Preparation method of antibacterial polypropylene monofilament and antibacterial polypropylene monofilament

Abstract

The invention discloses a preparation method of an antibacterial polypropylene monofilament and the antibacterial polypropylene monofilament. Polypropylene monofilaments are pretreated, and the pretreated polypropylene monofilaments are immersed in an ethanol water solution of a silane coupling agent to react for set time; preparing a quaternized chitosan aqueous solution and a genipin aqueous solution, uniformly mixing the quaternized chitosan aqueous solution and the genipin aqueous solution to form a mixed solution, and immersing the reacted polypropylene monofilaments into the mixed solution for reaction; and immersing the polypropylene monofilament into an aqueous solution containing a zwitterionic monomer and an initiator for reaction. The zwitterionic polymer on the outer layer of the antibacterial polypropylene monofilament forms complexation through strong electrostatic interaction with quaternized chitosan, so that the zwitterionic polymer and the quaternized chitosan form a stable compound, and the hydration of the zwitterionic polymer forms a'hydration layer ', so that initial adhesion of protein and bacteria is effectively resisted; the quaternized chitosan on the inner layer is used for killing bacteria breaking through a defense line in a contact manner, and the quaternized chitosan and the quaternized chitosan cooperate with each other, so that the antibacterial efficiency is higher and more durable, and a biological membrane can be effectively prevented from being formed.

Description

Technical Field

[0001] This invention generally relates to the field of monofilaments, and more particularly to a method for preparing antibacterial polypropylene monofilaments and the antibacterial polypropylene monofilaments themselves. Background Technology

[0002] Polypropylene (PP) is an inexpensive material that is easy to process and mold, and has good thermal and chemical stability, making it widely applicable, especially in the medical field. Polypropylene monofilaments are strong and stable, making them ideal materials for medical implants such as sutures and patches. However, the hydrophobic surface of polypropylene monofilaments results in poor antibacterial properties, making medical implants susceptible to bacterial infection during treatment. After implantation, these implants can easily cause infection and inflammatory reactions, affecting wound healing and causing pain or a foreign body sensation in the user.

[0003] Therefore, developing a medical polypropylene monofilament that is firmly bonded, biocompatible, and possesses highly efficient and long-lasting antibacterial capabilities is of significant clinical importance and market value. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a method for preparing antibacterial polypropylene monofilament and an antibacterial polypropylene monofilament.

[0005] In a first aspect, a method for preparing antibacterial polypropylene monofilament is provided, the method comprising: The polypropylene monofilaments were pretreated by immersing them in an ethanol-water solution of silane coupling agent for a set time, and then removed and ultrasonically cleaned and dried with ethanol and deionized water. Prepare a quaternized chitosan aqueous solution and a genipin aqueous solution, mix them evenly according to a set volume ratio to form a mixed solution, adjust its pH value to 10, immerse the reacted polypropylene monofilament in the mixed solution and react for a set time, then take out the polypropylene monofilament, wash and dry it. The above-mentioned polypropylene monofilament is immersed in an aqueous solution containing a zwitterionic monomer and an initiator, and reacted under nitrogen for a set time. The monofilament is then removed, washed, and dried to obtain the antibacterial polypropylene monofilament; wherein the zwitterionic monomer is methacryloyloxysulfobetaine.

[0006] As a possible approach, the "pretreatment of polypropylene monofilaments" includes: The polypropylene monofilament is placed in a low-temperature plasma treatment instrument, and the working gas is introduced. It is then treated for 1-3 minutes at a power of 50-200W. The working gas is oxygen or air; the discharge mode of the low-temperature plasma is glow discharge.

[0007] As an example, the silane coupling agent is 3-aminopropyltriethoxysilane, wherein the volume ratio of ethanol to water in the aqueous ethanol solution is 95 / 5; The volume ratio of the silane coupling agent to the aqueous ethanol solution is 2%.

[0008] As an example, the concentration of the quaternized chitosan aqueous solution is 1% w / v, the concentration of the genipin aqueous solution is 0.5% w / v, and the two are mixed at a volume ratio of 5:1.

[0009] As an achievable method, the quaternized chitosan in the aqueous solution has a molecular weight of 80-150 kDa and a degree of quaternization of 40-60%.

[0010] As an feasible method, the pH of the mixed solution of quaternized chitosan aqueous solution and genipin aqueous solution is adjusted using a 1 mol / L sodium hydroxide solution.

[0011] As one possible approach, the methacryloyloxysulfonate betaine has the following chemical structural formula: .

