Wound dressing based on weft-knitted spacer fabric and application thereof

Abstract

The invention belongs to the technical field of medical dressings, and particularly relates to a wound dressing based on weft-knitted spacer fabric and application thereof.The modified cotton yarn with the high water absorption capacity and the hemostatic effect is obtained by conducting carboxymethylation modification on cotton yarn on the basis of the two-dimensional knitting and three-dimensional knitting technology; performing two-dimensional weaving on polyester monofilaments and the modified cotton yarns to obtain interval yarns with supporting performance; the spacer yarn is soaked in a methylene blue solution and dried, then the spacer yarn, the modified cotton yarn and the hydrophobic polyethylene filament are subjected to cross knitting through a flat knitting machine, and the wound dressing is obtained. The wound dressing has good supporting performance, adhesion resistance, liquid absorption and retention capability, horizontal and vertical air permeability, water vapor permeability, hemostasis, antibiosis and wound healing promotion capability, and can be used for preparing biomedical hemostatic materials or medicines for promoting wound healing.

Description

Technical Field

[0001] The invention belongs to the technical field of medical dressings, and in particular relates to a wound dressing based on weft-knitted spacer fabric and application thereof. Background Art

[0002] During the wound repair process, optimization of the wound environment is crucial. An ideal wound environment should meet the following basic conditions: effectively block external pollution and prevent the invasion of harmful substances such as bacteria; maintain appropriate moisture to avoid excessive dryness that causes damage to new tissue, and prevent excessive accumulation of exudate that causes infection; at the same time, the wound environment needs to have good water vapor permeability and breathability to promote gas exchange and support key repair processes such as fibroblast proliferation and collagen synthesis; in addition, the risk of infection and the possibility of secondary injury must be minimized. The exudate from acute wounds is rich in inflammatory mediators and immune cells, which can effectively eliminate pathogens and promote repair; however, the exudate from chronic wounds may lead to the inactivation of growth factors due to long-term inflammatory stimulation, and excessive accumulation of exudate may become a breeding ground for bacteria, further increasing the risk of infection.

[0003] The "moist healing theory" has been widely accepted. A moderately moist environment can accelerate the wound repair process, but the precise control of liquid balance is the key to achieving this goal. Although traditional dressings such as gauze, foam dressings and gel dressings are widely used, they have many limitations: they are easy to adhere to the wound after absorbing liquid, causing secondary damage during dressing changes; they have poor water absorption and air permeability, affecting the stability of the wound microenvironment; they are prone to residual fibers and other foreign matter, interfering with healing; they have insufficient support and protection for the wound, making it difficult to meet the mechanical requirements of complex wounds; and most of them lack long-term antibacterial ability, making it difficult to meet the infection prevention and control requirements of long-term treatment. Therefore, the current research and development of new dressings is moving towards the direction of multi-material composites and special structural designs, in order to develop new medical dressings with synergistic or multiple functions.

[0004] Currently, new dressings can be categorized by their mode of action, including interactive, bioactive, tissue-engineered, and intelligent types. These dressings are often based on traditional dressings (such as semipermeable membranes, fabrics, foams, and hydrocolloids), with performance enhanced by the introduction of functional ingredients such as antimicrobial and antioxidant components and the use of advanced processes such as electrospinning, 3D printing, and directional freezing. However, when addressing complex wound types and healing stages, existing new dressings struggle to balance the requirements of efficient fluid management, dynamic environmental regulation, and long-term antimicrobial protection. Furthermore, with patients' increasing demands for comfort and faster healing, there is an urgent need to develop dressings with improved performance and wider applicability. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a wound dressing based on weft-knitted spacer fabric and its application. The wound dressing provided by the present invention has good support, anti-adhesion, liquid absorption and retention capacity, horizontal and vertical air permeability, water vapor permeability, hemostasis, antibacterial and wound healing promotion capabilities, and can be used to prepare biomedical hemostatic materials or drugs that promote wound healing.

[0006] To achieve the above object, the specific technical solutions of the present invention are as follows: A first aspect of the present invention provides a wound dressing based on a weft-knitted spacer fabric, which is prepared by the following steps: Carboxymethylation is performed on cotton yarn to obtain modified cotton yarn with strong water absorption capacity and hemostatic effect; With polyester monofilament as the core and modified cotton yarn as the shell, the polyester monofilament and modified cotton yarn are two-dimensionally woven to obtain supportive spacer yarn; The spacer yarn is immersed in a methylene blue solution and dried to obtain a methylene blue composite modified spacer yarn with antibacterial properties; The polyethylene filaments and modified cotton yarns are used as surface layers, and the polyethylene filaments, modified cotton yarns and methylene blue composite modified spacer yarns are cross-woven to obtain the wound dressing.

[0007] Furthermore, the modified cotton yarn has a count of 10s / 2 or 40s / 2.

[0008] Furthermore, the cotton yarn is immersed in an alkalizing agent at 20°C~30°C for 1h~1.5h of alkalization reaction, and then a carboxymethylating agent is added at 55°C~70°C for etherification reaction for 4h~5h, the pH value of the system is adjusted to neutral, washed, and dried.

