An antibacterial dressing suitable for wound assessment and treatment of deep infection in hot and humid environments

Abstract

The present invention relates to the field of medical dressing materials, and specifically to an antibacterial dressing suitable for the assessment and treatment of deep infected wounds in a hot and humid environment and its application. The antibacterial dressing of the present invention uses multifunctional carbon nanomaterial graphene oxide to prepare an anti-inflammatory and bactericidal layer nanofiber membrane, which has strong antibacterial ability, no bacterial resistance, and stable antibacterial effect. The exudate adsorption and detumescence layer is prepared by mixing five external detumescence and anti-inflammatory Chinese medicines, which has strong adsorption capacity and has obvious swelling reduction and anti-inflammatory effects. The wound infection indicator layer can continuously assess the infection degree of the wound. The functions of each layer are independent of each other, but they work together with each other, which can not only accelerate the process of inhibiting infection, but also synergistically increase the efficacy of anti-inflammatory and detumescence, and can also evaluate the anti-infection effect of sterilization and drainage in real time, and determine the next dressing change strategy, which has broad clinical application prospects.

Description

Technical Field

[0001] The invention relates to the field of medical dressing materials, and in particular to an antibacterial dressing suitable for assessing and treating deep infected wounds in a hot and humid environment. Background Art

[0002] For personnel working in hot and humid environments such as jungles, mountains and islands, once a body surface injury occurs, if it is not treated in time, wound infection is likely to occur. However, there is a lack of formal medical institutions for treating infected wounds in the wild environment. Therefore, there is an urgent need to develop an antibacterial dressing suitable for hot and humid environments.

[0003] For infected wounds, controlling the growth and spread of bacteria is the key to promoting healing. Antibiotics are the most commonly used anti-infection treatment, but bacteria have strong reproductive capacity in a hot and humid environment. Antibiotic treatment sometimes cannot completely cure the wound and is prone to drug resistance. Therefore, it is very important to use dressings made of high-tech anti-infection materials.

[0004] High temperature and high humidity environment can accelerate bacterial reproduction, while inhibiting the body's own resistance, increasing oxygen consumption, and vigorous energy metabolism, which speeds up the inactivation of wound tissue. Necrotic tissue can produce a large amount of exudate, which not only becomes a good bacterial culture medium, but also delays wound healing. Especially in a hot and humid environment, the ability of normal dressings to absorb exudate is weakened, and it is necessary to develop dressings that keep the wound locally cool and have continuous strong adsorption capacity.

[0005] At present, the application of nanomaterials in antibacterial applications has received increasing attention. Graphene is a kind of carbon atom in the form of sp 2 The emerging two-dimensional multifunctional carbon nanomaterial composed of hexagonal honeycomb lattices composed of hybrid orbitals has strong antibacterial ability, a wide antibacterial spectrum, no drug resistance, simple preparation process, good biocompatibility, and has shown great application value in the field of medical antibacterial. Its antibacterial mechanism includes four aspects: ① Physical killing: Graphene can "capture bacteria" by wrapping, isolate them from the surrounding medium, and then "cut" and destroy the cell wall and membrane structure through its sharp physical edges, leading to their death; ② Chemical destruction: Graphene materials have a large specific surface area and hydrophobicity, which can bind or adsorb phospholipid molecules on the surface of bacterial cell membranes to destroy the cell membrane, and can also destroy the cell membrane structure through oxidative stress; ③ Charge conduction: Graphene can conduct the surface charge of bacteria, causing the physiological activities and metabolic functions of the cell membrane to be disordered, and promoting cell death; ④ Photothermal / photodynamic effect: that is, when graphene-based materials are combined with light, their excellent photocatalytic activity is used to generate active oxygen free radicals and release heat locally in the bacteria, achieving photodynamic and photothermal sterilization effects. Among them, the property of converting light into bactericidal activity in mechanism ④ is more suitable for treating infected wounds in hot and humid environments in the wild.

[0006] After the wound is infected, the ammonia produced by bacterial decomposition and metabolism will increase the local pH value, so the pH value of the exudate is one of the important indicators for judging local infection. As the wound improves, the pH value tends to decrease. The pH of human skin is between 4.5-6.5, while pathogenic bacteria can increase the pH to between 7.2-7.4. The judgment of pH can be made clear by the color of the acid-base test paper.

[0007] In addition to delayed healing, the most prominent manifestations of wound infection are more local exudate and increased skin temperature. The local environment of high temperature and high humidity provides a favorable environment and conditions for bacterial reproduction and growth. Many Chinese herbal medicines have the functions of clearing away heat and swelling, softening and dispersing nodules, astringing and regenerating muscles, and absorbing moisture and healing sores. They have been used in surgical diseases for a long time. As recorded in "Ben Cao Zheng Yi": "Atractylodes lancea has a strong smell, which is stronger than Atractylodes macrocephala. It can penetrate from top to bottom, dry dampness and dissipate phlegm and fluid, and its fragrance can ward off filth." Another example is stated in "Bi Xiao Fang": "It is used to treat bee and silkworm stings: apply mint on it." The combination of Chinese herbal medicine and dressings has significant effects on dehumidification, anti-inflammatory and antipyretic effects on infected wounds.

