Medical dressing and preparation method thereof

Abstract

The invention discloses a medical dressing and a preparation method thereof. In order to reduce the use cost of the medical dressing loaded with the silver antibacterial agent in the prior art, the Cu-Co composite nano-particles are selected to replace Ag nano-particles in the prior art to serve as the antibacterial agent. The research shows that when the content of Co is 8wt%-35wt%, the Cu-Co composite nano antibacterial particles prepared by magnetron sputtering have excellent antibacterial performance and biocompatibility. The medical dressing is economical and practical, and the antibacterial property of the medical dressing can be comparable with that of a silver-loaded medical dressing.

Description

Technical Field

[0001] The invention relates to the field of magnetron sputtering (C23C14 / 35), and in particular to a medical dressing and a preparation method thereof. Background Art

[0002] Medical dressings are wound dressings used to cover sores, wounds or other injuries. With the advancement of medicine, people have a deeper understanding of the wound healing process, and medical dressings are also constantly improving and developing. According to the different materials used, medical dressings are currently roughly divided into natural materials, synthetic polymer materials and composite materials.

[0003] For medical dressings, antibacterial properties are one of the most important requirements. Chinese patent CN201210006020 prepared nanosilver particles on a substrate through a physical vapor deposition process, thereby obtaining a medical dressing with strong antibacterial properties. However, metallic silver is a precious metal, and its high price hinders the widespread application of such dressings. Therefore, there is an urgent need to find a cheap alternative to medical dressings. Summary of the invention

[0004] The object of the present invention is to provide a medical dressing which is cheap, has excellent antibacterial performance and good biocompatibility.

[0005] The technical solution of the present invention is as follows:

[0006] A method for preparing a medical dressing comprises the following steps:

[0007] Substrate pretreatment: Use cotton nonwoven fabric as the substrate, cut it into a suitable size, wash it in anhydrous ethanol for 15-30 minutes, then rinse it in deionized water for 15-30 minutes, take it out and dry it under nitrogen for later use;

[0008] Preparation of Cu-Co composite nano antibacterial particles by magnetron sputtering: The dried cotton nonwoven fabric was placed in a magnetron sputtering coating machine, and the Cu-Co composite target material was used as the sputtering source. The mass content of Co in the composite target material was 8%-35%. Argon was used as the working gas to prepare Cu-Co composite nano antibacterial particles on the substrate surface. During the sputtering process, the background vacuum degree was 5×10 -4 Pa, argon flow rate is 50-60sccm, working pressure is 2.0-3.5Pa, sputtering temperature is 100-120℃, sputtering time is 20-30min;

[0009] Iodine tincture soaking: Place the substrate containing the Cu-Co composite nano antibacterial particles into medical iodine tincture and soak it for 18-24 hours before taking it out.

[0010] Preferably, the argon gas flow rate is 50 sccm.

[0011] Preferably, the working pressure is 2.0Pa.

[0012] Preferably, the sputtering temperature is 100°C.

[0013] Preferably, the sputtering time is 20 minutes.

[0014] Preferably, the soaking time is 24 hours.

[0015] Furthermore, the present invention also provides a medical dressing, which is prepared by the above method.

[0016] In order to reduce the use cost of the medical dressing loaded with silver antibacterial agent in the prior art, the present invention selects Cu-Co composite nanoparticles to replace Ag nanoparticles in the prior art as antibacterial agent. Studies have shown that when the Co content is 8wt%-35wt%, the Cu-Co composite nano antibacterial particles prepared by magnetron sputtering have excellent antibacterial properties and biocompatibility. The medical dressing is economical and practical, and its antibacterial properties are comparable to those of silver-loaded medical dressings. DETAILED DESCRIPTION

[0017] The technical effects of the present invention are verified below through specific examples, but the embodiments of the present invention are not limited thereto.

