A dual antimicrobial polyurethane dressing and a method of making the same

Abstract

The application discloses a kind of dual antibacterial polyurethane dressings and preparation method thereof, the preparation method of the dual antibacterial polyurethane dressings includes the following steps: adding sodium periodate in sodium acetate buffer solution, after mixing, adding dopamine hydrochloride, then polyurethane sponge is soaked in it and is reacted, after reaction is finished, after washing, the modified product is obtained;The modified product is soaked in silver nitrate solution, ultraviolet light irradiation is carried out in dark condition, after ultrasonic washing, dry, the dual antibacterial polyurethane dressing is prepared.The polyurethane antibacterial sponge prepared in the application not only has good inherent antibacterial effect, but also can obtain certain photothermal antibacterial capacity by external near-infrared irradiation.More importantly, under natural environment, the polymerization of dopamine can only occur under alkaline conditions, usually needs several days of reaction time, the application creatively selects the method of acidic environment and oxidizing agent, greatly shortens reaction time, and improves work efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of medical materials, in particular to a dual antibacterial polyurethane dressing and a preparation method thereof. Background Art

[0002] Advances in technology have led to increasing demands for medical dressings. Traditional dressings, such as gauze and cotton, are prone to bacterial growth. Wound exudate easily forms a scab with dry dermal tissue, hindering epithelialization. Furthermore, the wound surface easily adheres to the dressing, causing secondary trauma to the patient during dressing changes. Therefore, the development of a novel wound dressing is crucial. Foam-type polyurethane sponge dressings not only absorb excess wound exudate, block foreign matter and some bacteria, protect exposed nerve endings, and alleviate pain, but also help keep the wound moist, preventing excessive evaporation of wound exudate and the formation of dry scabs. This prevents patients from sustaining secondary mechanical damage during dressing changes, thus promoting wound healing. However, traditional polyurethane lacks antibacterial properties, and bacterial infection is inevitable during medical treatment. Therefore, the development of a polyurethane sponge dressing with excellent antibacterial properties is of great significance. Silver nanoparticles are a common antibacterial material, but how to load silver nanoparticles onto polyurethane sponges remains an unresolved problem. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention aims to provide a dual antibacterial polyurethane dressing and a preparation method thereof.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A method for preparing a dual antibacterial polyurethane dressing comprises the following steps:

[0006] (1) Sodium periodate was added to sodium acetate buffer, mixed well, and then dopamine hydrochloride was added. Then, a polyurethane sponge was immersed in the buffer to react. After the reaction was completed, the first modified product was obtained after washing, which was recorded as PUF@PDA sponge.

[0007] (2) The PUF@PDA sponge described in step (1) is immersed in a silver nitrate solution, irradiated with ultraviolet light in dark conditions, and dried after ultrasonic washing to prepare the dual antibacterial polyurethane dressing, which is recorded as PUF@PDA@Ag polyurethane antibacterial sponge.

[0008] Preferably, in step (1), the concentration of the sodium acetate buffer is 40-100 mM.

[0009] Preferably, in step (1), the pH of the sodium acetate buffer is 2-6.

[0010] Preferably, in step (1), the concentration of sodium periodate in sodium acetate buffer is 4-15 mM.

[0011] Preferably, in step (1), the concentration of dopamine hydrochloride in sodium acetate buffer is 5-15 mM.

[0012] Preferably, in step (1), the reaction time is 20 to 60 minutes.

[0013] Preferably, in step (1), washing is performed with deionized water.

[0014] Preferably, in step (2), the concentration of the silver nitrate solution is 0.05 to 1M.

[0015] Preferably, in step (2), the wavelength of ultraviolet light irradiation is 365 nm.

[0016] Preferably, in step (2), the ultraviolet light irradiation time is 10 to 60 minutes.

[0017] Preferably, the drying in step (2) is vacuum drying, the vacuum drying temperature is 60° C., and the vacuum drying time is 2 h.

[0018] The double antibacterial polyurethane dressing prepared by the preparation method of the double antibacterial polyurethane dressing is disclosed.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) During the use of PUF@PDA@Ag polyurethane antibacterial sponge dressing, silver nanoparticles are released continuously and stably, and have certain antibacterial properties, which enables the patient's wound site to resist the invasion of external bacteria.

