An antibacterial and anti-inflammatory absorbable suture and a method for preparing the same

Abstract

This invention discloses an antibacterial and anti-inflammatory absorbable suture and its preparation method, relating to the field of medical materials technology. The antibacterial and anti-inflammatory absorbable suture comprises the following raw materials in parts by weight: 55-63 parts polylactic acid, 15-20 parts modified polylactic acid, 15-20 parts hydrophilic compatibilizer, 10-15 parts polyglycolic acid, 12-18 parts polyethylene glycol, and 0.4-0.8 parts lubricant. The modified polylactic acid is prepared by reacting methimazole with eugenol to generate a sulfide compound; then reacting it with octadecane bromide to generate a quaternary ammonium salt compound; then reacting it with L-arginine to obtain an aminomethylphenol compound; and finally reacting it with polylactic acid. The antibacterial and anti-inflammatory absorbable suture prepared by this invention has excellent tensile strength, antibacterial properties, and hydrophilicity, meeting the requirements of clinical medical applications.

Description

Technical Field

[0001] This invention relates to the field of medical materials technology, specifically to an antibacterial and anti-inflammatory absorbable suture and its preparation method. Background Technology

[0002] Absorbable surgical sutures are special sutures used in surgical procedures for wound ligation, hemostasis, and tissue repair. They decompose within the body to form soluble substances that are absorbed and gradually excreted, avoiding postoperative pain and the risk of secondary infection associated with suture removal. Polylactic acid (PLA), an environmentally friendly and biodegradable polymer, is widely used in absorbable medical sutures due to its excellent biocompatibility and biodegradability. However, PLA sutures cannot effectively inhibit bacterial growth, potentially leading to postoperative infection. Furthermore, the hydrophobicity of PLA makes it difficult for cells to adhere to and multiply on its surface, affecting wound healing speed and potentially prolonging the degradation period. Due to the polarity difference between the hydrophobic and hydrophilic components of PLA, their compatibility is poor, easily forming weak interfacial bonds and phase separation structures, affecting the material's mechanical properties. To improve the safety and reliability of absorbable sutures in clinical applications, it is crucial to optimize and enhance their antibacterial and hydrophilic properties.

[0003] Chinese invention patent CN105079868A discloses a biocompatible absorbable medical suture and its preparation method. The preparation method of the absorbable medical suture includes the following steps: S1, preparing suture fibers; S2, preparing a coating solution; S3, coating weaving. Although this suture has good biocompatibility, facilitating cell adhesion and proliferation, good mechanical properties, and is degradation-resistant, and is simple to operate, its antibacterial properties are relatively poor. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide an antibacterial, anti-inflammatory, absorbable suture and its preparation method.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An antibacterial and anti-inflammatory absorbable suture comprises the following raw materials in parts by weight:

[0007] 55-63 parts polylactic acid, 15-20 parts modified polylactic acid, 15-20 parts hydrophilic compatibilizer, 10-15 parts polyglycolic acid, 12-18 parts polyethylene glycol, and 0.4-0.8 parts lubricant;

[0008] The modified polylactic acid is prepared by the following method:

[0009] S1: Methimazole reacts with eugenol to form a thioether compound; the reaction equation is shown below.

[0010]

[0011] S2: The sulfide compound reacts with octadecane bromide to form a quaternary ammonium salt compound; the reaction equation is shown below.

[0012]

[0013] S3: The quaternary ammonium salt compound reacts with L-arginine to yield an aminomethylphenol compound; the reaction equation is shown below.

[0014]

[0015] S4: Aminomethylphenol compounds react with polylactic acid to generate modified polylactic acid; in this reaction, the carboxyl group in the aminomethylphenol compound undergoes an esterification reaction with the terminal hydroxyl group of polylactic acid.

[0016] In step S1, the molar ratio of methimazole to eugenol is 1:(1.2-1.5).

[0017] In step S2, the molar ratio of the thioether compound to bromooctadecane is 1:(1.0-1.2).

[0018] In step S3, the molar ratio of the quaternary ammonium salt compound to L-arginine is 1:(1.1-1.3).

