CN220938291U - A kind of silk nonwoven medical dressing - Google Patents

Abstract

The utility model discloses a silk non-woven medical dressing, comprising a release layer, a core layer and an adhesive tape layer laminated from top to bottom, wherein the core layer is a silk non-woven fabric, and the release layer is an adhesive tape, which is used to cover and protect the core layer. The multifunctionality of the silk non-woven medical dressing of the utility model is caused by the multiple advantages of silk. In fact, the structure is simple, and the release layer, the core layer, the adhesive layer and the adhesive tape layer are composited. The core layer does not need to be compositely punctured with hemostatic materials, moisturizing materials, wound healing materials, antioxidant components and antibacterial components, and does not need to be designed with air holes. The manufacturing process is simple and the price is low.

Description

A kind of silk nonwoven medical dressing

Technical Field

The utility model relates to the medical field, in particular to a medical dressing, and in particular to a silk non-woven fabric medical dressing.

Background technique

Injuries accompanied by bleeding occur in quite a few cases. In general, bleeding from minor wounds can be solved by the body's own coagulation function and some simple care measures. When the wound and bleeding are minor, the blood coagulation function is normal, and simple first aid using a hemostatic patch can solve the problem. In daily life and work, minor trauma often occurs, which requires hemostatic bandages to avoid excessive blood loss, affected wound healing, and infection. Common Band-Aid benzalkonium chloride patches, Yunnan Baiyao, and furazolidone bandages have similar basic functions. The main ingredients are disinfectant dressings and bactericidal components. The dressings have limited hemostatic effects, and poor air permeability and wound healing.

Minimally invasive surgical wounds and venous puncture sites in clinical practice also often require hemostasis care. Minimally invasive surgical wound hemostasis care requires hemostasis and anti-inflammation, keeping the wound environment moist and healing, etc. The commonly used medicated degreased gauze is applied or embedded in the wound, which cannot meet these requirements well. In clinical practice, the puncture site should be hemostatic immediately after venous puncture. When the hemostasis effect is not good, infection or subcutaneous bleeding/hematoma will occur. At present, the traditional method of sticking an infusion patch on the venous puncture site to stop bleeding is still used. The structure of the infusion patch is simply a thin cotton piece in the middle of the tape, which needs to be pressed to stop bleeding, but the accurate pressing time is not easy to grasp, and the hemostasis effect cannot be guaranteed. In particular, arteriovenous fistula is a commonly used vascular access for patients undergoing maintenance hemodialysis. The maintenance of the fistula is extremely important for patients undergoing frequent dialysis. Correct compression of the hemostatic point is an important part of protecting the fistula. The hemostatic method uses a ball of sterile gauze to press the bleeding point, and then fix it with a bandage or adhesive tape. Improper pressure may cause subcutaneous hematoma, external bleeding or damage to blood vessels, and even cause fistula occlusion. The appropriate pressure standard is that it can both stop bleeding and feel blood vessel vibration. The pressure should be loosened in the middle, which is inconvenient to operate.

Silk is the thinnest and softest natural fiber, which is comfortable to the skin. It is mainly composed of sericin and fibroin, and has the advantages of moisture absorption, breathability, softness, very strong antibacterial properties, flame retardancy, UV resistance, oxidation resistance and good extensibility. The most special function of mulberry silk is that wounds and skin inflammations can be directly bandaged with mulberry silk, which can accelerate wound healing. The hygroscopicity of silk fiber comes from its specific composition and structure. The composition of many hydrophilic polar groups and the internal porosity of up to about 30% make silk fiber have the ability to absorb moisture in the air. On the contrary, wet silk fiber releases moisture in dry air. Since the amino acids in the polar side chains of sericin account for 74.61%, its moisture absorption and release properties are better than fibroin.