[0009] Furthermore, the alkalizing agent is sodium hydroxide, potassium hydroxide, calcium hydroxide or barium hydroxide; and the carboxymethylating agent is chloroacetic acid, bromoacetic acid or iodoacetic acid.

[0010] Furthermore, the mass ratio of the sodium hydroxide to the chloroacetic acid is 2-3:1.

[0011] Furthermore, the cross-knitting method is 0 stitches, 1 stitches or 2 stitches.

[0012] Furthermore, the mass fraction of the methylene blue solution is 1 w / v%.

[0013] Furthermore, the immersion time is 1 h to 1.5 h.

[0014] A second aspect of the present invention provides a use of the aforementioned wound dressing in the preparation of a biomedical hemostatic material.

[0015] A third aspect of the present invention provides a use of the wound dressing described above in the preparation of a medicament for promoting wound healing.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a wound dressing based on a weft-knitted spacer fabric, which is prepared by the following steps: carboxymethylation modification of cotton yarn to obtain modified cotton yarn; using polyester monofilament as the core and modified cotton yarn as the shell to prepare spacer yarn by two-dimensional weaving, and then immersing and drying in a methylene blue solution to obtain a methylene blue composite modified spacer yarn; using polyethylene filament and modified cotton yarn as the surface layer, combined with the methylene blue composite modified spacer yarn, and cross-weaving to construct a three-dimensional weft-knitted spacer structure, and finally obtaining a wound dressing. (1) Carboxymethylation modification is used to regulate the microstructure of the cotton yarn to enhance its liquid adsorption and water retention capabilities. (2) In the weaving structure, polyester monofilament is selected as the core material of the spacer yarn. The polyester monofilament has high strength and stability, laying the foundation for the three-dimensional structure of the dressing, ensuring that the dressing still has good mechanical properties and air permeability in a wet environment. Through the synergistic combination of carboxymethylation modified cotton yarn and hydrophobic polyethylene filament, the directional liquid conduction of the dressing surface layer and the liquid retention balance of the bottom layer are achieved. (3) By immersing the spacer yarn in a methylene blue solution, the antibacterial components are evenly loaded on the surface and inside of the fiber, thereby forming an antibacterial barrier in the wound environment to resist bacterial invasion.

[0017] The wound dressing provided by the present invention is a wound dressing with good support, anti-adhesion, liquid absorption and retention capacity, horizontal and vertical air permeability, water vapor permeability, hemostasis, antibacterial and wound healing promoting abilities, and can be used to prepare biomedical hemostatic materials or drugs that promote wound healing.

[0018] (1) Compared with the spacer fabrics on the market that can hardly absorb water and the wound dressings that have not been modified by carboxymethylation, the wound dressing provided by the present invention can transfer liquid to the liquid storage layer through the spacer yarn within 10 seconds, and absorb liquid until the liquid storage layer is completely wet within 20 seconds. It has good water absorption and liquid storage capacity, which can ensure that the dressing can handle wound exudate in time.

[0019] (2) The use of hydrophobic polyethylene filaments and the hydrocolloid properties of carboxymethyl modified spacer yarns give the wound dressing a certain degree of anti-adhesion ability, reducing the possibility of secondary damage to the wound.

[0020] (3) Thanks to the three-dimensional knitted structure, the wound dressing provided by the present invention can still maintain a vertical air permeability of 234.71 mm / s and a horizontal air permeability of 6.2 L / min after complete swelling, as well as good mechanical properties, indicating that the wound dressing provided by the present invention can protect the wound from external damage to a certain extent.

[0021] (4) Experiments have shown that the wound dressing provided by the present invention has excellent antibacterial properties, can inhibit more than 90% of Staphylococcus aureus and Escherichia coli, and can largely prevent wounds from being invaded by bacteria. Due to the material selection, structural design and loading of antibacterial substances, the wound dressing can provide low moisture content, a good breathable environment, support and protection, hemostatic properties and antibacterial effects to the wound. When applied to full-thickness skin incisions in mice, it can promote wound healing faster than the control group. It can be used to prepare biomedical hemostatic materials or drugs that promote wound healing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 Figure A is a schematic diagram of the preparation process of wound dressing. Figure A is a schematic diagram of the preparation process of SFD dressing. Figure B is a schematic diagram of the preparation process of wound dressing SFD-MB.

[0024] Figure 2 Figure A and Figure B are pictures and schematic diagrams of knitting methods, respectively. Figure C and Figure D are pictures and schematic diagrams of knitting with an interval of 1 needle, respectively. Figure E and Figure F are pictures and schematic diagrams of knitting with an interval of 2 needles, respectively.

[0025] Figure 3 Figures A, B, and C show the states of water droplets on the surface of unmodified cotton yarn at 0s, 0.1s, and 1s, respectively. Figures D, E, and F show the states of water droplets on the surface of modified cotton yarn at 0s, 0.1s, and 0.2s, respectively.

