Preparation method of pH response cotton swab for wound infection monitoring

Abstract

A preparation method of a pH response cotton swab for wound infection monitoring comprises the steps that natural cotton fibers are soaked in a bromocresol green solution for dyeing, and the color of the bromocresol green solution is blue in the dyeing process; the soaked natural cotton fibers are washed with a buffer solution; extruding redundant buffer solution, and drying the natural cotton fibers to obtain orange-yellow natural cotton fibers; and finally, fixing the dried natural cotton fiber at the top end of the slender rod to obtain the pH response cotton swab. According to the method, the color change after the wound is wiped by the pH response cotton swab is utilized, the wound infection type of a patient is rapidly judged, and the pH value is 4.0-6.0 corresponding to an acute wound; the pH value of 7.0-10.0 corresponds to a chronic wound, and a corresponding treatment strategy is adopted based on the type of the wound, so that the working efficiency of medical personnel can be improved; meanwhile, compared with a traditional dressing form, the cotton swab avoids the risk of secondary infection caused by uncovering the dressing for multiple times.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices, and in particular relates to a method for preparing a pH-responsive cotton swab for wound infection monitoring. Background Art

[0002] Microbial infection of wounds is a serious problem that can hinder the healing of chronic wounds. Accurate, timely, and early detection of infection, and real-time monitoring of various wound healing biomarkers associated with infection are important for the treatment and care of chronic wounds. However, the clinical approach to regular wound assessment and care requires in-person visits to wound care clinics or hospitals, and dedicated medical staff to spend time regularly determining wound infection. Rapid detection of infection, especially chronic wound infection, is an important step in improving wound management and reducing antibiotic treatment. Medical staff can quickly give diagnostic results and take measures to treat infected wounds in a timely manner, which is crucial for wound healing.

[0003] The pH value of wound exudate is a key parameter for judging wound infection. Many physiological processes such as inflammatory response, collagen formation and angiogenesis will affect the change of pH value of wound exudate. Therefore, monitoring the pH value of the wound is helpful to judge the infection of the wound. Currently, most of the products used to monitor wound infection on the market are dressings, hydrogels, etc.; Publication No. CN202210263468.4 discloses a dressing for judging wound infection, which is based on bacterial cellulose gel produced by fermentation of Acetobacter xylinum. The fluorescent substrate 4-methylumbelliferyl-β-D glucuronide is loaded, and the enzymatic reaction with β-glucuronidase (β-GUS) secreted by bacteria generates fluorescent substances to quickly detect bacterial infection in situ, and the wound can be directly judged by observing the fluorescence. Whether it is infected. Similarly, Publication No. CN201910621326.9 discloses a method for preparing a pH-responsive photonic crystal gel-based for skin wound treatment, and prepares CS / PAA / nano-Cu 2 Wlq 4 The composite hydrogel is loaded with a pH-responsive photonic crystal base. Because the wound infection site is weakly acidic, the pH-responsive photonic crystal base can react in color under Bragg diffraction, and the color change can be observed by naked human eyes to determine whether the wound is infected. The above technology has problems such as complex preparation process, high cost, and inconvenient use. How to prepare a low-cost, easy-to-use, and pH-responsive cotton swab that can be used to detect wound infection is a problem that needs to be solved urgently. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a pH-responsive cotton swab for wound infection monitoring, which has a simple preparation process and low cost, in view of the above problems existing in the prior art.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A method for preparing a pH-responsive cotton swab for wound infection monitoring, the preparation method comprising: The natural cotton fiber is soaked in a bromocresol green solution for dyeing, and the color of the bromocresol green solution during the dyeing process is blue; The soaked natural cotton fibers are rinsed with a buffer solution; Dry the natural cotton fibers after squeezing out the excess buffer; The pH-responsive cotton swab can be obtained by fixing the dried natural cotton fiber on the top of a thin rod.

[0006] The dyeing is carried out at 60-90° C. for 20-30 minutes.

[0007] The bromocresol green solution is obtained by dissolving bromocresol green powder in an ethanol aqueous solution.

[0008] The mass ratio of the bromocresol green powder to the natural cotton fiber is 0.5-5:100.

[0009] The mass volume ratio of the natural cotton fiber to the bromocresol green solution is 1 g:50 mL.

[0010] The volume ratio of ethanol to deionized water in the ethanol aqueous solution is 1:1-9:1.

[0011] The buffer is a phosphate buffer or an acetate buffer.