[0021] (2) When infection occurs, 808nm near-infrared laser irradiation can be applied during the use of PUF@PDA@Ag polyurethane antibacterial sponge dressing to raise the temperature of the infected area to 55-65℃, killing bacteria through physical action without damaging the patient's skin tissue or causing irritation.

[0022] (3) The present invention creatively uses an acidic environment and an oxidant to promote dopamine polymerization, which greatly shortens the reaction time and improves the reaction efficiency.

[0023] The reaction principle or mechanism involved in the present invention is:

[0024] The polymerization of dopamine is a time-dependent process. In the initial stage, a dopamine quinone structure is formed, which further forms polydopamine, and then aggregates. Using an acidic environment (sodium acetate buffer) and an oxidant (sodium periodate) can accelerate the polymerization of dopamine and delay its aggregation process, so that it is evenly loaded on the surface of the polyurethane sponge to be modified, forming a uniform and firm intermediate layer, which builds a reaction platform for further silver loading. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a line graph comparing the sterilization rates of the PUF@PDA@Ag polyurethane antibacterial sponges prepared in Examples 1 to 5 with and without near-infrared irradiation, where "without NIR" represents no near-infrared irradiation and "with NIR" represents near-infrared irradiation.

[0026] Figure 2 This is a bar chart comparing the cytotoxicity of the PUF@PDA@Ag polyurethane antibacterial sponges prepared in Examples 1 to 5. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] The three-dimensional dimensions of the polyurethane sponge described in the embodiment are 1 cm*1 cm*0.5 cm.

[0029] Example 1

[0030] A method for preparing a dual antibacterial polyurethane dressing comprises the following steps:

[0031] First, 50 mL of 80 mM sodium acetate buffer was used to prepare an acidic solution. Sodium periodate was added to a concentration of 5 mM to create an oxidizing environment. After mixing thoroughly, dopamine hydrochloride was added to a concentration of 10 mM. The polyurethane sponge was then quickly immersed in the solution. After a 20-minute reaction, the polyurethane sponge was removed and washed with deionized water to obtain the first-step modified product, the PUF@PDA sponge. This was followed by the second step: the PUF@PDA sponge was immersed in a 0.1 M silver nitrate solution. After irradiation with 365 nm ultraviolet light for 30 minutes in the dark, the sponge was ultrasonically washed with deionized water, and then dried in a vacuum drying oven (drying temperature: 60°C, time: 2 hours) to obtain the PUF@PDA@Ag polyurethane antibacterial sponge.

[0032] Example 2

[0033] A method for preparing a dual antibacterial polyurethane dressing comprises the following steps:

[0034] First, 50 mL of 100 mM sodium acetate buffer was prepared as an acidic solution. Sodium periodate was added to a concentration of 8 mM to create an oxidizing environment. After mixing, dopamine hydrochloride was added to a concentration of 6 mM. The polyurethane sponge was then quickly immersed in the solution. After 40 minutes of reaction, the polyurethane sponge was removed and washed with deionized water to obtain the first-step modified product, PUF@PDA sponge. The second step was then carried out: the PUF@PDA sponge was immersed in a 0.5 M silver nitrate solution, irradiated with 365 nm UV light for 40 minutes in the dark, and then ultrasonically washed with deionized water. The sponge was then dried in a vacuum drying oven (drying temperature: 60°C, time: 2 hours) to obtain the PUF@PDA@Ag polyurethane antibacterial sponge.

[0035] Example 3

[0036] A method for preparing a dual antibacterial polyurethane dressing comprises the following steps:

[0037] First, 50 mL of 80 mM sodium acetate buffer was used to prepare an acidic solution. Sodium periodate was added to a concentration of 4 mM to create an oxidizing environment. After mixing thoroughly, dopamine hydrochloride was added to a concentration of 15 mM. The polyurethane sponge was then quickly immersed in the solution. After a 20-minute reaction, the polyurethane sponge was removed and washed with deionized water to obtain the first-step modified product, the PUF@PDA sponge. This was followed by the second step: the PUF@PDA sponge was immersed in a 0.05 M silver nitrate solution. After irradiation with 365 nm ultraviolet light for 20 minutes in the dark, the sponge was ultrasonically washed with deionized water, and then dried in a vacuum drying oven (drying temperature: 60°C, time: 2 hours) to obtain the PUF@PDA@Ag polyurethane antibacterial sponge.