Wettability refers to the ability of a liquid to wet a solid surface, which is measured by the static contact angle θ. If the static contact angle of a droplet on the surface of a solid material is 90° to 180°, we call the surface of the material a hydrophobic surface; when the static contact angle of a droplet on the surface of a solid material is greater than 150°, we call the surface of the material a super-hydrophobic surface. There are four models for hydrophobicity: Young’s equation is applicable to ideal smooth and uniform surfaces. The Wenzel model only considers the situation where the grooves on the rough surface are filled with liquid, in which case the liquid is in contact with only one medium. In fact, the liquid is not only in contact with one medium. Therefore, Cassie and Baxter made relevant supplements to the Wenzel theory and proposed the Cassie-Baxter model, in which the liquid is in composite contact with two interfaces, the solid surface and the air; there is also a Wenzel and Cassie coexistence model. The researchers discovered the reason for the super-hydrophobic surface: low surface energy substances and rough structures exist on the surface at the same time, such as the "lotus effect" is a composite structure composed of waxy substances with very low surface energy and micro- and nano-structures. The preparation of super-hydrophobic surface on the material can be mainly done by forming a rough structure on the surface of the material, and then modifying it with low surface energy materials or directly constructing a rough structure on the surface of the material with low surface energy. People require the functional requirements of fabrics to have waterproof function, antibacterial function, self-cleaning function, anti-ultraviolet function, etc. Super-hydrophobic fabrics can be widely used in fields such as waterproof cloth and medical fabrics due to their excellent waterproof, anti-adhesive and self-cleaning properties. After the fabric is steam ironed at 200°C, due to the high temperature, the hydrophobic grafted chain segments migrate from the inside of the fiber to the surface of the fiber, so that the super-hydrophobicity of the cotton fabric is enhanced. Some methods for preparing super-hydrophobic fabrics have complex processes, harsh industrial conditions, and high preparation costs; some have certain hazards to the environment, some have insufficient mechanical stability, are prone to aging and failure, are not practical, and cannot be mass-produced industrially.

The natural flame resistance prevents the flame from spreading on the fabric, and the UV protection function of mulberry silk avoids skin damage. Non-woven medical accessories are highly absorbent, non-bacterial, non-irritating, non-mildew, and do not contain fluorescent agents. They are pioneer products with many advantages. They are safe and reliable for human contact, non-toxic and side effects, non-irritating, non-allergenic, and environmentally friendly. The preparation methods of non-woven fabrics include needle punching, spunlace, meltblowing, and spunbonding. However, there are many disadvantages of medical non-woven fabrics on the market, including single function, poor breathability, inability to absorb exudate, insufficient uniformity, poor portability, and promotion of wound infection.

In summary, it is necessary to develop a non-woven dressing that has multiple functions such as hemostasis, moisturizing, promoting wound healing and antibacterial, and has the advantages of good breathability and self-applying. Silk has many advantages and is expected to be used to prepare a medical non-woven dressing that can achieve multiple functions.

Summary of the invention

In view of the technical problems existing in the prior art, the present application provides a silk non-woven medical dressing.

A silk nonwoven medical dressing comprises a release layer, a core layer and an adhesive tape layer which are laminated and composited from top to bottom. The core layer is a silk nonwoven fabric, and the release layer is an adhesive tape, which is used for covering and protecting the core layer.

Preferably, an adhesive layer is provided between the core layer and the adhesive tape layer.

Preferably, the adhesive layer is medical pressure-sensitive adhesive, zinc oxide-coated hot melt adhesive or acrylic adhesive.

Preferably, the release layer is adhered to the adhesive tape layer by a pressure-sensitive adhesive to cover the core coating layer.

Preferably, an opening for tearing is provided at the edge or the middle of the release layer, so as to tear open the release layer to expose the core coating layer.

Preferably, the adhesive tape layer is a medical nonwoven plain cloth or a medical nonwoven elastic cloth.

Preferably, the release layer and the adhesive tape layer are rectangular, square or circular with the same size.

Preferably, the length and width or circular diameter of the release layer and the adhesive tape layer are greater than the size or diameter of the core coating layer.

The following is a further detailed description of this application:

The purpose of the present application is to solve the deficiencies of existing products and to provide a silk non-woven medical dressing which has multiple functions, is breathable and comfortable, has a simple structure, is easy to use and easy to store.

The present invention reduces the hydrophilic sericin content and increases the hydrophobic silk fibroin content, and also causes the hydrophobic component to migrate to the fiber surface through high temperature treatment. The rough and porous surface of the non-woven fabric improves the hydrophobic structure.

