Antibacterial composite film as well as preparation method and application thereof

Abstract

The invention discloses an antibacterial composite film as well as a preparation method and application thereof. The antibacterial composite film takes chitosan, arginine, a modifier, sodium carboxymethyl cellulose and sodium alginate as raw materials. The preparation method comprises the following steps: firstly, modifying chitosan into arginine acidified chitosan by using a modifier; secondly, sodium carboxymethyl cellulose, sodium alginate and arginine acidified chitosan are mixed and dried, and the antibacterial composite film is obtained. The prepared composite film is good in hydrophilicity, controllable in degradation speed and excellent in antibacterial property and biocompatibility, and most performance defects of existing medical composite films are overcome. The method has good application and development prospects in the biomedical field, especially in the aspect of wound surface recovery.

Description

Technical Field

[0001] This invention belongs to the field of biomedical materials technology, and specifically relates to an antibacterial composite film, its preparation method, and its application. Background Technology

[0002] Traditional dressings (such as dry gauze and oily gauze) primarily serve a basic isolation function in skin wound care, but their breathability, antibacterial properties, and biocompatibility are all deficient, making them increasingly inadequate for the functional dressing requirements of modern medicine. Antibacterial composite films, on the other hand, not only possess excellent hydrophilicity and controllable degradation characteristics but also exhibit significant antibacterial properties, better meeting the current needs of skin wound repair. These antibacterial composite films are made from natural raw materials and are biocompatible. Furthermore, selecting different polymers to form the composite film can overcome the shortcomings of traditional single-material dressings, resulting in flexibility, moderate mechanical strength, and properties that accelerate wound healing.

[0003] Chitosan (CS) is a common natural alkaline polysaccharide widely used in the biomedical field, especially as a polymer carrier. It boasts advantages such as good biodegradability and renewability, and is widely used in fibers and membrane materials. Furthermore, it exhibits good biocompatibility, antibacterial properties, and wound-healing capabilities, making it a common biomedical material. Sodium carboxymethyl cellulose (CMC) possesses excellent film-forming ability, biodegradability, and low toxicity, along with strong hydrophilicity and a stable internal network structure. These properties can be used to improve the performance of composite membranes. Sodium alginate (SA), due to its excellent wound-healing properties, good hygroscopicity, good moisture permeability, and high aqueous solution viscosity, has been widely used in biomedicine and the preparation of novel materials. However, each individual material has limitations in various aspects, such as water solubility, mechanical strength, and antibacterial properties. Summary of the Invention

[0004] This invention provides an antibacterial composite film, its preparation method, and its application. This invention uses natural materials and low-toxicity and harmless materials for cross-linking, which solves the problems of insufficient mechanical properties, water solubility, and antibacterial properties of single materials in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An antibacterial composite film is made by modifying chitosan into argininated chitosan, then mixing it with sodium carboxymethyl cellulose aqueous solution and sodium alginate in different proportions, and then processing it through a series of processes.

[0007] A method for preparing an antibacterial composite film includes the following steps:

[0008] Step 1: Weigh chitosan and L-arginine in different molar ratios, disperse them in 100 mL of distilled water, and transfer them to a 250 mL flask; then add a modifier; adjust the pH to 5.5 with 0.1 mol / L hydrochloric acid to ensure complete dissolution of all reactants, including chitosan, to form a homogeneous reaction system, and react at 30 °C for 12 h. After the reaction is complete, adjust the pH of the system to 8 with 0.5 mol / L sodium hydroxide solution. Then dialyze, collect the product, and freeze-dry to obtain argininated chitosan.

[0009] Step 2: Prepare a 12% sodium carboxymethyl cellulose aqueous solution under magnetic stirring in a constant temperature water bath, and let it stand for 12 hours for deoxygenation.

[0010] Step 3: Prepare 100 ml of 2.0% w / v acetic acid solution, heat at 25°C, add argininated chitosan until the argininated chitosan is completely dissolved, then add 1 ml of 1.0% w / v glycerol. Take out the solutions from Step 3 and Step 2 at different mass ratios.

