Hydrophilic antibacterial modified polylactic acid wire, preparation method thereof and application of hydrophilic antibacterial modified polylactic acid wire as medical suture

Abstract

The invention provides a preparation method of a hydrophilic antibacterial modified polylactic acid wire, which comprises the following steps: S1) plying and twisting polylactic acid filaments to obtain polylactic acid plied yarns; s2) weaving the polylactic acid plied yarn to obtain a polylactic acid wire; s3) performing low-temperature plasma treatment on the polylactic acid fiber to obtain a surface-activated polylactic acid wire; and S4) transferring the treatment solution to the surface of the surface-activated polylactic acid wire rod to obtain the hydrophilic antibacterial modified polylactic acid wire rod. Compared with the prior art, the preparation method disclosed by the invention has the advantages that a low-temperature plasma technology and a carboxyl-terminated hyperbranched polymer / polydopamine blended solution coating technology are utilized to achieve a synergistic effect, hydrophilic and antibacterial functions are simultaneously given to the modified polylactic acid wire rod, and the modification effect is ensured to have very high stability and durability; in addition, according to the method, the main component of the polylactic acid in the suture fibers is reserved, and the biocompatibility and the biological safety of the polylactic acid material are ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of medical textiles, and in particular relates to a hydrophilic antibacterial modified polylactic acid wire, a preparation method thereof and an application thereof as a medical suture. Background Art

[0002] Medical sutures are a type of linear material used to suture wounds, connect tissues and ligate blood vessels during wound healing. They are the most common biomedical textiles for surgical transplantation and are widely used in various surgical operations. They can be divided into absorbable sutures and non-absorbable sutures. Among them, absorbable sutures include natural fiber and synthetic polymer sutures.

[0003] Polylactic acid (PLA) is a green and environmentally friendly degradable polymer material. Due to its good biocompatibility and biodegradability, PLA is widely used in the biomedical field, and degradable medical sutures are one of its applications. However, the degradation rate of PLA fibers is slow, which cannot meet the requirements of some medical sutures for degradation in a short period of time. In addition, PLA is hydrophobic, cells cannot adhere and reproduce well on the fibers, the degradation cycle is long, and it is easy to cause inflammation. Therefore, it is necessary to provide a suture with antibacterial and hydrophilic properties.

[0004] At present, some work has been done on the antibacterial and hydrophilic modification of PLA, but they all have the following problems: on the one hand, the process is relatively complicated and industrial application is relatively difficult; on the other hand, there is a problem that hydrophilicity and antibacterial properties cannot be combined. In addition, the mechanical properties of the modified sutures are damaged, and the sutures have high requirements for their mechanical properties. For example, the Chinese patent with application number CN201510496172.7 discloses a method for preparing an absorbable medical suture with good tensile strength, wherein modified chitosan, diisopropylcarbodiimide, glucose and cinnamon oil are mixed, and an absorbable medical suture with good tensile strength is prepared by a melt spinning method. The suture has the characteristics of good tensile strength, easy knotting, high mechanical properties, and good compatibility with biological tissues. However, there is a problem that the antibacterial and anti-inflammatory effects are over but the degradation of PLA is not complete, which stimulates cell tissues. The Chinese patent with application number CN201510492506.3 discloses a method for preparing an absorbable medical suture, wherein modified PLA, epoxy soybean oil, genipin, and castor oil are mixed and prepared by melt spinning to obtain an absorbable medical suture, wherein the modified PLA contains chitosan components, thereby giving PLA hydrophilicity. Application number CN201510492487.4 discloses a degradation-resistant and compatible absorbable medical suture and a method for preparing the same, wherein polyglycolide, modified PLA, glutaraldehyde, mannitol, and vanillin are used to prepare a first core, and PLA, polyglycolide, modified PLA, glutaraldehyde, mannitol, and vanillin are used to prepare a second core, which is woven through a coating to obtain an absorbable suture that is resistant to degradation, has good mechanical properties, and is compatible with biological tissues. However, there are problems that the suture does not have antibacterial and anti-inflammatory effects, and that PLA degradation stimulates cells, and there is also the problem of uneven coating weaving. A Chinese patent with application number CN201810911852.4 discloses a method for preparing a hydrophilic PLA surgical suture, in which lipase in a phosphate buffer is used to treat PLA filament yarn to increase the number of hydroxyl groups on the yarn surface, and an acetic acid solution of chitosan is used to treat the yarn treated with lipase to graft the hydrophilic substance chitosan onto the surface of the PLA filament yarn, thereby effectively improving the hydrophilicity of the PLA filament yarn. However, this method will damage the mechanical properties of the PLA filament yarn. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a biodegradable hydrophilic antibacterial modified polylactic acid wire with high mechanical properties, a preparation method thereof and an application thereof as a medical suture.