[0012] As an example, the initiator is potassium persulfate, and the concentration of the zwitterionic monomer in the aqueous solution is 1 mol / L, and the concentration of potassium persulfate is 0.05 mol / L.

[0013] Secondly, an antibacterial polypropylene monofilament is provided, prepared using the aforementioned method for preparing antibacterial polypropylene monofilament.

[0014] According to the technical solution provided in the embodiments of this application, by using a silane coupling agent to form a strong covalent bond Si-OC with the surface of polypropylene, the stability of the modified layer is significantly improved and it is not easy to fall off; and by using natural and non-toxic genipin as a crosslinking agent, the risk of cytotoxicity is avoided, making the prepared polypropylene monofilament material have high overall biosafety and more suitable for use as a medical monofilament. Furthermore, one end of the genipin crosslinking agent reacts with the amino group of the silane layer, and the other end reacts with the amino group of the quaternized chitosan, covalently grafting the quaternized chitosan onto the surface of the polypropylene monofilament; The zwitterionic polymer on the outer layer of the antibacterial polypropylene monofilament forms a complex with quaternized chitosan through strong electrostatic interaction, thus forming a stable complex that is firmly fixed to the surface of the polypropylene monofilament. The hydration of the zwitterionic polymer forms a "hydration layer" that effectively resists the initial adhesion of proteins and bacteria, i.e., it has anti-adhesion properties. The inner quaternized chitosan layer kills bacteria that break through the defenses through contact, thus having a bactericidal function. The two work synergistically to achieve higher and longer-lasting antibacterial efficiency and effectively prevent biofilm formation. Attached Figure Description

[0015] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a flowchart illustrating the preparation method of antibacterial polypropylene monofilament in this embodiment. Detailed Implementation

[0016] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] Please refer to Figure 1 A method for preparing antibacterial polypropylene monofilament is provided, the method comprising: The polypropylene monofilaments were pretreated by immersing them in an ethanol-water solution of silane coupling agent for a set time, and then removed and ultrasonically cleaned and dried with ethanol and deionized water. Prepare an aqueous solution of quaternized chitosan and an aqueous solution of genipin, mix them evenly according to a set volume ratio to form a mixed solution, adjust its pH value to 10, immerse the reacted polypropylene monofilament in the mixed solution and react for a set time, then take out the polypropylene monofilament, wash and dry it. The above-mentioned polypropylene monofilament is immersed in an aqueous solution containing a zwitterionic monomer and an initiator, and reacted under nitrogen for a set time. The monofilament is then removed, washed, and dried to obtain the antibacterial polypropylene monofilament; wherein the zwitterionic monomer is methacryloyloxysulfobetaine.

[0019] This embodiment utilizes a silane coupling agent to form a strong covalent bond Si-OC with the polypropylene surface, significantly improving the stability of the modified layer and making it less prone to detachment. Furthermore, the use of natural and non-toxic genipin as a crosslinking agent avoids the risk of cytotoxicity, resulting in high overall biocompatibility of the prepared polypropylene monofilament material, making it more suitable for use as a medical monofilament. Additionally, one end of the genipin crosslinking agent reacts with the amino group of the silane layer, while the other end reacts with the amino group of the quaternized chitosan, covalently grafting the quaternized chitosan onto the surface of the polypropylene monofilament. The zwitterionic polymer on the outer layer of the antibacterial polypropylene monofilament forms a complex with quaternized chitosan through strong electrostatic interaction, thus forming a stable complex that is firmly fixed to the surface of the polypropylene monofilament. The hydration of the zwitterionic polymer forms a "hydration layer" that effectively resists the initial adhesion of proteins and bacteria, i.e., it has anti-adhesion properties. The inner quaternized chitosan layer kills bacteria that break through the defenses through contact, thus having a bactericidal function. The two work synergistically to achieve higher and longer-lasting antibacterial efficiency and effectively prevent biofilm formation.

[0020] Specifically, the polypropylene monofilament is first pretreated by placing it in a low-temperature plasma treatment instrument, introducing working gas, and treating it for 1-3 minutes at a power of 50-200W. The working gas is oxygen or air; the discharge mode of the low-temperature plasma is glow discharge.

[0021] In this embodiment, a low-temperature plasma method is used to pretreat the monofilament, which can not only improve the surface activity of the monofilament but also avoid damaging its original properties. At the same time, this pretreatment method is clean, efficient, and environmentally friendly.