[0026] Figure 4 These are the wettability test results of polyethylene filaments. Figure A shows the state of the droplet just when it contacts the polyethylene filament, Figure B shows the state of the droplet 0.5s after contacting the polyethylene filament, and Figure C shows the state of the droplet 5s after contacting the polyethylene filament. Figure D is an enlarged view of the red frame part of the droplet on the right side of Figure C. The droplet remains independent and has a large contact angle, indicating that the polyethylene filament is hydrophobic.

[0027] Figure 5 This is the vertical air permeability test result of the wound dressing when it is dry.

[0028] Figure 6 This is the vertical air permeability test result of the wound dressing after absorbing water.

[0029] Figure 7 Schematic diagram of the device for measuring the horizontal air permeability of wound dressing.

[0030] Figure 8 It is the test result of horizontal air permeability of wound dressing when dry and fully absorbed with water.

[0031] Figure 9 These are the air permeability test results of commercially available PU foam dressings in dry and wet states.

[0032] Figure 10 This is a statistical chart of water vapor transmission rate of wound dressings.

[0033] Figure 11 The compressive strength test results of wound dressings.

[0034] Figure 12 These are the dynamic water absorption displays of SFD1 and SG dressings. Figures A, B, C, and D respectively show the dynamic water absorption of SFD1 dressing at 0s, 1s, 10s, and 20s. Figures E, F, G, and H respectively show the dynamic water absorption of SG dressing at 0s, 1s, 20s, and 90s.

[0035] Figure 13 These are the test results of the water absorption performance of wound dressings.

[0036] Figure 14 These are diagrams showing the anti-adhesion effect of SFD1 dressing. Figures A, B, and C respectively show the state after the dressing was applied on the mouse wound for 48 hours, the state after the dressing was removed, and the state after the dressing was completely removed.

[0037] Figure 15 Figure 1 shows the plate antibacterial test of SFD1 dressing. Figures A and B show the growth of Escherichia coli and Staphylococcus aureus in the blank control group, and Figures C and D show the growth of Escherichia coli and Staphylococcus aureus in the experimental group treated with SFD1 dressing.

[0038] Figure 16 These are the test results of the blue dye retention effect of SFD1 dressing. The pictures in row A, row B, and row C are pictures of the initial state, the state after adding dye, and the state after adding deionized water, respectively.

[0039] Figure 17 These are pictures of the dynamic coagulation process of SFD1 dressing. Pictures in rows A, B, and C are pictures of the state when rabbit blood was added, deionized water was added, and shaking was performed for 15 seconds, respectively.

[0040] Figure 18 This is a statistical chart of the coagulation index of SFD1 dressing.

[0041] Figure 19Figures A, B, C, and D are the wound healing images of the control group on the 1st, 4th, 7th, and 15th day of treatment, respectively. Figures E, F, G, and H are the wound healing images of the SFD-MB dressing on the 1st, 4th, 7th, and 15th day of treatment, respectively.

[0042] Figure 20 The results of H&E staining and Masson staining of wound skin treated with SFD1 dressing on the 7th and 15th days. DETAILED DESCRIPTION

[0043] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited by the specific embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. The experimental methods described in the embodiments of the present invention are conventional methods unless otherwise specified, and the materials, reagents, etc. used in the following embodiments can be obtained from commercial sources unless otherwise specified.

[0044] When addressing complex wound types and healing stages, existing dressings struggle to balance efficient fluid management, dynamic environmental regulation, and long-term antimicrobial needs. Furthermore, patients' demands for comfort and faster healing are increasing, necessitating the development of a dressing with improved performance and wider applicability.

[0045] The present invention provides a wound dressing based on a weft-knitted spacer fabric and its application. Based on two-dimensional weaving and three-dimensional knitting technologies, the invention carboxylmethylates cotton yarn to produce a modified cotton yarn with both strong water absorption and hemostatic properties. Polyester monofilament and the modified cotton yarn are then two-dimensionally woven to produce a supportive spacer yarn. The spacer yarn is then immersed in a methylene blue solution and dried, and then woven with the modified cotton yarn and hydrophobic polyethylene filaments using a flat knitting machine to produce a wound dressing. This wound dressing exhibits excellent support, anti-adhesion properties, fluid absorption and retention, horizontal and vertical air permeability, water vapor permeability, hemostatic and antibacterial properties, and wound healing-promoting abilities. It can be used to prepare biomedical hemostatic materials or wound-healing-promoting drugs.

[0046] Example 1: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 20 wt% sodium hydroxide aqueous solution at 25°C for 1 hour. Then, 14.8 g of chloroacetic acid was added to the solution and etherified at 70°C for 4 hours. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0047] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0048] The BM-P spacer yarn was immersed in 1 w / v% methylene blue (MB) solution for 1 h and then dried to obtain BM-P-MB yarn.

[0049] AM yarn and polyethylene filament are used as two surface layers, BM-P-MB yarn is used as spacer yarn, and they are woven on a flat knitting machine in a 1-0-1 cross pattern to obtain a wound dressing SFD-MB, which is marked as material SFD1.