[0008] Chinese patent document CN106075535A discloses a medical dressing and a preparation method thereof, wherein the material of the medical dressing is a non-woven fabric, a waterproof and breathable layer is sprayed on the front side of the non-woven fabric, the waterproof and breathable layer is composed of a polyurethane nanofiber membrane, gelatin nanoparticles are coated on the surface of the polyurethane nanofiber membrane, and the gelatin nanoparticles are loaded with an antibacterial agent; at the same time, a waterproof layer is sprayed on the reverse side of the non-woven fabric. Chinese patent document CN108671263A discloses a preparation method of a medical antibacterial hydrogel dressing, wherein carboxymethyl chitosan is first modified with graphene oxide, so that the graphene oxide is wrapped in the carboxymethyl chitosan, and then the graphene oxide is spun, freeze-dried, and crushed to form fibers, and then reacted with sodium alginate oxide and carboxymethyl chitosan to form a hydrogel dressing. Chinese patent document CN110152049A discloses a method for preparing a chitosan-based drug-loaded nanofiber membrane that can be used for medical wound dressings, and relates to a method for preparing a chitosan-based nanofiber membrane: first, preparing a spinning precursor solution; second, preparing a drug-loaded nanofiber membrane to obtain a chitosan-based drug-loaded nanofiber membrane that can be used for medical wound dressings, thereby solving the problems of poor drug release sustainability and low drug release rate of existing medical wound dressings. Chinese patent document CN110772659A discloses a method for preparing a chitosan graphene nano medical dressing for antibacterial and wound healing, comprising: step S1, mixing chitosan and graphene oxide dispersion dissolved in acetic acid evenly under ultrasonic action, adding an initiator to react for 4 hours to obtain a graphene grafted modified chitosan solution; step S2, adding a reducing agent to the graphene grafted modified chitosan dispersion obtained in step S1 to react at 80-90°C, filtering under reduced pressure, and vacuum drying to obtain a reduced graphene-chitosan functional masterbatch; step S3, dissolving and mixing the reduced graphene-chitosan functional masterbatch, auxiliary components, and a reinforcing agent obtained in step S2, spinning and filming to obtain chitosan-graphene nanofiber felt, and liquid-phase reinforced crosslinking in an acid solution to obtain an antibacterial and wound healing chitosan graphene nano medical dressing. The wound dressing material can be endowed with a special physical therapy healing function, especially in terms of physical antibacterial and far-infrared radiation to promote wound healing. Chinese patent document CN110859988A discloses an activated carbon fiber biofunctional dressing, comprising a wound repair layer, an adhesive layer and a sealing release paper; the sealing release paper is bonded to both sides of the adhesive layer and seals the wound repair layer; the wound repair layer comprises a base layer and a coating layer, and the base layer is an activated carbon fiber felt and is arranged in the middle of the adhesive layer, and the coating layer is attached to the base layer; it is easy to use, has excellent hygroscopicity and antibacterial properties, has a good hemostatic effect, can quickly absorb moisture, blood, exudate and other liquids on the surface of the wound, effectively prevents the wound from being soaked for a long time by the tissue fluid secreted by the wound, and can form a gel protective layer on the wound surface, which fills the tissue to prevent pathogenic microorganisms from contacting the wound, is beneficial to wound healing, and effectively prevents the occurrence of infection.

[0009] However, there is no report on an antibacterial dressing suitable for the assessment and treatment of deep infected wounds in hot and humid environments. Summary of the invention

[0010] In the special environment of damp heat, wound infection occurs early, progresses quickly, exudates a lot, delays healing and easily develops drug resistance. The purpose of the present invention is to provide a multifunctional Chinese and Western medicine combined antibacterial dressing suitable for wound assessment and treatment of deep infection wounds in damp heat environment and its application.

[0011] According to a first aspect of the present invention, there is provided an antibacterial dressing suitable for the assessment and treatment of deep infected wounds in a hot and humid environment, wherein the antibacterial dressing comprises a three-layer structure, wherein the first layer is a bottom adhesive layer provided with a self-adhesive ring, the second layer covers the first layer and comprises a wound infection indicator layer arranged in the center and a heat-clearing and cooling layer on the periphery, and the third layer covers the second layer and comprises an exudate absorption and swelling-reducing layer arranged in the center and an anti-inflammatory and bactericidal layer on the periphery.

[0012] Furthermore, the bottom adhesive layer is made of transparent material, preferably polyurethane film material but not limited to this material, and the outer circle of the bottom adhesive layer is provided with a self-adhesive ring, and the self-adhesive is polyacrylate adhesive, and is provided with release paper for easy removal.

[0013] Furthermore, the wound infection indicator layer is composed of a thin layer of gauze at the top and a pH test paper near the bottom adhesive layer. The thin layer of gauze is close to the wound side, and the exudate can reach the pH test paper through the thin layer of gauze. The pH test paper displays different colors according to the change in the pH value of the exudate. According to the color change of the pH test paper, the pH value range of the wound exudate can be judged, and according to the change in pH value at different stages of wound healing, the change in the degree of wound infection can be judged.

[0014] Furthermore, the heat-clearing and temperature-reducing layer is a traditional Chinese medicine extract gel, which is prepared by mixing borneol and mint extracts with hydrogel, wherein the mass percentages of hydrogel, borneol and mint are 97.5%, 2% and 0.5% respectively.

[0015] Among them, mint contains ingredients such as menthol, which will produce a cool sensation when applied to the affected area, and is suitable for relieving the heat, swelling and pain caused by inflammatory reactions of wounds; borneol is obtained by steam distillation and recrystallization of the stems and leaves of Artemisia balsamifera in the Asteraceae family or the branches and leaves of Camphora borneol in the Lauraceae family. It tastes pungent and bitter, and has the functions of clearing away heat and detoxifying, opening the orifices and refreshing the mind. It can be used externally for swollen and painful sores and those that do not heal after ulcers.