[0022] The pretreated polypropylene monofilaments were then immersed in an ethanol-water solution of a silane coupling agent for reaction. The reacted polypropylene monofilaments were then washed with ethanol and deionized water and dried. The silane coupling agent used was 3-aminopropyltriethoxysilane, and the volume ratio of ethanol to water in the ethanol-water solution was 95 / 5; the volume ratio of the silane coupling agent to the ethanol-water solution was 2%. The silane coupling agent forms strong covalent bonds with the surface of the polypropylene, which has undergone low-temperature plasma activation. This method results in a highly stable modified layer on the polypropylene that is not easily detached.

[0023] Subsequently, the aqueous solutions of quaternized chitosan and genipin were prepared and mixed to form a mixed solution. In this embodiment, natural and non-toxic genipin was selected as the crosslinking agent. Since genipin is an iridoid glycoside extracted from gardenia fruit and is the main active metabolite of geniposide, it can be used as a natural biological crosslinking agent. Furthermore, genipin can be used to prepare biomaterials such as artificial bones, wound dressings, fingerprint collection reagents, and tissue-engineered blood vessels through crosslinking of proteins, collagen, and chitosan. It can also be used as a crosslinking agent for immobilized enzymes. Its toxicity is lower than that of chemical crosslinking agents such as glutaraldehyde, and it also has pharmacological activities such as hypoglycemic, hepatoprotective, choleretic, anti-inflammatory, antitumor, and hypotensive effects. The use of genipin avoids the cytotoxicity risk of the prepared polypropylene monofilaments, resulting in a high overall biocompatibility of the material. In this embodiment, genipin, as a crosslinking agent, reacts with the amino groups of the silane layer at one end and with the amino groups of the quaternized chitosan at the other end, grafting the quaternized chitosan onto the surface of the polypropylene monofilament. The concentration of the quaternized chitosan aqueous solution was 1% w / v, and the concentration of the genipin aqueous solution was 0.5% w / v. The two were mixed at a volume ratio of 5:1, and the pH of the above mixed solution was adjusted to 10 by using a 1 mol / L sodium hydroxide solution.

[0024] The quaternized chitosan aqueous solution used above has a molecular weight of 80-150 kDa and a degree of quaternization of 40-60%.

[0025] The aforementioned polypropylene monofilament was then immersed in an aqueous solution of zwitterionic monomer and initiator. In this embodiment, methacryloyloxysulfobetaine is preferably selected as the zwitterionic monomer, with the following chemical structural formula: , Since polysulfobetaine (PSBMA) is a typical zwitterionic polymer, with methacryloyloxysulfobetaine as the monomer, each repeating unit of the polymer is composed of anionic and cationic groups. Due to the electrostatic interaction between it and water, a strong hydration layer is formed, which can serve as a high-performance antifouling material. The zwitterionic polymer forms a "hydration layer" through strong hydration, which can effectively resist non-specific protein adsorption and initial bacterial adhesion, making the polypropylene monofilament prepared in this embodiment more suitable for application in the medical field.

[0026] In the above embodiments, the zwitterionic polymer forms a complex through the strong electrostatic interaction between quaternized chitosan, thereby forming a stable complex with chitosan and firmly fixing it to the surface of polypropylene monofilament. In addition, the hydration of the zwitterionic polymer forms a hydration layer, which effectively resists the initial adhesion of proteins and bacteria and has an anti-adhesion effect. The inner quaternized chitosan in the inner layer kills bacteria that break through the defenses through contact, and has a bactericidal effect. The two work synergistically, resulting in higher antibacterial efficiency, better and longer-lasting antibacterial effect, and effective prevention of biofilm formation.

[0027] This embodiment also provides an antibacterial polypropylene monofilament, which is prepared by the above-described preparation method. The prepared polypropylene monofilament has excellent antibacterial effect and can be applied in the medical field.

[0028] In the preparation process of the polypropylene monofilament provided in the above embodiments, the surface of the polypropylene monofilament is first activated by plasma treatment, and then a stable aminated layer is introduced using a silane coupling agent. Subsequently, quaternized chitosan is grafted onto the aminated silane layer using the crosslinking agent genipin. Then, an anti-adhesion hydration layer is formed by complexing the zwitterionic polymer polysulfobetaine in the outermost layer. The mechanism of surface modification of polypropylene monofilament is as follows: the surface-modified polypropylene monofilament has an antibacterial mechanism with synergistic antibacterial and bactericidal effects, which overcomes the disadvantage of easy failure of a single bactericidal mechanism and has the advantages of long-lasting antibacterial effect and high biosafety.