[0019] In step S4, the mass ratio of the aminomethylphenol compound to polylactic acid is 1:(55-60).

[0020] The hydrophilic modified compatibilizer is prepared by the following method:

[0021] N1: Pentaerythritol reacts with L-lactide to form a four-armed polyester compound; the reaction equation is shown below:

[0022]

[0023] N2: A four-armed polyester compound reacts with sodium hyaluronate to generate a hydrophilic modified compatibilizer; in this reaction, the hydroxyl groups of the four-armed polyester compound react with the carboxyl groups of sodium hyaluronate to obtain the hydrophilic modified compatibilizer.

[0024] In step N1, the molar ratio of pentaerythritol to L-lactide is 1:24.5.

[0025] In step N2, the mass ratio of the four-armed polyester compound to sodium hyaluronate is 2:5.

[0026] The lubricant is calcium stearate.

[0027] A method for preparing an antibacterial, anti-inflammatory, absorbable suture, characterized by comprising the following steps:

[0028] (1) Weigh out the following by weight: 55-63 parts of polylactic acid, 15-20 parts of modified polylactic acid, 10-20 parts of hydrophilic modified compatibilizer, 10-15 parts of polyglycolic acid, 12-18 parts of polyethylene glycol, and 0.4-0.8 parts of lubricant;

[0029] (2) Add the above components to a high-speed mixer and mix them. Then, feed the mixture into a twin-screw extruder for extrusion and granulation, and air-cool it to obtain masterbatch.

[0030] (3) Add the masterbatch to the melt electrospinning machine for spinning, and then stretch it to obtain the antibacterial and anti-inflammatory absorbable suture.

[0031] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include:

[0032] (1) The present invention introduces imidazole ring, quaternary ammonium salt, guanidine group and long chain alkyl into polylactic acid through covalent bond, which not only improves its dispersibility, but also destroys bacterial cell membrane through multiple action mechanisms, thereby enhancing the antibacterial properties of absorbable sutures.

[0033] (2) The hydrophilic modified compatibilizer prepared in this invention improves the tensile strength and hydrophilicity of absorbable sutures by reducing interfacial tension, forming a three-dimensional network to disperse stress and by steric hindrance. Detailed Implementation

[0034] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0035] Example 1: Preparation of modified polylactic acid:

[0036] S1: 200 ml of dichloromethane, 0.1 mol of methimazole, and 0.12 mol of eugenol were added to a reaction vessel and stirred until well mixed. 0.6 g of photoinitiator 184 was added, and the mixture was irradiated under 300 W UV light for 5 min with stirring. The mixture was then distilled under reduced pressure at 30 °C for 2 h to obtain the sulfide compound. Its 1H NMR spectrum data are as follows: 1 H NMR (300 MHz, DMSO- d6) δ 7.57 (s, 1H), 7.16 (d, J = 3.6 Hz, 1H), 7.08 (dt, J = 3.6, 0.6 Hz, 1H), 6.79 - 6.62 (m, 3H), 3.83 (s, 3H), 3.71 (d, J = 0.7 Hz, 3H), 3.03 (d, J = 13.0 Hz, 2H), 2.72 (ddd,J = 7.7, 6.8, 0.9 Hz, 2H), 1.91 (tt, J = 7.6, 6.5 Hz, 2H);

[0037] S2: 300 ml of ethyl acetate, 0.1 mol of the thioether compound, and 0.1 mol of bromooctadecane were added to a reaction vessel, stirred and mixed, heated to 50 °C, and reacted for 15 h. The mixture was then cooled to 0 °C to precipitate a solid, kept at this temperature for 4 h, filtered, and recrystallized using a mixture of 300 ml of ethyl acetate and anhydrous ethanol (ethyl acetate to anhydrous ethanol volume ratio 8:2). The crystals were dried under vacuum at 60 °C for 24 h to obtain the quaternary ammonium salt compound. Its 1H NMR data are as follows: 1 H NMR (300 MHz, DMSO- d 6) δ 7.75 (dd, J = 3.8, 0.6Hz, 1H), 7.66 (d, J = 3.8 Hz, 1H), 7.57 (s, 1H), 6.74 (d, J = 8.7 Hz, 1H), 6.66 (s, 2H), 4.59 (td, J = 5.2, 0.9 Hz, 2H), 3.88 - 3.80 (m, 6H), 3.15 (t, J= 6.1 Hz, 2H), 2.76 - 2.67 (m, 2H), 2.18 (tt, J = 7.7, 5.2 Hz, 2H), 1.93 (tt,J = 7.6, 6.1 Hz, 2H), 1.57 - 1.44 (m, 2H), 1.27 (d, J = 2.5 Hz, 28H), 0.93 -0.82 (m, 3H);

