Intelligent dressing for dynamically monitoring wound infection and preparation method and application thereof

Abstract

The invention provides an intelligent dressing for dynamically monitoring wound infection and a preparation method of the intelligent dressing. The intelligent dressing sequentially comprises a contact layer, a hydrophilic layer, a color developing layer and a fixing layer from inside to outside. PP / PLA bi-component non-woven fabric is adopted as the contact layer and is coated with a chitosan coating after plasma treatment, and calcium alginate / CMC composite hydrogel is adopted as the hydrophilic layer; the color developing layer comprises a region A and a region B; the A region is used for detecting staphylococcus aureus, and the B region is used for detecting hemolytic streptococcus. The intelligent dressing provided by the invention is used for nursing the wound surface, and can quickly and accurately detect whether the wound surface is infected with staphylococcus aureus and hemolytic streptococcus, so that the potential infection risk can be found in time, and anti-infection treatment can be adopted in time. The preparation method has the advantages of low cost, good biocompatibility and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of medical dressings, and particularly to an intelligent dressing for dynamic monitoring of wound infections and a preparation method thereof. Background Art

[0002] Wound infection is a common problem in clinical treatment. If not detected and treated in time, it will lead to delayed wound healing, deterioration of the condition, and even endanger life. At present, the detection of wound infection mainly relies on laboratory culture and detection methods, which have problems such as long detection time, complex operation, and high cost, and cannot meet the needs of clinical real-time monitoring. Traditional dressings cannot monitor infections in real time (for example, patent CN201510023456.X only relies on silver ion antibacterial), and electronic sensor dressings (such as US20180104021A1) are costly and require external equipment. Color-changing dressings mostly use synthetic dyes (such as the azo dyes in CN108310528A), which pose a risk of cytotoxicity. Therefore, developing an intelligent dressing that can quickly and accurately detect wound infections has important clinical significance and market value.

[0003] In the domestic market, with the increasing attention of people to medical health and the advent of an aging society, the number of patients with chronic wounds is gradually increasing. This intelligent dressing is expected to be widely used in the domestic market due to its advantages such as low cost, rapid detection, and good biocompatibility. At the same time, the national support and encouragement policies for the medical device industry also provide a favorable policy environment for the promotion of this product. In the international market, wound infection detection remains an urgent problem to be solved. The open design scheme and unique technical advantages of this intelligent dressing give it strong competitiveness in the international market. It can be promoted to regions such as Europe, America, and Asia through cooperation with international medical institutions and enterprises to meet the market demands of different countries and regions. Summary of the Invention

[0004] The purpose of the present invention is to provide an intelligent dressing for dynamic monitoring of wound infections and a preparation method thereof. This intelligent dressing is used for wound care and can also quickly and accurately detect whether the wound is infected with Staphylococcus aureus and Streptococcus hemolyticus, and has advantages such as low cost and good biocompatibility. Another purpose of the present invention is to provide a preparation method for the intelligent dressing.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows: An intelligent dressing for dynamic monitoring of wound infections, which sequentially includes a contact layer, a hydrophilic layer, a color-changing layer, and a fixing layer from the inside to the outside.

[0006] As a preferred embodiment, for the intelligent dressing for dynamic monitoring of wound infection described above, the contact layer adopts a PP / PLA bicomponent non-woven fabric, which is coated with a chitosan coating after being treated by plasma.

[0007] As a preferred embodiment, for the intelligent dressing for dynamic monitoring of wound infection described above, the hydrophilic layer is a calcium alginate / CMC composite hydrogel.

[0008] As a preferred embodiment, for the intelligent dressing for dynamic monitoring of wound infection described above, the color-developing layer includes area A and area B; area A is used to detect Staphylococcus aureus, and its components include 1.2-1.8% agarose, 0.08-0.12% curcumin, 4-6% casein, and the balance is water; Area B is used to detect hemolytic streptococcus, and its components include 5-7% agarose, 4-6% freeze-dried sheep red blood cells, 0.03-0.07% betacyanin, and the balance is water.