[0029]

[0030] The following provides several sets of embodiments and comparative examples: Example 1

[0031] S1: Select 100 g of polypropylene monofilament with a diameter of 0.1 mm, clean the polypropylene monofilament with ethanol, and dry it. Place it in a plasma treatment instrument, introduce oxygen, and treat it at a power of 50W for 2 minutes.

[0032] S2: The treated monofilament is immersed in a 2% (v / v) aminosilane coupling agent 3-aminopropyltriethoxysilane in an ethanol / water (95 / 5, v / v) solution and reacted at 60 °C for 6 hours. After removal, it is ultrasonically cleaned with ethanol and deionized water and dried. S3: Quaternized chitosan with a molecular weight of 80 kDa and a degree of quaternization of 60% was selected. A 1% (w / v) quaternized chitosan solution and a 0.5% (w / v) genipin solution were prepared and mixed thoroughly at a volume ratio of 5:1. The pH of the solution was adjusted to 10 with 1 mol / L sodium hydroxide solution. The monofilament obtained in S2 was immersed in the above mixed solution and reacted at 50 °C for 12 h. After the reaction was completed, the monofilament was removed, thoroughly washed with deionized water, and dried. S4: The monofilaments obtained in S3 were immersed in an aqueous solution containing 1 mol / L methacryloyloxysulfobetaine monomer and 0.05 mol / L potassium persulfate, and nitrogen gas was purged to remove oxygen. The reaction was carried out at 60°C for 4 hours. After the reaction was completed, the mixture was thoroughly washed with deionized water and dried to obtain the final product.

[0033] Antibacterial polypropylene medical monofilaments were obtained. The grafting rate was evaluated by the weight gain rate of the monofilaments before and after treatment, and the grafting rate was 3.7%. Example 2

[0034] S1: Select 150 g of polypropylene monofilament with a diameter of 0.1 mm, place the monofilament in a low-temperature plasma treatment instrument, evacuate and introduce oxygen as the working gas, the plasma treatment power is 100 W, and the treatment time is 2 min. S2-S4 are the same as in Example 1, yielding antibacterial polypropylene medical monofilaments with a grafting rate of 4.2%. Example 3

[0035] S1: Select 100 g of polypropylene monofilament with a diameter of 0.12 mm, place the monofilament in a low-temperature plasma treatment instrument, evacuate and introduce oxygen as the working gas, the plasma treatment power is 150 W, and the treatment time is 2 min. S2-S4 are the same as in Example 1, yielding antibacterial polypropylene medical monofilaments with a grafting rate of 5.1%. Example 4

[0036] S1: Select 100 g of polypropylene monofilament with a diameter of 0.1 mm. Clean the polypropylene monofilament with ethanol and dry it. Place it in a plasma treatment instrument, introduce oxygen, and set the plasma treatment power to 200 W for 2 minutes. S2 is the same as in Example 1; In S3, quaternized chitosan with a molecular weight of 120 kDa and a quaternization degree of 50% was selected, and the rest was the same as in Example 1. The grafting rate of the prepared antibacterial polypropylene medical monofilament was 5.3%. Example 5

[0037] S1: Select 100 g of polypropylene monofilament with a diameter of 0.1 mm. Clean the polypropylene monofilament with ethanol and dry it. Place it in a plasma treatment instrument, introduce oxygen, and set the plasma treatment power to 100 W for 3 minutes. S2 is the same as in Example 1; In S3, quaternized chitosan with a molecular weight of 160 kDa and a quaternization degree of 40% was selected, and the rest was the same as in Example 1. The grafting rate of the prepared antibacterial polypropylene medical monofilament was 4.8%.

[0038] Comparative Example 1 S1: Select 100 g of polypropylene monofilament with a diameter of 0.1 mm, place the monofilament in a low-temperature plasma treatment instrument, evacuate and introduce air as the working gas, the plasma treatment power is 100 W, the treatment time is 2 min, after the treatment is completed, put the monofilament into a sealed bag for storage, and obtain antibacterial polypropylene medical monofilament.

[0039] Comparative Example 2 100 g of polypropylene monofilament with a diameter of 0.1 mm was selected and treated according to Examples S2-S5 without plasma treatment to obtain antibacterial polypropylene medical monofilament with a grafting rate of 2.8%.

[0040] The tensile breaking strength of the antibacterial polypropylene monofilaments prepared in Examples 1-5 and Comparative Examples 1-2 was tested, and the test results are shown in Table 1 below: Table 1 Tensile breaking strength of different polypropylene monofilaments

[0041] According to the test results in Table 1, plasma treatment and chemical grafting have little effect on the mechanical properties of the monofilament. The strength of the monofilament is almost unchanged. The plasma treatment power is 200 W and the treatment time is 2 min. The tensile breaking strength of the monofilament is 4.5 cN / dtex, which can meet the requirements of use.