[0038] S3: 500 ml of deionized water, 0.1 mol of quaternary ammonium salt compound, and 0.11 mol of L-arginine were added to a reaction vessel and stirred until well mixed. The mixture was heated to 60 °C, and 12 g of 37 wt% formaldehyde solution was added dropwise over 30 min. The reaction was allowed to proceed for 8 h, cooled to room temperature, and then distilled under reduced pressure at 60 °C for 3 h. Finally, the mixture was dried under vacuum at 70 °C for 24 h to obtain the aminomethylphenol compound. Its 1H NMR spectrum data are as follows: 1 H NMR (300 MHz, DMSO-d 6) δ 11.01 (s, 1H), 8.40 (s, 1H), 7.75 (dq, J = 3.8, 0.7 Hz, 1H), 7.66(dt, J = 3.8, 0.8 Hz, 1H), 7.61 (s, 1H), 7.55 (s, 1H), 3.63 (dt, J = 7.8, 6.0 Hz, 1H), 3.25 - 3.07 (m,4H), 2.77 - 2.65 (m, 2H), 2.18 (tt, J = 7.7, 5.2 Hz, 2H), 1.95 (tt, J = 7.5,6.1 Hz, 2H), 1.85 - 1.45 (m, 6H), 1.27 (d, J = 2.5 Hz, 28H), 0.96 - 0.82 (m,3H);

[0039] S4: Under nitrogen protection, 1000 ml DMSO, 2 g aminomethylphenol compound, 1.7 g N,N-dicyclohexylcarboimide (DCC), and 0.5 g 4-dimethylaminopyridine (DMAP) were added to a reaction vessel. The mixture was heated to 60 °C and stirred for 2 h to activate the carboxyl groups. 110 g polylactic acid was added, and the reaction was carried out for 48 h. The mixture was cooled to room temperature and distilled under reduced pressure at 80 °C for 3 h. Then, 500 ml dichloromethane was added and stirred to dissolve the mixture. 800 ml anhydrous ethanol was added and stirred to precipitate the precipitate. The precipitate was filtered and dried under vacuum at 60 °C for 12 h to obtain modified polylactic acid.

[0040] Example 2: Preparation of modified polylactic acid:

[0041] S1: Add 200 ml of dichloromethane, 0.1 mol of methimazole and 0.14 mol of eugenol to a reaction vessel, stir and mix well, add 0.6 g of photoinitiator 184, and under stirring conditions, irradiate under 300 W ultraviolet light for 10 min, and distill under reduced pressure at 30 °C for 2 h to obtain sulfide compounds.

[0042] S2: Add 300 ml of ethyl acetate, 0.1 mol of thioether compound, and 0.11 mol of bromooctadecane to a reaction vessel, stir and mix well, heat to 55 °C, react for 14 h, cool to 0 °C to precipitate solid, keep warm for 4 h, filter, recrystallize using a mixture of 300 ml of ethyl acetate and anhydrous ethanol (volume ratio of ethyl acetate to anhydrous ethanol 8:2), and dry under vacuum at 60 °C for 24 h to obtain quaternary ammonium salt compound;

[0043] S3: Add 500 ml of deionized water, 0.1 mol of quaternary ammonium salt compound, and 0.12 mol of L-arginine to a reaction vessel, stir and mix well, heat to 70 °C, add 12 g of 37 wt% formaldehyde solution dropwise over 30 min, react for 7 h, cool to room temperature, distill under reduced pressure at 60 °C for 3 h, and dry under vacuum at 70 °C for 24 h to obtain aminomethylphenol compound;

