1) to 5) are the same as in Example 1; the difference from Example 1 is that in step 1), the amount of carrageenan used is 0.2, 0.3, 0.4, and 0.6 g, respectively. The mechanical and adhesive properties of the obtained polysaccharide composite films are shown in Table 1 and [Table data would be inserted here]. Figure 4 .

[0062] Examples 6-10: Effects of different TA contents on high-strength and tough konjac-based biopolysaccharide composite membranes

[0063] The preparation and testing steps 1) to 5) are the same as in Example 1; the difference from Example 1 is that in step 1), the amount of tannic acid used is 0.2, 0.3, 0.4, 0.6, and 1.0 g, respectively. The adhesive properties of the obtained polysaccharide composite membranes are shown in Table 1 and... Figure 5 .

[0064] Examples 11-14: Effects of different in-situ drying ambient temperatures on high-strength and tough konjac-based biopolysaccharide composite membranes

[0065] The preparation and testing steps 1) to 5) are the same as in Example 1; the difference from Example 1 is that in step 4), the in-situ drying temperatures of the prepared composite gel membranes are 10, 20, 30, and 40°C, respectively. The adhesive properties of the obtained polysaccharide composite membranes are shown in Table 1 and... Figure 6 .

[0066] Examples 15-18: Effects of different in-situ drying environmental humidity on high-strength and tough konjac-based biopolysaccharide composite membranes

[0067] The preparation and testing steps 1) to 5) are the same as in Example 1; the difference from Example 1 is that in step 4), the relative humidity of the in-situ drying environment for the prepared composite gel membrane is 60%, 70%, 80%, and 90%, respectively. The adhesive properties of the obtained polysaccharide composite membranes are shown in Table 1 and... Figure 7 .

[0068] Examples 19-21: Effects of different surface densities of water on the substrate surface on high-strength and tough konjac-based biopolysaccharide composite membranes

[0069] 1) to 5) The preparation and testing steps are the same as in Example 1; the difference from Example 1 is that in step 4), the areal density of water on the glass slide substrate surface of the prepared composite gel film is 40, 60, and 80 g / m² when the overlap-shear adhesion performance test is performed. 2 The adhesive properties of the obtained polysaccharide composite membranes are shown in Table 1 and 2. Figure 8 .

[0070] Example 22: Preparation method of high-strength and tough konjac-based biopolysaccharide composite membrane with underwater interfacial adhesion ability

[0071] 1) Weigh 0.1g of sodium tetraborate at room temperature and dissolve it completely in a flask containing a certain amount of pure water to prepare a sodium tetraborate solution (keeping the total mass at 100g). Then weigh 3.0g of konjac powder, 0.5g of carrageenan and 0.8g of tannic acid and add them to the solution in sequence. Stir in an 80℃ water bath for 5 minutes, then add 10mL of 0.10mol / L aluminum trichloride solution and continue stirring for 30 minutes until a homogeneous mixture is formed.

[0072] 2)–4) The preparation and testing steps are the same as in Example 1;

[0073] 5) Cut the polysaccharide composite film (KGM / KC / TA-Al) obtained in step 4) into a rectangular sample with dimensions of 25×20×0.03mm. Place the glass slide substrate in water and quickly (within 30 seconds) adhere the polysaccharide composite film to the glass slide in the water (see the specific adhesion method). Figure 10 ), and at the same time according to Figure 2 The method involves attaching another glass slide to the sample surface, applying pressure (2N) underwater at 25°C for at least 3 minutes, removing the pressure, and then quickly testing the lap-shear adhesion performance using a tensile testing machine. The underwater adhesion strength of the polysaccharide composite membrane is then accurately evaluated according to the calculation formula given in step 5) of Example 1.

[0074] The experimentally measured tensile breaking strength of the obtained polysaccharide composite membrane was 178.10 MPa, Young's modulus was 4295.65 MPa, and tensile breaking energy was 18.83 MJ / m. 3 The elongation at break was 14.64%, and the adhesive strength was 151.94 kPa.