[0042] The antibacterial properties of antimicrobial polypropylene medical monofilament were tested, and the test results are shown in Table 2.

[0043] Table 2. Antibacterial rates of different polypropylene monofilaments

[0044] According to the test results in Table 2, the polypropylene monofilaments treated with plasma and chemically grafted exhibited good antibacterial effects, showing good antibacterial activity against Staphylococcus aureus and Escherichia coli. The antibacterial activity of the polypropylene monofilaments without chemical grafting was comparable to that of the untreated polypropylene monofilaments, while the antibacterial activity of the chemically grafted polypropylene monofilaments was significantly improved. Furthermore, the antibacterial activity of polypropylene monofilaments that underwent plasma treatment only on the chemically grafted portion was lower than that of monofilaments treated with both steps simultaneously.

[0045] In summary, the polypropylene monofilaments prepared using the steps described in the above embodiments do not have their tensile strength and other parameters affected, and have the same tensile strength as polypropylene monofilaments prepared using conventional steps. Furthermore, the polypropylene monofilaments treated with plasma and chemically grafted exhibit good antibacterial effects against Staphylococcus aureus and Escherichia coli, satisfying both the inherent properties of the monofilaments and their excellent antibacterial function, thus meeting medical requirements.

[0046] It should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used above to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention; the directional terms "inner" and "outer" refer to the inside or outside relative to the outline of each component itself. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0047] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for producing an antibacterial polypropylene monofilament, characterized by, The method comprises: pretreating the polypropylene monofilament, immersing the pretreated polypropylene monofilament in an ethanol aqueous solution of silane coupling agent for a set time, and then taking out the polypropylene monofilament for ultrasonic cleaning with ethanol and deionized water and drying; preparing a quaternary ammonium chitosan aqueous solution and a genipin aqueous solution, mixing the two solutions uniformly according to a set volume ratio to form a mixed solution, adjusting the pH value of the mixed solution to 10, immersing the reacted polypropylene monofilament in the mixed solution for a set time, and then taking out the polypropylene monofilament for washing and drying; immersing the polypropylene monofilament in an aqueous solution containing a zwitterionic monomer and an initiator, reacting under nitrogen for a set time, and then taking out the monofilament for cleaning and drying to obtain the antibacterial polypropylene monofilament; wherein the zwitterionic monomer is methacryloyloxy sulfobetaine.

2. The method of producing an antibacterial polypropylene monofilament according to claim 1, characterized by, The "pretreating the polypropylene monofilament" comprises: placing the polypropylene monofilament in a low-temperature plasma treatment instrument, introducing a working gas, and treating at a power of 50-200 W for 1-3 min; wherein the working gas is oxygen or air; and the discharge mode of the low-temperature plasma is glow discharge.

3. The method of producing an antibacterial polypropylene monofilament according to claim 1, characterized by, The silane coupling agent is 3-aminopropyl triethoxysilane, and the volume ratio of ethanol to water in the ethanol aqueous solution is 95 / 5. The volume ratio of the silane coupling agent to the ethanol aqueous solution is 2%.

4. The method of producing an antibacterial polypropylene monofilament according to claim 1, characterized by, The concentration of the quaternary ammonium chitosan aqueous solution is 1% w / v, and the concentration of the genipin aqueous solution is 0.5% w / v, and the two are mixed according to a volume ratio of 5:

1.

5. The method of producing an antibacterial polypropylene monofilament according to claim 4, characterized by, The molecular weight of the quaternary ammonium chitosan in the quaternary ammonium chitosan aqueous solution is 80-150 kDa, and the degree of quaternization is 40-60%.

6. The method of making an antimicrobial polypropylene monofilament according to claim 1, wherein, The 1 mol / L sodium hydroxide solution is used to adjust the pH value of the mixed solution of the quaternary ammonium chitosan aqueous solution and the genipin aqueous solution.

7. The method of making an antimicrobial polypropylene monofilament according to claim 1, wherein, The methacryloyloxy sulfobetaine has a chemical structural formula of: .

8. The method of making an antimicrobial polypropylene monofilament according to claim 1, wherein, The initiator is potassium persulfate, and the concentration of the zwitterionic monomer in the aqueous solution is 1 mol / L, and the concentration of potassium persulfate is 0.05 mol / L.

9. An antibacterial polypropylene monofilament, characterized by, The antibacterial polypropylene monofilament is prepared by using the preparation method of any one of claims 1-8.

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