[0044] S4: Under nitrogen protection, 1000 ml DMSO, 2 g aminomethylphenol compound, 1.7 g N,N-dicyclohexylcarboimide (DCC), and 0.5 g 4-dimethylaminopyridine (DMAP) were added to a reaction vessel. The mixture was heated to 60 °C and stirred for 2 h to activate the carboxyl groups. 116 g polylactic acid was added, and the reaction was carried out for 48 h. The mixture was cooled to room temperature and distilled under reduced pressure at 80 °C for 3 h. Then, 500 ml dichloromethane was added and stirred to dissolve the mixture. 800 ml anhydrous ethanol was added and stirred to precipitate the precipitate. The precipitate was filtered and dried under vacuum at 60 °C for 12 h to obtain modified polylactic acid.

[0045] Example 3: Preparation of modified polylactic acid:

[0046] S1: Add 200 ml of dichloromethane, 0.1 mol of methimazole and 0.15 mol of eugenol to the reaction vessel, stir and mix well, add 0.6 g of photoinitiator 184, and under stirring conditions, irradiate under 300 W ultraviolet light for 15 min, and distill under reduced pressure at 30 °C for 2 h to obtain the sulfide compound.

[0047] S2: Add 300 ml of ethyl acetate, 0.1 mol of thioether compound, and 0.12 mol of bromooctadecane to a reaction vessel, stir and mix well, heat to 60 °C, react for 12 h, cool to 0 °C to precipitate solid, keep warm for 4 h, filter, recrystallize using a mixture of 300 ml of ethyl acetate and anhydrous ethanol (volume ratio of ethyl acetate to anhydrous ethanol 8:2), and dry under vacuum at 60 °C for 24 h to obtain quaternary ammonium salt compound;

[0048] S3: Add 500 ml of deionized water, 0.1 mol of quaternary ammonium salt compound, and 0.13 mol of L-arginine to a reaction vessel, stir and mix well, heat to 75 °C, add 12 g of 37 wt% formaldehyde solution dropwise over 30 min, react for 6 h, cool to room temperature, distill under reduced pressure at 60 °C for 3 h, and dry under vacuum at 70 °C for 24 h to obtain aminomethylphenol compound;

[0049] S4: Under nitrogen protection, 1000 ml DMSO, 2 g aminomethylphenol compound, 1.7 g N,N-dicyclohexylcarboimide (DCC), and 0.5 g 4-dimethylaminopyridine (DMAP) were added to a reaction vessel. The mixture was heated to 60 °C and stirred for 2 h to activate the carboxyl groups. 120 g polylactic acid was added, and the reaction was carried out for 48 h. The mixture was cooled to room temperature and distilled under reduced pressure at 80 °C for 3 h. Then, 500 ml dichloromethane was added and stirred to dissolve the mixture. 800 ml anhydrous ethanol was added and stirred to precipitate the precipitate. The precipitate was filtered and dried under vacuum at 60 °C for 12 h to obtain modified polylactic acid.

[0050] Example 4: Preparation of hydrophilic modified compatibilizer:

[0051] N1: Under nitrogen protection, 1000 ml DMF, 2.45 mol L-lactide, 0.1 mol pentaerythritol, and 6 g stannous octoate were added to a reaction vessel and stirred for 20 min. The mixture was then heated to 130 °C and reacted for 5 h. After cooling to room temperature, the mixture was distilled under reduced pressure at 80 °C for 3 h. 600 ml chloroform was added and stirred to dissolve the solid. 1000 ml methanol was added and stirred to precipitate the solid. The solid was filtered and dried under vacuum at 65 °C for 10 h to obtain a tetra-armed polyester compound with a number-average molecular weight of 3428.