[0016] Furthermore, the preparation method of the traditional Chinese medicine extract gel comprises the following steps:

[0017] (A) Steam distillation of peppermint for 3 hours, collecting the distillate, and separating the peppermint oil with a separatory funnel;

[0018] (B) Add 10 times the amount of water to borneol and extract twice, each time for 1 hour. Concentrate the extract to a relative density of 1.01-1.04 (25°C, based on water). Add 4% by weight of povidone and 12% by weight of polyethylene glycol. Stir well and spread on the backing layer to a thickness of 1 mm.

[0019] Furthermore, the anti-inflammatory and bactericidal layer is a graphene-modified nanofiber membrane.

[0020] Furthermore, the anti-inflammatory and bactericidal layer is made of multifunctional carbon nanomaterial graphene oxide with bactericidal function, and is prepared into a nanofiber membrane by the following process:

[0021] (a) preparing a graphene oxide solution: adding graphene oxide to deionized water and performing ultrasonic treatment until the mixture is uniformly mixed to prepare a graphene suspension;

[0022] (b) preparing a silk protein solution: dissolving silk protein with a purity of 100% in formic acid with a concentration of 98wt%, stirring until the silk protein is completely dissolved to obtain a silk protein solution with a concentration of 15wt%-25wt%;

[0023] (c) mixing a silk spinning solution with a graphene suspension and a low molecular weight chitosan (at a concentration of 1 wt% to 3 wt%), stirring the mixture thoroughly to form a uniform and stable spinning solution, and then electrospinning the solution to form a nanofiber membrane by using an aluminum foil or fabric to receive the nanofilaments;

[0024] (d) Then, the graphene-modified nanofiber membrane is obtained by heating and curing under the protection of inert gas.

[0025] Further preferably, in the step (a), the ultrasonic treatment time is 10-30 min.

[0026] Further preferably, in the step (a), the concentration of the graphene suspension is 2-20 mg / mL.

[0027] Further preferably, in the step (c), the mass ratio of the silk protein solution to chitosan in the silk spinning solution is about 15:1~5:1; the graphene suspension is added to the mixed solution of silk protein and chitosan, and the mixture is fully stirred to form a spinning solution, wherein the graphene accounts for about 1wt%~5wt% of the total mass of the spinning solution.

[0028] Further preferably, in the step (c), the parameters of the electrospinning are: voltage of 15-30 KV, discharge distance of 8-20 cm, and spinning rate of 0.5 mL / hour.

[0029] Further preferably, in step (d), the inert gas is nitrogen or argon.

[0030] Further preferably, in the step (d), the temperature for heating and curing the nanofiber membrane is 80-100°C.

[0031] Further preferably, in the step (d), the thickness of the graphene-modified nanofiber membrane is 0.3-1 μm.

[0032] Furthermore, the exudate absorption and swelling-reducing layer is prepared by mixing five externally applied swelling-reducing and anti-inflammatory Chinese medicines, namely, Glauber's salt, Atractylodes macrocephala, Angelica dahurica, Gallnut and cuttlefish bone.

[0033] The preferred process is to grind each medicinal ingredient into powder and mix them for use. The main component of mirabilite is sodium sulfate, which has the effects of clearing heat and reducing swelling, softening and dispersing nodules, and anti-inflammatory; the main components of Atractylodes are β-eucalyptol and cypermethrin, which have the effects of drying dampness and relieving itching, reducing swelling and anti-inflammatory; Angelica dahurica, Galla chinensis and Sepia bone all have the effects of absorbing moisture, astringing sores, draining pus and stopping bleeding.

[0034] Furthermore, the preparation method of the exudate absorption and detumescence layer comprises the following steps:

[0035] (1) Soak the five medicinal materials of Glauber's Salt, Atractylodes, Angelica Dahurica, Gallnut, and Cuttlefish Bone in a weight ratio of 1:1.5:1.5:2:1 for 12 hours, add 10 times the amount of water, extract twice, the first time for 2 hours, the second time for 1 hour, and concentrate to a relative density of 1.04-1.06 (25°C, based on water);

[0036] (2) Add ethanol in a volume ratio of 1:1 and precipitate for 24 hours. Centrifuge at 12000 rpm / min and take the supernatant to recover the ethanol until there is no alcohol smell.

[0037] (3) Add 4% by weight of povidone and 12% by weight of polyethylene glycol, stir evenly and spread evenly on the lining layer.

[0038] The exudate absorption and swelling reduction layer is placed deep in the subcutaneous fat, superficial fascia and muscle gap of the wound when in use to absorb fat and superficial fascia exudate. The layer is in the shape of a "ridge", with a narrow upper cross section and a wide lower cross section, so as to be suitable for an open deep incision. The two side walls are the continuation of the graphene nanofiber membrane of the anti-inflammatory and bactericidal layer, which has a bactericidal effect on the soft tissue of the wound, and the semi-permeable membrane material is used between the exudate absorption and swelling reduction layer and the wound infection indicator layer, and polypropylene material is preferably used but not limited to this material.