[0038] Example 4

[0039] A method for preparing a dual antibacterial polyurethane dressing comprises the following steps:

[0040] First, 50 mL of 40 mM sodium acetate buffer was used to prepare an acidic solution. Sodium periodate was added to a concentration of 6 mM to create an oxidizing environment. After mixing, dopamine hydrochloride was added to a concentration of 10 mM. The polyurethane sponge was then quickly immersed in the solution. After a 60-minute reaction, the polyurethane sponge was removed and washed with deionized water to obtain the first-step modified product, the PUF@PDA sponge. This was followed by the second step: the PUF@PDA sponge was immersed in a 0.8 M silver nitrate solution. After irradiation with 365 nm UV light for 60 minutes in the dark, the sponge was ultrasonically washed with deionized water, and then dried in a vacuum drying oven (drying temperature: 60°C, time: 2 hours) to obtain the PUF@PDA@Ag polyurethane antibacterial sponge.

[0041] Example 5

[0042] A method for preparing a dual antibacterial polyurethane dressing comprises the following steps:

[0043] First, 50 mL of 50 mM sodium acetate buffer was prepared as an acidic solution. Sodium periodate was added to a concentration of 10 mM to create an oxidizing environment. After mixing thoroughly, dopamine hydrochloride was added to a concentration of 5 mM. The polyurethane sponge was then quickly immersed in the solution. After a 20-minute reaction, the polyurethane sponge was removed and washed with deionized water to obtain the first-step modified product, the PUF@PDA sponge. This was followed by the second step: the PUF@PDA sponge was immersed in a 0.2 M silver nitrate solution. After irradiation with 365 nm UV light for 30 minutes in the dark, the sponge was ultrasonically washed with deionized water, and then dried in a vacuum drying oven (drying temperature: 60°C, time: 2 hours) to obtain the PUF@PDA@Ag polyurethane antibacterial sponge.

[0044] Antibacterial performance test of PUF@PDA@Ag antibacterial dressing:

[0045] The direct contact method was used to detect the inherent antibacterial ability and photothermal synergistic antibacterial ability of the dual antibacterial polyurethane dressing prepared by the present invention. 0.05 g of the polyurethane antibacterial sponges prepared in Examples 1 to 5 were added to a sterile 24-well plate and divided into a common group and a photothermal group. 50 μL of bacterial suspension (Staphylococcus aureus, 106 CFU / mL) was added to each sponge. For the photothermal group, an 808 nm near-infrared laser (1 W / cm 2 ) for 10 minutes. Incubate the 24-well plate at 37°C, 160 rpm for 4 hours. Then, add 500 μL of sterile PBS buffer (pH 7.2-7.4) to each well to resuspend the live bacteria. Sterile PBS solution serves as a negative control. Then, aspirate 50 μL of the resuspended bacterial solution and spread it onto an LB agar plate. Incubate at 37°C for 24 hours, then count the colonies. Calculate the sterilization rate using the following formula:

[0046]

[0047] In the formula, blank represents the negative control group, and smple represents the normal group or photothermal group.

[0048] Biocompatibility testing of PUF@PDA@Ag antibacterial dressing:

[0049] The cytotoxicity test of the dressing was carried out by cell counting kit-8 (CCK-8). The cell culture method: L929 cells were inoculated into a culture flask, and 4 mL of DMEM complete medium (preparation method: 100 mL of complete medium, DMEM basal medium 90 mL, 10 mL of calf serum, 100 U / mL of penicillin, 100 U / mL of streptomycin) was added. The culture flask was placed in a cell culture box (37℃, 5% carbon dioxide), and the culture medium was replaced every 1-2 days. After 3 times, the cells in the logarithmic growth phase were collected, digested with 0.25% trypsin, added to fresh culture medium, and uniformly distributed to obtain a cell suspension.