[0052] N2: Place 1000g of deionized water and 10g of sodium hyaluronate into a reaction vessel, stir to dissolve, add 12g of strong acid cation exchange resin, stir at room temperature for 5h, filter, adjust the pH of the filtrate to 7 using tetrabutylammonium hydroxide, add 2000ml of anhydrous ethanol, stir to precipitate solid, filter, vacuum dry at 60℃ for 24h, dissolve in 300ml of anhydrous DMSO, add 4.5g of N,N-dicyclohexylcarboimide (DCC) and 1g of 4-dimethylaminopyridine (DMAP), stir at 60℃ for 2h to activate the carboxyl group, add 4g of a tetra-armed polyester compound, react at 60℃ for 48h, cool to room temperature, filter, add 500ml of acetone, stir to precipitate solid, filter, vacuum dry at 60℃ for 12h to obtain the hydrophilic modified compatibilizer.

[0053] Example 5: Preparation of antibacterial and anti-inflammatory absorbable sutures:

[0054] (1) Weigh out: 550g of polylactic acid, 150g of modified polylactic acid (prepared in Example 1), 150g of hydrophilic modified compatibilizer (prepared in Example 4), 100g of polyglycolic acid, 120g of polyethylene glycol, and 4g of calcium stearate;

[0055] (2) Add the above components to a high-speed mixer and mix them at a mixing temperature of 170°C, a mixing speed of 80 r / min, and a mixing time of 20 min. Then, introduce the mixture into a twin-screw extruder for extrusion and granulation. The screw speed of the extruder is 10 r / s. The temperature of the conveying section of the twin-screw extruder is 170°C, the temperature of the melting section is 180°C, the temperature of the mixing section is 185°C, and the temperature of the homogenization section is 170°C. The mixture is then air-cooled to obtain masterbatch.

[0056] (3) Add the masterbatch to the melt electrospinning machine, the spinning temperature is 210℃ and the spinning speed is 180m / min to obtain nascent fibers with a diameter of 1mm, and then stretch them three times in a water bath at 70℃ to obtain antibacterial and anti-inflammatory absorbable sutures with a diameter of 0.4mm.

[0057] Example 6: Preparation of antibacterial and anti-inflammatory absorbable sutures:

[0058] (1) Weigh out: 600g of polylactic acid, 180g of modified polylactic acid (prepared in Example 2), 190g of hydrophilic modified compatibilizer (prepared in Example 4), 120g of polyglycolic acid, 160g of polyethylene glycol, and 6g of calcium stearate;

[0059] (2) Add the above components to a high-speed mixer and mix them at a mixing temperature of 170°C, a mixing speed of 80 r / min, and a mixing time of 20 min. Then, introduce the mixture into a twin-screw extruder for extrusion and granulation. The screw speed of the extruder is 10 r / s. The temperature of the conveying section of the twin-screw extruder is 170°C, the temperature of the melting section is 180°C, the temperature of the mixing section is 185°C, and the temperature of the homogenization section is 170°C. The mixture is then air-cooled to obtain masterbatch.

[0060] (3) Add the masterbatch to the melt electrospinning machine, the spinning temperature is 210℃ and the spinning speed is 180m / min to obtain nascent fibers with a diameter of 1mm, and then stretch them 3 times in a water bath at 80℃ to obtain antibacterial and anti-inflammatory absorbable sutures with a diameter of 0.4mm.

[0061] Example 7: Preparation of antibacterial and anti-inflammatory absorbable sutures:

[0062] (1) Weigh out: 630g of polylactic acid, 200g of modified polylactic acid (prepared in Example 3), 200g of hydrophilic modified compatibilizer (prepared in Example 4), 150g of polyglycolic acid, 180g of polyethylene glycol, and 8g of calcium stearate;

[0063] (2) Add the above components to a high-speed mixer and mix them at a mixing temperature of 170°C, a mixing speed of 80 r / min, and a mixing time of 20 min. Then, introduce the mixture into a twin-screw extruder for extrusion and granulation. The screw speed of the extruder is 10 r / s. The temperature of the conveying section of the twin-screw extruder is 170°C, the temperature of the melting section is 180°C, the temperature of the mixing section is 185°C, and the temperature of the homogenization section is 170°C. The mixture is then air-cooled to obtain masterbatch.

[0064] (3) Add the masterbatch to the melt electrospinning machine, the spinning temperature is 210℃ and the spinning speed is 180m / min to obtain nascent fibers with a diameter of 1mm, and then stretch them 3 times in a water bath at 90℃ to obtain antibacterial and anti-inflammatory absorbable sutures with a diameter of 0.4mm.

