Preparation method of berberine-loaded silk fibroin antibacterial coating

Abstract

The invention discloses a preparation method of a berberine-loaded silk fibroin antibacterial coating. The preparation method comprises the following steps: S1, pretreating silk fibroin; s2, optimizing the mixing proportion of silk fibroin and berberine; s3, modifying the silk fibroin-berberine material with glycerol; and S4, preparing an antibacterial coating solution. The preparation method has the technical effects and advantages that the antibacterial effect is obvious, and bacterial biofilms are not easy to generate.

Description

Technical Field

[0001] The invention relates to the field of antibacterial coatings, and more specifically to a method for preparing a berberine-loaded silk fibroin antibacterial coating. Background Art

[0002] The surface coating of Chinese patent medicine mainly plays the following roles:

[0003] 1. Protect drugs: The surface coating can effectively isolate harmful substances such as moisture, oxygen and microorganisms in the air, prevent drugs from getting damp, oxidized and deteriorating, thereby extending the shelf life of drugs.

[0004] 2. Improve drug efficacy: Some coating materials have a sustained-release effect, which can slowly release drugs in the body and maintain long-lasting and stable drug efficacy. In addition, some coatings can also improve the bioavailability of drugs, making them easier to be absorbed by the human body.

[0005] 3. Enhanced user experience: Surface coating can improve the taste of the drug, reduce the irritation and side effects of the drug, and improve the patient's comfort in taking the drug.

[0006] Currently, the bacterial infection problems caused by existing biological coatings are mainly treated by antibiotic intervention, but they are prone to problems such as abnormal bleeding and bacterial resistance. Summary of the invention

[0007] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for preparing a berberine-loaded silk fibroin antibacterial coating.

[0008] The invention solves the problem that the antibacterial effect of current biomedical coatings is not obvious and bacterial biofilm is easily generated.

[0009] The technical solution of the present invention is as follows:

[0010] A method for preparing a berberine-loaded silk fibroin antibacterial coating comprises the following steps:

[0011] 1. Pretreatment of silk fibroin

[0012] For the pretreatment of silk fibroin, the team used glycerol modification to improve the structure and performance of silk fibroin. On the one hand, the silk fibroin film contains more than 30% glycerol. After drying in a fume hood, the secondary structure of silk fibroin can be transformed from the water-soluble Silk I configuration to the stable Silk II configuration, which has the effect of delaying drug release; on the other hand, glycerol modification makes the silk fibroin material have good softness and smoothness and can reduce the friction coefficient of the coating surface.

[0013] 2. Optimization of the mixing ratio of silk fibroin and berberine

[0014] ① Preparation of experimental materials: Use the extracted and prepared berberine and silk fibroin solution;

[0015] ② Design the mass ratio gradient of silk fibroin and berberine: set six gradients of 100:0, 90:10, 80:20, 70:30, 60:40, and 50:50 in sequence and mix them evenly.

[0016] ③Observe whether floccules are produced: Figure 1 It can be seen that a large amount of flocs were produced during the mixing process of the solutions with a mass ratio of silk fibroin to berberine of 80:20, 70:30, 60:40 and 50:50, while no flocs were produced in the 90:10 solution.

[0017] ④ Screening and optimization experiment: Silk fibroin solution (7% w / v) and berberine (4 mg / mL) dissolved in deionized water were selected, and the mass ratio of silk fibroin to berberine was designed to be 10:0, 10:1, 20:1, 30:1, 40:1, 50:1. After mixing evenly, the mixture was dried at 60°C, and then the dried material was treated with steam at 60°C for 6 hours to obtain the steam-treated silk fibroin / berberine antibacterial material. Escherichia coli and Staphylococcus aureus were selected for agar plate diffusion experiments to determine the antibacterial effect of silk fibroin / berberine under different mass ratios.

[0018] 3. Glycerol modified silk fibroin-berberine material

[0019] Silk fibroin / berberine material was prepared at a mass ratio of silk fibroin to berberine of 10:1, and was treated with steam and modified with glycerol respectively.

[0020] 4. Preparation of antibacterial coating solution

[0021] According to the experimental conclusions drawn from the above three experiments, the antibacterial coating solution was prepared. The experimental process is as follows:

[0022] ① Weigh berberine powder and dissolve it in deionized water. The concentration of berberine solution is 4 mg / mL;

[0023] ② Dilute the silk fibroin solution with deionized water to a concentration of 7% (w / v), add glycerol to the silk fibroin solution, the mass proportion of glycerol is 30%, and mix well;

[0024] ③ Evenly mix the 4 mg / mL berberine solution and the silk fibroin glycerol mixed solution, wherein the mass ratio of silk fibroin to berberine is 10:1.