[0050] Example 2: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 20 wt% sodium hydroxide aqueous solution at 23°C for 1 hour, followed by 16.7 g of chloroacetic acid and etherification at 60°C for 5 hours. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0051] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0052] The BM-P spacer yarn was immersed in 1 w / v% methylene blue (MB) solution for 1 h and then dried to obtain BM-P-MB yarn.

[0053] AM yarn and polyethylene filament are used as two surface layers, BM-P-MB yarn is used as spacer yarn, and they are woven on a flat knitting machine in a 1-0-1 cross pattern to obtain a wound dressing SFD-MB.

[0054] Example 3: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 20 wt% sodium hydroxide aqueous solution at 20°C for 1.5 h. Then, 14.8 g of chloroacetic acid was added to the solution and etherified at 65°C for 4 h. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0055] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0056] The BM-P spacer yarn was immersed in 1 w / v% methylene blue (MB) solution for 1 h and then dried to obtain BM-P-MB yarn.

[0057] AM yarn and polyethylene filament are used as two surface layers, BM-P-MB yarn is used as spacer yarn, and they are knitted on a flat knitting machine in a cross-knitting manner with an interval of 0 stitches to obtain a wound dressing SFD-MB, which is marked as SFD0.

[0058] Example 4: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 20 wt% sodium hydroxide aqueous solution at 25°C for 1 hour, followed by etherification with 14.8 g of chloroacetic acid at 55°C for 5 hours. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0059] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0060] The BM-P spacer yarn was immersed in 1 w / v% methylene blue (MB) solution for 1 h and then dried to obtain BM-P-MB yarn.

[0061] AM yarn and polyethylene filament are used as two surface layers, BM-P-MB yarn is used as spacer yarn, and they are knitted on a flat knitting machine in a cross-knitting manner with an interval of 2 needles to obtain a wound dressing SFD-MB, which is marked as SFD2.

[0062] Comparative Example 1: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 15 wt% sodium hydroxide aqueous solution at 25°C for 1 hour. Then, 25 g of chloroacetic acid was added to the solution and etherified at 60°C for 4 hours. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0063] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0064] The BM-P spacer yarn was immersed in 1 w / v% methylene blue (MB) solution for 1 h and then dried to obtain BM-P-MB yarn.

[0065] AM yarn and polyethylene filament are used as two surface layers, BM-P-MB yarn is used as spacer yarn, and the yarns are knitted on a flat knitting machine in a cross-knitting manner with an interval of one needle to obtain a wound dressing.

[0066] Comparative Example 2: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 15 wt% sodium hydroxide aqueous solution at 25°C for 1 hour. Then, 16.7 g of chloroacetic acid was added to the solution and etherified at 60°C for 4 hours. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0067] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0068] The BM-P spacer yarn was immersed in 1 w / v% methylene blue (MB) solution for 1 h and then dried to obtain BM-P-MB yarn.

[0069] AM yarn and polyethylene filament are used as two surface layers, BM-P-MB yarn is used as spacer yarn, and the yarns are knitted on a flat knitting machine in a cross-knitting manner with an interval of one needle to obtain a wound dressing.

[0070] Comparative Example 3: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively, according to the following procedures. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 25 wt% sodium hydroxide aqueous solution at 25°C for 1 hour, followed by etherification with 25 g of chloroacetic acid at 60°C for 4 hours. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0071] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0072] The BM-P spacer yarn was immersed in 1 w / v% methylene blue (MB) solution for 1 h and then dried to obtain BM-P-MB yarn.

[0073] AM yarn and polyethylene filament are used as two surface layers, BM-P-MB yarn is used as spacer yarn, and the yarns are knitted on a flat knitting machine in a cross-knitting manner with an interval of one needle to obtain a wound dressing.

[0074] Comparative Example 4: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 25 wt% sodium hydroxide aqueous solution at 25°C for 1 hour. Then, 16.7 g of chloroacetic acid was added to the solution and etherified at 60°C for 4 hours. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0075] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0076] The BM-P spacer yarn was immersed in 1 w / v% methylene blue (MB) solution for 1 h and then dried to obtain BM-P-MB yarn.

[0077] AM yarn and polyethylene filament are used as two surface layers, BM-P-MB yarn is used as spacer yarn, and the yarns are knitted on a flat knitting machine in a cross-knitting manner with an interval of one needle to obtain a wound dressing.

[0078] Comparative Example 5: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 30 wt% sodium hydroxide aqueous solution at 25°C for 1 hour. Then, 25 g of chloroacetic acid was added to the solution and etherified at 60°C for 4 hours. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0079] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0080] The BM-P spacer yarn was immersed in 1 w / v% methylene blue (MB) solution for 1 h and then dried to obtain BM-P-MB yarn.

[0081] AM yarn and polyethylene filament are used as two surface layers, BM-P-MB yarn is used as spacer yarn, and the yarns are knitted on a flat knitting machine in a cross-knitting manner with an interval of one needle to obtain a wound dressing.