[0075] Examples 23-25: Different coordinated metal ions (including Mg) 2+ Zn 2+ Ca 2+ The effect of hybridization on high-strength and tough konjac-based biopolysaccharide composite membranes with underwater interfacial adhesion capabilities

[0076] The preparation and testing steps 1) to 5) are the same as in Example 22; the difference from Example 12 is that in step 1), 10 mL of 0.10 mol / L aluminum trichloride solution is replaced with 10 mL of 0.10 mol / L magnesium chloride, zinc chloride, and calcium chloride solutions, respectively. The mechanical and adhesive properties of the obtained polysaccharide composite films (KGM / KC / TA-Mg, KGM / KC / TA-Zn, KGM / KC / TA-Ca) are shown in Table 1 and... Figure 11 .

[0077] Examples 26-29: Effects of different aluminum ion concentrations on high-strength and tough konjac-based biopolysaccharide composite membranes with underwater interfacial adhesion capabilities

[0078] The preparation and testing steps 1) to 5) are the same as in Example 22; the difference is that in step 1), the concentrations of the aluminum trichloride solution are 0.03, 0.05, 0.15, and 0.20 mol / L, respectively. The mechanical and adhesive properties of the obtained polysaccharide composite membranes are shown in Table 1 and [Table data would be inserted here]. Figure 12 .

[0079] Examples 30-34: Adhesion properties of the polysaccharide composite membrane prepared in Example 1 at different solution interfaces

[0080] 1)–5) The preparation and testing steps are the same as in Example 1; the difference from Example 1 is that a 0.15 mol / L aqueous solution of the soluble metal salt is sprayed using a spray method, and the surface density of the aqueous solution of the soluble metal salt is controlled to be 50 g / m³. 2 The soluble metal salts are FeCl3, KCl, NaCl, MgCl2, and ZrOCl2, respectively.

[0081] The interfacial adhesion strengths of solutions with different ions vary considerably. The interfacial adhesion strengths of FeCl3, KCl, NaCl, MgCl2, and ZrOCl2 solutions are 64.93 kPa, 210.35 kPa, 161.44 kPa, 102.51 kPa, and 103.74 kPa, respectively (see...). Figure 17 Due to internal interactions and interfacial competition, the adhesion strength of the KGM / KC / TA polysaccharide composite membrane at the FeCl3, ZrOCl2, and MgCl2 solution interfaces is weaker compared to the deionized water interface (146.38 kPa). At the ZrOCl2 solution interface, the adhesion strength of the KGM / KC / TA polysaccharide composite membrane is also weaker. 4+ It forms strong metal coordination bonds with the sulfonic acid groups inside the polysaccharide composite membrane, enhancing internal interactions and exhibiting strong mechanical properties, but low adhesive strength; Fe 3+ The hydroxyl groups of o-phenol form coordination bonds, competing with surface adhesive groups, resulting in low adhesion strength. Simultaneously, under MgCl2, significant TA precipitation weakens the interaction, leading to a substantial decrease in mechanical properties. Due to accelerated phase separation and molecular chain aggregation interactions, adhesive groups are exposed, resulting in enhanced adhesion strength in KCl and NaCl solutions compared to the deionized water interface. Furthermore, due to the KCl... + Na +It can form ion-dipole interactions with hydroxyl, sulfonic acid, and phenolic hydroxyl groups on polysaccharide molecular chains, enhancing the hydrogen bond network between molecular chains and improving interfacial adhesion and cohesion. Although the KGM / KC / TA polysaccharide composite membrane exhibits differences at different ionic solution interfaces, the minimum adhesion strength can still be maintained above 60 kPa, making it suitable for use at various ionic solution interfaces.

[0082] Comparative Example 1

[0083] The preparation and testing steps 1) to 5) are the same as in Example 1; the difference from Example 1 is that in step 5), the two glass slide substrates used for the overlap-shear adhesion performance test of the polysaccharide composite gel film are in a dry state. According to the test method in step 5), the sample exhibits completely non-adhesive behavior to the glass slide substrate, that is, the adhesion strength is 0.00 kPa.