[0018] Example 1

[0019] Substrate pretreatment: Use cotton nonwoven fabric as the substrate, cut it into a suitable size, wash it in anhydrous ethanol for 15 minutes, then rinse it in deionized water for 15 minutes, take it out and dry it under nitrogen for later use;

[0020] Preparation of Cu-Co composite nano antibacterial particles by magnetron sputtering: The dried cotton nonwoven fabric was placed in a magnetron sputtering coating machine, and Cu-Co composite target material was used as the sputtering source (Co mass content was 8%), and argon was used as the working gas to prepare Cu-Co composite nano antibacterial particles on the substrate surface. During the sputtering process, the background vacuum degree was 5×10 -4 Pa, argon flow rate is 50sccm, working pressure is 2.0Pa, sputtering temperature is 120℃, and sputtering time is 20min;

[0021] Iodine tincture soaking: The substrate containing the Cu-Co composite nano antibacterial particles is placed in medical iodine tincture and soaked for 24 hours and then taken out.

[0022] Example 2

[0023] Substrate pretreatment: Use cotton nonwoven fabric as the substrate, cut it into a suitable size, wash it in anhydrous ethanol for 15 minutes, then rinse it in deionized water for 15 minutes, take it out and dry it under nitrogen for later use;

[0024] Preparation of Cu-Co composite nano antibacterial particles by magnetron sputtering: The dried cotton nonwoven fabric was placed in a magnetron sputtering coating machine, and Cu-Co composite target material was used as the sputtering source (Co mass content was 15%), and argon was used as the working gas to prepare Cu-Co composite nano antibacterial particles on the substrate surface. During the sputtering process, the background vacuum degree was 5×10 -4 Pa, argon flow rate is 50sccm, working pressure is 2.0Pa, sputtering temperature is 120℃, and sputtering time is 20min;

[0025] Iodine tincture soaking: The substrate containing the Cu-Co composite nano antibacterial particles is placed in medical iodine tincture and soaked for 24 hours and then taken out.

[0026] Example 3

[0027] Substrate pretreatment: Use cotton nonwoven fabric as the substrate, cut it into a suitable size, wash it in anhydrous ethanol for 15 minutes, then rinse it in deionized water for 15 minutes, take it out and dry it under nitrogen for later use;

[0028] Preparation of Cu-Co composite nano antibacterial particles by magnetron sputtering: The dried cotton nonwoven fabric was placed in a magnetron sputtering coating machine, and Cu-Co composite target material was used as the sputtering source (Co mass content was 21.7%), and argon was used as the working gas to prepare Cu-Co composite nano antibacterial particles on the substrate surface. During the sputtering process, the background vacuum degree was 5×10 -4 Pa, argon flow rate is 50sccm, working pressure is 2.0Pa, sputtering temperature is 120℃, and sputtering time is 20min;

[0029] Iodine tincture soaking: The substrate containing the Cu-Co composite nano antibacterial particles is placed in medical iodine tincture and soaked for 24 hours and then taken out.

[0030] Example 4

[0031] Substrate pretreatment: Use cotton nonwoven fabric as the substrate, cut it into a suitable size, wash it in anhydrous ethanol for 15 minutes, then rinse it in deionized water for 15 minutes, take it out and dry it under nitrogen for later use;

[0032] Preparation of Cu-Co composite nano antibacterial particles by magnetron sputtering: The dried cotton nonwoven fabric was placed in a magnetron sputtering coating machine, and Cu-Co composite target material was used as the sputtering source (Co mass content was 29%), and argon was used as the working gas to prepare Cu-Co composite nano antibacterial particles on the substrate surface. During the sputtering process, the background vacuum degree was 5×10 -4 Pa, argon flow rate is 50sccm, working pressure is 2.0Pa, sputtering temperature is 120℃, and sputtering time is 20min;

[0033] Iodine tincture soaking: The substrate containing the Cu-Co composite nano antibacterial particles is placed in medical iodine tincture and soaked for 24 hours and then taken out.