The technical solution adopted in this application is: a multifunctional silk non-woven medical dressing, which includes a laminated composite release layer, a core layer, an adhesive layer and a tape layer from top to bottom. The core layer is a silk non-woven fabric mesh layer. The silk is treated at high temperature and then made by needle punching or hydroentanglement.

The present application discloses a multifunctional silk non-woven medical dressing, which includes a laminated composite release layer, a core layer, an adhesive layer and a tape layer from top to bottom. The core layer is a silk non-woven fiber mesh layer, in which the silk is subjected to high-temperature physical treatment and then made by acupuncture or spunlace. Because of the excellent properties of silk such as hygroscopicity, promotion of wound healing, anti-oxidation, antibacterial and breathability, the core layer does not need to be formed by a composite acupuncture of hemostatic materials, moisturizing materials, wound healing materials, antioxidant components and antibacterial components, and does not need to be designed with air holes. The manufacturing process is simple and the price is low. Also, because silk is heat-resistant, flame-resistant and UV-resistant, the medical dressing has the advantages of high stability, easy storage and carrying. The medical dressing has multiple functions such as hemostasis, moisturizing, promotion of wound healing and antibacterial; it also has the advantages of good breathability and the edge is not easy to curl, so the patient can change the wound by himself, which is more convenient.

A multifunctional silk nonwoven medical dressing, the nonwoven fabric comprises a laminated composite release layer, a core layer, an adhesive layer and a tape layer, the core layer is a silk nonwoven web layer, the silk is treated at high temperature to obtain a silk nonwoven blank, which is then made by needle punching or hydroentanglement.

As a further improvement scheme, the core layer is a silk non-woven fabric web layer. The silk is subjected to high-temperature physical treatment to obtain a silk non-woven fabric blank, which is then made by a needle punching method.

The acupuncture preparation method comprises the following steps:

(1) Blank material: The silk cocoons are boiled, reeled, refined and processed, during which glutaraldehyde can be used to cross-link and fix sericin to reduce the loss of sericin in the refining process. After being made into a silk quilt, it is cut into short cloths of a certain length and width, and subjected to physical treatment to improve hydrophobicity, such as high-temperature baking at 200°C to 230°C (0.5 hour to 2 hours), to obtain a silk non-woven fabric blank;

(2) Opening: The nonwoven fabric blank is first manually torn and opened, and then placed in an opening machine for opening pretreatment, and fiber impurities are removed during opening;

(3) Combing: The opened fibers are transported to a single-cylinder double-doffer carding machine to be combed into a fiber web. In order to reduce the unevenness of the fiber web and improve the quality, a double-doffer configuration is used to form two layers of fiber web, which are finally superimposed together to form a slightly thicker fiber web;

(4) Laying the web: Cross-laying is adopted. The thin fiber web output by the carding machine passes through the oblique curtain to the top horizontal curtain, and then enters the clamping curtain, swinging back and forth to form a fiber web of a certain thickness. The thickness of the cloth can be accurately controlled by controlling the number of laying layers;

(5) Acupuncture: Use a needle with a triangular cross-section (or other shape) and hooked edges in a needle punching machine to repeatedly needle the fluffy fiber web to strengthen it into a whole, forming a needle-punched nonwoven fabric.

As a further improvement, the core layer is a silk non-woven fabric web layer, and the silk is physically treated at high temperature to improve its hydrophobicity and then made by a water-entanglement method.

The spunlace preparation method comprises the following steps:

(1) Blank material: The silk cocoons are boiled, reeled, refined and processed, during which glutaraldehyde can be used to cross-link and fix sericin to reduce the loss of sericin in the refining process. After being made into a silk quilt, it is cut into short cloths of a certain length and width, and subjected to a physical treatment to improve hydrophobicity at a high temperature of 200° C. to 230° C. for 0.5 hour to 2 hours to obtain a silk non-woven fabric blank;

(2) Modification (optional): Because physical treatments such as high temperature treatment will cause the sericin in silk to denature and reduce its hydrophilicity, the silk non-woven fabric blank can be treated with hydrophilic modification to partially restore its hydrophilicity and achieve better initial wound adhesion. Hydrophilic treatment methods include plasma, ultrasound, microwave, lauryl alcohol, hydrogen peroxide, baking soda, edible alkali and edible salt;

(3) Opening: The nonwoven fabric blank is first manually torn and opened, and then placed in an opening machine for opening pretreatment, and fiber impurities are removed during opening;

(4) The hydrophilically modified or unmodified silk non-woven fabric blank is subjected to opening and combing, cross-laying, hydroentanglement, oven drying and winding and storage to obtain the non-woven fabric.

