Conjugated electrostatic spinning pomegranate peel microcapsule nano-yarn core-spun yarn and preparation method thereof

Abstract

The invention relates to the technical field of spinning, and provides conjugated electrostatic spinning pomegranate peel microcapsule nano-yarn core-spun yarn and a preparation method thereof. The covering yarn comprises a core yarn and nanofibers covering the surface of the core yarn. The nanofiber is mainly prepared from PLA (polylactic acid) and a composite microcapsule, a shell layer of the composite microcapsule is mainly composed of chitosan and gelatin, and a core layer of the composite microcapsule is mainly composed of a pomegranate peel extract. By selecting the specific composite microcapsule, the core spun yarn with multiple properties such as mechanical property, slow release property, surface structure regularity, antibacterial property, cytotoxicity, anti-inflammatory activity and oxidation resistance is prepared.

Description

Technical Field

[0001] The invention relates to the technical field of spinning, and in particular to a conjugated electrostatically spun pomegranate peel microcapsule nano yarn core-covered yarn and a preparation method thereof. Background Art

[0002] With the advancement of new textile materials technology, the strategic value of composite yarns in cross-disciplinary applications is becoming increasingly prominent. Core-spun yarns based on nanofiber coating technology, with their unique structural-functional integration, show potential for breakthrough applications in the biomedical field. For example, by coating a high-strength core yarn with biodegradable nanofibers (such as a polycaprolactone / chitosan composite), the resulting core-spun sutures possess both tensile strength (>50 cN / tex) and sustained drug release. Another example is the use of hollow core-spun yarns loaded with anticancer drugs (such as paclitaxel), with a thermosensitive nanofiber coating enabling precise controlled release. Another example is the electrospinning of conductive nanofibers (such as a polypyrrole / silk fibroin composite) onto a water-soluble vinyl core yarn to create a three-dimensional guiding structure. This scaffold has demonstrated a significant 2.3-fold increase in axonal extension velocity in animal experiments.

[0003] However, the core-spun yarn based on nanofiber coating technology is also prone to the situation where the core-spun yarn function is difficult to meet expectations due to reasons such as poor structural regularity of the nanofiber coating layer and poor interface bonding strength. In particular, in the field of biomedicine, when it is necessary to simultaneously meet multiple performance requirements such as mechanical properties, sustained-release properties, surface structural regularity, antibacterial properties, cytotoxicity, anti-inflammatory activity, and antioxidant capacity, the technical difficulty of preparing core-spun yarn with the aforementioned functions is very great. Summary of the Invention

[0004] The present invention provides a conjugated electrospun pomegranate peel microcapsule nano yarn core-spun yarn and a preparation method thereof. By selecting specific composite microcapsules, the preparation of core-spun yarn with multiple properties such as mechanical properties, sustained-release properties, surface structure regularity, antibacterial properties, cytotoxicity, anti-inflammatory activity, and antioxidant capacity is achieved.

[0005] In a first aspect, the present invention provides a core-spun yarn, comprising: A core yarn, and nanofibers coated on the surface of the core yarn; The nanofibers are mainly composed of PLA and composite microcapsules; The shell layer of the composite microcapsule is mainly composed of chitosan and gelatin, and the core layer of the composite microcapsule is mainly composed of pomegranate peel extract.

[0006] Different polymers have different spinnability, and different types of polymers have large differences in mechanical properties and surface properties. Experiments have found that using PLA as the spinning matrix can not only achieve good wrapping of the composite microcapsules, but also significantly improve the various properties of the resulting core-spun yarn, due to other common polymer types.

[0007] According to the core-spun yarn provided by the present invention, the mass ratio of PLA to composite microcapsules is 4-6:1.

[0008] According to the core-spun yarn provided by the present invention, the average diameter of the nanofibers is 600-700 nm. Experiments have found that when the average diameter of the nanofibers is within this range, the corresponding nanofiber drug loading is high, the encapsulation is good, the fiber / core yarn interface bonding strength is high, and the processing is stable. When the nanofibers are too thin, the fiber specific surface area is high, it is difficult to effectively encapsulate microcapsules, and the yarn breaking strength is low. When the nanofiber diameter is too thick (usually >800 nm), the yarn specific surface area is significantly reduced, the drug loading rate is low, and the drug release rate is accelerated. The physical bonding points between the fiber and the core yarn are reduced, the interfacial shear strength is reduced, the core-spun yarn breaking strength is reduced, and the fiber bending stiffness is increased, resulting in a harder yarn feel and a shorter dynamic fatigue life.