[0009] As a preferred embodiment, for the intelligent dressing for dynamic monitoring of wound infection described above, the fixing layer is a microporous TPU film.

[0010] The preparation method of the intelligent dressing for dynamic monitoring of wound infection described in the present invention includes the following steps: (1) Preparation of the contact layer Perform plasma treatment on the PP / PLA bicomponent non-woven fabric to increase the surface activity of the non-woven fabric; Prepare a chitosan solution, dissolve chitosan in an acetic acid solution, soak the treated non-woven fabric in the chitosan solution, and then take it out to dry to form a chitosan coating; (2) Preparation of the hydrophilic layer Prepare a calcium alginate solution and a sodium carboxymethylcellulose solution respectively, then mix the two solutions in proportion, stir evenly, pour them into a mold, and dry to form a calcium alginate / sodium carboxymethylcellulose composite hydrogel; (3) Preparation of the color-developing layer Preparation of area A: Dissolve curcumin, casein and agarose in distilled water according to the mass ratio, heat and stir until completely dissolved, evenly coat it on a nitrocellulose membrane, dry it at room temperature, and cut it into a suitable size to form area A; Preparation of area B: Dissolve betacyanin, freeze-dried sheep red blood cells and agarose in distilled water according to the mass ratio, heat and stir until completely dissolved, evenly coat it on a nitrocellulose membrane, dry it at room temperature, and cut it into a suitable size to form area B; To prevent area A and area B from contaminating and interfering with each other in color development, separate them with a wax thread between area A and area B.

[0011] (4) Assembly Stack the contact layer, hydrophilic layer, color display layer, and fixing layer in sequence, and assemble them by hot pressing or bonding to make the intelligent dressing.

[0012] As a preferred solution, for the preparation method of the intelligent dressing for dynamic monitoring of wound infection described above, step (1) Preparation of the contact layer: Perform plasma treatment on the PP / PLA bicomponent non-woven fabric, with a treatment power of 50 - 300 W and a treatment time of 30 s - 5 min to increase the surface activity of the non-woven fabric; Prepare a chitosan solution by dissolving chitosan in a 1% - 2% acetic acid solution with a pH of 4 - 5 to obtain a concentration of 0.5% - 5%. Immerse the treated non-woven fabric in the chitosan solution for 5 - 30 minutes, then take it out and dry it to form a chitosan coating.

[0013] As a preferred solution, for the preparation method of the intelligent dressing for dynamic monitoring of wound infection described above, step (2) Preparation of the hydrophilic layer: Prepare a calcium alginate solution and a sodium carboxymethyl cellulose solution respectively. The concentration of the calcium alginate solution is 1 - 3%, and the concentration of the sodium carboxymethyl cellulose solution is 2 - 5%; then mix the two solutions in a volume ratio of 1:1 - 1:2, stir evenly, pour them into a mold, and dry them at 40 - 50 °C for 12 - 24 hours to form a calcium alginate / sodium carboxymethyl cellulose composite hydrogel.

[0014] As a preferred solution, for the preparation method of the intelligent dressing for dynamic monitoring of wound infection described above, step (3) Preparation of the color display layer: Preparation of area A: Dissolve curcumin, casein, and agarose in a mass ratio of 1:33.3 - 75:10 - 22.5 in distilled water, heat and stir until completely dissolved, evenly coat it on a nitrocellulose membrane, and dry it at room temperature. Cut it into a suitable size to form area A; Area A: Used to detect Staphylococcus aureus. Its components include 1.2 - 1.8% agarose, 0.08 - 0.12% curcumin, and 4 - 6% casein. When curcumin encounters Staphylococcus aureus, it will undergo a specific chemical reaction with certain metabolites produced by Staphylococcus aureus. The metabolites of Staphylococcus aureus can change the molecular structure of curcumin, thereby changing its absorption and emission spectra, and then producing a red color display phenomenon. Casein provides nutrients for bacteria, promotes the growth and metabolism of bacteria, and enables the reaction to occur more quickly and significantly. Agarose, as a gel matrix, provides a stable environment for the growth and reaction of bacteria, and also helps to maintain the uniform distribution of each component.