As a further improvement, the release layer is a protective layer for protecting the core coating layer.

As a further improvement, the release layer is bonded to the adhesive tape layer through the pressure-sensitive adhesive and covers the core coating layer.

As a further improvement, an opening for tearing is provided at the edge or in the middle of the release layer, so as to tear open the core layer for covering the wound.

As a further improvement, the core layer near the adhesive tape is coated with medical pressure-sensitive adhesive/zinc oxide hot melt adhesive/acrylic adhesive for bonding to the adhesive tape. Alternatively, a hot pressing roller can be used to heat-press the silk nonwoven fabric and the adhesive tape.

As a further improvement scheme, the adhesive layer on the adhesive tape is medical pressure-sensitive adhesive/zinc oxide-coated hot melt adhesive/acrylic adhesive.

As a further improvement, the adhesive tape layer is a medical nonwoven plain fabric or a medical nonwoven elastic fabric.

As a further improvement, the release layer and the adhesive tape layer are rectangular, square or circular with the same size.

As a further improvement, the length and width or circular diameter of the release layer and adhesive tape layer are greater than the size or diameter of the dressing layer.

As a further improvement, the medical dressing can be used for stopping bleeding in small amounts in daily life and work, stopping bleeding in minimally invasive surgical wounds, stopping bleeding at puncture points after venous puncture, preventing bleeding at arteriovenous fistula sites in hemodialysis patients with renal failure, and providing health care pads.

The specific plan is further elaborated next.

The core layer is a silk non-woven fabric web layer. The silk is treated at high temperature and then made by needle punching, spunlace or other non-woven fabric preparation methods. The needle punching preparation method includes the following steps:

(1) Blank material: The silk cocoons are boiled, reeled, refined and processed, during which glutaraldehyde can be used to cross-link and fix sericin to reduce the loss of sericin in the refining process. After being made into a silk quilt, it is cut into short cloths of a certain length and width, and subjected to a physical treatment to improve the hydrophobicity, such as high temperature treatment at 200° C. to 230° C. (0.5 hour to 2 hours), to obtain a silk non-woven fabric blank;

(2) Opening: The nonwoven fabric blank is first manually torn and opened, and then placed in an opening machine for opening pretreatment, and fiber impurities are removed during opening;

(3) Combing: The opened fibers are transported to a single-cylinder double-doffer carding machine to be combed into a fiber web. In order to reduce the unevenness of the fiber web and improve the quality, a double-doffer configuration is used to form two layers of fiber web, which are finally superimposed together to form a slightly thicker fiber web;

(4) Laying the web: Cross-laying is adopted. The thin fiber web output by the carding machine passes through the oblique curtain to the top horizontal curtain, and then enters the clamping curtain, swinging back and forth to form a fiber web of a certain thickness. The thickness of the cloth can be accurately controlled by controlling the number of laying layers;

(5) Acupuncture: Use a needle with a triangular cross-section (or other shape) and hooked edges in a needle punching machine to repeatedly needle the fluffy fiber web to strengthen it into a whole, forming a needle-punched nonwoven fabric.

The release layer is a protective layer for protecting the core layer, which is bonded to the tape through the pressure-sensitive adhesive and covers the core layer. An opening for tearing is provided at the edge or in the middle of the release layer, which is used to tear open the core layer covering the wound. The release layer serves to isolate the adhesive of the tape layer before the product is used, thereby ensuring the stickiness of the tape layer.

The core layer near the tape is coated with medical pressure-sensitive adhesive/zinc oxide hot melt adhesive/acrylic adhesive for bonding to the tape. Alternatively, a hot pressing roller can be used to heat-press the silk non-woven fabric and the tape, which is efficient and environmentally friendly.

The adhesive tape layer is a medical nonwoven plain cloth or a medical nonwoven elastic cloth; the adhesive layer on the adhesive tape is a medical pressure-sensitive adhesive/zinc oxide-coated hot melt adhesive/acrylic adhesive.