[0065] Comparative Example 1

[0066] The raw material composition and process of the antibacterial and anti-inflammatory absorbable suture are basically the same as those in Example 6, except that the modified polylactic acid (prepared in Example 2) added to the components is replaced with an equal mass of a mixture prepared by the following method:

[0067] The aminomethylphenol compound (prepared in step S3 of Example 2) was mixed with polylactic acid at a mass ratio of 1:58 to obtain a mixture.

[0068] Comparative Example 2

[0069] The raw material composition and process of the antibacterial and anti-inflammatory absorbable suture are basically the same as those in Example 6, except that the modified polylactic acid (prepared in Example 2) added to the components is replaced with an equal mass of modified polylactic acid prepared by the following method:

[0070] The preparation method of modified polylactic acid is basically the same as that in Example 2, except that the methimazole in step S1 is replaced with an equimolar amount of 6-(dimethylamino)hexane-1-thiol (CAS: 68402-57-3).

[0071] Comparative Example 3

[0072] The raw material composition and process of the antibacterial and anti-inflammatory absorbable suture are basically the same as those in Example 6, except that the modified polylactic acid (prepared in Example 2) added to the components is replaced with an equal mass of modified polylactic acid prepared by the following method:

[0073] The preparation method of modified polylactic acid is basically the same as that in Example 2, except that L-arginine in step S3 is replaced with an equimolar amount of glycine.

[0074] Comparative Example 4

[0075] The raw material composition and process of the antibacterial and anti-inflammatory absorbable suture are basically the same as those in Example 6, except that the modified polylactic acid (prepared in Example 2) added to the components is replaced with an equal mass of modified polylactic acid prepared by the following method:

[0076] S1: Add 200 ml of dichloromethane, 0.1 mol of methimazole and 0.14 mol of eugenol to a reaction vessel, stir and mix well, add 0.6 g of photoinitiator 184, and under stirring conditions, irradiate under 300 W ultraviolet light for 10 min, and distill under reduced pressure at 30 °C for 2 h to obtain sulfide compounds.

[0077] S2: Add 500 ml of deionized water, 0.1 mol of thioether compound, and 0.12 mol of L-arginine to a reaction vessel, stir and mix well, heat to 70 °C, add 12 g of 37 wt% formaldehyde solution dropwise over 30 min, react for 7 h, cool to room temperature, distill under reduced pressure at 60 °C for 3 h, and dry under vacuum at 70 °C for 24 h to obtain aminomethylphenol compound;

[0078] S3: Under nitrogen protection, 1000 ml DMSO, 2 g aminomethylphenol compound, 1.7 g N,N-dicyclohexylcarboimide (DCC), and 0.5 g 4-dimethylaminopyridine (DMAP) were added to a reaction vessel. The mixture was heated to 60 °C and stirred for 2 h to activate the carboxyl groups. 116 g polylactic acid was added, and the reaction was carried out for 48 h. The mixture was cooled to room temperature and distilled under reduced pressure at 80 °C for 3 h. Then, 500 ml dichloromethane was added and stirred to dissolve the mixture. 800 ml anhydrous ethanol was added and stirred to precipitate the precipitate. The precipitate was filtered and dried under vacuum at 60 °C for 12 h to obtain modified polylactic acid.

[0079] Comparative Example 5

[0080] The raw material composition and process of the antibacterial and anti-inflammatory absorbable suture are basically the same as those in Example 6, except that the hydrophilic compatibilizer (prepared in Example 4) added to the components is replaced with an equal mass of a mixture prepared by the following method:

[0081] A mixture was prepared by mixing a tetra-armed polyester compound (prepared in step N1 of Example 4) with sodium hyaluronate at a mass ratio of 2:5.

[0082] Comparative Example 6

[0083] The raw material composition and process of the antibacterial and anti-inflammatory absorbable suture are basically the same as those in Example 6, except that the hydrophilic modified compatibilizer (prepared in Example 4) added to the components is replaced with an equal mass of hydrophilic modified compatibilizer prepared by the following method:

[0084] The preparation method of the hydrophilic modified compatibilizer is basically the same as that in Example 4, except that L-lactide in step N1 is replaced with an equimolar amount of 6-caprolactone.

