Negative poisson ratio silk-based fabric dressing

Abstract

The application relates to a negative Poisson's ratio silk-based fabric dressing, and relates to the medical textile field. The negative Poisson's ratio silk-based fabric dressing is formed by transverse knitting of front and back needle beds, and the negative Poisson's ratio silk-based fabric dressing is knitted by using polyamide DTY filaments and non-elastic medical-grade degradable silk, wherein the non-elastic medical-grade degradable silk comprises moisture-absorbing and water-retaining silk A as a face yarn and antibacterial silk B as a lining yarn. In this case, in view of the technical problems that traditional dressings cause stress concentration at joint wounds, exudation and inflammation in wound recovery, the negative Poisson's ratio silk-based fabric dressing which meets the actual application requirements and can be integrally formed, uniformly disperses tensile stress, and has the functions of permeation and antibiosis is provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical textiles, in particular to a negative Poisson's ratio silk-based fabric dressing. BACKGROUND

[0002] The Poisson's ratio of a material is defined as the negative of the ratio of the transverse strain to the longitudinal strain. Conventional materials usually exhibit a positive Poisson's ratio, i.e. they narrow transversely when stretched and widen transversely when compressed. Negative Poisson's ratio materials are the opposite, i.e. they widen transversely when stretched and narrow transversely when compressed. The possible Poisson's ratio range of a uniform isotropic material is -1 < v < 0.5, while the range of anisotropic solid materials can be larger. The Poisson's ratio of most metallic materials is between 0.25 and 0.35, the Poisson's ratio of rubber is close to 0.5, almost incompressible, the Poisson's ratio of a wooden plug is close to 0, and there are almost no engineering materials with negative Poisson's ratio. At present, a large number of negative Poisson's ratio materials have been found, prepared and synthesized, which can be mainly divided into four categories: natural materials, polymers, composite materials and fabrics. Many scholars have established a series of negative Poisson's ratio material structure models, such as concave structure, rotating structure, node fibril structure, chiral structure, liquid crystal model, helical structure, etc. Knitted negative Poisson's ratio textile material is a special structure fabric with negative Poisson's ratio effect formed by using textile knitting technology. Different negative Poisson's ratio structure models can be achieved by organization process. In addition, the textile fabric has good structure designability and knitting forming performance, and its high preparation efficiency and low weaving cost are a relatively ideal negative Poisson's ratio structure material production method. Compared with traditional fabrics, the negative Poisson's ratio effect brings many enhanced properties to the fabric, such as mechanical properties, indentation resistance, fracture toughness, energy absorption, etc., and is considered to be the most promising structural material in the current international. Although the negative Poisson's ratio structure has been deeply studied in the field of traditional engineering materials, the research in the field of biological textile medical materials represented by medical dressings is still in its infancy.

[0003] Since Caddock and Evans et al. proposed and prepared a polytetrafluoroethylene material with negative Poisson's ratio effect and named it auxetic material, scholars have carried out research work on different topological configurations and different negative Poisson's ratio structure models. Miller and Hook et al. prepared a negative Poisson's ratio yarn by using two different modulus fibers. Hu et al. prepared several weft-knitted fabrics with negative Poisson's ratio effect according to the deformation principle of square rotation structure and concave hexagonal structure. Hassam et al. studied the compression performance and impact resistance of the negative Poisson's ratio structure as a reinforcing material, and its application in friction nanogenerator, molecular structure, etc. Ma Shibobo and Chang Yuping et al. used the instability of polygon to prepare warp-knitted spacer fabric which can produce negative Poisson's ratio effect in the plane.

[0004] However, the above researches all focus on the preparation of materials with negative Poisson's ratio structure or its application as a reinforcing material in building engineering and other materials, and none of them involve the application of negative Poisson's ratio structure in medical dressings. Establishing a negative Poisson's ratio structure model and applying it in the preparation of wound medical dressings to explore its positive role in the healing and recovery of human joint wounds has a promoting effect on the structure design and industrial application of such materials.