The release layer and the adhesive tape layer are rectangular, square or circular with the same size; the length and width or circular diameter of the release layer and the adhesive tape layer are larger than the size or diameter of the dressing layer.

This application has the following advantages:

(1) The multifunctionality of the silk nonwoven medical dressing of the present application is caused by the multiple advantages of silk. In fact, the structure is simple, and it is composed of a release layer, a core layer, an adhesive layer and a tape layer. The core layer does not need to be formed by a compound needle puncture of hemostatic materials, moisturizing materials, wound healing materials, antioxidant components and antibacterial components, nor does it need to be designed with ventilation holes. The manufacturing process is simple and the price is low.

(2) Because silk is heat-resistant, flame-resistant, and UV-resistant, the medical dressing has the advantages of high stability and easy storage and carrying.

(3) The medical dressing has multiple functions such as hemostasis, moisturizing, promoting wound healing and antibacterial. It also has the advantages of good air permeability and not prone to curling at the edges. Patients can change the dressing on the wound by themselves, which is relatively convenient.

(4) The medical dressing of the present application has a wide range of uses and can be used to stop bleeding in small amounts in daily life and work, stop bleeding in minimally invasive surgical wounds, stop bleeding at puncture points after venous puncture, prevent bleeding at the arteriovenous fistula site of hemodialysis patients with renal failure, and provide health care pads, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly describe the technical solution of the present application, a brief introduction will be given below in conjunction with the accompanying drawings. Obviously, these drawings are only some specific implementation methods recorded in this application. The present invention includes but is not limited to these drawings.

FIG1 is a schematic structural diagram of a medical dressing according to Example 1;

FIG2 is the contact angle of the core layer silk nonwoven fabric of Example 2;

FIG3 is a scanning electron microscope image of the core-layer silk nonwoven fabric of Example 3;

FIG4 is the ignition residue of the core-layer silk nonwoven fabric of Example 4;

FIG5 is a graph showing the in vitro cytotoxicity of the extract of the core layer silk nonwoven fabric of Example 8;

FIG6 shows the hemostatic effect of the core layer silk nonwoven fabric of Example 11 in a mouse femoral artery bleeding model.

Detailed ways

In order to further understand the present invention, the exemplary scheme of the present invention will be described below in conjunction with the embodiments. These descriptions are only examples of some features and advantages of the silk nonwoven medical dressing of the present invention, and do not limit the protection scope of the present invention.

Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

The following is a detailed description of the silk nonwoven medical dressing of the present application in conjunction with the accompanying drawings:

A silk nonwoven medical dressing comprises a release layer 1, a core layer 2 and a tape layer 3 which are laminated from top to bottom. The core layer 2 is a silk nonwoven fabric (i.e., a silk nonwoven fabric web layer), and the release layer 1 is a tape used to cover and protect the core layer 2. The tape is made of a medical nonwoven fabric (or a medical nonwoven elastic fabric). An adhesive layer is also provided between the core layer 2 and the tape layer 3. The adhesive layer is a medical pressure-sensitive adhesive (or a zinc oxide-coated hot melt adhesive or an acrylic adhesive). The core layer 2 is fixed to the tape layer 3 through the adhesive layer. The tape layer 3 is made of a medical nonwoven fabric (or a medical nonwoven elastic fabric). The release layer 1 and the tape layer 3 are of the same size and are larger than the size of the core layer 2. The release layer 1 is bonded to the tape layer 3 by a pressure-sensitive adhesive to cover the core layer 2. The edge of the release layer 1 (or it can also be arranged in the middle) is provided with an opening 11 for tearing, so as to tear it open to expose the core layer 2.

Preferably, the release layer 1 and the adhesive tape layer 3 are rectangular, square or circular with the same size.

Example 1

Preparation of silk nonwoven core layer for medical dressing

Silk non-woven fabrics use the puncture action of the needles of the needle loom to entangle the fibers in the silk web, thus forming a core layer of silk non-woven fabrics. The preparation process is to open, comb and reinforce the short fibers with needles in sequence. In the needling process, the number of needling times, needling depth, needling density, needle model and needle arrangement are the main factors affecting the fluffiness and thickness of the finished product. Examples of needling machine parameters: needling frequency 800 punctures/minute, needle density 2200 needles/meter, needling depth 5mm. The present invention is not limited to this parameter.