[0082] Comparative Example 6: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 30 wt% sodium hydroxide aqueous solution at 25°C for 1 hour. Then, 16.7 g of chloroacetic acid was added to the solution and etherified at 60°C for 4 hours. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0083] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0084] The BM-P spacer yarn was immersed in 1 w / v% methylene blue (MB) solution for 1 h and then dried to obtain BM-P-MB yarn.

[0085] AM yarn and polyethylene filament are used as two surface layers, BM-P-MB yarn is used as spacer yarn, and the yarns are knitted on a flat knitting machine in a cross-knitting manner with an interval of one needle to obtain a wound dressing.

[0086] Comparative Example 7: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 35 wt% sodium hydroxide aqueous solution at 25°C for 1 hour. Then, 16.7 g of chloroacetic acid was added to the solution and etherified at 60°C for 4 hours. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0087] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0088] The BM-P spacer yarn was immersed in 1 w / v% methylene blue (MB) solution for 1 h and then dried to obtain BM-P-MB yarn.

[0089] AM yarn and polyethylene filament are used as two surface layers, BM-P-MB yarn is used as spacer yarn, and the yarns are knitted on a flat knitting machine in a cross-knitting manner with an interval of one needle to obtain a wound dressing.

[0090] Comparative Example 8: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: Use 10s / 2 cotton yarn as yarn A and 40s / 2 cotton yarn as yarn B; The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four B yarns as the sheath yarn and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a B-polyester monofilament two-dimensional braided yarn (referred to as BP spacer yarn).

[0091] The BP spacer yarn was immersed in 1 w / v% methylene blue solution for 1 h and then dried to obtain BP-MB yarn; A wound dressing was obtained by knitting A yarn and polyethylene filament as two surface layers and BP-MB yarn as a spacer yarn on a flat knitting machine in a cross-knitting manner with an interval of 1 stitch. The wound dressing was marked as SG.

[0092] Comparative Example 9: A wound dressing based on a weft-knitted spacer fabric is prepared by the following steps: 10s / 2 cotton yarn and 40s / 2 cotton yarn were carboxymethylated to obtain AM and BM yarns, respectively. The carboxymethylation modification steps were as follows: 4 g of cotton yarn was immersed in 50 mL of a 20 wt% sodium hydroxide aqueous solution at 25°C for 1 hour. Then, 14.8 g of chloroacetic acid was added to the solution and etherified at 60°C for 4 hours. Subsequently, the solution was adjusted to neutral pH with glacial acetic acid, washed with anhydrous ethanol, and finally dried in a 40°C oven.

[0093] The spacer yarn was prepared on a high-speed two-dimensional braiding machine (KBL-24-2-90, Xuzhou Henghui Braiding Machine Co., Ltd.) at a speed of 600 r / min. The spacer yarn consisted of four BM yarns as the sheath yarns and a single 0.2 mm diameter polyester monofilament as the core yarn. Two sheath yarns were symmetrically arranged in groups on the braiding machine and woven around the core yarn to form a BM-polyester monofilament two-dimensional braided yarn (referred to as BM-P spacer yarn).

[0094] AM yarn and polyethylene filament are used as two surface layers, BM-P yarn is used as a spacer yarn, and the wound dressing is knitted on a flat knitting machine in a cross-knitting manner with an interval of 1 stitch to obtain a wound dressing, which is marked as SFD3.

[0095] The carboxymethyl modification methods in Examples 1-2 and Comparative Examples 1-7 are different. The present invention first tests the relevant properties of the modified AM yarn and BM yarn in Examples 1-2 and Comparative Examples 1-7.

[0096] The modified AM yarn and BM yarn in Examples 1 and 2 showed obvious gelation after absorbing water, and the water absorption rate and water absorption capacity were significantly improved; the water absorption rate of the modified AM yarn and BM yarn in Comparative Examples 1 and 2 was significantly improved, and the water absorption rate increased, but there was no obvious swelling and gelation after absorbing water; the modified AM yarn and BM yarn in Comparative Examples 3, 4, 5, and 6 were too hard and brittle, which was not conducive to subsequent weaving on the machine; the modified AM yarn and BM yarn in Comparative Example 7 dissolved to a large extent after coming into contact with water.

[0097] Since Examples 1-4 have similar effects, for the convenience of subsequent discussion and reference, the test results of Example 1 are taken as an example. The following are the test results of Example 1.

[0098] The knitting methods in Example 1, Example 3 and Example 4 are respectively a cross knitting method of spacing 1 needle (marked as 1-0-1), spacing 0 needle (marked as 1-1) and spacing 2 needles (marked as 1-0-0-1). The knitting method diagram is shown in FIG. Figure 2 ,The weaving information of different fabrics is shown in Table 1.

[0099] Table 1 Weaving information of different fabrics Experimental Example 1: Test of water absorption and wound anti-adhesion performance of modified cotton yarn The present invention investigates the effects of the carboxymethyl-modified cotton yarn in Example 1 and the unmodified cotton yarn in Comparative Example 8 on wound dressings.

[0100] Figure 3The water contact angle test results of unmodified cotton yarn and modified cotton yarn are shown. It can be found that the modified cotton yarn can completely absorb the droplets in 0.2s, and its wettability is much better than the unmodified cotton yarn that has not absorbed all the droplets after 1s.