[0025] Technical effects and advantages of the present invention:

[0026] Compared with the biological coatings intervened by traditional antibiotics, the berberine-loaded silk fibroin antibacterial coating proposed in the present invention has significant advantages. First, by modifying the silk fibroin with glycerol, not only its structure and performance are improved, but also the stability of the coating and the delay of drug release are enhanced. Secondly, the optimized mixing ratio of silk fibroin and berberine ensures the uniform distribution of berberine in the silk fibroin, avoids the generation of flocs, and thus improves the antibacterial effect. The experimental results show that the coating under the optimal mixing ratio has a significant inhibitory effect on Escherichia coli and Staphylococcus aureus. In addition, glycerol modification also gives the coating good softness, smoothness and toughness, reduces the friction coefficient of the coating surface, and improves its biocompatibility and durability. In summary, the antibacterial coating of the present invention has broad application prospects in solving the problem of bacterial infection in biomedical coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Optical images of silk fibroin and berberine mixed in different proportions.

[0028] Figure 2 The antibacterial effect diagram of silk fibroin / berberine in different ratios;

[0029] A: Staphylococcus aureus; B: Escherichia coli

[0030] The mass ratio of silk fibroin to berberine is a: 10:1; b: 20:1; c: 30:1; d: 40:1; e: 50:1; f: 10:0.

[0031] Figure 3 Optical photos of silk fibroin / berberine materials; wherein, a: silk fibroin; b: silk fibroin / berberine; c: glycerol-modified silk fibroin / berberine;

[0032] d: Steam treatment-silk fibroin / berberine. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] 1.1 Pretreatment of silk fibroin

[0035] For the pretreatment of silk fibroin, the team used glycerol modification to improve the structure and performance of silk fibroin. On the one hand, the silk fibroin film contains more than 30% glycerol. After drying in a fume hood, the secondary structure of silk fibroin can be transformed from the water-soluble Silk I configuration to the stable Silk II configuration, which has the effect of delaying drug release; on the other hand, glycerol modification makes the silk fibroin material have good softness and smoothness and can reduce the friction coefficient of the coating surface.

[0036] 1.2 Optimization of the mixing ratio of silk fibroin and berberine

[0037] ①Experimental material preparation: extraction and preparation of berberine and silk fibroin solution;

[0038] ② Design the mass ratio gradient of silk fibroin and berberine: set six gradients of 100:0, 90:10, 80:20, 70:30, 60:40, and 50:50 in sequence and mix them evenly.

[0039] ③Observe whether floccules are produced: Figure 1 It can be seen that a large amount of flocs were produced during the mixing process of the solutions with a mass ratio of silk fibroin to berberine of 80:20, 70:30, 60:40 and 50:50, while no flocs were produced in the 90:10 solution.

[0040] The above experimental results show that the solubility of berberine in silk fibroin is limited, and berberine is prone to form flocs when the silk fibroin content is high.

[0041] ④ Screening and optimization experiment: Silk fibroin solution (7% w / v) and berberine (4 mg / mL) dissolved in deionized water were selected, and the mass ratio of silk fibroin to berberine was designed to be 10:0, 10:1, 20:1, 30:1, 40:1, 50:1. After mixing evenly, the mixture was dried at 60°C, and then the dried material was treated with steam at 60°C for 6 hours to obtain the steam-treated silk fibroin / berberine antibacterial material. Escherichia coli and Staphylococcus aureus were selected for agar plate diffusion experiments to determine the antibacterial effect of silk fibroin / berberine under different mass ratios.

[0042] The experimental results are as follows Figure 2 As shown in the figure, the antibacterial effect was the best when the mass ratio of silk fibroin to berberine was 10:1, the antibacterial effect of the mass ratio of 20:1 was better than that of 30:1, the mass ratios of 40:1 and 50:1 had almost no inhibitory effect, and the blank control sample pure silk fibroin had no antibacterial effect on the two bacteria. Therefore, the mass ratio of silk fibroin to berberine was determined to be 10:1 as the optimal mixing ratio.

[0043] 1.3 Glycerol-modified silk fibroin-berberine material

[0044] Silk fibroin / berberine material was prepared at a mass ratio of silk fibroin to berberine of 10:1, and was treated with steam and modified with glycerol respectively.