Results A fluffy and thin silk nonwoven core layer was successfully prepared, which is suitable for preparing medical dressings.

Example 2 Determination of hydrophobicity of core layer silk nonwoven fabric

The contact angle was measured using an optical contact angle meter (OCA 50AF, DataPhysics Instruments GmbH, Germany). The contact angle measured in Figure 2 (left) is nearly 150°. It is known that a contact angle greater than 90° indicates hydrophobicity, indicating that the core layer silk non-woven fabric is hydrophobic; the contact angle of cotton in Figure 2 (right) is 0°, indicating that cotton is super hydrophilic.

Example 3 Scanning electron microscopy observation of core layer silk nonwoven fabric

The nonwoven fabric was photographed under a scanning electron microscope (see Figure 3 for the results), and the fiber diameter of the scanning electron microscope photograph was measured using Image J, which was about 10 μm.

Example 4 Ignition residue of core layer silk nonwoven fabric

The ignition residue of the core layer silk non-woven fabric is determined according to the ignition residue test method of 0800 "Limited Inspection Method" - 0841 in the fourth part of the Pharmacopoeia. Take 1.0-2.0g of the test sample or the weight specified under each variety, put it in a crucible that has been ignited to constant weight, accurately weigh it, slowly ignite it until it is completely carbonized, and cool it; ignite it at 700-800℃ to constant weight. The results are shown in Figure 4. The ignition residue of the silk non-woven fabric is greater than that of the silk raw material, and both are less than 1%.

Example 5 Drying weight loss of core layer silk nonwoven fabric

The drying loss of the core layer silk non-woven fabric is determined according to the Pharmacopoeia Part IV General Chapter 0800 "Limited Inspection Method" - 0831 Drying loss determination method. Take the test sample, mix it evenly, take about 1g or the weight specified under each variety, put it in a flat weighing bottle dried to constant weight under the same conditions as the test sample, accurately weigh it, and dry it at 105℃ to constant weight unless otherwise specified. Calculate the drying loss of the test sample from the lost weight and the sample amount. Result: The drying loss of the non-woven fabric is 0.25%.

Example 6 Heavy Metal Content of Core Layer Silk Nonwoven Fabric

The contents of heavy metal elements chromium (Cr), arsenic (As), cadmium (Cd), lead (Pb) and mercury (Hg) were determined according to the general rules of quadrupole inductively coupled plasma mass spectrometry method GB/T 37837-2019. The main equipment used were Perkin Elmer Nex ION300X ICP-MS and Shanghai Yiyao TOPEX microwave digestion instrument. Determination method: The online internal standard method was adopted, and the test solution was mixed with the mixed internal standard solution and then entered into the ICP-MS instrument. During the determination, the isotopes of ⁵² Cr, ⁶³ Cu, and ⁷⁵ As were selected with ⁷⁴ Ge as the internal standard; ¹¹¹ Cd was selected with ¹¹⁵ In as the internal standard; ²⁰² Hg and ²⁰⁸ Pb were selected with ²⁰⁹ Bi as the internal standard. The series of mixed standard solutions, blank solutions and test solutions were analyzed respectively, and the standard curve method was used for quantification.

Results showed that the contents of the five heavy metals were all less than 1 mg/kg. Taking Cr in the international element IHE standard "ICH Harmonised Guideline, 16 December 2014" as an example, parenteral exposure was 1.07 mg/day, and calculated based on the use of no more than 10g of hemostatic material each time, the five heavy metals did not exceed the standard.

Example 7 Antibacterial test of core layer silk nonwoven fabric

Before the test, a 1×1cm 1mm thick silk nonwoven fabric sample was taken and placed in each well of a 24-well plate. After UV irradiation for 1h, a bacterial suspension (10μL, 10 ⁸ CFUs/mL bacteria) was dripped onto the surface of the material. After culturing at 37℃ for 2h, 1000μL of sterile PBS was added to each well to resuspend the surviving bacteria. 20μL of the resuspended bacterial solution was taken out and diluted 100 times to obtain the final diluted bacterial solution. 20μL of the diluted bacterial solution was spread on the surface of the LB agar plate and cultured at 37℃. After overnight culture, the CFUs formed on each LB agar plate were counted. The results showed that the silk nonwoven fabric had a significant bactericidal effect on Escherichia coli (ATCC25922), but had no bactericidal effect on Staphylococcus aureus (ATCC29213).