[0101] In addition, the present invention also tests the wettability of the polyethylene filaments in the wound dressing. Figure 4 It can be seen that the contact angle of the droplet on the coil formed by the polyethylene filament is greater than 90°, and the droplet is not absorbed due to its hydrophobicity. At the same time, the spacer yarn between the two polyethylene filament coils can completely absorb the droplet within 5 seconds, indicating that the anti-adhesive layer in contact with the wound can play a synergistic role in quickly absorbing exudate and preventing adhesion to the wound through the hydrophobic polyethylene filaments and the hydrophilic BM-P spacer yarn.

[0102] Experimental Example 2: Wound Dressing Air Permeability Test The air permeability of a fabric refers to the ability of air to penetrate the fabric when a pressure differential exists across the fabric. Specifically, it refers to the volume of air flowing through a unit area of ​​the fabric per unit time under a specified pressure differential across the fabric. To investigate the significant impact of spacer fabric structure on the performance of the final dressing, the present invention tested the air permeability of spacer fabrics with different structures: SFD0, SFD1, SFD2, and SG.

[0103] 1. Vertical breathability Vertical air permeability when dry: from Figure 5 It can be seen that due to the special loop structure of knitted fabrics and the three-dimensional structure of spacer fabrics, before absorbing water, SFD0, SFD1, and SFD2 spacer fabrics all have excellent air permeability, with the highest reaching 1809.08 mm / s.

[0104] Vertical air permeability in the fully watered state: In order to meet the wound's need for a breathable environment, the dressing should be able to maintain air circulation in the wound after absorbing exudate. Therefore, the present invention tests the air permeability of the wound dressing after it is fully watered.

[0105] The results are as follows Figure 6 As shown in the figure, after being fully absorbed with water, SFD0, SFD1, and SFD2 can still maintain air permeabilities of 281.38 mm / s, 234.71 mm / s, and 354.68 mm / s, respectively, but these are lower than the 895.17 mm / s of the SG spacer fabric. This indicates that the spacer fabric prepared with carboxymethyl-modified cotton yarn can maintain air circulation in the wound environment during the wound healing process, and the carboxymethyl-modified cotton yarn absorbs water and swells and produces gelation, making the dressing surface denser, which can avoid external contamination to a certain extent and better provide a certain degree of moisture to the wound.

[0106] 2. Horizontal air permeability use Figure 7The horizontal air permeability of the dressing was measured using the device shown in the figure. The results are as follows: Figure 8 As shown, SFD2 has better horizontal air permeability than SFD1 and SFD0, while SG, which has the same structure as SFD1, has slightly higher horizontal air permeability. This is because the carboxymethyl-modified yarn has a thicker diameter, leaving less space for air circulation in SFD1 than in SG. After being fully saturated with water, the three-dimensional structure reduces the internal space due to the expansion of the carboxymethyl-modified cotton yarn. However, the three dressings provided by this invention still have horizontal air permeabilities of 4.3 L / min, 6.2 L / min, and 8.2 L / min, respectively, ensuring air circulation within the wound.

[0107] 3. Comparison of air permeability with commercially available PU foam dressings The present invention also tested the horizontal and vertical air permeability of commercially available PU foam dressings. Figure 9 The results show that the air permeability of the PU foam dressing in the vertical and horizontal directions in the dry state is only 6.19 mm / s and 1.26 L / min, which is even much lower than that of the SFD0, SFD1, and SFD2 dressings after being fully absorbed with water, indicating that the wound dressing provided by the present invention has a great advantage in air permeability.

[0108] 4. Water vapor transmission rate The present invention further tests the water vapor transmission rate (WVTR) of the wound dressing, and the results are as follows: Figure 10 shown.

[0109] from Figure 10 It can be seen that the water vapor transmission rates of SFD0, SFD1 and SFD2 are 1592.36 g / m 2 / day, 1150.04g / m 2 / day, 1326.964 g / m 2 / day, the vapor permeability of the currently available PU foam dressing is 619.25 g / m 2 / day, the water vapor permeability of SFD0, SFD1, and SFD2 is much higher than that of commercially available dressings. The water vapor permeability required for skin injury is 279~5318g / m 2 / day. A too high WVTR can cause the wound to dry out too quickly, hindering wound healing. A too low WVTR can lead to accumulation of wound exudate, over-immersing the wound. An appropriate WVTR can promote gas exchange within the wound while providing a certain degree of moisture. Because both the air permeability and WVTR decrease to a certain extent after the dressing absorbs exudate, the wound dressing with a higher WVTR provided by the present invention can better ensure effective gas exchange within the wound than PU dressings.

[0110] Experimental Example 3: Compression Strength of Wound Dressing Most commercial dressings, such as gauze and non-woven fabrics, have little resistance to external forces. However, the wound dressing with a three-dimensional structure provided by the present invention has self-supporting properties due to the presence of its spacer yarn, thereby providing protection to the wound to a certain extent.