[0005] Wound healing is a dynamic and organized process, which can be roughly divided into three stages: inflammation period, proliferation period and tissue remodeling period. The longer the tissue remodeling lasts, the higher the risk of wound infection and even death. In order to adapt to different types of complex wounds, including infection, bleeding and diabetic wound, a lot of efforts have been put into the design of multifunctional wound dressings in current research. However, few studies focus on the accelerated healing and recovery of joint flexion stretchable wounds, such as human neck, knee, finger joint and ankle. Due to the frequent movement and bending of the joint area of human body, the stretching of the dressing adhered to the wound during the large-scale movement in the recovery process is inevitable. The dressing is stretched during the joint flexion movement, which produces a large pressure on the wound. Due to the characteristics of stretching and thinning of traditional dressings and the lack of sufficient stretchability and ductility, stress concentration occurs at the joint wound, which causes secondary injury of the wound and limitation of joint movement, thereby delaying wound healing. Therefore, how to design a medical dressing that can effectively promote the wound closure and healing of human joint and movement site skin and shorten the wound healing period has been a difficult problem to be solved. SUMMARY

[0006] The purpose of the present application is to provide a negative Poisson's ratio silk-based fabric dressing to solve the technical problems of stress concentration at the joint wound caused by the traditional dressing and leakage and inflammation during wound recovery.

[0007] To achieve the above purpose, the technical scheme adopted by the present application is:

[0008] A negative Poisson's ratio silk-based fabric dressing, wherein the negative Poisson's ratio silk-based fabric dressing is formed by knitting the front and back needle beds in a circular motion to create a rotating polygonal negative Poisson's ratio fabric structure. The negative Poisson's ratio silk-based fabric dressing is woven from nylon DTY filaments and non-elastic medical-grade biodegradable silk. The non-elastic medical-grade biodegradable silk includes moisture-absorbing and water-retaining yarn A as the outer yarn and antibacterial yarn B as the inner yarn.

[0009] In one possible implementation, the method for preparing the moisture-absorbing and water-retaining filament A and the antibacterial filament B includes:

[0010] The silk braided thread was immersed in a 4.8M LiBr solution, swollen at room temperature for 2 hours, washed with water and dried to obtain the pre-treated silk thread.

[0011] After the initial treatment, a portion of the yarn was placed in a 10wt% sodium acrylate solution, and then an appropriate amount of N,N'-methylenebisacrylamide and ammonium persulfate were added. The yarn was sealed and placed in a 70℃ constant temperature water bath for crosslinking for 10 hours. After thorough rinsing and drying, the moisture-absorbing and water-retaining yarn A was obtained.

[0012] Another portion of the pre-treated filament was mixed with 0.1 U / ml laccase and 1.5 g / L chitosan oligosaccharide solution at a liquid ratio of 20:1. The pH of the solution was adjusted to 4.5-5, sealed, and placed in a 50°C constant temperature water bath for 9 hours. After washing and drying, it was finally mixed with 0.3 g / L silver nitrate solution for in-situ deposition to obtain the antibacterial filament B.

[0013] In one possible implementation, the nylon DTY filament and the non-elastic medical-grade biodegradable silk are arranged in alternating loops at a ratio of 1:1 or 2:1.

[0014] In one possible implementation, the nylon DTY filament has a thickness range of 100-300D.

[0015] In one possible implementation, the diameter of the non-elastic medical-grade biodegradable silk ranges from 0.07 to 0.149 mm.

[0016] In one possible implementation, the tensile strength of the non-elastic medical-grade biodegradable silk ranges from 24 to 28 MPa.

[0017] In one possible implementation, the negative Poisson's ratio silk-based fabric dressing uses an 8×8 structure with positive and negative coils arranged according to a certain pattern as the smallest loop unit.

[0018] In one possible implementation, the negative Poisson's ratio silk-based fabric dressing is woven using a horizontal knitting machine with computer-controlled intelligent control and full-form knitting features.

[0019] The beneficial effects of the technical solution provided in this application include at least the following:

[0020] 1. The weaving equipment used in this application is a flat knitting machine with computer intelligent control and full-form knitting features, such as domestic computer flat knitting machines and Japanese Shima Seiki computer flat knitting machines. These are existing production equipment on the market, with mature operating technology, convenient and flexible process adjustment, and strong adjustability of product area size and specifications, making it easy to achieve cost control and customized mass production in this application.

[0021] 2. The negative Poisson's ratio of this application has a significant effect, which solves the problem of stress concentration during the stretching of the dressing during joint bending, and the effect is well maintained after repeated stretching and bending of the simulated joint.