[0006] The present invention provides a method for preparing a hydrophilic antibacterial modified polylactic acid wire, comprising the following steps:

[0007] S1) Plying and twisting the polylactic acid filaments to obtain polylactic acid strands;

[0008] S2) weaving the polylactic acid strands to obtain a polylactic acid wire;

[0009] S3) treating the polylactic acid fiber with low-temperature plasma to obtain a surface-activated polylactic acid wire;

[0010] S4) transferring the treatment solution to the surface of the surface-activated polylactic acid wire to obtain a hydrophilic antibacterial modified polylactic acid wire; the treatment solution comprises a carboxyl-terminated hyperbranched polymer, polydopamine and a solvent.

[0011] Preferably, the fineness of the polylactic acid filaments in step S1) is 75-300D; the molecular weight of the raw material polylactic acid used for the polylactic acid filaments is 80,000-200,000.

[0012] Preferably, the number of strands twisted in step S1) is 2 to 18; the twist of the strand twisting is 2.5 to 4.

[0013] Preferably, the number of spindles woven in step S2) is 10 to 20.

[0014] Preferably, the power of the low-temperature plasma treatment in step S3) is 100 to 500 W; and the time of the low-temperature plasma treatment is 1 to 5 minutes.

[0015] Preferably, in step S4), the mass ratio of the terminal carboxyl hyperbranched polymer to polydopamine is (6-9): (4-1);

[0016] The mass concentration of the terminal carboxyl hyperbranched polymer in the treatment solution is 0.5% to 5%.

[0017] Preferably, the pH value of the treatment solution is 4-7; and the transfer temperature is 40°C-50°C.

[0018] Preferably, the transfer method in step S4) is immersion; the immersion time is 30 to 300 seconds.

[0019] The present invention also provides a hydrophilic antibacterial modified polylactic acid wire prepared by the above preparation method; the water contact angle of the hydrophilic antibacterial modified polylactic acid wire is 0°.

[0020] The present invention also provides an application of the hydrophilic antibacterial modified polylactic acid wire as a medical suture.

[0021] The present invention provides a method for preparing a hydrophilic antibacterial modified polylactic acid wire, comprising the following steps: S1) twisting polylactic acid filaments to obtain polylactic acid strands; S2) weaving the polylactic acid strands to obtain polylactic acid wires; S3) treating the polylactic acid fibers with low-temperature plasma to obtain surface-activated polylactic acid wires; S4) transferring the treatment solution to the surface of the surface-activated polylactic acid wires to obtain hydrophilic antibacterial modified polylactic acid wires; the treatment solution comprises a carboxyl-terminated hyperbranched polymer, polydopamine and a solvent. Compared with the prior art, the present invention has a simple preparation process, low production cost and industrial application prospects; on the other hand, the present invention utilizes the synergistic effect of low-temperature plasma technology and carboxyl-terminated hyperbranched polymer / polydopamine blend solution coating technology to simultaneously impart hydrophilic and antibacterial functions to the modified polylactic acid wires, and ensures that the modification effect has high stability and durability; in addition, the method retains the main component of polylactic acid in the suture fiber, ensuring the biocompatibility and biosafety of the polylactic acid material.

[0022] Experiments show that the water contact angle of the hydrophilic antibacterial PLA medical suture prepared by the present invention is 0°, the antibacterial rate of Escherichia coli is 96% to 99.9%, the antibacterial rate of Staphylococcus aureus is 95% to 99.2%, and the degradation period is 15 to 90 days. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] The invention provides a method for preparing a hydrophilic antibacterial modified polylactic acid wire, comprising the following steps: S1) twisting polylactic acid filaments to obtain polylactic acid strands; S2) weaving the polylactic acid strands to obtain polylactic acid wires; S3) treating the polylactic acid fibers with low-temperature plasma to obtain surface-activated polylactic acid wires; S4) transferring a treatment solution to the surface of the surface-activated polylactic acid wires to obtain a hydrophilic antibacterial modified polylactic acid wire; the treatment solution comprises a carboxyl-terminated hyperbranched polymer, polydopamine and a solvent.

[0025] The present invention has no particular limitation on the sources of all raw materials, and any raw materials available on the market can be used.