[0011] Step 4: Add 0.5-1.5g of sodium alginate to the prepared sodium carboxymethyl cellulose aqueous solution, then mix with the solution obtained in Step 3 and stir magnetically. Next, cast the liquid film onto a petri dish, allow it to stand, and dry. Then, immerse the film in a 2.0% (w / w) calcium chloride aqueous solution for 2 minutes, and allow it to air dry at room temperature to obtain the antibacterial composite film.

[0012] The optimization involves setting the molar ratio of chitosan to L-arginine in step 1 to 1:1, and setting the dialysis time to 6 days.

[0013] The optimization involves using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) as a condensing agent and N-hydroxy-succinimide (NHS) as a coupling agent, with a molar ratio of chitosan to EDC and NHS of 1:1:1 to 1:3:3.

[0014] A further optimization is that the molar ratio of chitosan to EDC and NHS in step 1 is 1:1:1.

[0015] A further optimization is that the mass fraction of the sodium carboxymethyl cellulose aqueous solution in step 2 is 1%.

[0016] The optimization involves setting the stirring temperature to 60°C and the stirring time to 60 minutes in step 2.

[0017] The optimization involves using 0.5-1.5 g of argininated chitosan in step 3, and taking out the solutions from step 3 and step 2 at a mass ratio of 17:3.

[0018] Further optimizations are made in step 4, where the mass of sodium alginate is 1g, the standing temperature is 25℃, the standing time is 1h, the drying temperature is 60℃, and the drying time is 6h.

[0019] The application of the antibacterial composite film prepared by the above method in medical wound dressings.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The antibacterial composite film of the present invention is simple to manufacture, and uses natural materials and low-toxicity and harmless materials to crosslink, which is environmentally friendly;

[0022] (2) The antibacterial composite film of the present invention has excellent antibacterial effect and shows significant inhibitory ability against Escherichia coli, Staphylococcus aureus and other bacteria, effectively preventing wound infection, thereby expanding its application scope;

[0023] (3) The antibacterial composite film of the present invention has good tensile strength, which helps to protect the wound, resist external force and maintain the integrity of the wound, and promote wound healing. Attached Figure Description

[0024] Figure 1 The tensile strength comparison diagram shows the composite films prepared in Examples 1-3 and Comparative Example 1. Figure 2 The swelling properties of the composite films prepared in Examples 1-3 and Comparative Example 1 are compared. Figure 3 The diagram shows a comparison of the antibacterial effects of the composite films prepared in Examples 1-3 and Comparative Example 1. Detailed Implementation

[0025] The present invention will be further described below with reference to embodiments.

[0026] Example 1 (1) Weigh 1g of chitosan and 1.1g of L-arginine, disperse them in 100mL of distilled water, and transfer them to a 250mL flask; then add 0.8g of condensing agent 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and 1.2g of coupling agent N-hydroxy-succinimide (NHS), and keep stirring at a constant speed throughout the process; adjust the pH to 5.5 with 0.1mol / L hydrochloric acid to fully dissolve all reactants, including chitosan, to form a homogeneous reaction system, and react at 30℃ for 12h. After the reaction is completed, adjust the pH of the system to 8 with 0.5mol / L sodium hydroxide solution. After the product is fully separated, put it into a dialysis bag (MWCO: 8000-14,000Da) and dialyze it in deionized water for 5 days, changing the distilled water every 6h during the period to fully remove unreacted amino acids, condensing agents, coupling agents and by-products. The product was removed and freeze-dried to obtain argininated chitosan (CA).

[0027] (2) Weigh 1.0 g of sodium carboxymethyl cellulose (CMC) into a beaker and add 100 mL of distilled water. Stir the mixture with a magnetic stirrer in a 60 °C constant temperature water bath until the CMC is completely dissolved. Let the solution stand for 12 h to deoxygenate.

[0028] (3) Prepare 100 ml of 2.0% w / v acetic acid solution, heat at 25°C, add 0.5 g of argininated chitosan until the argininated chitosan is completely dissolved, and then add 1 ml of 1.0% w / v glycerol. Take out the solutions from step 3 and step 2 in a ratio of 17:3.

[0029] (4) Add 1g of sodium alginate to the prepared sodium carboxymethyl cellulose aqueous solution, mix the solutions, and stir magnetically for 30min. Then, cast the liquid film onto a petri dish, let it stand at 25℃ for 1h, and dry it at 60℃ for 6h. After that, immerse the film in a 2.0% calcium chloride aqueous solution for 2min, and let it air dry at room temperature to obtain the antibacterial composite film.