[0022] 3. The non-elastic medical-grade biodegradable silk used in this application has excellent moisture-absorbing and water-retaining properties as the outer gauze, which can absorb wound tissue fluid and provide an ideal moist environment for wound healing. The antibacterial silk thread B, which is used as the inner gauze, is cross-linked with loaded silver nanoparticles and chitosan oligosaccharides, which gives the dressing excellent antibacterial and anti-inflammatory functions. The silk fibroin it contains can activate the NF-κB signaling pathway and regulate various cellular behaviors in the wound healing process. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the present application and form part of the specification. They are used together with the embodiments of the present application to explain the application and do not constitute a limitation thereof. In the drawings:

[0024] Figure 1 This illustration shows a structural schematic diagram of a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application;

[0025] Figure 2 This illustration shows a schematic diagram of the weave pattern of a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application;

[0026] Figure 3 A schematic diagram of the minimum loop unit coil structure of a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application is shown.

[0027] Figure 4 This illustration shows a schematic diagram of the principle of negative Poisson's ratio in the tensile deformation of a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application;

[0028] Figure 5 This illustration shows a schematic diagram of the yarn configuration of a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application;

[0029] Figure 6This paper shows a comparison of joint bending pressure of a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application under the same conditions for different tissue structures;

[0030] Figure 7 This paper shows a comparison diagram of the hygroscopic properties of the moisture-absorbing and water-retaining yarn A provided in an exemplary embodiment of this application;

[0031] Figure 8 The image shows an EDS (a) and SEM (b) image of AgNPs in situ deposited on antibacterial filament B according to an exemplary embodiment of this application. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] In this specification, identical components are represented by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, while the terms "bottom surface," "top surface," "inner," and "outer" refer to directions towards or away from a specific component, respectively. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this specification, "multiple" means two or more.

[0034] First, a brief introduction to the terms used in the embodiments of this application:

[0035] DTY: Stretch Textured Yarn is a yarn made from pre-oriented yarn that is simultaneously stretched and false-twisted on a texturing machine, causing it to undergo stretching deformation and heat setting, thus presenting a crimped yarn.

[0036] LiBr: Lithium bromide.

[0037] NF-κB signaling pathway: NF-κB is an enhancement of the K-light chain in B cells activated by nuclear factor. It is an important intracellular nuclear transcription factor that participates in the body's inflammatory response and immune response, and can regulate apoptosis and stress response. The NF-κB signaling pathway is a protein complex signal transduction pathway.

[0038] EDS: Electron Microprobe, is an instrument for analyzing the elements in a substance, often used in conjunction with a scanning electron microscope or a transmission electron microscope.

[0039] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0040] Figure 1 The diagram shows a structural schematic of a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application. The negative Poisson's ratio silk-based fabric dressing is formed into a rotating polygonal negative Poisson's ratio fabric structure by knitting the front and back needle beds in a circular pattern.

[0041] In this embodiment, the negative Poisson's ratio silk-based fabric dressing is woven using a flat knitting machine with computer-controlled intelligent operation and full-form knitting features. Optionally, the production equipment is an E14-E18 computerized flat knitting machine, and the machine size can be determined according to the fabric density and the fineness of the raw material. Computerized flat knitting machines with front and rear needle beds and a needle-turning function provided by various domestic and foreign flat knitting machine brands are all suitable, such as the Shima Seiki E18 model flat knitting machine from Japan.

[0042] Figure 2 This illustration shows a schematic diagram of the weave pattern of a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application. The negative Poisson's ratio silk-based fabric dressing uses an 8×8 structure with positive and negative coils arranged in a certain pattern as the smallest loop unit.

[0043] Figure 3 This illustration shows a schematic diagram of the minimum loop unit coil structure of a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application. The negative Poisson's ratio silk-based fabric dressing is woven from nylon DTY filament 1 with excellent abrasion resistance and non-elastic medical-grade biodegradable silk 2.

[0044] Optionally, the nylon DTY filaments are available in a fineness range of 100-300D.

[0045] Optionally, the diameter of the non-elastic medical-grade biodegradable silk ranges from 0.07 to 0.149 mm.

[0046] Optionally, the tensile strength of non-elastic medical-grade biodegradable silk ranges from 24 to 28 MPa.

[0047] Furthermore, the non-elastic medical-grade biodegradable silk 2 includes moisture-absorbing and water-retaining yarn A as the outer gauze and antibacterial yarn B as the inner gauze.