[0085] Comparative Example 7

[0086] The raw material composition and process of the antibacterial and anti-inflammatory absorbable suture are basically the same as those in Example 6, except that the hydrophilic modified compatibilizer (prepared in Example 4) added to the components is replaced with an equal mass of hydrophilic modified compatibilizer prepared by the following method:

[0087] The preparation method of the hydrophilic modified compatibilizer is basically the same as that in Example 4, except that pentaerythritol in step N1 is replaced with an equimolar amount of ethylene glycol.

[0088] The PLA used in the embodiments and comparative examples of this application is of type JHMS®PL05 (number-average molecular weight of 32kDa), the polyglycolic acid is of type JHMS®PG15, and it is produced by Sichuan Zhuoxin Biomaterials Research Co., Ltd.; the polyethylene glycol is PEG2000; the sodium hyaluronate is cosmetic grade, with a viscosity-average molecular weight of 11kDa, and it is produced by Zhenjiang Dongyuan Biotechnology Co., Ltd.; the strong acid cation exchange resin is a polymer of divinylbenzene and sodium vinylbenzene sulfonate, and its brand name is Amberlite® IMAC HP1110 resin.

[0089] The antibacterial and anti-inflammatory absorbable sutures prepared in Examples 5-7 and Comparative Examples 1-7 were subjected to tests of breaking strength, antibacterial properties, and water absorption. The test results are shown in Table 1.

[0090] The breaking strength was tested using an electronic single-fiber tensile tester. The test conditions were as follows: the suture was cut into 20cm pieces, the clamping distance was 12.5cm, the stretching speed was 20mm / min, and the suture was stretched until it broke completely. The breaking strength was then obtained. The test was repeated 3 times and the average value was taken.

[0091] Antibacterial performance test: The suture was cut into 5cm pieces. The test bacteria were Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The 5cm suture pieces were then placed in a 1×10⁻⁶ suture medium. 8 CFU / mL bacterial suspensions were co-cultured on agar-coated culture dishes and placed in a 37℃ bacterial incubator for 24 hours. The width D of the outer ring of the inhibition zone and the sample diameter d (0.4 mm) were measured. Three parallel measurements were taken, and the average value was calculated to determine the width of the inhibition zone: H = (Dd) / 2.

[0092] Water absorption test: Cut the suture into 5cm pieces, 20 pieces per group, and dry them in a 50℃ oven for 24 hours. Weigh the sample m0. Soak the sample in 37℃ distilled water for 24 hours. Remove the sample and quickly wipe off all the water on the sample surface with a clean dry cloth or filter paper. Weigh each group of samples m1 again. Measure three parallel data points, take the average value, and calculate the water absorption rate R = (m1 - m0) / m1 × 100%.

[0093] Table 1 Performance Test Data

[0094]

[0095] As can be seen from Examples 5, 6 and 7 in Table 1, the antibacterial and anti-inflammatory absorbable sutures prepared by the present invention have excellent tensile strength, antibacterial properties and hydrophilicity.

[0096] The modified polylactic acid prepared in this invention contains an imidazole ring, a quaternary ammonium salt, a guanidine group, and a long-chain alkyl group, which are covalently linked to the polylactic acid structure. This improves its dispersibility in the polylactic acid matrix and enhances its antibacterial properties. The quaternary ammonium salt cation and the positively charged guanidine group are adsorbed onto the negatively charged bacterial cell membrane surface through electrostatic attraction, interfering with the function of proteins (such as transport proteins and enzymes) on the cell membrane and weakening its barrier function. In addition, the guanidine group can also inhibit the activity of enzymes (such as adenosine triphosphatase and ATPase) on the cell membrane, affecting their metabolism and thus inhibiting bacterial growth and reproduction. The three-dimensional structure of the imidazole ring can increase the contact area between the molecule and the cell membrane, exacerbating the disordered arrangement of phospholipid molecules and thus accelerating cell membrane disintegration. The long-chain alkyl group can insert into and disrupt the lipid bilayer structure of the cell membrane through hydrophobic interactions, disrupting its order.