[0012] The pH value of the buffer solution is 1.0-3.0.

[0013] The pH value of the buffer solution is 4.0-5.0.

[0014] The drying temperature is 40-60°C.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a preparation method of a pH-responsive cotton swab for wound infection monitoring. The method comprises the following steps: firstly, natural cotton fibers are soaked in a bromocresol green solution for dyeing, wherein the color of the bromocresol green solution is blue during the dyeing process; the soaked natural cotton fibers are rinsed with a buffer solution; then, the excess buffer solution is squeezed out and dried; finally, the dried natural cotton fibers are fixed to the top of a thin rod to obtain a pH-responsive cotton swab. The present invention utilizes the color change after the prepared pH-responsive cotton swab is wiped on the wound, so that the pH value of the patient's wound can be quickly determined, and the type of wound infection can be determined according to the pH value of the wound. The wound type corresponding to a pH value of 4.0-6.0 is an acute wound; the wound type corresponding to a pH value of 7.0-10.0 is a chronic wound. The corresponding treatment strategy is adopted based on the wound type, which helps to improve the work efficiency of medical staff; at the same time, the cotton swab avoids the risk of secondary infection caused by repeatedly uncovering the dressing compared to the traditional dressing form; in addition, the preparation process of the present preparation method is simple, low-cost, and can be widely promoted and applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of bromocresol green at different pH values.

[0017] Figure 2 The color change of the pH-responsive cotton swab in Example 1 when immersed in an acid-base solution, the pH gradient of the acid-base solution is 6.0-12.0.

[0018] Figure 3 This is the color change of the pH-responsive cotton swab of Example 9 when immersed in an acid-base solution, and the pH gradient of the acid-base solution is 6.0-12.0.

[0019] Figure 4 The K / S value curve of the pH responsive cotton swab obtained in Examples 1-4 is shown.

[0020] Figure 5 The K / S value curves of the pH-responsive cotton swabs obtained in Examples 1 and 5-7 are shown.

[0021] Figure 6 The K / S value curves of the pH response cotton swabs obtained in Example 7 and Comparative Example 2 are shown. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with specific implementations and drawings.

[0023] A method for preparing a pH-responsive cotton swab for wound infection monitoring, the preparation method comprising: The natural cotton fiber is soaked in a bromocresol green solution for dyeing, and the color of the bromocresol green solution during the dyeing process is blue; The soaked natural cotton fibers are rinsed with a buffer solution; Dry the natural cotton fibers after squeezing out the excess buffer; The pH-responsive cotton swab can be obtained by fixing the dried natural cotton fiber on the top of a thin rod.

[0024] The dyeing is carried out at 60-90° C. for 20-30 minutes.

[0025] The bromocresol green solution is obtained by dissolving bromocresol green powder in an ethanol aqueous solution.

[0026] The mass ratio of the bromocresol green powder to the natural cotton fiber is 0.5-5:100.

[0027] The mass volume ratio of the natural cotton fiber to the bromocresol green solution is 1 g:50 mL.

[0028] The volume ratio of ethanol to deionized water in the ethanol aqueous solution is 10:0-5:5.

[0029] The buffer is a phosphate buffer or an acetate buffer.

[0030] The pH value of the buffer solution is 1.0-3.0.

[0031] The pH value of the buffer solution is 4.0-5.0.

[0032] The drying temperature is 40-60°C.

[0033] The principle of the present invention is described as follows: Bromocresol green is an extremely sensitive pH indicator. Figure 1 The three forms A, B, and C are shown. Form A exists under extremely acidic conditions (pH value less than 3) or in powder form and is orange-yellow. Form B is a monoanionic form under acidic conditions (pH=3-4). Form C is a dianionic form under pH>5 and is blue.

[0034] The preparation method of the present invention first soaks the natural cotton fiber in a bromocresol green solution and heats it to 60-90°C for dyeing. Since there is protein in the natural cotton fiber, the amino group (-NH 2 ) is converted to NH during high temperature dyeing 3+ At the same time, due to the neutral pH of the dye system, the color of bromocresol green is blue, which means that bromocresol green is converted into a di-anionic form. The di-anionic form of bromocresol green can both electrostatically bond with natural cotton fibers and bind to NH 3+The groups are combined by electrostatic attraction, so that bromocresol green is loaded on the surface of natural cotton fibers; then the natural cotton fibers are washed with phosphate buffer or acetate buffer, the excess buffer is squeezed out, and the dyed natural cotton fibers are dried at 40-60°C to obtain dyed natural cotton fibers, and pH-responsive cotton swabs are prepared using the dyed natural cotton fibers. When the pH value of the buffer is 1.0-3.0, the dyed natural cotton fibers are orange-yellow, and when the pH value of the buffer is 4.0-5.0, the dyed natural cotton fibers are light yellow-green.