[0039] Therefore, different models can be set according to the depth of the wound. The thickness of human skin, subcutaneous fat and superficial fascia ranges from about 3 to 10 cm. Therefore, this layer can be roughly set to four different models according to the thickness: T1 (thickness 2 cm), T2 (thickness 5 cm), T3 (thickness 7 cm) and T4 (thickness 10 cm). The width of the dressing layer is about 2 to 5 cm. After absorbing the exudate, the adsorption effect will tighten the open wound, and the dressing layer will expand after absorbing the exudate, and the surface area can be increased by about 5% to 10%. Therefore, it is suitable for wounds with a width of 2 to 7 cm.

[0040] Furthermore, the semipermeable membrane material of the anti-inflammatory and bactericidal layer, the exudate absorption and detumescence layer, the thin gauze of the wound infection indicator layer, and the heat-clearing and cooling layer are compounded together by hot pressing technology (the contact part is coated with pressure-sensitive adhesive), and the pH test papers of the heat-clearing and cooling layer and the wound infection indicator layer are adhered to the bottom adhesive layer by viscose material.

[0041] A second aspect of the present invention provides a use of the antibacterial dressing as described above in the preparation of a medical dressing material suitable for assessing and treating deep infected wounds in a hot and humid environment.

[0042] The beneficial effects of the present invention are:

[0043] The multifunctional Chinese and Western medicine combined antibacterial dressing suitable for wound assessment and treatment of deep infection in hot and humid environment of the present invention has the advantages of strong antibacterial ability - no bacterial resistance, strong adsorption ability - clearing away heat and swelling, no need for daily dressing change, timely assessment - flexible change of treatment strategy. The Chinese and Western medicine combined antibacterial dressing group of the present invention is superior to the iodine dressing group and the blank control group in terms of reducing the scope of wound redness and swelling, reducing the bacterial content of exudate and promoting wound healing.

[0044] 1. The dressing of the present invention has strong antibacterial ability. The multifunctional carbon nanomaterial graphene oxide is used to prepare the anti-inflammatory and bactericidal nanofiber membrane. Its bactericidal principle is to destroy the bacterial cell membrane by physical and chemical methods. It has a wide antibacterial spectrum and does not produce drug resistance. The antibacterial effect is stable.

[0045] 2. The dressing of the present invention has a strong adsorption capacity. The exudate adsorption and detumescence layer is made of five traditional Chinese medicines for external use to reduce swelling and inflammation, which has obvious effects of reducing swelling and anti-inflammatory. It breaks the conventional "paper-like" form and takes a "ridge" form. The protruding part of the "ridge" has an adsorption function, which can penetrate deep into the open incision and fully contact it, and continuously adsorb the exudate. The adsorption material is made of five medicinal materials, such as mirabilite, atractylodes, angelica, gallnut, and cuttlefish bone, and has a strong adsorption capacity and antibacterial effect, which can keep the wound dry and clean. At the same time, the heat-clearing and cooling hydrogel layer composed of mint and borneol also has a cooling and detumescence effect.

[0046] 3. The dressing of the present invention can continuously evaluate the infection degree of the wound. The pH value of the exudate can reflect the local infection degree. After bacterial decomposition and metabolism, the ammonia content increases and the pH value increases. After the infection improves, the pH value drops to the pH value level of normal skin. In the wound infection indicator layer, the thin layer of gauze is close to the wound side, and the exudate can reach the pH test paper through the thin layer of gauze. The pH test paper displays different colors according to the change in the pH value of the exudate. According to the color change of the pH test paper, it can be judged in which range the pH value of the wound exudate is, and the bacterial content of the wound exudate can be evaluated by the color of the pH test paper. According to the change in pH value at different stages of wound healing, the change in the infection degree of the wound can be judged.

[0047] 4. The functions of each layer of the dressing of the present invention are independent of each other, but they work together. The bactericidal effect of graphene oxide combined with the moistening and sore-healing effect of traditional Chinese medicine can accelerate the process of inhibiting infection. The adsorption of exudate and cooling and antipyretic can synergistically increase the anti-inflammatory and swelling effects, and the infection indicator layer can evaluate the anti-infection effect of the bactericidal layer and the adsorption layer in real time, and determine the next dressing change strategy, which has a wide range of clinical application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 . Schematic diagram of the structure of each layer of the antibacterial dressing of the present invention;

[0049] Figure 2 . Demonstration of the application of the antibacterial dressing of the present invention in deep wounds;

[0050] Figure 3 . Diagram of the antibacterial effect of graphene oxide solution.

[0051] The reference numerals and components involved in the drawings are as follows:

[0052] 1-adhesive ring; 2-adhesive layer;

[0053] 3-wound infection indicator layer; 4-heat-clearing and temperature-reducing layer;

[0054] 5- Anti-inflammatory and bactericidal layer; 6- Exudate absorption and detumescence layer. DETAILED DESCRIPTION

[0055] The specific implementation methods provided by the present invention are described in detail below in conjunction with examples.

[0056] Embodiment 1:

[0057] The structural schematic diagram of the antibacterial dressing of the present invention is shown in Figure 1 .

[0058] The antibacterial dressing comprises a three-layer structure, wherein the first layer is a bottom adhesive layer 2 provided with a self-adhesive ring 1, the second layer covers the first layer and comprises a wound infection indicator layer 3 arranged in the center and a heat-clearing and cooling layer 4 arranged on the periphery, and the third layer covers the second layer and comprises an exudate absorption and swelling-reducing layer 6 arranged in the center and an anti-inflammatory and bactericidal layer 5 arranged on the periphery.