[0111] like Figure 11 The stress-strain curves of the three SFD spacer fabrics show that SFD1 has better mechanical properties than SFD0 and SFD2. This may be because there is no cross-intersection of the spacer yarns in SFD0, and there is no friction between the spacer yarns, resulting in its weak compressive performance. In addition, the inclination angle of the spacer yarns in SFD2 is larger, which is more easily pressed to the horizontal, and also weakens the compressive ability of the spacer fabric.

[0112] Experimental Example 4: Effect of Methylene Blue on Water Transport and Water Retention Capacity of Wound Dressings Spacer yarn plays an important role in water transport in wound dressings, and the addition of substances may affect this water transport ability. To investigate whether wound dressings maintain good water transport capabilities after adding methylene blue, the present invention tested the water transport capacity of SFD1 dressing (with methylene blue) and SG dressing (without methylene blue).

[0113] Place SFD1 and SG in culture dishes respectively, inject 2 mL of deionized water with blue dye added along the edge each time, observe the process of liquid absorption and take photos to record.

[0114] from Figure 12 It can be seen from the figure that the SFD1 dressing can transfer the liquid to the liquid storage layer through the spacer yarn within 10 seconds, and absorb the liquid until the liquid storage layer is completely wet within 20 seconds. However, the SG dressing has not completely absorbed 2 mL of liquid at 20 seconds, and no liquid diffusion has appeared on the upper surface of the SG dressing at 90 seconds after absorbing the liquid. The sharp contrast between the two shows that the carboxymethyl modification has greatly improved the overall water absorption capacity and transfer performance of the spacer fabric dressing.

[0115] Figure 13 The water absorption and retention capacity (MMT) test results show that the BM-P-MB spacer yarn in the wound dressing provided by the present invention can transfer most of the droplets dropped on the anti-adhesive layer to the liquid storage layer within 18 seconds, and can reach a water content of about 80% in 90 seconds, indicating that this wound dressing has good water absorption and liquid storage capabilities; The above results indicate that the addition of MB does not affect the water transport capacity of wound dressings and can ensure the dressing's ability to handle exudate in a timely manner.

[0116] Experimental Example 5: Anti-adhesion performance test of wound dressing During the wound healing experiment, the anti-adhesion properties of SFD1 dressing were further tested.

[0117] The SFD1 dressing was applied to the wound of the mouse for 24 hours and then removed after 24 hours. Figure 14 As shown, it was clearly found that there was no adhesion between the dressing and the wound. After the dressing was removed, the wound surface was intact and there was no dressing residue, indicating that the dressing had good anti-adhesion properties, proving that the use of polyethylene filaments can effectively prevent adhesion to the wound and cause secondary trauma.

[0118] Experimental Example 6: In vitro antibacterial performance test of wound dressing Biological fluids containing bacteria can be expelled to a reservoir away from the wound through the spacer yarn's transport function, but some bacteria inevitably remain on the wound bed. To prevent bacterial infection or inflammation, the present invention loads the spacer yarn with an organic cationic antimicrobial dye, MB. The ionic compounds formed by MB in aqueous solution compete with microbial enzymes for hydrogen ions, inactivating the enzymes and ultimately rendering the microorganisms inactive. The present invention used an agar plate count method to study the antimicrobial activity of the wound dressing against Staphylococcus aureus and Escherichia coli.

[0119] from Figure 15 It can be seen that compared with the blank control group with dense colonies, there is very little colony growth of Escherichia coli and Staphylococcus aureus on the culture dish of SFD1 dressing. The SFD1 dressing can achieve an antibacterial effect of more than 90%, and the inhibition rate of Escherichia coli is 92.6%, indicating that the wound dressing provided by the present invention has a significant inhibitory effect on Staphylococcus aureus and Escherichia coli.

[0120] Experimental Example 7: Hemostatic Performance Test of Wound Dressing The dressing's ability to retain blue dye was tested to simulate its coagulation ability. Figure 16 , SFD1 dressing has better liquid retention than gauze, PU foam and SG dressings, and has certain potential in hemostasis.

[0121] The present invention further tested the hemostatic effect of SFD1 dressing by using anticoagulated rabbit blood (1:9) with calcium chloride added to perform dynamic coagulation experiments and measure blood coagulation index (BCI) of different dressings.

[0122] from Figure 17Images of the dynamic coagulation process show that after adding 100 μL of deionized water to the blank control, SG dressing, PU foam dressing, and medical gauze, blood clearly diffused into the deionized water. However, only a small amount of red diffused into the solution of the SFD1 dressing, and after shaking for 15 seconds, the red color of the solution was significantly lighter than that of the other groups, indicating that the SFD1 dressing can coagulate blood faster and better. This result indicates that when blood comes into contact with the SFD1 dressing, the cotton yarn in the SFD1 dressing, modified with carboxymethyl groups, swells and gels, forming a mechanical blockage to stop bleeding. Simultaneously, platelets rapidly aggregate on the rough surface of the yarn, stimulating a release and decomposition reaction, forming a thrombus, and thus achieving hemostasis.