[0048] In this embodiment, moisture-absorbing and water-retaining yarn A and antibacterial yarn B are added together in the weaving process. Due to the difference in moisture absorption properties between moisture-absorbing and water-retaining yarn A and antibacterial yarn B, a tissue fluid wetting gradient is formed, and antibacterial yarn B enables the fabric to achieve antibacterial function.

[0049] Specifically, the preparation methods for moisture-absorbing and water-retaining yarn A and antibacterial yarn B include:

[0050] The silk braided thread was immersed in a 4.8M LiBr solution, swollen at room temperature for 2 hours, washed with water and dried to obtain the pre-treated silk thread.

[0051] After preliminary treatment, a portion of the yarn was placed in a 10wt% sodium acrylate solution, and then an appropriate amount of N,N'-methylenebisacrylamide and ammonium persulfate were added. The yarn was sealed and placed in a 70℃ constant temperature water bath for crosslinking for 10 hours. After thorough rinsing and drying, moisture-absorbing and water-retaining yarn A was obtained.

[0052] Another portion of the pre-treated filament was mixed with 0.1 U / ml laccase and 1.5 g / L chitosan oligosaccharide solution at a liquid ratio of 20:1. The pH of the solution was adjusted to 4.5-5, sealed, and placed in a 50°C constant temperature water bath for 9 hours. After washing and drying, it was finally mixed with 0.3 g / L silver nitrate solution for in-situ deposition to obtain antibacterial filament B.

[0053] Figure 4 This illustration shows a schematic diagram of the tensile deformation principle of a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application. The rotating polygonal negative Poisson's ratio fabric structure of the negative Poisson's ratio silk-based fabric dressing is shown in the figure: positive and negative loops are formed in a certain regular sequence, and positive and negative loop action areas are formed in the transverse direction of the fabric. When stretched, due to the presence of elastic yarns and non-elastic lines, the polygonal structure area rotates and deforms in the desired direction under unbalanced force, thereby realizing the negative Poisson's ratio effect.

[0054] Figure 5 This illustration shows a schematic diagram of the yarn configuration of a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application. Nylon DTY filaments and non-elastic medical-grade biodegradable silk are arranged in alternating rows and loops at a ratio of 1:1 or 2:1, and the woven fabrics all have a negative Poisson's ratio effect.

[0055] In this embodiment, elastic yarn (nylon DTY filament) and non-elastic yarn (non-elastic medical-grade biodegradable silk) are alternately woven, and the deformation directions are different when subjected to force, so as to assist deformation.

[0056] It is worth mentioning that in the production process of the aforementioned negative Poisson's ratio silk-based fabric dressings, parameters such as fabric area, fabric density, and machine speed must be set according to different human joint application scenarios and fabric stretching effects. Furthermore, the negative Poisson's ratio effect and tensile elongation distribution in different areas of the fabric can be adjusted based on the joint bending characteristics.

[0057] Performance testing:

[0058] Figure 6This illustration shows a comparison of joint flexure pressure under the same conditions for a negative Poisson's ratio silk-based fabric dressing provided in an exemplary embodiment of this application, with different weave structures. In this embodiment, three cross-knit fabrics with different weave structures were used, employing the same yarn raw materials, raw material configuration, and process parameters. N1 is the fabric with the designed structure of this application (negative Poisson's ratio silk-based fabric dressing), which exhibits a negative Poisson's ratio effect; S1 is a single-sided knitted plain weave fabric; and S2 is a single-sided knitted striped weave fabric. Pressure measurements were taken on the fabrics against the skin of the joint during wrist flexion, and the pressure values ​​at 45° and 90° wrist flexion were statistically analyzed. Figure 6 As shown, the fabric (negative Poisson's ratio silk-based fabric dressing) provided in this application embodiment has a lower pressure value than the other two structural fabrics that do not have a negative Poisson's ratio effect under the same test conditions and different bending angles.

[0059] Figure 7 A comparative diagram showing the hygroscopicity of a moisture-absorbing and water-retaining yarn A provided in an exemplary embodiment of this application is illustrated. In this embodiment, a hygroscopicity test was conducted on the moisture-absorbing and water-retaining yarn A, as shown... Figure 7 As shown, the moisture-absorbing and water-retaining silk thread A has better moisture absorption than the untreated raw silk thread, with a moisture absorption rate as high as 164.6%, which meets the moisture absorption needs of dressings.