[0059] The bottom adhesive layer 2 is made of a transparent polyurethane film material, and a self-adhesive ring 1 is arranged on the outer ring of the bottom adhesive layer. The self-adhesive ring 1 is made of polyacrylate adhesive and is provided with a release paper for easy removal.

[0060] The wound infection indicator layer 3 is composed of a thin layer of gauze at the top and a pH test paper near the bottom adhesive layer 2. The thin layer of gauze is close to the wound side, and the exudate can reach the pH test paper through the thin layer of gauze. The pH test paper displays different colors according to the change in the pH value of the exudate. According to the color change of the pH test paper, the pH value range of the wound exudate can be judged, and according to the change in pH value at different stages of wound healing, the change in the degree of wound infection can be judged.

[0061] The heat-clearing and temperature-reducing layer 4 is a traditional Chinese medicine extract gel, which is prepared by mixing borneol, mint extracts and hydrogel, wherein the mass percentages of hydrogel, borneol and mint are 97.5%, 2% and 0.5% respectively.

[0062] The method for preparing the traditional Chinese medicine extract gel comprises the following steps:

[0063] (A) Steam distillation of peppermint for 3 hours, collecting the distillate, and separating the peppermint oil with a separatory funnel;

[0064] (B) Add 10 times the amount of water to borneol and extract twice, each time for 1 hour. Concentrate the extract to a relative density of 1.03 (25°C, based on water). Add 4% povidone and 12% polyethylene glycol, stir well and spread on the backing layer to a thickness of 1 mm.

[0065] The anti-inflammatory and bactericidal layer 5 is a graphene-modified nanofiber membrane, which is prepared by the following process using graphene oxide, a multifunctional carbon nanomaterial with bactericidal function:

[0066] (a) Preparing a graphene oxide solution: adding graphene oxide to deionized water and subjecting the solution to ultrasonic treatment until the mixture is uniformly mixed to prepare a graphene suspension; the ultrasonic treatment time is 10-30 min, and the concentration of the graphene suspension is 2-20 mg / mL.

[0067] (b) preparing a silk protein solution: dissolving silk protein with a purity of 100% in formic acid with a concentration of 98wt%, stirring until the silk protein is completely dissolved to obtain a silk protein solution with a concentration of 15wt%-25wt%;

[0068] (c) Mix the silk spinning solution with the graphene suspension and low molecular weight chitosan (concentration of 1wt%-3wt%), stir well to make a uniform and stable spinning solution, and then perform electrospinning, with aluminum foil or fabric receiving the nanofilaments to form a nanofiber membrane; the mass ratio of silk protein solution to chitosan in the silk spinning solution is about 15:1~5:1; add the graphene suspension to the mixed solution of silk protein and chitosan, stir well to make a spinning solution, in which the graphene accounts for about 1wt%~5wt% of the total mass of the spinning solution. The parameters of electrospinning are: voltage of 15-30KV, discharge distance of 8-20cm, and spinning rate of 0.5mL / hour.

[0069] (d) Then, the graphene-modified nanofiber membrane is obtained by heating and curing under the protection of an inert gas. The inert gas is nitrogen or argon. The temperature for heating and curing the nanofiber membrane is 80-100°C. The thickness of the graphene-modified nanofiber membrane is 0.3-1 μm.

[0070] The exudate absorption and swelling-reducing layer 6 is made of a mixture of five external anti-swelling and anti-inflammatory Chinese medicines, namely, Glauber's salt, Atractylodes lancea, Angelica dahurica, Gallnut and Sepia bone. The medicinal ingredients are ground into powders and mixed for use. Glauber's salt is mainly composed of sodium sulfate, which has the effects of clearing away heat and swelling, softening and dispersing nodules, and anti-inflammatory; the main components of Atractylodes lancea are β-eucalyptol and cypermethrin, which have the effects of drying dampness and relieving itching, reducing swelling and anti-inflammatory; Angelica dahurica, Gallnut and Sepia bone all have the effects of absorbing moisture, astringing sores, discharging pus and stopping bleeding.

[0071] The method for preparing the exudate absorption and detumescence layer comprises the following steps:

[0072] (1) Sodium sulfate, Atractylodes macrocephala, Angelica dahurica, Gallnut, and cuttlefish bone, with a weight ratio of 1:1.5:1.5:2:1; soak for 12 hours, add 10 times the amount of water, extract twice, the first time for 2 hours, the second time for 1 hour, and concentrate to a relative density of 1.05 (25°C, based on water);

[0073] (2) Add ethanol in a volume ratio of 1:1 and precipitate for 24 hours. Centrifuge at 12000 rpm / min and take the supernatant to recover the ethanol until there is no alcohol smell.

[0074] (3) Add 4% povidone and 12% polyethylene glycol, stir well and spread evenly on the lining layer with a thickness of 1 mm.

[0075] The exudate absorption and swelling reduction layer 6 is placed deep in the subcutaneous fat, superficial fascia and muscle gap of the wound when in use to absorb fat and superficial fascia exudate. The layer is in the shape of a "ridge", with a narrow upper cross section and a wide lower cross section, so as to be suitable for an open deep incision. The two side walls are the continuation of the graphene nanofiber membrane of the anti-inflammatory and bactericidal layer 5, which has a bactericidal effect on the soft tissue of the wound, and the semi-permeable membrane material is used between the exudate absorption and swelling reduction layer 6 and the wound infection indicator layer 3, and polypropylene material is preferably used but not limited to this material.