[0034] Example 5

[0035] Substrate pretreatment: Use cotton nonwoven fabric as the substrate, cut it into a suitable size, wash it in anhydrous ethanol for 15 minutes, then rinse it in deionized water for 15 minutes, take it out and dry it under nitrogen for later use;

[0036] Preparation of Cu-Co composite nano antibacterial particles by magnetron sputtering: The dried cotton nonwoven fabric was placed in a magnetron sputtering coating machine, and Cu-Co composite target material was used as the sputtering source (Co mass content was 35%), and argon was used as the working gas to prepare Cu-Co composite nano antibacterial particles on the substrate surface. During the sputtering process, the background vacuum degree was 5×10 -4 Pa, argon flow rate is 50sccm, working pressure is 2.0Pa, sputtering temperature is 120℃, and sputtering time is 20min;

[0037] Iodine tincture soaking: The substrate containing the Cu-Co composite nano antibacterial particles is placed in medical iodine tincture and soaked for 24 hours and then taken out.

[0038] Comparative Example 1

[0039] Substrate pretreatment: Use cotton nonwoven fabric as the substrate, cut it into a suitable size, wash it in anhydrous ethanol for 15 minutes, then rinse it in deionized water for 15 minutes, take it out and dry it under nitrogen for later use;

[0040] Preparation of Cu nano antibacterial particles by magnetron sputtering: The dried cotton nonwoven fabric was placed in a magnetron sputtering coating machine, and Cu target material was used as the sputtering source and argon gas was used as the working gas to prepare Cu nano antibacterial particles on the substrate surface. During the sputtering process, the background vacuum degree was 5×10 -4 Pa, argon flow rate is 50sccm, working pressure is 2.0Pa, sputtering temperature is 120℃, and sputtering time is 20min;

[0041] Iodine tincture soaking: The substrate containing the Cu nano antibacterial particles is placed in medical iodine tincture and soaked for 24 hours before being taken out.

[0042] Comparative Example 2

[0043] Substrate pretreatment: Use cotton nonwoven fabric as the substrate, cut it into a suitable size, wash it in anhydrous ethanol for 15 minutes, then rinse it in deionized water for 15 minutes, take it out and dry it under nitrogen for later use;

[0044] Preparation of Cu-Co composite nano antibacterial particles by magnetron sputtering: The dried cotton nonwoven fabric was placed in a magnetron sputtering coating machine, and Cu-Co composite target material was used as the sputtering source (Co mass content was 60%), and argon was used as the working gas to prepare Cu-Co composite nano antibacterial particles on the substrate surface. During the sputtering process, the background vacuum degree was 5×10 -4 Pa, argon flow rate is 50sccm, working pressure is 2.0Pa, sputtering temperature is 120℃, and sputtering time is 20min;

[0045] Iodine tincture soaking: The substrate containing the Cu-Co composite nano antibacterial particles is placed in medical iodine tincture and soaked for 24 hours and then taken out.

[0046] Next, we evaluated the antibacterial properties and biocompatibility of the samples in Examples 1-5 and Comparative Examples 1-2, and the specific method was as follows:

[0047] Antibacterial performance: The bacterial solution concentration is selected to be 4×10 8 cfu / ml of Staphylococcus aureus was used as the test bacterial solution. 0.2 ml of the test bacterial solution was dripped on the sample surface and cultured for 48 hours at 37°C and relative humidity RH>90%. Then the sample was taken out for live bacteria count and the antibacterial rate was obtained by counting. Five parallel tests were performed for each sample. The antibacterial rate calculation formula is:

[0048] R(%)=(AB) / A×100

[0049] In the formula: R represents the antibacterial rate;

[0050] A represents the average number of recovered bacteria in the control group;

[0051] B represents the average number of recovered bacteria in the examples or comparative examples.