[0030] Example 2 Except for step (3), where the argininated chitosan is changed to 1g, the rest is the same as in Example 1.

[0031] Example 3 Except for step (3), where the argininated chitosan is changed to 1.5g, the rest is the same as in Example 1.

[0032] Comparative Example 1 Weigh 1.0 g of sodium carboxymethyl cellulose (CMC) into a beaker and add 100 mL of distilled water. Stir the mixture with a magnetic stirrer in a 60°C constant temperature water bath until the CMC is completely dissolved to obtain an aqueous solution of sodium carboxymethyl cellulose. Let the solution stand for 12 h to deoxygenate. Prepare 100 mL of 2.0% acetic acid solution, heat at 25°C, and then add 1 mL of 1.0% w / v glycerol. Mix this solution with the sodium carboxymethyl cellulose aqueous solution at a ratio of 17:3. Add 1 g of sodium alginate to the separated sodium carboxymethyl cellulose aqueous solution, mix the solutions, and stir magnetically for 30 min. Then, cast the liquid film onto a petri dish, let it stand at 25°C for 1 h, and dry it at 60°C for 6 h. After that, immerse the film in a 2.0% calcium chloride aqueous solution for 2 min and let it air dry at room temperature to obtain an antibacterial composite film.

[0033] Performance testing The CA / CMC / SA composite films prepared in Examples 1-3 and Comparative Example 1 were characterized by tensile strength testing, swelling properties, and antibacterial properties, as detailed below:

[0034] Tensile strength test: A universal electronic tensile testing machine was used to prepare the composite film sample into a strip shape with dimensions of (50mm × 10mm × 4mm). The original gauge length, i.e., the effective tensile length, was set to 40mm, and the tensile rate was set to 50mm / min. At least five samples of different film components were prepared to ensure that multiple repeated tests could be performed to reduce testing errors.

[0035] Antibacterial performance test: Staphylococcus aureus and Escherichia coli were first cultured in liquid culture medium, then the bacterial suspension was centrifuged, and then dispersed in physiological saline to achieve a concentration of 10. 6 The bacterial suspension was set at CFU / mL. A liquid membrane was added to 1 mL of this bacterial suspension and subjected to near-infrared spectroscopy (808 nm, 2 W / cm²). 2 Irradiate for 12 minutes under the specified conditions. Then, take 100 μL of the treated bacterial suspension and transfer it to a solid culture medium at 37°C. After incubation overnight, photograph the colonies and count their number to obtain the inhibition rate.

[0036] Swelling performance test: Weigh the dried film sample and record its mass. Place it in an appropriate amount of PBS buffer and immerse it at a constant temperature of 25°C. Remove the sample at set time intervals, remove excess solvent, weigh it again, and calculate the swelling ratio. Continue testing until swelling equilibrium is reached. Plot the swelling ratio-time curve and analyze the swelling rate, equilibrium time, and other properties. Compare the results with those of Examples 1-3 and Comparative Example 1.

[0037] Figure 1The tensile strength test results show that as the content of argininated chitosan increases, the tensile strength of the composite film also increases. In Example 3, the tensile strength reaches 60 MPa.

[0038] Figure 2 The swelling performance test results show that as the arginine-modified chitosan increases, the swelling rate of the composite film first increases and then decreases, reaching a basic swelling equilibrium after 48 hours. The swelling rate is below 200%, which is within the reasonable swelling range for medical dressings.

[0039] Figure 3 The antibacterial performance test results show that with the increase of argininated chitosan content, it exhibits a significant inhibitory effect on Escherichia coli and Staphylococcus aureus.

[0040] The test results are shown in Table 1.

[0041] Table 1 Comparison of various performance parameters of antibacterial composite films.

[0042]

[0043] As can be seen from Table 1, although the CMC / SA composite film crosslinked with sodium carboxymethyl cellulose (CMC) and sodium alginate (SA) in Comparative Example 1 also had low cytotoxicity, it was inferior to the antibacterial composite film prepared with arginized chitosan, sodium carboxymethyl cellulose and sodium alginate in terms of swelling rate and antibacterial performance. Furthermore, the tensile strength increased with the increase of arginized chitosan content.