[0076] Therefore, different models can be set according to the depth of the wound. The thickness of human skin, subcutaneous fat and superficial fascia ranges from about 3 to 10 cm. Therefore, this layer can be roughly set to four different models according to the thickness: T1 (thickness 2 cm), T2 (thickness 5 cm), T3 (thickness 7 cm) and T4 (thickness 10 cm). The width of the dressing layer is about 2 to 5 cm. After absorbing the exudate, the adsorption effect will tighten the open wound, and the dressing layer will expand after absorbing the exudate, and the surface area can be increased by about 5% to 10%. Therefore, it is suitable for wounds with a width of 2 to 7 cm.

[0077] Example 2: Observation on the effect of graphene oxide solution of anti-inflammatory and bactericidal layer on inhibiting the growth of Staphylococcus aureus

[0078] ①Method:

[0079] Preparation of graphene oxide solution: adding graphene oxide to deionized water, ultrasonic treatment until mixed uniformly, to prepare a graphene suspension; the ultrasonic treatment time is 20 minutes, and the concentration of the graphene suspension is 12 mg / mL.

[0080] The blank group of bacterial culture medium used LB solid agar medium, the positive control group used LB solid agar medium containing penicillin, and the experimental group used LB solid agar medium containing graphene oxide solution. 8 50~100 μL of CFU / mL Staphylococcus aureus suspension was evenly scraped on LB solid agar plate. Three culture media were used for colony scraping in each group.

[0081] ②Results: Figure 3 As shown in Table 1, the antibacterial rate of Staphylococcus aureus in the culture medium treated with graphene oxide solution was (96.15±0.98)%, and the sterilization rate of the culture medium treated with penicillin was (91.85±1.59)%. The sterilization rates of the experimental group and the positive control group were significantly higher than those of the blank control group (P<0.001), and the antibacterial rate of the experimental group was also significantly higher than that of the positive control group (P=0.016), indicating that the graphene oxide solution has a significant antibacterial effect.

[0082] Table 1 Antibacterial rate of each group of culture medium (%)

[0083]

[0084] Example 3: Observation on the effect of the five-flavor Chinese herbal medicine combination in the detumescence layer on inhibiting rat paw swelling (rat paw swelling method)

[0085] ①Methods: Thirty SD rats were randomly divided into three groups: normal group, model group and Chinese medicine group, with 10 rats in each group. The normal group was injected with 0.1 mL of normal saline per rat under the right hind paw plantar membrane, and the model group and Chinese medicine group were injected with 0.1 mL of adjuvant per rat under the right hind paw plantar membrane to induce inflammation. Five Chinese medicines (glauber's salt, atractylodes, angelica dahurica, gallnut and cuttlefish bone, weight ratio of 1:1.5:1.5:2:1) were combined into powder and applied to the inflamed part of the paw of the rats in the Chinese medicine group. The circumference of the right hind paw of the three groups of rats was measured 1, 2, 3, 4, 5 and 6 hours after inflammation, and the swelling rate was calculated.

[0086] ②Results: Compared with the normal group, the foot swelling rate of rats in the model group was significantly increased, indicating that the model was successfully established (P<0.01). The foot swelling rate of rats after Chinese medicine intervention was significantly decreased compared with the model group (P<0.01), indicating that the Chinese medicine composition can reduce the foot swelling of rats caused by adjuvants and has a significant anti-inflammatory effect. See Table 2 for details.

[0087] Table 2 Effects of plantar swelling in rats in each group

[0088]

[0089] Note: is the mean value and s is the variance.

[0090] Example 4: Observation on the effect of the Chinese herbal extract gel with heat-clearing and temperature-reducing layer on reducing the thermal pain reaction of the hind feet of mice (hot plate reaction of mice)

[0091] ①Method:

[0092] The Chinese herbal medicine extract gel is prepared by mixing borneol and mint extracts with hydrogel, wherein the mass percentages of hydrogel, borneol and mint are 97.5%, 2% and 0.5% respectively.

[0093] The method for preparing the traditional Chinese medicine extract gel comprises the following steps:

[0094] (A) Steam distillation of peppermint for 3 hours, collecting the distillate, and separating the peppermint oil with a separatory funnel;

[0095] (B) Add 10 times the amount of water to borneol and extract twice, each time for 1 hour. Concentrate the extract to a relative density of 1.03 (25°C, based on water). Add 4% povidone and 12% polyethylene glycol, stir well and spread on the backing layer to a thickness of 1 mm.

[0096] Thirty ICR mice were divided into a blank group, a Chinese medicine group, and a positive control group. There were 10 mice in each group. The Chinese medicine combination group applied Chinese medicine extract gel on the soles of the hind feet of the mice, and the positive control group sprayed ice water on the soles of the feet. The constant temperature water bath was heated to 55±0.5℃, and the bottom of the beaker was in contact with the water surface. After heating, it was used as a thermal stimulus. A stopwatch was used to record the time (s) from the time the mouse was put on the hot plate to the time it licked its hind feet as the pain threshold of the mouse. Female mice were placed on a 55±0.5℃ hot plate, and the pain threshold was measured 3 times. The mouse licking its hind feet was used as a pain response indicator, and mice with pain responses within 30 seconds were selected. The first licking time of mice in each group was recorded.