[0084] Comparative Example 2: Tensile and adhesive properties of the konjac-based biopolysaccharide composite gel membrane prepared in step 3) of Example 1.

[0085] 1)~3) The preparation steps are the same as in Example 1;

[0086] 4) Evaluate the tensile and adhesive properties of the konjac-based hydrogel composite film prepared in step 3) according to the test methods given in steps 4) and 5) of Example 1.

[0087] The experimentally measured tensile strength of the obtained polysaccharide composite gel membrane was 0.13 MPa, Young's modulus was 0.06 MPa, and tensile breaking energy was 0.16 MJ / m. 3 The elongation at break is 257.75%, and the adhesive strength is 1.55 kPa.

[0088] Comparative method for preparing pure 3KGM polysaccharide membrane

[0089] 1) Weigh 0.1g of sodium tetraborate at room temperature and completely dissolve it in a flask containing a certain amount of pure water to prepare a sodium tetraborate solution (keeping the total mass at 100g). Then weigh 3.0g of konjac powder and add it to the solution. Stir in an 80℃ water bath for 30 minutes until a uniform mixture is formed.

[0090] The preparation and testing steps for steps 2) to 5) are the same as in Example 1.

[0091] The experimentally measured tensile breaking strength of the obtained konjac polysaccharide pure film (KGM polysaccharide pure film) was 26.92 MPa, the Young's modulus was 1567.76 MPa, and the tensile breaking energy was 0.30 MJ / m. 3 The elongation at break was 2.48%; the adhesive strength of the sample obtained according to the test method in step 5) was 18.82 kPa.

[0092] Comparative Example: Preparation Method of 4KGM / TA Polysaccharide Composite Membrane

[0093] 1) Weigh 0.1g of sodium tetraborate at room temperature and completely dissolve it in a flask containing a certain amount of pure water to prepare a sodium tetraborate solution (keeping the total mass at 100g). Then weigh 3.0g of konjac powder and 0.8g of tannic acid and add them to the solution in sequence. Stir in an 80℃ water bath for 30 minutes until a uniform mixture is formed.

[0094] The preparation and testing steps for steps 2) to 5) are the same as in Example 1.

[0095] The experimentally measured tensile breaking strength of the obtained polysaccharide composite membrane (KGM / TA polysaccharide composite membrane) was 57.33 MPa, Young's modulus was 1958.76 MPa, and tensile breaking energy was 4.28 MJ / m. 3 The elongation at break was 7.28%; the adhesive strength of the sample obtained according to the test method in step 5) was 99.73 kPa.

[0096] Comparative Example: Preparation Method of 5KGM / KC Polysaccharide Composite Membrane

[0097] 1) Weigh 0.1g of sodium tetraborate at room temperature and completely dissolve it in a flask containing a certain amount of pure water to prepare a sodium tetraborate solution (keeping the total mass at 100g). Then weigh 3.0g of konjac powder and 0.5g of carrageenan and stir in an 80℃ water bath for 30 minutes until a uniform mixture is formed.

[0098] The preparation and testing steps for steps 2) to 5) are the same as in Example 1.

[0099] The experimentally measured tensile breaking strength of the obtained polysaccharide composite membrane (KGM / KC polysaccharide composite membrane) was 143.52 MPa, Young's modulus was 3468.58 MPa, and tensile breaking energy was 11.29 MJ / m. 3 The elongation at break was 10.78%; the adhesive strength of the sample obtained according to the test method in step 5) was 31.72 kPa.

[0100] Comparative Example 6

[0101] The preparation and testing steps 1) to 5) are the same as in Example 1; the difference from Example 1 is that in step 5), the in-situ drying temperature of the prepared composite gel membrane is 50°C. The adhesion strength of the sample obtained according to the testing method in step 5) is 54.07 kPa.

[0102] Comparative Example 7

[0103] 1) to 5) The preparation and testing steps are the same as in Example 1; the difference from Example 1 is that in step 4), the surface density of water on the glass slide surface of the prepared composite gel film is 190 g / m² when the overlap-shear adhesion performance test is performed. 2 The adhesive properties of the obtained polysaccharide composite membranes are shown in Table 1 and 2. Figure 8 .