[0044] In summary, the antibacterial composite film prepared by this invention has good tensile strength, antibacterial properties, good swelling rate, and no cytotoxicity, which can meet the standards required for practical applications.

[0045] This invention discloses an antibacterial composite film, its preparation method, and its application. The antibacterial composite film uses chitosan, arginine, a modifier, sodium carboxymethyl cellulose, and sodium alginate as raw materials. Its preparation first involves modifying chitosan into argininated chitosan using a modifier. Then, sodium carboxymethyl cellulose, sodium alginate, and argininated chitosan are mixed and dried to obtain the antibacterial composite film. The composite film prepared by this invention exhibits good hydrophilicity, controllable degradation rate, excellent antibacterial properties, and biocompatibility, overcoming most of the performance defects of current medical composite films. It has promising applications and development prospects in the biomedical field, especially in wound healing.

[0046] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An antibacterial composite film, characterized in that, Argininated chitosan obtained by chitosan modification is blended with sodium carboxymethyl cellulose and sodium alginate to form the antibacterial composite film.

2. The method for preparing the antibacterial composite film according to claim 1, characterized in that, Includes the following steps: Step 1: Weigh chitosan and L-arginine, disperse them in 100 mL of distilled water, and transfer them to a 250 mL flask; then add the modifier; adjust the pH to 5.5 with 0.1 mol / L hydrochloric acid to fully dissolve all reactants, including chitosan, to form a homogeneous reaction system, and react at 30 °C for 12 h; after the reaction is complete, adjust the pH of the system to 8 with 0.5 mol / L sodium hydroxide solution; then dialyze, collect the product, and freeze-dry to obtain argininated chitosan; Step 2: Prepare a sodium carboxymethyl cellulose aqueous solution with a mass fraction of 1-2% under magnetic stirring in a constant temperature water bath, and let it stand for 12 hours to deoxygenate. Step 3: Prepare 100 ml of 2.0% w / v acetic acid solution, heat at 25°C, add argininated chitosan until the argininated chitosan is completely dissolved, then add 1 ml of 1.0% w / v glycerol; take out the solutions from Step 3 and Step 2 at different mass ratios. Step 4: Add 0.5-1.5g of sodium alginate to the prepared sodium carboxymethyl cellulose aqueous solution, and then mix it with the solution obtained in Step 3. Stir magnetically. Then, cast the liquid film onto a petri dish, let it stand and dry. After that, immerse the film in a 2.0% calcium chloride aqueous solution for 2 minutes and let it dry naturally at room temperature to obtain the antibacterial composite film.

3. The preparation method according to claim 1, characterized in that, Includes the following steps: In step 1, the molar ratio of chitosan to L-arginine is 1:1, and the dialysis time is 6 days.

4. The preparation method according to claim 1, characterized in that, In step 1, the modifier uses 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride EDC as a condensing agent and N-hydroxy-succinimide NHS as a coupling agent. The molar ratio of chitosan to 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride EDC and N-hydroxy-succinimide NHS is 1:1:1 to 1:3:

3.

5. The preparation method according to claim 4, characterized in that, In step 1, the molar ratio of chitosan to 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxy-succinimide (NHS) is 1:1:

1.

6. The preparation method according to claim 1, characterized in that, In step 2, the mass fraction of the sodium carboxymethyl cellulose aqueous solution is 1%; in step 2, the stirring temperature is 60℃ and the stirring time is 60min.

7. The preparation method according to claim 1, characterized in that, In step 3, the mass of the argininated chitosan is 0.5-1.5g.

8. The preparation method according to claim 1, characterized in that, In step 4, the solution obtained in step 3 is mixed with the sodium carboxymethyl cellulose aqueous solution obtained in step 2 at a mass ratio of 17:

3.

9. The preparation method according to claim 1, characterized in that, In step 4, the mass of sodium alginate is 1g, the standing temperature is 25℃, the standing time is 1h, the drying temperature is 60℃, and the drying time is 6h.

10. The application of the antibacterial composite film prepared by any of the preparation methods according to claims 2-9 in medical wound dressings.

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