[0097] ②Results: The latency of paw licking in the blank group was (12.4±5.7) seconds, and that in the positive control group was (23.7±6.5) seconds, which were significantly longer than those in the blank group (P<0.05). The latency of paw licking in the mice treated with Chinese medicine was (28.6±8.4) seconds, which was significantly longer than those in the other two groups (P<0.01), indicating that the Chinese medicine extract gel (mint and borneol) has significant antipyretic and anti-inflammatory effects.

[0098] Example 5: Observation on the effect of the antibacterial dressing of the present invention on inhibiting wound infection in New Zealand white rabbits

[0099] ①Method:

[0100] The antibacterial dressing of Example 1 is used, wherein the anti-inflammatory and bactericidal layer 5 is a graphene-modified nanofiber membrane, and a multifunctional carbon nanomaterial graphene oxide with bactericidal function is selected to prepare the nanofiber membrane by the following process:

[0101] (a) preparing a graphene oxide solution: adding graphene oxide to deionized water and subjecting it to ultrasonic treatment until the mixture is uniformly mixed to prepare a graphene suspension; the ultrasonic treatment time is 20 min, and the concentration of the graphene suspension is 12 mg / mL;

[0102] (b) preparing a silk protein solution: dissolving silk protein with a purity of 100% in formic acid with a concentration of 98wt%, stirring until the silk protein is completely dissolved, to obtain a silk protein solution with a concentration of 20wt%;

[0103] (c) Mix the silk spinning solution with the graphene suspension and low molecular weight chitosan (concentration of 2wt%), stir them thoroughly to make a uniform and stable spinning solution, and then perform electrospinning, with aluminum foil or fabric receiving the nanofilaments to form a nanofiber membrane; the mass ratio of silk protein solution to chitosan in the silk spinning solution is about 10:1; add the graphene suspension to the mixed solution of silk protein and chitosan, stir them thoroughly to make a spinning solution, in which the graphene accounts for about 3wt% of the total mass of the spinning solution. The parameters of electrospinning are: voltage of 25KV, discharge distance of 14cm, and spinning rate of 0.5mL / hour.

[0104] (d) Then, the graphene-modified nanofiber membrane is obtained by heating and curing under the protection of an inert gas. The inert gas is nitrogen or argon. The temperature for heating and curing the nanofiber membrane is 100°C. The thickness of the graphene-modified nanofiber membrane is 0.5 μm.

[0105] 9 New Zealand white rabbits were divided into a blank group, an iodine dressing group, and an antibacterial dressing group of the present invention. There were 3 rabbits in each group, and the wound treatment method of the rabbits in each group was the same. The outer side of the left lower limb thigh was taken, and after local anesthesia, an incision of about 2.5 cm in length and about 1 cm in depth was made with an unsterilized knife with pepper water. After gauze was used to stop bleeding, no disinfection was performed within 24 hours. 24 hours after the injury, the blank group and the iodine dressing group were cleaned with physiological saline gauze and iodine gauze strips every three days respectively. The exudate absorption and detumescence layer of the antibacterial dressing group of the present invention penetrated deep into the wound, and the adhesive layer adhered to the surface of the wound ( Figure 2 ), and change it every three days. Record the redness and swelling around the wound every three days within 10 days of dressing change (mm), the bacterial content of the exudate (pH value qualitative), and the size of the wound (mm 2 ). The maximum distance between the edge of the redness and swelling around the wound and the wound, the bacterial content of the exudate is based on the pH value of the bottom layer of exudate contacted by the pH test paper, and the size of the wound is expressed as length × depth.

[0106] ② Results: As shown in Table 3: a. Wound redness and swelling range: Compared with the blank group, the redness and swelling range of the iodine dressing group and the antibacterial dressing group of the present invention was significantly reduced after the 4th, 7th and 10th day of dressing change (P<0.001), and the redness and swelling range of the antibacterial dressing group of the present invention was significantly lower than that of the iodine dressing group after the 7th and 10th day (P=0.018 and P=0.005). b. pH value: Compared with the blank group, the pH value of the wound exudate of the iodine dressing group and the antibacterial dressing group of the present invention was significantly reduced after the 4th, 7th and 10th day of dressing change (P<0.001), and the pH value of the antibacterial dressing group of the present invention was significantly lower than that of the iodine dressing group after the 7th and 10th day (P=0.047 and P=0.047). c. Wound size: Compared with the blank group, the wound size of the iodine dressing group and the antibacterial dressing group of the present invention was significantly reduced after the 4th, 7th and 10th day of dressing change. After the 10th day, the pH value of the antibacterial dressing group of the present invention was significantly lower than that of the iodine dressing group (P=0.034). The above results show that the Chinese and Western medicine combined antibacterial dressing group of the present invention is superior to the iodine dressing group and the blank control group in reducing the scope of wound redness and swelling, reducing the bacterial content of exudate and promoting wound healing.

[0107] Table 3 Comparison of the range of redness and swelling, bacterial content and wound size of rabbits in each group

[0108]

[0109] Note: is the mean value and s is the variance.