[0052] Biocompatibility: The biocompatibility of each sample is evaluated by a hemolysis test. The principle is to put the sample in direct contact with blood and measure the amount of hemoglobin released after the red blood cell membrane is ruptured to detect the degree of hemolysis of each sample in vitro. The absorption wavelength of hemoglobin is 545nm, and its concentration can be detected by a spectrophotometer. The specific operation steps are as follows:

[0053] (1) After anesthetizing and fixing a healthy rabbit, slowly draw 4 mL of venous blood from the rabbit's ear vein, add 0.2 mL of 2% potassium oxalate to make fresh anticoagulated blood, and add 5 mL of 0.9% sodium chloride injection to dilute.

[0054] (2) Take three siliconized test tubes, add the test sample and 10 mL of sodium chloride injection into one test tube, add 10 mL of sodium chloride saline into one blank test tube as a negative control group, and add 10 mL of distilled water into the other blank test tube as a positive control group.

[0055] (3) All test tubes were kept in a 37°C water bath for 30 min, 0.2 mL of anticoagulated rabbit blood was added to each tube, and the tubes were kept at 37°C for 60 min. The tubes were then centrifuged at 1000 rpm for 5 min.

[0056] (4) Take the supernatant from the test tube and measure the absorbance at a wavelength of 545 nm. Perform three parallel tests on each sample and take the average value.

[0057] The hemolysis rate was calculated as follows:

[0058] Hemolysis rate (%) = (average absorbance of sample - absorbance of negative group) / (absorbance of positive group - absorbance of negative group) × 100

[0059] The experimental results are shown in Table 1.

[0060] Table 1 Antibacterial rate and hemolysis rate of each sample

[0061] serial number Antibacterial rate / % Hemolysis rate / % Example 1 95.5 4.9 Example 2 95.8 3.1 Example 3 96.1 2.1 Example 4 93.1 2.6 Example 5 90.5 2.8 Comparative Example 1 95.3 7.6 Comparative Example 2 82.0 3.7

[0062] It can be seen from Table 1 that when the Co content is 8wt%-35wt%, the Cu-Co composite nano antibacterial particles prepared by magnetron sputtering have excellent antibacterial properties and biocompatibility. Comprehensively examining the antibacterial properties and biocompatibility, Example 3 is the most preferred technical solution.

[0063] In order to intuitively compare the antibacterial properties of different samples, the present invention uses ultra-high concentration bacterial solution in the antibacterial performance test, which is intended to ensure that the antibacterial rate of each sample cannot reach 100%. In the actual use scenario of medical dressings, there will not be such a high demand for antibacterial requirements.

[0064] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a medical dressing, characterized in that: The preparation method comprises the following steps: Substrate pretreatment: Use cotton nonwoven fabric as the substrate, cut it into a suitable size, wash it in anhydrous ethanol for 15-30 minutes, then rinse it in deionized water for 15-30 minutes, take it out and dry it under nitrogen for later use; Preparation of Cu-Co composite nano antibacterial particles by magnetron sputtering: The dried cotton nonwoven fabric was placed in a magnetron sputtering coating machine, and the Cu-Co composite target material was used as the sputtering source. The mass content of Co in the composite target material was 8%-35%. Argon was used as the working gas to prepare Cu-Co composite nano antibacterial particles on the substrate surface. During the sputtering process, the background vacuum degree was 5×10 -4 Pa, argon flow rate is 50-60sccm, working pressure is 2.0-3.5Pa, sputtering temperature is 100-120℃, sputtering time is 20-30min; Iodine tincture soaking: Place the substrate containing the Cu-Co composite nano antibacterial particles into medical iodine tincture and soak it for 18-24 hours before taking it out.

2. A preparation method according to claim 1, characterized in that: The argon gas flow rate is 50 sccm.

3. A preparation method according to claim 1, characterized in that: The working pressure is 2.0Pa.

4. A preparation method according to claim 1, characterized in that: The sputtering temperature is 100°C.

5. A preparation method according to claim 1, characterized in that: The sputtering time is 20 min.

6. A preparation method according to claim 1, characterized in that: The soaking time is 24 hours.

7. A medical dressing, characterized in that: The medical dressing is prepared by the method according to any one of claims 1 to 6.