Example 8 In vitro cytotoxicity test of silk nonwoven fabric

In vitro cytotoxicity was tested with L929 cells according to GBT16886.5. The results in Figure 6 show that the in vitro toxicity of the 100% extract of the 1mm thick No. 2 needle-punched non-woven fabric (X2) for 24 hours to L929 cells for 24 hours was a grade I reaction, and the non-woven raw material was a grade 1 reaction, both of which were qualified; the relative growth rate (RGR) of the positive control (0.3% phenol) was a grade II reaction, which was moderate to severe cytotoxicity; the 24h 100% extract of the positive hemostatic material of the Johnson Speed Yarn was added to the culture medium, and it immediately became yellow and turbid, and no adherent cells were seen under the microscope. The RGR of the intervention of L929 for 24 hours was a grade III reaction, which was moderate to severe cytotoxicity. Comprehensive comparison, the in vitro cytotoxicity test evaluation results of the powdered and needle-punched non-woven fabric JCJ showed that its safety was safer than the commercially available Johnson Speed Yarn.

Example 9

Skin irritation test of silk nonwoven fabrics

Carry out skin irritation test in accordance with GB/T 16886.10.

SD rats weighing 200-250 g with healthy skin and no damage were selected as test animals (female), and were allowed to drink water and eat freely. The experiment began after being raised in an SPF environment for one week.

The experimental site was the back of the rats, which were divided into an experimental group and a control group, with 5 animals in each group. The experimental group used the prepared extract supernatant, and the control group used normal saline. Two groups of experiments were conducted simultaneously on each test animal, namely the experimental group and the control group, with two test material areas and two blank control material areas respectively.

24 hours before the test, remove the hair of the animal's back spine in an area of about 8cm×8cm on both sides as the test and observation area. In order to facilitate observation, it may be necessary to remove the hair repeatedly.

The prepared extract was dripped onto a 4-layer medical gauze piece of 2.5 cm × 2.5 cm in size. The amount of extract used should be sufficient to soak the gauze piece. Generally, 0.5 mL was dripped onto each gauze piece and applied to both sides of the back of the test animal. Sterile saline was dripped onto a gauze piece of the same size and applied to the control contact area.

Cover with a layer of weighing paper, fix with adhesive tape, and then fix with a bandage (semi-occlusive or occlusive) for 4 hours. Remove the patch, mark the contact area with permanent ink, and remove the residual test material (such as washing with warm water or other suitable non-irritating solvents and carefully drying).

Observe the skin erythema and edema of the animal test area for 24 hours, record the conditions of each contact site, and score the skin erythema and edema according to Table (Skin Reaction Classification Scoring Standard).

Table 1 Skin reaction scoring table

Erythema and crusting reactions Edema reaction Scoring none No edema 0 Very mild erythema Very slight 1 Clear erythema Clear (raised, not beyond the edge of the area) 2 Moderate erythema Moderate (raised, about 1mm) 3 Severe erythema to eschar formation Severe (the bulge is greater than 1 mm and exceeds the contact range) 4

The results showed that except for the 10% SDS positive control site, which was scored 1-4 points according to Table 1, the skin reaction scores of other sites treated with cloth and saline were all 0 points, indicating that the biosafety of the charred cocoon material extract was relatively high.