[0026] The polylactic acid filaments are twisted to obtain polylactic acid strands; the fineness of the polylactic acid filaments is preferably 75-300D; optionally, the fineness of the polylactic acid filaments is 75D, 80D, 90D, 100D, 110D, 120D, 130D, 140D, 150D, 160D, 170D, 180D, 190D, 200D, 210D, 220D, 230D, 240D, 250D, 260D, 270D, 280D, 290D, 300D or a range between any two of the above values; the molecular weight of the raw material polylactic acid used for the polylactic acid filaments is preferably 80000-200000; optionally, the polylactic acid The molecular weight of the raw material polylactic acid used for the acid filament is 80000, 90000, 100000, 110000, 120000, 130000, 140000, 150000, 160000, 170000, 180000, 190000, 200000 or the range between any two of the above values; the number of strands of the ply twisting is preferably 2 to 18; optionally, the number of strands of the ply twisting is 2, 4, 6, 8, 10, 12, 14, 16 or 18; the twist of the ply twisting is preferably 2.5 to 4; optionally, the twist of the ply twisting is 2.5, 3, 3.5, 4 or the range between any two of the above values.

[0027] The polylactic acid strands are braided to obtain polylactic acid wires; the number of the braided spindles is preferably 10 to 20; more preferably 12 to 18, and even more preferably 12 to 16; in some embodiments provided by the present invention, the number of the braided spindles is specifically 12 or 16.

[0028] The polylactic acid fiber is subjected to low-temperature plasma treatment to obtain a surface-activated polylactic acid wire; the power of the low-temperature plasma treatment is preferably 100-500W, more preferably 150-400W; in some embodiments provided by the present invention, the power of the low-temperature plasma treatment is specifically 200W, 150W, 300W or 400W; the time of the low-temperature plasma treatment is preferably 1-5min, more preferably; in some embodiments provided by the present invention, the time of the low-temperature plasma treatment is specifically 1min, 5min or 2min; the treatment effect can be changed by adjusting the parameters of the low-temperature plasma treatment, thereby obtaining a surface-activated polylactic acid wire.

[0029] The treatment solution is transferred to the surface of the surface-activated polylactic acid wire; the treatment solution comprises a carboxyl-terminated hyperbranched polymer, polydopamine and a solvent; the carboxyl-terminated hyperbranched polymer is preferably a carboxyl-terminated hyperbranched polyamide; the molecular weight of the carboxyl-terminated hyperbranched polymer is preferably 20,000 to 30,000, more preferably 20,000 to 28,000, more preferably 20,000 to 26,000, more preferably 22,000 to 24,000, and most preferably 22,000; the molecular weight of the polydopamine is preferably 1,000 to 20,000; optionally, the poly The molecular weight of dopamine is 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000, 20000 or a range between any two of the above values; the mass ratio of the carboxyl-terminated hyperbranched polymer to polydopamine is preferably (6-9): (4-1); in some embodiments provided by the present invention, the carboxyl-terminated hyperbranched polymer The mass ratio of the polymer to polydopamine is specifically 8:2, 7:3 or 9:1; the solvent is an organic solvent well known to those skilled in the art, without any special restrictions, and is preferably ethyl acetate in the present invention; the mass concentration of the terminal carboxyl hyperbranched polymer in the treatment solution is preferably 0.5% to 5%; optionally, the mass concentration of the terminal carboxyl hyperbranched polymer in the treatment solution is 0.5%, 1%, 2%, 3%, 4%, 5% or a range between any two of the above values; the pH value of the treatment solution is preferably 4 to 7; in some embodiments provided by the present invention The pH value of the treatment solution is specifically 4, 6 or 7; the transfer temperature is preferably 40°C to 50°C; the transfer method is any method well known to those skilled in the art and is not particularly limited. In the present invention, immersion is preferred; the immersion time is preferably 30 to 300 s; optionally, the immersion time is 30 s, 50 s, 60 s, 80 s, 100 s, 120 s, 150 s, 180 s, 200 s, 220 s, 240 s, 260 s, 280 s, 300 s or a range between any two of the above values.

[0030] In a specific embodiment provided by the present invention, the treatment solution is prepared according to the following method: dissolving the terminal carboxyl hyperbranched polymer and polydopamine in a solvent, stirring and mixing at room temperature to obtain a treatment solution; the stirring and mixing time is preferably 1 to 5 hours.