[0050] CCK8 test: the counted fibroblast suspension was inoculated in a 96-well cell culture plate for 24 hours, and the cells adhered to the wall. The original culture medium was removed from the 96-well plate, and PBS buffer (PH 7.2-7.4) was added, and each well was washed twice. 0.05 g of polyurethane antibacterial sponge prepared in examples 1-5 was added to the 96-well plate, and was cultured in a CO2 incubator (37℃, 5%) respectively. After 1 day of culture, the plate was removed, 10 μL of CCK-8 solution was added, and was transferred to a cell culture (37℃, 5% carbon dioxide) box for 2 hours. The absorbance of the solution at 450 nm was measured by an enzyme-labeled instrument. Five parallel experimental data were taken for each hydrogel extract sample group to reduce errors. In addition, 100 μL of fresh whole cell culture medium solution (100 uL of DMEM complete medium for cells) was added to the well as a positive control, and only the medium and CCK-8 hole as a background control.

[0051] The relative cell viability was calculated according to the following formula:

[0052]

[0053] In the formula, OD1 is the absorbance of the sample group, OD2 is the absorbance of the blank group (without cells), and OD3 is the absorbance of the positive control (fresh medium).

[0054] Figure 1 The bar graph of the bactericidal rate of the PUFAgPDA@Ag polyurethane antibacterial sponge prepared in examples 1-5 with and without near-infrared irradiation. From the figure, it can be seen that Figure 1 It can be seen that without near-infrared irradiation, the bactericidal rate of the PUFAgPDA@Ag antibacterial dressing is about 50%, which can ensure that the wound is not infected under normal circumstances. After applying 808 near-infrared light, the bactericidal rate of the PUFAgPDA@Ag antibacterial dressing increases to about 85%, which can greatly kill bacteria.

[0055] Figure 2The bar chart shows the cytotoxicity comparison of the PUF@PDA@Ag polyurethane antibacterial sponges prepared in Examples 1 to 5. Figure 2 It can be seen that the PUF@PDA@Ag polyurethane antibacterial sponge prepared in the present invention has basically no cytotoxicity to L929 cells, which can be judged that this antibacterial sponge has good biocompatibility.

[0056] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a dual antibacterial polyurethane dressing, characterized in that: The steps include: (1) Sodium periodate was added to sodium acetate buffer, mixed well, and dopamine hydrochloride was added. Then, a polyurethane sponge was immersed in the buffer to react. After the reaction was completed, the PUF@PDA sponge was obtained after washing. The concentration of the sodium acetate buffer in step (1) is 40-100 mM; The concentration of sodium periodate in sodium acetate buffer in step (1) is 4-15 mM; (2) Soaking the PUF@PDA sponge in step (1) in a silver nitrate solution, irradiating it with ultraviolet light in the dark, and drying it after ultrasonic washing to prepare a dual antibacterial polyurethane dressing; the ultraviolet irradiation time in step (2) is 10 to 60 minutes; the concentration of the silver nitrate solution in step (2) is 0.05 to 1M.

2. The method for preparing a dual antibacterial polyurethane dressing according to claim 1, characterized in that: The concentration of dopamine hydrochloride in the sodium acetate buffer in step (1) is 5-15 mM.

3. The method for preparing a dual antibacterial polyurethane dressing according to claim 2, characterized in that: The reaction time of step (1) is 20 to 60 minutes.

4. The method for preparing a dual antibacterial polyurethane dressing according to claim 1, characterized in that: The wavelength of the ultraviolet light irradiation in step (2) is 365 nm.

5. The method for preparing a dual antibacterial polyurethane dressing according to claim 4, characterized in that: The drying in step (2) is vacuum drying, the vacuum drying temperature is 60°C, and the vacuum drying time is 2 hours; The washing in step (1) is carried out with deionized water.

6. A dual antibacterial polyurethane dressing prepared by the method for preparing a dual antibacterial polyurethane dressing according to any one of claims 1 to 5.

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