[0035] Affected by active neutrophils, acute wounds are more acidic, with a pH value between 4.0-6.0, while chronic wounds are often weakly alkaline, with a pH value between 7.0-10.0, which is more conducive to bacterial growth and reproduction, making the wounds susceptible to bacterial invasion and leading to infection and inflammation; the pH-responsive cotton swab prepared by the present invention has a pH value within the range of 4.0-12.0, and exhibits obvious color changes as the environmental pH value increases, which enables medical personnel to judge whether the wound is an acute wound or a chronic wound based on the color change of the pH-responsive cotton swab after wiping the wound, and thus select the corresponding treatment strategy.

[0036] If the natural cotton fiber is dried directly instead of being rinsed with buffer, the dried natural cotton fiber will appear light blue, resulting in no observable color change of the cotton swab when the pH value of the wound is around 9.0 in actual testing; in order to improve the pH response effect, it is rinsed with phosphate buffer or acetate buffer with a lower pH value (1.0-3.0) to wash away the bromocresol green solution floating on the surface of the natural cotton fiber, and convert the bromocresol green loaded on the natural cotton fiber into form A, making the natural cotton fiber appear orange-yellow. After being rinsed with buffer, the color change of the orange-yellow natural cotton fiber at a pH value between 4.0-12.0 can be better distinguished by the human eye.

[0037] The present invention utilizes ethanol aqueous solution to dissolve bromocresol green to obtain bromocresol green solution; this is because pectin and wax, hydrophobic substances on the surface of natural cotton fibers, are easily soluble in ethanol during the high-temperature dyeing process, so that the dyed natural cotton fibers have better hydrophilicity than ordinary natural cotton fibers, and a small amount of body fluid exuded from the wound can meet the detection requirements of the pH-responsive cotton swab for wound infection.

[0038] Embodiment 1: A method for preparing a pH-responsive cotton swab for wound infection monitoring is carried out in the following steps: S1. Soak 2 g of natural cotton fiber in a conical flask containing 100 mL of bromocresol green solution, place the conical flask in a 40°C water bath and heat it to 90°C, and continue heating for 25 minutes. During the heating process, the color of bromocresol green turns blue. After the heating is completed, take the conical flask out of the water bath, let it stand and cool to room temperature; wherein the bromocresol green solution is obtained by dissolving 0.01 g of bromocresol green powder in 100 mL of ethanol-water solution, and the volume ratio of anhydrous ethanol to deionized water in the ethanol-water solution is 9:1; the natural cotton fiber is Xinjiang cotton; S2, washing the natural cotton fiber with a phosphate buffer, wherein the pH value of the phosphate buffer is 2.0; S3, squeeze out the excess buffer, place the natural cotton fiber in an oven at 50°C for 6 hours, and the natural cotton fiber after drying is orange-yellow; S4. Take 0.05 g of dried natural cotton fiber and fix it on the top of a thin rod to obtain a pH-responsive cotton swab.

[0039] Embodiment 2: The difference from Example 1 is that: The volume ratio of anhydrous ethanol to deionized water in the ethanol aqueous solution is 8:2.

[0040] Embodiment 3: The difference from Example 1 is that: The volume ratio of anhydrous ethanol to deionized water in the ethanol aqueous solution is 7:3.

[0041] Embodiment 4: The difference from Example 1 is that: The volume ratio of anhydrous ethanol to deionized water in the ethanol aqueous solution is 1:1.

[0042] Embodiment 5: The difference from Example 1 is that: The amount of bromocresol green powder used was 0.02 g (1% owf).

[0043] Embodiment 6: The difference from Example 1 is that: The amount of bromocresol green powder used was 0.06 g (3% owf).

[0044] Embodiment 7: The difference from Example 1 is that: The amount of bromocresol green powder used is 0.1 g (5% owf).

[0045] Embodiment 8: The difference from Example 1 is that: Exchange the phosphate buffer for acetate buffer.