[0031] Finally, the hydrophilic antibacterial modified polylactic acid wire is obtained after drying and sterilization. The drying temperature is preferably 50°C to 60°C. The sterilization method is a method well known to those skilled in the art and is not particularly limited. In the present invention, ethylene oxide sterilization is preferred.

[0032] The present invention also provides a hydrophilic antibacterial modified polylactic acid wire prepared by the above preparation method; the water contact angle of the hydrophilic antibacterial modified polylactic acid wire is 0°.

[0033] In a specific embodiment provided by the present invention, the hydrophilic antibacterial modified polylactic acid wire comprises a polylactic acid wire whose surface is activated by low-temperature plasma treatment and a terminal carboxyl hyperbranched polymer and polydopamine grafted on the surface of the polylactic acid wire whose surface is activated by low-temperature plasma treatment; the polylactic acid wire is obtained by weaving polylactic acid strands; the polylactic acid strands are obtained by twisting polylactic acid filaments.

[0034] In a specific embodiment provided by the present invention, the antibacterial rate of Escherichia coli of the hydrophilic antibacterial modified polylactic acid wire is 96% to 99.9%.

[0035] In a specific embodiment provided by the present invention, the antibacterial rate of the hydrophilic antibacterial modified polylactic acid wire against Staphylococcus aureus is 95% to 99.2%.

[0036] In a specific embodiment provided by the present invention, the degradation period of the hydrophilic antibacterial modified polylactic acid wire is 15 to 90 days.

[0037] The present invention also provides an application of the hydrophilic antibacterial modified polylactic acid wire as a medical suture.

[0038] The main component of the medical suture provided by the invention is PLA, and the introduced modifier can also be biodegradable, does not destroy the biodegradability and mechanical properties of the PLA suture, and at the same time gives the PLA suture hydrophilic and antibacterial functions.

[0039] To further illustrate the present invention, a hydrophilic antibacterial modified polylactic acid wire material, a preparation method thereof and an application thereof as a medical suture provided by the present invention are described in detail below in conjunction with embodiments.

[0040] The reagents used in the following examples are all commercially available.

[0041] Example 1

[0042] (1) First, PLA filaments with a molecular weight of 200,000 (fineness 75D) are twisted together to form 12 strands, and the twisted PLA filament yarns (twist degree of 4) are braided together using a 12-spindle braiding machine to obtain PLA braided medical sutures.

[0043] (2) Placing the PLA medical suture in a low-temperature plasma device for treatment at a treatment power of 200 W for a treatment time of 1 minute, thereby obtaining a surface-activated PLA medical suture.

[0044] (3) Dissolve the terminal carboxyl hyperbranched polyamide (molecular weight 22000) and polydopamine (molecular weight 2000, Shanghai Boka Chemical Technology Co., Ltd.) (mass ratio 8:2) in ethyl acetate, stir with a magnetic stirrer at room temperature for 1 hour until completely mixed, and obtain a treatment solution (the mass concentration of the terminal carboxyl hyperbranched polyamide in the treatment solution is 2%); place the surface activated PLA suture thread in the terminal carboxyl hyperbranched polymer solution, and perform surface coating by immersion for 30 seconds at pH 4 and temperature 50°C to obtain a modified PLA medical suture thread.

[0045] (4) The modified PLA medical suture was dried at 60° C. and sterilized with ethylene oxide.

[0046] The water contact angle of the hydrophilic antibacterial PLA medical suture thread is 0°, the antibacterial rate of Escherichia coli is 97.9%, the antibacterial rate of Staphylococcus aureus is 97.2%, and the degradation period is 65 days.

[0047] Example 2

[0048] (1) First, PLA filaments with a molecular weight of 100,000 (fineness 110D) are twisted together to form 16 strands, and the twisted PLA filament yarns (twist degree 3) are braided together using a 16-spindle braiding machine to obtain PLA braided medical sutures.

[0049] (2) Placing the PLA medical suture in a low-temperature plasma device for treatment at a treatment power of 150 W for a treatment time of 5 minutes, thereby obtaining a surface-activated PLA medical suture.

[0050] (3) Dissolve the terminal carboxyl hyperbranched polyamide (molecular weight 22000) and polydopamine (molecular weight 5000, Shanghai Boka Chemical Technology Co., Ltd.) (mass ratio 7:3) in ethyl acetate, stir with a magnetic stirrer at room temperature for 5 hours until completely mixed, and obtain a treatment solution (the mass concentration of the terminal carboxyl hyperbranched polyamide in the treatment solution is 2%); place the surface activated PLA suture thread in the terminal carboxyl hyperbranched polymer solution, and perform surface coating by immersion for 60 seconds at pH 6 and temperature 50°C to obtain a modified PLA medical suture thread.