[0104] Comparative Example 8

[0105] 1) to 5) The preparation and testing steps are the same as in Example 1; the difference from Example 1 is that in step 4), the surface density of water on the glass slide surface of the prepared composite gel film is 20 g / m² when the overlap-shear adhesion performance test is performed. 2 The adhesive properties of the obtained polysaccharide composite membranes are shown in Table 1 and 2. Figure 8 .

[0106] Table 1. Mechanical and adhesive properties of konjac-based biopolysaccharide composite membranes obtained in the examples and comparative examples.

[0107]

[0108]

[0109] Examples 1-5 are konjac-based biopolysaccharide composite membranes prepared with different KC contents. Figure 4 Examples 1 and 6-10 are konjac-based biopolysaccharide composite membranes prepared with different TA contents. Figure 5 Examples 1 and 11-14 are konjac-based biopolysaccharide composite membranes prepared at different in-situ drying temperatures. Figure 6 Examples 1 and 15-18 are konjac-based biopolysaccharide composite membranes prepared under different in-situ drying environmental humidity conditions. Figure 7 Examples 1 and 19-21 show konjac-based biopolysaccharide composite films "activated" when the surface density of water on the substrate is different. Figure 8 Examples 22, 26-29 show konjac-based biopolysaccharide composite membranes formed when different aluminum ion concentrations are introduced. Figure 12 Comparative Example 1 is a polysaccharide composite membrane prepared with the same formulation as Example 1, but which was not "activated" by water molecules during the adhesion performance evaluation; Comparative Example 2 is a konjac-based hydrogel composite membrane prepared with the same formulation as Example 1; Comparative Examples 3-5 are KGM polysaccharide pure membrane, KGM / TA polysaccharide composite membrane, and KGM / KC polysaccharide composite membrane prepared with the same preparation method as Example 1, respectively. Figure 3 Comparative Example 6 uses a polysaccharide composite membrane with the same formulation as Example 1, but the in-situ drying temperature is 50°C. Figure 6Comparative Examples 7 and 8 are polysaccharide composite films with the same formulation as Example 1, but with a surface density of water on the substrate surface of 190 g / m³. 2 and 20g / m 2 ( Figure 8 ).

[0110] As can be seen from the mechanical and adhesive properties data of Example 1 and Comparative Example 1 in Table 1, the prepared konjac-based biopolysaccharide composite membrane must undergo an appropriate water molecule "activation" process to achieve good adhesive properties. Comparing Example 1 and Comparative Example 2, it can be seen that the surface of the prepared polysaccharide composite membrane must undergo in-situ evaporation drying under suitable conditions to obtain excellent mechanical and adhesive properties. The tensile breaking strength, Young's modulus, tensile breaking work, and adhesive strength of the prepared polysaccharide composite membrane are 161.50 MPa, 4048.90 MPa, and 12.77 MJ / m, respectively. 3 The tensile strength and adhesion strength of the KGM / KC / TA polysaccharide composite membranes were 1242 times, 67482 times, 19.3 times, and 94.4 times, respectively, compared to those of the corresponding konjac-based hydrogel composite membranes. Comparison of Example 1 and Comparative Examples 3-5 shows that the prepared KGM / KC / TA polysaccharide composite membrane significantly outperformed the pure KGM polysaccharide membrane, the KGM / TA polysaccharide composite membrane, and the KGM / KC polysaccharide composite membrane in both tensile properties and wetted interface adhesion strength. This comparative data is mainly attributed to the synergistic effects of the dual-network structure, strong hydrogen bonding between molecular chains, and the in-situ evaporation, drying, and concentration process under suitable conditions in the polysaccharide composite membrane designed and prepared in this invention. These factors significantly enhance its network cohesion. Simultaneously, the polysaccharide composite membrane also needs to absorb an appropriate amount of interfacial water molecules to "activate" the polar groups enriched on the surface due to interface induction, thereby improving its interfacial adhesion and effectively regulating its "cohesion-adhesion" balance, achieving rapid and high adhesion at wetted interfaces.