[0123] The coagulation index is commonly used to evaluate the in vitro coagulation performance of various wound dressings. The smaller the coagulation index value, the stronger the coagulation ability of the material.

[0124] Depend on Figure 18 It can be seen that the coagulation index of SFD1 dressing is 26.3%, which is much lower than 79.41% of gauze and 82.01% of SG-MB group, and slightly lower than 48.79% of PU foam dressing. In addition, the coagulation process image ( Figure 16 、 Figure 17 ), while the presence of MB in the SFD1 dressing also altered the solution's color, the SFD1 solution was the lightest of the three groups. These results demonstrate that the wound dressing provided by this invention exhibits enhanced coagulation and has the potential to stop bleeding in practical applications.

[0125] Experimental Example 8: Determination of wound healing ability of wound dressing A healing experiment was conducted on full-thickness skin wounds in mice. By comparing the control group (no treatment) and the experimental group (wounds treated with SFD1 dressing), photos of the wound sites of mice were taken on the 1st, 4th, 7th, and 15th days for comparative observation.

[0126] After 15 days of observation, the results are as follows Figure 19 As shown, infected wounds treated with the SFD1 dressing healed faster than those in the control group, particularly on day 7. The average wound healing rate in the experimental group reached 54.58%, compared to 40.17% in the control group. Furthermore, on day 15, the average wound healing rate in the SFD1 group was also higher than that in the control group, demonstrating that the wound dressing provided by the present invention can promote the healing of infected wounds.

[0127] The wounds were further subjected to histological analysis to verify the effect of the wound dressing provided by the present invention on wound healing at different stages: wound samples were collected from the experimental group (wounds treated with SFD1 dressing) and the control group mice on days 7 and 15, and immunohistochemical analysis (CD31, IL6) was performed to observe wound inflammation and angiogenesis. The wounds were also stained with HE and Masson to observe the epithelial tissue structure and collagen deposition.

[0128] The experimental results are as follows Figure 20 As shown, on the 7th day, the skin tissue injury site of the control group still had a defect, a large amount of necrotic tissue fragments were visible on the surface, and a large amount of inflammatory cell infiltration was visible (black arrow), while the skin injury site of the experimental group was completely filled with granulation tissue, fibroblast proliferation was active, fibrous tissue proliferation (yellow arrow), a large amount of new blood vessels were generated (red arrow), accompanied by more inflammatory cell infiltration (black arrow), more collagen fibers were generated at the skin tissue injury site (yellow arrow), and the new collagen fibers were slender and arranged relatively loosely; on the 15th day, the skin tissue injury site defect of the control group still existed, a small amount of epidermis regenerated at the edge of the injury (blue arrow), a small amount of collagen fibers were generated at the skin tissue injury site (yellow arrow), and the arrangement was loose and disordered, while the epidermis at the skin injury site of the experimental group was completely regenerated (blue arrow), and the new epidermis had a regular morphology. The above results indicate that the wound dressing provided by the present invention is helpful for wound healing.

[0129] It should be noted that when numerical ranges are mentioned in the present invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints may be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes preferred embodiments. Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they understand the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0130] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A wound dressing based on a weft-knitted spacer fabric, characterized in that: The wound dressing is prepared by the following steps: Carboxymethylation is performed on cotton yarn to obtain modified cotton yarn; With polyester monofilament as core and modified cotton yarn as shell, polyester monofilament and modified cotton yarn are two-dimensionally woven to obtain spacer yarn; The spacer yarn is immersed in a methylene blue solution and dried to obtain a methylene blue composite modified spacer yarn; The polyethylene filaments and modified cotton yarns are used as surface layers, and the polyethylene filaments, modified cotton yarns and methylene blue composite modified spacer yarns are cross-woven to obtain the wound dressing.

2. The wound dressing according to claim 1, characterized in that The modified cotton yarn has a count of 10s / 2 or 40s / 2.

3. The wound dressing according to claim 1, characterized in that The carboxymethylation modification steps are: immersing the cotton yarn in an alkalizing agent at 20° C. to 30° C. for 1 hour to 1.5 hours, then adding a carboxymethylating agent at 55° C. to 70° C. for etherification for 4 hours to 5 hours, adjusting the pH value of the system to neutral, washing, and drying.

4. The wound dressing according to claim 3, characterized in that The alkalizing agent is sodium hydroxide, potassium hydroxide, calcium hydroxide or barium hydroxide; the carboxymethylating agent is chloroacetic acid, bromoacetic acid or iodoacetic acid.

5. The wound dressing according to claim 4, characterized in that The mass ratio of the sodium hydroxide to the chloroacetic acid is 2-3:

1.

6. The wound dressing according to claim 1, characterized in that The cross-knitting mode is 0-needle interval, 1-needle interval or 2-needle interval.

7. The wound dressing according to claim 1, characterized in that The immersion time is 1 h to 1.5 h.

8. Use of the wound dressing according to any one of claims 1 to 7 in the preparation of a biomedical hemostatic material.

9. Use of the wound dressing according to any one of claims 1 to 7 in the preparation of a medicament for promoting wound healing.

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