[0060] Figure 8 The images show an EDS (a) and SEM (b) image of AgNPs in situ deposition on antibacterial filament B, according to an exemplary embodiment of this application. In this embodiment, characterization tests for the in-situ deposition of Ag nanoparticles on antibacterial filament B were performed, such as... Figure 8 As shown in (a), EDS elemental content determination showed that the surface content of Ag particles reached 1.63%, meeting the antibacterial function requirements of the dressing; Figure 8 (b) shows an electron micrograph of the surface of antibacterial filament B, where Ag nanoparticles are uniformly arranged on the surface of antibacterial filament B.

[0061] In summary, on the one hand, the weaving equipment used in this application is a flat knitting machine with computer intelligent control and full-form knitting characteristics, such as domestic computer flat knitting machines and Japanese Shima Seiki computer flat knitting machines. These are existing production equipment on the market, with mature operating technology, convenient and flexible process adjustments, and strong adjustability in product area and specifications, making it easy to achieve cost control and customized mass production. On the other hand, the negative Poisson's ratio effect of this application is significant, solving the problem of stress concentration during the stretching process of the joint bending dressing, and the effect is well maintained after repeated stretching and bending of simulated joints. Furthermore, the non-elastic medical-grade biodegradable silk used in this application, specifically the moisture-absorbing and water-retaining yarn A as the outer gauze, has superior moisture absorption and water retention properties, absorbing wound tissue fluid and providing an ideal moist environment for wound healing. The antibacterial yarn B as the inner gauze is cross-linked with loaded silver nanoparticles and chitosan oligosaccharides, giving the dressing excellent antibacterial and anti-inflammatory functions. The silk fibroin it contains can activate the NF-κB signaling pathway, regulating various cellular behaviors during the wound healing process.

[0062] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A negative Poisson ratio silk-based fabric dressing, characterized in that, The negative Poisson's ratio silk-based fabric dressing is formed by knitting a rotating polygonal negative Poisson's ratio fabric structure through the front and back needle beds of a flat knitting machine, and is knitted by using polyamide DTY filaments and non-elastic medical-grade degradable silk, wherein the non-elastic medical-grade degradable silk comprises moisture-absorbing and water-retaining silk threads A as face yarns and antibacterial silk threads B as lining yarns. The preparation method of the moisture-absorbing and water-retaining silk threads A and the antibacterial silk threads B comprises the following steps: The silk knitting threads are immersed in a 4.8M LiBr solution, and after swelling at room temperature for 2h, the threads are washed and dried to obtain the preliminarily treated silk threads; A part of the preliminarily treated silk threads is placed in a 10wt% sodium acrylate solution, and then an appropriate amount of N,N'-methylenebisacrylamide and ammonium persulfate are added, and the mixture is sealed and placed in a 70℃ constant-temperature water bath for crosslinking for 10h, and after being washed and dried, the moisture-absorbing and water-retaining silk threads A are obtained; Another part of the preliminarily treated silk threads is mixed with a 0.1U / ml laccase solution and a 1.5g / L chitosan oligosaccharide solution at a liquid ratio of 20:1, the solution PH is adjusted to 4.5-5, and the mixture is sealed and placed in a 50℃ constant-temperature water bath for reaction for 9h, and then washed and dried, and finally mixed with a 0.3g / L silver nitrate solution for in-situ deposition to obtain the antibacterial silk threads B.

2. The negative Poisson ratio silk-based fabric dressing of claim 1, wherein, The polyamide DTY filaments and the non-elastic medical-grade degradable silk are alternately knitted in rows at a ratio of 1:1 or 2:

1.

3. The negative Poisson Ratio silk-based fabric dressing of claim 1, wherein, The polyamide DTY filaments have a fineness range of 100-300D.

4. The negative Poisson Ratio silk-based fabric dressing of claim 1, wherein, The non-elastic medical-grade degradable silk has a diameter range of 0.07-0.149mm.

5. The negative Poisson Ratio silk-based fabric dressing of claim 1, wherein, The non-elastic medical-grade degradable silk has a tensile strength range of 24-28MPa.

6. The negative Poisson Ratio silk-based fabric dressing of claim 1, wherein, The negative Poisson's ratio silk-based fabric dressing selects an 8*8 structure organization formed by regular positive and negative loops as the smallest cycle unit.

7. The negative Poisson's ratio silk-based fabric dressing according to any one of claims 1 to 6, which is knitted by using a flat knitting machine with computerized intelligent control and full-forming knitting characteristics.

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