[0051] (4) The modified PLA medical suture was dried at 60° C. and sterilized with ethylene oxide.

[0052] The water contact angle of the hydrophilic antibacterial PLA medical suture thread is 0°, the antibacterial rate of Escherichia coli is 96%, the antibacterial rate of Staphylococcus aureus is 95%, and the degradation period is 15 days.

[0053] Example 3

[0054] (1) First, PLA filaments with a molecular weight of 160,000 (fineness 180D) are twisted together to form 12 strands, and the twisted PLA filament yarns (twist degree 2.5) are braided together using a 12-spindle braiding machine to obtain PLA braided medical sutures.

[0055] (2) Placing the PLA medical suture in a low-temperature plasma device for treatment at a power of 300 W for a treatment time of 1 minute, thereby obtaining a surface-activated PLA medical suture.

[0056] (3) Dissolve the terminal carboxyl hyperbranched polyamide (molecular weight 22000) and polydopamine (molecular weight 1000, Shanghai Boka Chemical Technology Co., Ltd.) (mass ratio 9:1) in ethyl acetate, stir with a magnetic stirrer at room temperature for 3 hours until completely mixed, and obtain a treatment solution (the mass concentration of the terminal carboxyl hyperbranched polyamide in the treatment solution is 2%); place the surface activated PLA suture thread in the terminal carboxyl hyperbranched polymer solution, and perform surface coating by immersion for 80 seconds under the conditions of pH [7 and temperature 40°C to obtain a modified PLA medical suture thread.

[0057] (4) The modified PLA medical suture was dried at 50° C. and sterilized with ethylene oxide.

[0058] The water contact angle of the hydrophilic antibacterial PLA medical suture thread is 0°, the antibacterial rate of Escherichia coli is 99.9%, the antibacterial rate of Staphylococcus aureus is 99.2%, and the degradation period is 90 days.

[0059] Example 4

[0060] (1) First, PLA filaments with a molecular weight of 120,000 (fineness 240D) are twisted together to form 16 strands, and the twisted PLA filament yarns (twist degree 3) are braided together using a 16-spindle braiding machine to obtain PLA braided medical sutures.

[0061] (2) Placing the PLA medical suture in a low-temperature plasma device for treatment at a treatment power of 300 W for a treatment time of 2 minutes, thereby obtaining a surface-activated PLA medical suture.

[0062] (3) Dissolve the carboxyl-terminated hyperbranched polyamide (molecular weight 22,000) and polydopamine (molecular weight 1,000, Shanghai Boca Chemical Technology Co., Ltd.) (mass ratio 8:2) in ethyl acetate, stir with a magnetic stirrer at room temperature for 1 hour until completely mixed, and obtain a treatment solution (the mass concentration of the carboxyl-terminated hyperbranched polyamide in the treatment solution is 2%); place the surface-activated PLA suture thread in the carboxyl-terminated hyperbranched polymer solution, and perform surface coating by immersion for 120 seconds at pH [4 and temperature 50°C to obtain a modified PLA medical suture thread.

[0063] (4) The modified PLA medical suture was dried at 60° C. and sterilized with ethylene oxide.

[0064] The water contact angle of the hydrophilic antibacterial PLA medical suture thread is 0°, the antibacterial rate of Escherichia coli is 97.8%, the antibacterial rate of Staphylococcus aureus is 97.5%, and the degradation period is 54 days.

[0065] Example 5

[0066] (1) First, PLA filaments with a molecular weight of 80,000 (fineness 300D) are twisted together to form 12 strands, and the twisted PLA filament yarns (twist degree 3.5) are woven together using a 12-spindle braiding machine to obtain PLA braided medical sutures.

[0067] (2) Placing the PLA medical suture in a low-temperature plasma device for treatment at a treatment power of 400 W for a treatment time of 2 minutes, thereby obtaining a surface-activated PLA medical suture.

[0068] (3) Dissolve the terminal carboxyl hyperbranched polyamide (molecular weight 22000) and polydopamine (molecular weight 20000, Shanghai Boka Chemical Technology Co., Ltd.) (mass ratio 9:1) in ethyl acetate, stir with a magnetic stirrer at room temperature for 1 hour until completely mixed, and obtain a treatment solution (the mass concentration of the terminal carboxyl hyperbranched polyamide in the treatment solution is 2%); place the surface activated PLA suture thread in the terminal carboxyl hyperbranched polymer solution, and perform surface coating by immersion for 300 seconds under the conditions of pH [7 and temperature 50°C to obtain a modified PLA medical suture thread.