[0046] Embodiment 9: The difference from Example 1 is that: The pH value of the phosphate buffer solution is 4.0; the natural cotton fiber after drying is light yellow-green.

[0047] Comparative Example 1: The difference from Example 1 is that: The pH value of the phosphate buffer solution is 7.0, and the natural cotton fiber after drying is light blue.

[0048] Comparative Example 2: The difference from Example 1 is that: Replace natural cotton fibers with cotton wool.

[0049] Performance Test: 1. Soak the pH response cotton swabs of Example 1 and Example 9 in 0.1 mL of an acid-base solution, wherein the pH gradient of the acid-base solution is 6.0-12.0, and observe the change of the color of the cotton swab with the pH of the acid-base solution; the observation results of Example 1 and Example 9 are as follows: Figure 2 , Figure 3 shown by Figure 2 , Figure 3 It can be seen that the pH responsive cotton swab of the present invention can intuitively display color changes within the pH range of 6.0-12.0, and only 0.1 mL of acid-base solution is required to change the color of the pH responsive cotton swab. It can be seen that a very small amount of solution can meet the detection requirements.

[0050] 2. Draw the K / S value curve of the pH response cotton swab of Examples 1-4, such as Figure 3 shown; from Figure 3 It can be seen that the rinsing with phosphate buffer can preserve the bromocresol green on the natural cotton fiber; the K / S value of the maximum absorption peak is used to represent the dyeing performance. The larger the K / S value of the maximum absorption peak, the better the dyeing performance. The K / S value of the maximum absorption peak of Example 1 is the largest among Examples 1-4, reaching 0.258, indicating that the dyeing effect is better when the volume ratio of anhydrous ethanol to deionized water is 9:1.

[0051] 3. Draw the K / S value curve of the pH response cotton swabs of Examples 1, 5-7, as shown in FIG. Figure 5 shown; from Figure 5 It can be seen that within the dye concentration range of 0.1-5% owf, as the dye concentration increases, the dyeing effect becomes better.

[0052] 4. Draw the K / S value curve of the pH response cotton swab of Example 7 and Comparative Example 2, as shown in FIG. Figure 6 shown; from Figure 6It can be seen that the K / S value of absorbent cotton is much lower than that of natural cotton fiber. This is because the absorbent cotton removes the protein substances that bind to bromocresol green, making it difficult for the absorbent cotton to form a stable bond with bromocresol green.

Claims

1. A method for preparing a pH-responsive cotton swab for wound infection monitoring, Features: The preparation method comprises: The natural cotton fiber is soaked in a bromocresol green solution for dyeing, and the color of the bromocresol green solution during the dyeing process is blue; The soaked natural cotton fibers are rinsed with a buffer solution; Dry the natural cotton fibers after squeezing out the excess buffer; The pH-responsive cotton swab can be obtained by fixing the dried natural cotton fiber on the top of a thin rod.

2. A method for preparing a pH-responsive cotton swab for wound infection monitoring according to claim 1, Features: The dyeing is carried out at 60-90° C. for 20-30 minutes.

3. A method for preparing a pH-responsive cotton swab for wound infection monitoring according to claim 1 or 2, Features: The bromocresol green solution is obtained by dissolving bromocresol green powder in an ethanol aqueous solution.

4. A method for preparing a pH-responsive cotton swab for wound infection monitoring according to claim 3, Features: The mass ratio of the bromocresol green powder to the natural cotton fiber is 0.5-5:

10.

5. A method for preparing a pH-responsive cotton swab for wound infection monitoring according to claim 4, Features: The mass volume ratio of the natural cotton fiber to the bromocresol green solution is 1 g:50 mL.

6. A method for preparing a pH-responsive cotton swab for wound infection monitoring according to claim 5, Features: The volume ratio of ethanol to deionized water in the ethanol aqueous solution is 1:1-9:

1.

7. A method for preparing a pH-responsive cotton swab for wound infection monitoring according to claim 1 or 2, Features: The buffer is a phosphate buffer or an acetate buffer.

8. A method for preparing a pH-responsive cotton swab for wound infection monitoring according to claim 7, Features: The pH value of the buffer solution is 1.0-3.

0.

9. The method for preparing a pH-responsive cotton swab for wound infection monitoring according to claim 7, Features: The pH value of the buffer solution is 4.0-5.

0.

10. A method for preparing a pH-responsive cotton swab for wound infection monitoring according to claim 1 or 2, Features: The drying temperature is 40-60°C.

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