Example 10

Guinea pig sensitization test of silk nonwoven fabrics

The skin sensitization test was carried out in accordance with GB/T 16886.10. The closed patch test (Buehler) of GBT 16886.10-2017 was used. The experimental group was the silk non-woven fabric extract, the negative control group was saline, and the positive control group was 0.5% 2,4-dinitrochlorobenzene solution prepared with ethanol. The experiment was divided into two stages: induction stage (7 days + 14 days) and stimulation stage (6 hours). Preparation stage: a) Before the start of the experiment, completely cut or remove the hair of all test parts of the animal; b) For local application, soak a three-layer absorbent gauze block (2.5cm×2.5cm) with the test sample, apply it to the hair removal part of the animal, and then fix it with a closed bandage for (6±0.5)h; c) For local application, apply appropriate filter paper or gauze to the hair removal skin, and then wrap the animal trunk with a closed bandage to fix it. Main test: (1) Three-week induction stage. 24 hours before the experiment, prepare the hair of the 3×3cm area on the upper left back of the guinea pig as the test site; before the experiment, use 70% ethanol to clean the test area, and place three layers of absorbent gauze (2.5cm×2.5cm) soaked with the test sample; repeat this step for 3 consecutive days in 1 week, and operate in the same way for 3 weeks. (2) Provocation phase. (14±1) days after the last induction patch, apply the corresponding solution to the untested area of each animal, and apply the patch, cover it with a layer of weighing paper, and fix it with adhesive tape; remove the bandage and patch after (6±0.5) hours, mark the contact area with permanent ink, and remove the residual test material; remove the provocation patch 24h and 48h, and score according to the grading standard given in Table 1 (skin reaction classification scoring standard), and observe the erythema and edema of the provocation site of the experimental animals.

According to the standards in Table 1 and Table 2, the scoring and grading were performed, and the results of the sensitization evaluation of guinea pigs are shown in Table 3. 24 hours after the stimulation, the tested parts of the animals in the positive control group showed different degrees of erythema and edema, and the sensitization degree reached 100%. According to the Mafhusson sensitization reaction grading standard, the sensitization reaction of the positive control group was grade V, indicating that 0.5% 2,4-dinitrochlorobenzene solution (DNCB) had a strong sensitization effect on guinea pigs under this experimental condition. No significant erythema or edema was found in the skin of the negative control group and the leaching liquid group. There was no significant difference between the experimental group and the negative control group, and the score was 0, indicating no sensitization effect.

Table 2 Mafhusson sensitization grading standard

Sensitization rate (%) Grading Classification 0-8 Ⅰ No difference from negative control 9-28 Ⅱ Mild reaction 29-64 III Moderate reaction 65-80 IV Strong reaction 81-100 Ⅴ Very strong reaction

Table 3 Guinea pig sensitization evaluation results

Embodiment 11

Hemostasis test of silk nonwoven fabric in mouse femoral artery bleeding model

The results of the hemostasis test in the mouse femoral artery bleeding model showed (Figure 6) that the hemostasis time of the silk non-woven fabric (X3) was equivalent to that of the strong speed yarn (Q), about 40s, and the hemostasis time of the burnt ash cocoon (H) was slightly higher than that of the strong speed yarn, but there was no significant difference. The hemostasis time of the non-woven fabric was significantly shorter than that of the raw material (X0, about 60s).

The embodiments described in the above specification are only some embodiments of the present invention. Without departing from the protection concept and scope of the present invention, various changes and improvements based on the present invention fall within the scope of the present invention to be protected.

Claims (7)

1. A silk nonwoven medical dressing, characterized in that it comprises a release layer, a core layer and an adhesive tape layer laminated from top to bottom, wherein the core layer is a silk nonwoven fabric, the release layer is an adhesive tape, and is used to cover and protect the core layer, and the silk nonwoven fabric is short fibers, which are sequentially opened, combed and needle-punched for reinforcement; The edge of the release layer is provided with an opening for tearing, so as to tear open the core coating layer. 2. A silk non-woven medical dressing according to claim 1, characterized in that an adhesive layer is provided between the core layer and the adhesive tape layer. 3. A silk nonwoven medical dressing according to claim 2, characterized in that the adhesive layer is medical pressure-sensitive adhesive, zinc oxide-coated hot melt adhesive or acrylic adhesive. 4. A silk nonwoven medical dressing according to claim 1, characterized in that: the release layer is bonded to the adhesive tape layer by a pressure-sensitive adhesive to cover the core dressing layer. 5. A silk nonwoven medical dressing according to claim 1, characterized in that the adhesive tape layer is a medical nonwoven plain cloth or a medical nonwoven elastic cloth. 6. A silk nonwoven medical dressing according to any one of claims 1 to 5, characterized in that the release layer and the adhesive tape layer are rectangular, square or circular with the same size. 7. A silk nonwoven medical patch according to any one of claims 1-5, characterized in that the length and width or circular diameter of the release layer and the adhesive tape layer are greater than the size or diameter of the core layer.