[0015] Preparation of Area B: Dissolve betacyanin, freeze-dried sheep red blood cells, and agarose in distilled water at a mass ratio of 3 - 7:400 - 600:500 - 700. Heat and stir until completely dissolved, then evenly coat it on a nitrocellulose membrane. Let it dry at room temperature and cut it into a suitable size to form Area B. Area B: Used for detecting hemolytic streptococcus. Its components include 5 - 7% agarose, 4 - 6% freeze-dried sheep red blood cells, and 0.03 - 0.07% betacyanin. Hemolytic streptococcus can produce hemolysin. When hemolytic streptococcus exists in the wound exudate and contacts the freeze-dried sheep red blood cells in Area B, the hemolysin will damage the cell membrane of the sheep red blood cells, causing the red blood cells to rupture and release hemoglobin. Betacyanin changes color under the action of hemoglobin, producing a purple-red color reaction. At the same time, the rupture of red blood cells forms a hemolysis zone. Agarose, as a coagulant, helps to maintain the structural stability of Area B, enabling the reaction to occur in a relatively fixed area.

[0016] To prevent cross-contamination and interference in color development between Area A and Area B, separate them with a wax thread. In step (3), the color development layer can also be extended to detect and add a detection area for Pseudomonas aeruginosa, and the cyanophycin turns green.

[0017] The fixing layer of the present invention is a microporous TPU membrane, which has good air permeability and waterproofness. The microporous TPU membrane ensures gas exchange inside the dressing, maintains the stability of the microenvironment of the entire dressing system, and at the same time prevents the intrusion of external bacteria and pollutants.

[0018] As a preferred solution, for the preparation method of the intelligent dressing for dynamic monitoring of wound infection described above, in step (4), the assembly can be carried out at a hot pressing temperature of 80 - 100°C, a pressure of 0.5 - 5 μPa, and a time of 1 - 10 minutes; or the binder is polyacrylate and the bonding time is 20 minutes.

[0019] Beneficial effects: The present invention has the following advantages: Innovation: The present invention adopts a four-layer optimized structure design, with clear functions and mutual cooperation of each layer, realizing the dynamic monitoring of wound infection. The dual-zone independent detection system of the color development layer can simultaneously detect two common wound infection bacteria, greatly improving the accuracy and specificity of detection. It has a low cost and good market application prospects.

[0020] Practicality: This intelligent dressing has strong practicality. Its low cost enables the product to be applied in a wider range. Whether in clinical medicine or home care, it can provide convenient and efficient wound care and infection detection methods for patients and medical staff. The rapid response time (15 - 40 minutes) can detect infections in a timely manner, buying time for treatment. The good biocompatibility is proved by passing all items of biocompatibility tests of medical device biology evaluation GB / T16886, ensuring the safety of product use.

[0021] Clinically, this intelligent dressing can be used for real-time monitoring of postoperative wounds, promptly detecting possible infections so that doctors can adjust treatment plans in a timely manner. For example, after orthopedic surgery, burn surgery, etc., the risk of wound infection is relatively high. Using this dressing can detect Staphylococcus aureus or hemolytic streptococcus infections in the early stage, avoiding the further deterioration of the infection. In the intensive care unit (ICU), for the pressure ulcers of long-term bedridden patients, the intelligent dressing can dynamically monitor the wound infection situation, providing accurate information for medical staff and helping to formulate personalized care plans.

[0022] For some patients with chronic wounds, such as diabetic foot patients, they can use this intelligent dressing at home by themselves for wound monitoring. Patients only need to regularly observe the color change of the dressing to know whether the wound is infected, communicate with the doctor in a timely manner, and reduce the trouble of frequent medical treatment. During outdoor sports, such as hiking, mountain climbing, etc., if skin abrasions occur, carrying this intelligent dressing can handle and monitor the wound in the first time, and detect potential infection risks in a timely manner. Brief Description of the Drawings

[0023] Figure 1 It is a schematic diagram of color display zones.