[0045] The experimental results are as follows Figure 3 As shown: berberine was observed to be evenly distributed on the silk fibroin, and the color of the silk fibroin was yellow-green at this time. The glycerol-modified silk fibroin / berberine could be bent arbitrarily, had good toughness, and a smooth and elastic surface, while the silk fibroin / berberine treated with water vapor was wrinkled and uneven as a whole, and was easy to break and crack when picked up with tweezers; therefore, glycerol modification was used to treat the silk fibroin-berberine material.

[0046] 1.5 Preparation of antimicrobial coating solution

[0047] According to the experimental conclusions drawn from the above three experiments, the antibacterial coating solution was prepared. The experimental process is as follows:

[0048] ① Weigh berberine powder and dissolve it in deionized water. The concentration of berberine solution is 4 mg / mL;

[0049] ② Dilute the silk fibroin solution with deionized water to a concentration of 7% (w / v), add glycerol to the silk fibroin solution, the mass proportion of glycerol is 30%, and mix well;

[0050] ③ Evenly mix the 4 mg / mL berberine solution and the silk fibroin glycerol mixed solution, wherein the mass ratio of silk fibroin to berberine is 10:1.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a berberine-loaded silk fibroin antibacterial coating, characterized in that: The following steps are involved: S1, pretreatment of silk fibroin; S2, optimization of the mixing ratio of silk fibroin and berberine; S3, glycerol-modified silk fibroin-berberine material; S4. preparing an antibacterial coating solution.

2. The method for preparing a berberine-loaded silk fibroin antibacterial coating according to claim 1, characterized in that: Pretreatment of silk fibroin, including: For the pretreatment of silk fibroin, the team used glycerol modification to improve the structure and properties of silk fibroin; on the one hand, the silk fibroin film contains more than 30% glycerol, and after drying in the fume hood, the secondary structure of the silk fibroin can be transformed from the water-soluble Silk I configuration to the stable Silk II configuration, which has the effect of delaying drug release; on the other hand, glycerol modification makes the silk fibroin material have good softness and smoothness and can reduce the friction coefficient of the coating surface.

3. The method for preparing a berberine-loaded silk fibroin antibacterial coating according to claim 1, characterized in that: The mixing ratio of silk fibroin and berberine is optimized, including: ①Experimental material preparation: berberine and silk fibroin solution; ② Design the mass ratio gradient of silk fibroin and berberine: set six gradients of 100:0, 90:10, 80:20, 70:30, 60:40, and 50:50 in sequence for uniform mixing; ③ Observe whether flocs are produced: a large amount of flocs were produced during the mixing process of the solutions with a mass ratio of silk fibroin to berberine of 80:20, 70:30, 60:40 and 50:50, while no flocs were produced in the 90:10 solution; ④ Screening and optimization experiment: Select silk fibroin solution (7% w / v) and berberine (4 mg / mL) dissolved in deionized water, and design six gradients of silk fibroin and berberine mass ratios of 10:0, 10:1, 20:1, 30:1, 40:1, and 50:

1. After mixing evenly, dry them at 60°C, and then steam treat the dried materials with the treatment parameters of 60°C for 6 hours to obtain steam-treated silk fibroin / berberine antibacterial materials; select Escherichia coli and Staphylococcus aureus to carry out agar plate diffusion experiment to determine the antibacterial effect of silk fibroin / berberine under different mass ratios.

4. The method for preparing a berberine-loaded silk fibroin antibacterial coating according to claim 1, characterized in that: Glycerol-modified silk fibroin-berberine material, including: Silk fibroin / berberine material was prepared at a mass ratio of silk fibroin to berberine of 10:1, and was treated with steam and modified with glycerol respectively.

5. The method for preparing a berberine-loaded silk fibroin antibacterial coating according to claim 1, characterized in that: An antimicrobial coating solution is prepared, comprising: According to the experimental conclusions drawn from the above three experiments, the antibacterial coating solution was prepared. The experimental process is as follows: ① Weigh berberine powder and dissolve it in deionized water. The concentration of berberine solution is 4 mg / mL; ② Dilute the silk fibroin solution with deionized water to a concentration of 7% (w / v), add glycerol to the silk fibroin solution, the mass proportion of glycerol is 30%, and mix well; ③ Evenly mix the 4 mg / mL berberine solution and the silk fibroin glycerol mixed solution, wherein the mass ratio of silk fibroin to berberine is 10:1.

Images