[0111] As can be seen from the mechanical and adhesive properties data of Examples 1-2, 4 and Examples 8-9 in Table 1, the addition of KC and TA affects the double network structure and strong hydrogen bonding between molecular chains of the prepared polysaccharide composite membrane, thereby affecting the distribution of polar groups enriched due to induction on its surface. This effectively regulates its "cohesion-adhesion" balance, thus having a certain impact on its mechanical and wetted interface adhesive properties. As can be seen from the adhesive properties data of Examples 11, 14, Comparative Example 6 and Examples 15, 18 in Table 1, during the in-situ evaporation and drying process of the polysaccharide hydrogel composite membrane, the ambient temperature and humidity of the sample affect the water migration rate inside the membrane and the density of polar groups migrating from the membrane to the surface, thereby affecting the adhesive strength of its wetted interface. As can be seen from the adhesion performance data of Examples 19, 21, Comparative Example 1 and Comparative Examples 7-8 in Table 1, the water density on the substrate surface significantly affects the degree of "activation" of the polar groups on the surface of the polysaccharide composite film. If the water density on the substrate surface is too low, the polar groups on the film surface will not be sufficiently "activated". However, if the water density is too high, the polar groups on the film surface will form too many hydrogen bonds with water molecules and the composite film will swell sufficiently, reducing its own cohesion. Therefore, neither of these is conducive to the formation of high adhesion at the wet interface.

[0112] As can be seen from the mechanical and adhesive property data of Examples 22-29 in Table 1, further introducing metal coordination bonds into the KGM / KC / TA polysaccharide composite membrane network can effectively improve the membrane's cohesion, thereby effectively improving its mechanical properties within a certain range of metal ion concentration. Furthermore, the introduction of metal coordination bonds also effectively enhances the composite membrane's resistance to dissolution and swelling during underwater use, effectively regulating the "cohesion-adhesion" balance of its network structure, thus achieving sustained high adhesion in underwater environments. These comparative data fully demonstrate the innovation and practicality of this invention.

[0113] Related application performance tests

[0114] The following are some applications of the high-strength and tough konjac-based biopolysaccharide composite membrane with controllable wetting interface adhesion, but the content of the present invention is not limited to the listed applications.

[0115] 1. Self-healing

[0116] Because the polymer network in the polysaccharide composite membrane of this invention is mainly constructed based on dynamic bonds such as hydrogen bonds and borate ester bonds, the polysaccharide composite membrane has good self-healing properties after being damaged. Figure 13As shown, the polysaccharide composite membrane obtained in Example 1 was first swollen in pure water for 10 minutes until it reached a gel state, at which point the polysaccharide composite membrane network was loose. Then, the polysaccharide composite membrane was cut into two sections and the cut surfaces were joined together. It was then left to stand at 50°C for 30 minutes without any external force. Finally, it was cooled to room temperature, and the composite gel membrane was placed on a glass plate and kept in an environment with a temperature of 25°C and a relative humidity of 80% until it was completely dried in situ, thus obtaining a self-healed polysaccharide composite membrane (Self-healed KGM / KC / TA). The tensile breaking strength of the self-healing polysaccharide composite membrane was measured to be 134.34 MPa, Young's modulus was 3416.17 MPa, and tensile breaking energy was 9.91 MJ / m², according to the test methods given in steps 4) and 5) of Example 1. 3 The elongation at break was 10.25%, and the adhesive strength was 97.42 kPa, which were 83%, 84%, 77.6%, 102%, and 67% of the polysaccharide composite film (original sample) in Example 1, respectively, demonstrating excellent self-healing properties.

[0117] 2. Reusable bonding

[0118] The reusability of high-strength and tough adhesives has always been a significant challenge. Because the polymer network in the polysaccharide composite membrane of this invention is primarily constructed based on dynamic bonds such as hydrogen bonds and borate ester bonds, it can achieve multiple "binding-dissociation" reuse characteristics. For example... Figure 14 As shown, the polysaccharide composite film sample after the overlap-shear adhesion performance test in step 5) of Example 1 was subjected to 5 cycles of adhesion performance test under the same conditions. The results showed that the adhesion strength of the sample could still be maintained above 50 kPa after 5 tests, which showed excellent repeatable adhesion characteristics.