[0024] Figure 2 It is a schematic diagram of the structure of the intelligent dressing. Specific Implementation Method

[0025] The present invention will be further clarified below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. After reading the present invention, various equivalent modifications made by those skilled in the art to the present invention fall within the scope defined by the appended claims of this application.

[0026] The following describes in detail the specific implementation manners of the technical solution of the present invention.

[0027] Example 1

[0028] 1. A preparation method of an intelligent dressing for dynamic monitoring of wound infection, comprising the following steps: (1) Preparation of the contact layer: The PP / PLA bicomponent non-woven fabric was subjected to plasma treatment at a treatment power of 50 W and a treatment time of 5 min to increase the surface activity of the non-woven fabric; A chitosan solution was prepared by dissolving chitosan in a 2% acetic acid solution with a pH of 4 - 5 to obtain a chitosan solution with a mass concentration of 2%. The treated non-woven fabric was immersed in the chitosan solution for 10 minutes and then taken out and dried to form a chitosan coating.

[0029] (2)Preparation of the hydrophilic layer: A calcium alginate solution and a sodium carboxymethylcellulose solution were respectively prepared with water, obtaining a calcium alginate solution concentration of 3% and a sodium carboxymethylcellulose solution concentration of 2%; then the two solutions were mixed in a volume ratio of 1:1, stirred evenly, poured into a mold, and dried at 40 °C for 12 hours to form a calcium alginate / sodium carboxymethylcellulose composite hydrogel.

[0030] (3)Preparation of the color-developing layer: Preparation of area A: Curcumin, casein, and agarose were dissolved in distilled water according to a mass ratio of 1:33.3:10, heated and stirred until completely dissolved, and evenly coated on a nitrocellulose membrane (5 μ / cm 3 ), air-dried at room temperature, and cut into a suitable size of 5 mm * 5 mm to form area A.

[0031] Preparation of area B: Betacyanin, freeze-dried sheep red blood cells, and agarose were dissolved in distilled water according to a mass ratio of 3:400:500, heated and stirred until completely dissolved, and evenly coated on a nitrocellulose membrane (5 μ / cm 3 ), air-dried at room temperature, and cut into a suitable size of 5 mm * 5 mm to form area B.

[0032] To prevent cross-contamination and interference in color development between area A and area B, they were separated by a wax thread.

[0033] (4)Assembly: Assembly was carried out by hot pressing, with a hot pressing temperature of 80 - 100 °C, a pressure of 0.5 - 5 μPa, and a time of 1 - 10 minutes.

[0034] 2. Detection and performance testing Simulated wound exudates containing different concentrations of Staphylococcus aureus and Streptococcus hemolyticus were taken and respectively dropped on area A and area B of the intelligent dressing. The color development situation was observed and the color development time was recorded. The results showed that when the concentration of Staphylococcus aureus was 10 4 CFU / mL, an obvious red color development appeared in area A within 20 minutes; when the concentration of Streptococcus hemolyticus was 10 5 CFU / mL, a purple-red color development and a hemolysis zone appeared in area B within 30 minutes.

[0035] 3. Stability study Although the intelligent dressing of the present invention has shown good detection performance in the above embodiments, in order to ensure its reliability in actual use, further stability studies are needed. The prepared intelligent dressings are placed under different temperature (such as 25°C, 37°C, 45°C), humidity (such as 30%, 60%, 90%) and light conditions, and the changes in their appearance and detection performance are observed regularly. The research results show that in an environment of normal temperature (25°C) and relative humidity of 60%, the intelligent dressing can be stored stably for 180 days without obvious decline in detection performance.