[0097] The polyester structure in the hydrophilic modified compatibilizer prepared in this application exhibits good compatibility with the polylactic acid (PLA) matrix, reducing interfacial tension and promoting interfacial fusion. The four-armed star-shaped topology forms a three-dimensional entangled network with the PLA molecular chains, effectively enhancing tensile strength through stress dispersion. Simultaneously, the steric hindrance effect of the four-armed structure prevents the aggregation of sodium hyaluronate structures within the PLA matrix, resulting in excellent hydrophilic properties. The difference between the hydrophilic modified compatibilizer used in Comparative Example 6 and Example 6 lies in replacing the poly-L-lactide segments with poly-6-caprolactone segments. Both are hydrophobic segments, having minimal impact on water absorption. Compared to the poly-L-lactide segments, the poly-6-caprolactone segments have poorer compatibility with the PLA matrix, leading to a decrease in tensile strength.

[0098] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. An antibacterial, anti-inflammatory, absorbable suture, characterized in that, The ingredients include the following parts by weight: 55-63 parts polylactic acid, 15-20 parts modified polylactic acid, 15-20 parts hydrophilic compatibilizer, 10-15 parts polyglycolic acid, 12-18 parts polyethylene glycol, and 0.4-0.8 parts lubricant; The modified polylactic acid is prepared by the following method: S1: Methimazole reacts with eugenol to form a sulfide compound. S2: Thioether compounds react with octadecane bromide to form quaternary ammonium salt compounds. S3: Quaternary ammonium salt compounds react with L-arginine to yield aminomethylphenol compounds. S4: Aminomethylphenol compounds react with polylactic acid to produce modified polylactic acid; The hydrophilic modified compatibilizer is prepared by the following method: N1: Pentaerythritol reacts with L-lactide to form a four-armed polyester compound. N2: A four-armed polyester compound reacts with sodium hyaluronate to generate a hydrophilic modified compatibilizer.

2. The antibacterial and anti-inflammatory absorbable suture according to claim 1, characterized in that, In step S1, the molar ratio of methimazole to eugenol is 1:(1.2-1.5).

3. The antibacterial and anti-inflammatory absorbable suture according to claim 1, characterized in that, In step S2, the molar ratio of the thioether compound to bromooctadecane is 1:(1.0-1.2).

4. The antibacterial and anti-inflammatory absorbable suture according to claim 1, characterized in that, In step S3, the molar ratio of the quaternary ammonium salt compound to L-arginine is 1:(1.1-1.3).

5. The antibacterial and anti-inflammatory absorbable suture according to claim 1, characterized in that, In step S4, the mass ratio of the aminomethylphenol compound to polylactic acid is 1:(55-60).

6. The antibacterial and anti-inflammatory absorbable suture according to claim 1, characterized in that, In step N1, the molar ratio of pentaerythritol to L-lactide is 1:24.

5.

7. The antibacterial and anti-inflammatory absorbable suture according to claim 1, characterized in that, In step N2, the mass ratio of the four-armed polyester compound to sodium hyaluronate is 2:

5.

8. The antibacterial and anti-inflammatory absorbable suture according to claim 1, characterized in that, The lubricant is calcium stearate.

9. A method for preparing an antibacterial and anti-inflammatory absorbable suture according to any one of claims 1-8, characterized in that, Includes the following steps: (1) Weigh out the following by weight: 55-63 parts of polylactic acid, 15-20 parts of modified polylactic acid, 10-20 parts of hydrophilic modified compatibilizer, 10-15 parts of polyglycolic acid, 12-18 parts of polyethylene glycol, and 0.4-0.8 parts of lubricant; (2) Add the above components to a high-speed mixer and mix them. Then, feed the mixture into a twin-screw extruder for extrusion and granulation, and air-cool it to obtain masterbatch. (3) Add the masterbatch to the melt electrospinning machine for spinning, and then stretch it to obtain the antibacterial and anti-inflammatory absorbable suture.

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