[0119] 3. Recyclable

[0120] Because the polymer network in the polysaccharide composite membrane of this invention is mainly constructed based on dynamic bonds such as hydrogen bonds and borate ester bonds, this type of dynamic bond network also endows it with excellent recyclability. For example... Figure 15 As shown, the polysaccharide composite membrane fragments tested for tensile and adhesive properties in Example 1 were collected, dissolved in deionized water, heated and stirred at 80°C for 30 minutes, poured into a mold, cooled and shaped again, and dried in situ to form a film using the same method as step 4) of Example 1, resulting in a recycled polysaccharide composite membrane (Recycled KGM / KC / TA). The tensile breaking strength of the recycled polysaccharide composite membrane was measured to be 151.12 MPa, Young's modulus was 4080.29 MPa, and tensile breaking energy was 10.60 MJ / m², according to the test methods given in steps 4) and 5) of Example 1. 3The elongation at break was 9.79%, and the adhesive strength was 118.16 kPa, which were 94%, 101%, 83%, 97%, and 81% of the original sample in Example 1, respectively, demonstrating excellent recyclability and reducing usage costs.

[0121] 4. Can be used for wound repair and regeneration

[0122] The present invention can be applied to wound repair scenarios including, but not limited to: 1) debridement of wounds of medium or large area on the limbs and trunk; 2) debridement of infected skin ulcers caused by various infectious diseases and diabetes; 3) debridement of wounds in skin folds and deep cavities; 4) large-area skin defects caused by skin degloving injuries and other causes, requiring flap transplantation and skin grafting surgery.

[0123] 1) Weigh 0.1g of sodium tetraborate at room temperature and dissolve it completely in a flask containing a certain amount of pure water to prepare a sodium tetraborate solution (keeping the total mass at 100g). Then weigh 3.0g of konjac powder, 0.5g of carrageenan and 0.8g of tannic acid and add them to the solution in sequence. Stir in an 80℃ water bath for 5 minutes, then add 10mL of 0.10ppm silver nitrate solution and continue stirring for 30 minutes until a homogeneous mixture is formed.

[0124] Preparation steps 2) to 4) are the same as in Example 1, yielding a silver ion hybridized polysaccharide composite membrane (KGM / KC / TA / Ag). + ).

[0125] The following experiments were conducted using the polysaccharide composite membrane from Example 1 and the silver ion-hybridized polysaccharide composite membrane as the experimental groups:

[0126] The blank control group will receive 10 μL containing 1×10 5 A suspension of L929 cells was seeded in 150 μL of DMEM high-glucose medium containing 10% fetal bovine serum; the experimental group was seeded in 10 μL of DMEM high-glucose medium containing 1×10⁻⁶ fetal bovine serum. 5 A suspension of L929 cells was inoculated onto the surface of a polysaccharide composite membrane with a diameter of 5 mm and a thickness of 0.03 mm. Four parallel experiments were set up for each group of samples. After 30 minutes, 150 μL of DMEM high-glucose medium containing 10% fetal bovine serum was added. The cells were cultured at 37℃ and 5% CO2 for 1 day and 3 days, respectively. After detection by CCK8 and live / dead cell staining, 50 μL of Staphylococcus aureus bacterial suspension was inoculated onto the surface of LB solid medium. After the colonies filled the culture dish, the polysaccharide composite membrane with a diameter of 5 mm was placed in each group. The size of the inhibition zone of the polysaccharide composite membrane in each group was observed after 1 day.