[0110] The preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. An antibacterial dressing suitable for the assessment and treatment of deep infected wounds in hot and humid environments, characterized in that: The antibacterial dressing comprises a three-layer structure, wherein the first layer is a bottom adhesive layer provided with a self-adhesive ring, the second layer covers the first layer and comprises a wound infection indicator layer arranged at the center and a heat-clearing and temperature-reducing layer arranged at the periphery, and the third layer covers the second layer and comprises a fluid absorption and swelling-reducing layer arranged at the center and an anti-inflammatory and sterilization layer arranged at the periphery; The bottom adhesive layer is made of transparent material, and the outer ring of the bottom adhesive layer is provided with a self-adhesive ring, and the self-adhesive ring is made of polyacrylate adhesive and is provided with release paper for easy removal; The wound infection indicator layer is composed of a thin layer of gauze on the top and a pH test paper on the bottom; The heat-clearing and temperature-reducing layer is a traditional Chinese medicine extract gel, which is made by mixing borneol and mint extracts with hydrogel, wherein the mass percentages of hydrogel, borneol and mint are 97.5%, 2% and 0.5% respectively; The anti-inflammatory and bactericidal layer is a graphene-modified nanofiber membrane; The exudate absorption and detumescence layer is made of a mixture of five medicinal powders of mirabilite, atractylodes, angelica dahurica, gallnut and cuttlefish bone, with a weight ratio of 1:1.5:1.5:2:1; the exudate absorption and detumescence layer is in the shape of a "ridge", with a cross section narrow at the top and wide at the bottom, so as to be suitable for an open deep incision; the two side walls are the continuation of the graphene-modified nanofiber membrane of the anti-inflammatory and bactericidal layer, and the semi-permeable membrane polypropylene material is between the exudate absorption and detumescence layer and the wound infection indicator layer; The anti-inflammatory and bactericidal layer, the semipermeable membrane material of the exudate absorption and detumescence layer, the thin gauze of the wound infection indicator layer and the heat-clearing and cooling layer are compounded together by hot pressing technology, and the pH test papers of the heat-clearing and cooling layer and the wound infection indicator layer are adhered to the bottom adhesive layer by viscose material.

2. The antibacterial dressing according to claim 1, characterized in that: The method for preparing the traditional Chinese medicine extract gel comprises the following steps: (A) Steam distillation of peppermint for 3 hours, collecting the distillate, and separating the peppermint oil with a separatory funnel; (B) Add 10 times the amount of water to borneol and extract twice, each time for 1 hour. Concentrate the extract to a relative density of 1.01-1.04 at 25°C, based on water. Add 4% by weight of povidone and 12% by weight of polyethylene glycol, stir well and spread on the backing layer to a thickness of 1 mm.

3. The antibacterial dressing according to claim 1, characterized in that: The method for preparing the anti-inflammatory and bactericidal layer comprises the following steps: (a) preparing a graphene oxide solution: adding graphene oxide to deionized water and performing ultrasonic treatment until the mixture is uniformly mixed to prepare a graphene suspension; (b) preparing a silk protein solution: dissolving silk protein with a purity of 100% in formic acid with a concentration of 98wt%, stirring until the silk protein is completely dissolved to obtain a silk protein solution with a concentration of 15wt%-25wt%; (c) mixing a silk spinning solution with a graphene suspension and a low molecular weight chitosan with a concentration of 1wt%-3wt%, stirring the mixture to obtain a uniform and stable spinning solution, and then electrospinning the solution to form a nanofiber membrane by using an aluminum foil or fabric to receive the nanofilaments; (d) Then, the graphene-modified nanofiber membrane is obtained by heating and curing under the protection of inert gas.

4. The antibacterial dressing according to claim 3, characterized in that: In the step (a), the ultrasonic treatment time is 10-30 minutes; and the concentration of the graphene suspension is 2-20 mg / mL.

5. The antibacterial dressing according to claim 3, characterized in that: In the step (c), the mass ratio of silk protein solution to chitosan in the silk spinning solution is 15:1~5:1; the graphene suspension is added to the mixed solution of silk protein and chitosan, and the mixture is fully stirred to form a spinning solution, wherein the graphene accounts for 1wt%~5wt% of the total mass of the spinning solution; the parameters of electrospinning are: voltage of 15-30KV, discharge distance of 8-20cm, and spinning rate of 0.5mL / hour.

6. The antibacterial dressing according to claim 3, characterized in that: In the step (d), the inert gas is nitrogen or argon; the temperature for heating and curing the nanofiber membrane is 80-100°C.

7. The antibacterial dressing according to claim 3, characterized in that: The thickness of the graphene-modified nanofiber membrane is 0.3-1 μm.

8. The antibacterial dressing according to claim 1, characterized in that: The method for preparing the exudate absorption and detumescence layer comprises the following steps: (1) The weight ratio of mirabilite, atractylodes, angelica dahurica, gallnut and cuttlefish bone is 1:1.5:1.5:2:1; soak for 12 hours, add 10 times the amount of water, extract twice, the first time for 2 hours, the second time for 1 hour, and concentrate to a relative density of 1.04-1.06 at 25℃, based on water; (2) Add ethanol in a volume ratio of 1:1 and precipitate for 24 hours. Centrifuge at 12000 rpm / min and take the supernatant to recover the ethanol until there is no alcohol smell. (3) Add 4% by weight of povidone and 12% by weight of polyethylene glycol, stir well and spread evenly on the lining layer to obtain the product.

9. The antibacterial dressing according to claim 1, characterized in that: The exudate absorption and swelling-reducing layer is provided in four different models: thickness is 2cm, 5cm, 7cm and 10cm; width is 2-5cm.

10. Use of the antibacterial dressing according to any one of claims 1 to 9 in the preparation of a medical dressing material suitable for assessing and treating deep infected wounds in a hot and humid environment.

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