[0036] Example 2 1. A preparation method of an intelligent dressing for dynamic monitoring of wound infection, comprising the following steps: (1) Preparation of the contact layer: The PP / PLA bicomponent non-woven fabric is subjected to plasma treatment with a treatment power of 50 W and a treatment time of 3 min to increase the surface activity of the non-woven fabric; A chitosan solution is prepared by dissolving chitosan in a 2% acetic acid solution with a pH of 4-5 to obtain a chitosan solution with a mass concentration of 3%. The treated non-woven fabric is immersed in the chitosan solution for 8 minutes and then taken out and dried to form a chitosan coating.

[0037] (2) Preparation of the hydrophilic layer: A calcium alginate solution and a sodium carboxymethylcellulose solution are prepared with water respectively, so that the concentration of the calcium alginate solution is 4% and the concentration of the sodium carboxymethylcellulose solution is 3%; then the two solutions are mixed in a volume ratio of 1:2, stirred evenly, poured into a mold, and dried at 50°C for 8 hours to form a calcium alginate / sodium carboxymethylcellulose composite hydrogel.

[0038] (3) Preparation of the color-developing layer: Preparation of area A: Curcumin, casein and agarose are dissolved in distilled water according to a mass ratio of 1:50:20, heated and stirred until completely dissolved, and evenly coated on a nitrocellulose membrane (5 μ / cm 3 ), air-dried at room temperature, and cut into a suitable size of 5 mm * 5 mm to form area A.

[0039] Preparation of area B: Betacyanin, freeze-dried sheep red blood cells and agarose are dissolved in distilled water according to a mass ratio of 3:500:600, heated and stirred until completely dissolved, and evenly coated on a nitrocellulose membrane (5 μ / cm 3 ), air-dried at room temperature, and cut into a suitable size of 5 mm * 5 mm to form area B.

[0040] To prevent the mutual contamination and interference of color development between area A and area B, a wax thread is used to separate area A and area B.

[0041] (4) Assembly: The assembly is carried out by bonding. The binder is polyacrylate and the bonding time is 20 minutes.

[0042] 2. Detection performance test Take the simulated wound exudates containing Staphylococcus aureus and Streptococcus hemolyticus at different concentrations and drop them on areas A and B of the intelligent dressing respectively. Observe the color change and record the color development time. The results show that the intelligent dressing has good detection effects on Staphylococcus aureus and Streptococcus hemolyticus, and the color development times are slightly shortened, being 18 minutes and 25 minutes respectively.

[0043] 3. Stability study Although the intelligent dressing of the present invention shows good detection performance in the above embodiments, in order to ensure its reliability in actual use, further stability studies are needed. Place the prepared intelligent dressings under different temperatures (such as 25 °C, 37 °C, 45 °C), humidities (such as 30%, 60%, 90%) and light conditions, and regularly observe the changes in their appearance and detection performance. The research results show that in an environment of normal temperature (25 °C) and relative humidity of 60%, the intelligent dressing can be stored stably for 180 days and the detection performance has no obvious decline.

[0044] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An intelligent dressing for dynamic monitoring of wound infection, characterized in that, It sequentially includes a contact layer, a hydrophilic layer, a color-developing layer, and a fixing layer from the inside to the outside.

2. The intelligent dressing for dynamic monitoring of wound infection according to claim 1, characterized in that, The contact layer uses a PP / PLA bicomponent non-woven fabric, which is coated with a chitosan coating after plasma treatment.

3. The intelligent dressing for dynamic monitoring of wound infection according to claim 2, wherein The hydrophilic layer is a calcium alginate / CMC composite hydrogel.

4. The intelligent dressing for dynamic monitoring of wound infection according to claim 1, wherein The color-developing layer includes area A and area B; area A is used to detect Staphylococcus aureus, and its components include 1.2 - 1.8% agarose, 0.08 - 0.12% curcumin, 4 - 6% casein, and the balance is water; Area B is used to detect hemolytic streptococcus, and its components include 5 - 7% agarose, 4 - 6% freeze-dried sheep red blood cells, 0.03 - 0.07% betacyanin, and the balance is water.

5. The intelligent dressing for dynamic monitoring of wound infection according to claim 1, wherein The fixing layer is a microporous TPU membrane.