[0127] like Figure 16As shown, the results indicate that both the polysaccharide composite membrane of Example 1 and the composite membrane further incorporating 0.01 ppm silver ions (silver ion hybridized polysaccharide composite membrane) have good biocompatibility and a low cell death rate after inoculation. Figure 16 a and c). Experimental results show that ( Figure 16 (b) The polysaccharide composite membrane and the silver ion hybrid polysaccharide composite membrane of Example 1 of the present invention have excellent antibacterial properties. The polysaccharide composite membrane prepared by the present invention has advantages such as moisturizing and strong adhesion, low immunogenicity and high biocompatibility, excellent antibacterial properties and wound regeneration ability, and has the ability to be prepared into various negative pressure suction dressings, thus having good application prospects in the field of wound repair.

[0128] The above description is merely a preferred embodiment of the present invention, and should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a high-toughness konjac-based biopolymer composite film, characterized in that, Comprising the following steps: 1) dissolving a crosslinking agent in water to prepare a solution, adding konjac powder, carrageenan, and tannic acid in sequence, and stirring at a certain temperature until a uniform mixture is formed; wherein the mass ratio of konjac powder to crosslinking agent is 30:(0.5-1.5); the mass ratio of konjac powder to carrageenan is 30:(2-6); and the mass ratio of konjac powder to tannic acid is 30:(2-10); 2) centrifuging the uniform mixture in step 1) under certain conditions for a certain time to obtain a uniform mixed solution without air bubbles; 3) injecting the uniform mixed solution after the defoaming treatment in step 2) into a glass mold, and under certain pressure conditions, the mold is pressed and annealed for a certain time, then the mold is opened and cooled to form a konjac-based hydrogel composite film; 4) placing the konjac-based hydrogel composite film obtained in step 3) on a hydrophilic glass substrate, and drying in situ under certain environmental temperature and humidity conditions to obtain a high-toughness konjac-based biological polysaccharide composite film, which has controllable wet interface adhesion ability. The crosslinking agent in step 1) is one or more of sodium tetraborate, sodium trimetaphosphate, epichlorohydrin, and glutaraldehyde. Step 4) the controllable wettable interface is an interface with a liquid surface density of 30-80 g / m 2 ; the liquid is water or an aqueous solution of a soluble metal salt; the soluble metal salt is an aqueous solution of one or more of Li + , Na + , K + , Ag + , Mg 2+ , Ca 2+ , Zn 2+ , Cu 2+ , Al 3+ , Fe 3+ , or Zr 4+ , and the concentration of the aqueous solution is 0.005-0.2 mol / L.

2. The method for preparing the high-strength and tough konjac-based biopolysaccharide composite membrane according to claim 1, characterized in that, The metal coordination ion compound is additionally added in the uniform mixture in step 1) in the preparation method, a high-toughness konjac-based biological polysaccharide composite film with underwater interfacial adhesion capacity is prepared, and the metal coordination ion is one or more of Ag + , Mg 2+ , Ca 2+ , Zn 2+ , Al 3+ , Fe 3+ , Zr 4+ , and the concentration of the metal coordination ion in the uniform mixture is 0.005-0.02 mol / L.

3. The production method according to claim 1 or 2, characterized by, The stirring temperature in step 1) is 70-95℃, and the stirring time is 30-60 minutes; the centrifugal defoaming conditions in step 2) are temperature 70-95℃, rotation speed 8000-10000 rpm, and defoaming time 10-30 minutes; and / or 4. The production method according to claim 1 or 2, characterized by, The mold pressing conditions in step 3) are mold pressing pressure 1 MPa and mold pressing time 5 minutes, and the annealing treatment temperature is room temperature, and the time is 24-48 hours. The in-situ drying conditions in step 4) are temperature 10-40℃ and environmental relative humidity 60-90%.

5. The production method according to claim 1 or 2, characterized by, Prepared by the method of claim 1.

6. A high-toughness konjac-based biopolymer composite film with controllable wetting interfacial adhesion, characterized in that, Prepared by the method of claim 2.

7. A high-toughness konjac-based biopolymer composite film with underwater interfacial adhesion capability, characterized in that, The application is to prepare a wound dressing or a tissue surface adhesive substitute.

8. The use of the high-toughness konjac-based biopolysaccharide composite film according to claim 6 or 7, characterized in that, ​

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