[0069] (4) The modified PLA medical suture was dried at 60° C. and sterilized with ethylene oxide.

[0070] The water contact angle of the hydrophilic antibacterial PLA medical suture thread is 0°, the antibacterial rate of Escherichia coli is 99.9%, the antibacterial rate of Staphylococcus aureus is 99.2%, and the degradation period is 75 days.

[0071] Example 6

[0072] (1) First, PLA filaments with a molecular weight of 140,000 (fineness 200D) are twisted together to form 12 strands, and the twisted PLA filament yarns (twist degree 3) are braided together using a 12-spindle braiding machine to obtain PLA braided medical sutures.

[0073] (2) Placing the PLA medical suture in a low-temperature plasma device for treatment at a treatment power of 400 W for a treatment time of 5 minutes, thereby obtaining a surface-activated PLA medical suture.

[0074] (3) Dissolve the terminal carboxyl hyperbranched polyamide (molecular weight 22,000) and polydopamine (molecular weight 16,000, Shanghai Boka Chemical Technology Co., Ltd.) (mass ratio 7:3) in ethyl acetate, stir with a magnetic stirrer at room temperature for 4 hours until completely mixed, and obtain a treatment solution (the mass concentration of the terminal carboxyl hyperbranched polyamide in the treatment solution is 2%); place the surface-activated PLA suture thread in the terminal carboxyl hyperbranched polymer solution, and perform surface coating by immersion for 240 seconds at pH 6 and temperature 50°C to obtain a modified PLA medical suture thread.

[0075] (4) The modified PLA medical suture was dried at 60° C. and sterilized with ethylene oxide.

[0076] The water contact angle of the hydrophilic antibacterial PLA medical suture thread is 0°, the antibacterial rate of Escherichia coli is 96.3%, the antibacterial rate of Staphylococcus aureus is 95.2%, and the degradation period is 26 days.

[0077] 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 principle 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 hydrophilic antibacterial modified polylactic acid wire, characterized in that: The following steps are involved: S1) Plying and twisting the polylactic acid filaments to obtain polylactic acid strands; S2) weaving the polylactic acid strands to obtain a polylactic acid wire; S3) treating the polylactic acid fiber with low-temperature plasma to obtain a surface-activated polylactic acid wire; S4) transferring the treated solution to the surface of the surface-activated polylactic acid wire to obtain a hydrophilic antibacterial modified polylactic acid wire; The treatment solution comprises a carboxyl-terminated hyperbranched polymer, polydopamine and a solvent.

2. The preparation method according to claim 1, characterized in that: The fineness of the polylactic acid filaments in step S1) is 75-300D; the molecular weight of the raw material polylactic acid used for the polylactic acid filaments is 80,000-200,000.

3. The preparation method according to claim 1, characterized in that: The number of strands in the ply twisting in step S1) is 2 to 18; the twist of the ply twisting is 2.5 to 4.

4. The preparation method according to claim 1, characterized in that: The number of spindles woven in step S2) is 10 to 20.

5. The preparation method according to claim 1, characterized in that: The power of the low temperature plasma treatment in step S3) is 100 to 500 W; the time of the low temperature plasma treatment is 1 to 5 minutes.

6. The preparation method according to claim 1, characterized in that: In the step S4), the mass ratio of the terminal carboxyl hyperbranched polymer to polydopamine is (6-9): (4-1); The mass concentration of the terminal carboxyl hyperbranched polymer in the treatment solution is 0.5% to 5%.

7. The preparation method according to claim 1, characterized in that: The pH value of the treatment solution is 4-7; the transfer temperature is 40°C-50°C.

8. The preparation method according to claim 1, characterized in that: The transfer method in step S4) is immersion; the immersion time is 30 to 300 seconds.

9. The hydrophilic antibacterial modified polylactic acid wire prepared by the preparation method according to any one of claims 1 to 8; the water contact angle of the hydrophilic antibacterial modified polylactic acid wire is 0°.

10. Use of the hydrophilic antibacterial modified polylactic acid wire prepared by the preparation method according to any one of claims 1 to 8 or the hydrophilic antibacterial modified polylactic acid wire according to claim 9 as medical sutures.