6. The preparation method of the intelligent dressing for dynamic monitoring of wound infection according to any one of claims 1 to 5, characterized in that, It includes the following steps: (1) Preparation of the contact layer Perform plasma treatment on the PP / PLA bicomponent non-woven fabric to increase the surface activity of the non-woven fabric; Prepare a chitosan solution by dissolving chitosan in an acetic acid solution, soak the treated non-woven fabric in the chitosan solution, and then take it out to dry to form a chitosan coating; (2) Preparation of the hydrophilic layer Prepare a calcium alginate solution and a sodium carboxymethylcellulose solution respectively, then mix the two solutions in proportion, stir evenly, pour them into a mold, and dry to form a calcium alginate / sodium carboxymethylcellulose composite hydrogel; (3) Preparation of the color-developing layer Preparation of area A: Dissolve curcumin, casein, and agarose in distilled water according to the mass ratio, heat and stir until completely dissolved, then evenly coat it on a nitrocellulose membrane, dry at room temperature, and cut to a suitable size to form area A; Preparation of area B: Dissolve betacyanin, freeze-dried sheep red blood cells, and agarose in distilled water according to the mass ratio, heat and stir until completely dissolved, then evenly coat it on a nitrocellulose membrane, dry at room temperature, and cut to a suitable size to form area B; To prevent area A and area B from contaminating and interfering with each other's color development, separate them with a wax thread between area A and area B; (4) Assembly Stack the contact layer, the hydrophilic layer, the color-developing layer, and the fixing layer in sequence, and assemble them by hot pressing or bonding to make an intelligent dressing.

7. The preparation method of the intelligent dressing for dynamic monitoring of wound infection according to claim 6, characterized in that, Step (1) Preparation of the contact layer: Perform plasma treatment on the PP / PLA bicomponent non-woven fabric, with a treatment power of 50 - 300W and a treatment time of 30s - 5min to increase the surface activity of the non-woven fabric; Prepare a chitosan solution by dissolving chitosan in a 1% - 2% acetic acid solution with a pH of 4 - 5 to obtain a concentration of 0.5% - 5%, soak the treated non-woven fabric in the chitosan solution for 5 - 30 minutes, and then take it out to dry to form a chitosan coating.

8. The preparation method of the intelligent dressing for dynamic monitoring of wound infection according to claim 6, characterized in that, Step (2) Preparation of the hydrophilic layer: Prepare a calcium alginate solution and a sodium carboxymethylcellulose solution respectively, with the calcium alginate solution concentration of 1 - 3% and the sodium carboxymethylcellulose solution concentration of 2 - 5%; then mix the two solutions in a volume ratio of 1:1 - 1:2, stir evenly, pour them into a mold, and dry at 40 - 50°C for 12 - 24 hours to form a calcium alginate / sodium carboxymethylcellulose composite hydrogel.

9. The preparation method of the intelligent dressing for dynamic monitoring of wound infection according to claim 6, wherein Step (3) Preparation of the color-developing layer: Preparation of Area A: Dissolve curcumin, casein, and agarose in distilled water at a mass ratio of 1:33.3 - 75:10 - 22.5, heat and stir until completely dissolved, evenly coat it on a nitrocellulose membrane, air-dry at room temperature, cut to a suitable size to form Area A; Preparation of Area B: Dissolve betacyanin, freeze-dried sheep red blood cells, and agarose in distilled water at a mass ratio of 3 - 7:400 - 600:500 - 700, heat and stir until completely dissolved, evenly coat it on a nitrocellulose membrane, air-dry at room temperature, cut to a suitable size to form Area B; To prevent cross-contamination and interference in color development between Area A and Area B, separate them with a wax thread.

10. The preparation method of the intelligent dressing for dynamic monitoring of wound infection according to claim 9, characterized in that, In step (3), the color development layer can also be extended to detect and add a Pseudomonas aeruginosa detection area, and the cyanophycin turns green.

11. Use of the intelligent dressing for dynamic monitoring of wound infection according to any one of claims 1 - 5 in wound infection care.

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