[0009] According to the core-spun yarn provided by the present invention, the nanofibers account for 40-50% of the total mass of the core-spun yarn. Experimental results show that when the nanofiber proportion is less than 10%, the core yarn breaks primarily, the nanofibers are not tightly wrapped, and the yarn has high hairiness. When the proportion is 40-50%, the nanofiber / core yarn breaks synergistically, the yarn breaking strength reaches a peak, the nanofibers are evenly and tightly wrapped, and the yarn has low hairiness. At higher proportions, stress concentration occurs due to fiber agglomeration, and the nanofiber layer fails first.

[0010] According to the core-spun yarn provided by the present invention, the mass ratio of chitosan to gelatin is 10-20:1.

[0011] Preferably, a chitosan to gelatin mass ratio of 15:1 achieves an optimal balance of positive and negative charges between the wall material components, enabling the gelatin and chitosan molecules to form a dense three-dimensional network structure, effectively improving the inclusion efficiency of the microcapsule wall. However, deviations from this optimal ratio (e.g., 5:1 or 25:1) can cause excess positive or negative charges in the system to self-aggregate wall material molecules not involved in cross-linking, resulting in a loose microcapsule wall structure and a significant decrease in the core material inclusion efficiency. System optimization and mechanistic analysis indicate that selecting a gelatin / chitosan wall material mass ratio of 15:1 achieves both charge balance and a structurally stable microcapsule wall, making it the optimal process parameter under these experimental conditions.

[0012] According to the core-spun yarn provided by the present invention, the inclusion rate of the composite microcapsules is greater than 80%. Studies have found that the core-spun yarn structure can achieve a 72-hour sustained release of PPE. If the inclusion rate is low, the drug in the core-spun yarn will experience a burst release of more than 80% of the drug within 24 hours, failing to achieve a sustained release effect.

[0013] According to the core-spun yarn provided by the present invention, the core yarn is selected from cotton yarn, polyester filament, nylon filament or spandex filament, preferably cotton yarn.

[0014] According to the core-spun yarn provided by the present invention, the breaking strength of the core-spun yarn is greater than 440 cN / dtex, the hairiness index is less than 70, and the CV% value of the yarn is less than 9.85%.

[0015] In a second aspect, the present invention further provides a method for preparing the core-spun yarn as described above, comprising: A PLA solution comprising dissolving PLA in a solvent; The composite microcapsules are mixed with the PLA solution to obtain a spinning solution; the shell layer of the composite microcapsules is mainly composed of chitosan and gelatin, and the core layer of the composite microcapsules is mainly composed of pomegranate peel extract; Cotton yarn is used as core yarn, and a conjugate electrostatic spinning process is adopted to make the spinning solution form nanofibers on the surface of the core yarn to obtain the core-spun yarn.

[0016] Preferably, the parameters of the yoke electrospinning process include: voltage of 5-15 kV, propulsion flow rate of 0.5-1.5 mL / h.

[0017] Preferably, the solvent is selected from hexafluoroisopropanol, trifluoroethanol or dimethylacetamide, and a mixed solution of dichloromethane and dimethylformamide in a volume ratio of 1:1 can also be used.

[0018] According to the method for preparing the core-spun yarn provided by the present invention, the rotation speed of the collecting roller is 2-4° / s; and / or the mass fraction of the PLA solution is 10-12%.

[0019] The present invention provides a conjugated electrospun pomegranate peel microcapsule nano yarn core-spun yarn and a preparation method thereof. By selecting specific composite microcapsules, the preparation of core-spun yarn with multiple properties such as mechanical properties, sustained-release properties, surface structure regularity, antibacterial properties, cytotoxicity, anti-inflammatory activity, and antioxidant capacity is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 is a morphology diagram of the nanofibers obtained in Examples 1 to 3 provided by the present invention, wherein: Figure 1 The magnification of the upper row is ×200. Figure 1 The magnification in the lower row is ×1000.

[0022] Figure 2 is a morphology diagram of the nanofibers obtained in Examples 1 and 4 and Comparative Example 1 provided by the present invention, wherein: Figure 2 The magnification of the upper row is ×200. Figure 2 The magnification in the lower row is ×1000.

[0023] Figure 3 is a morphology diagram of the nanofibers obtained in Examples 1, 5 and Comparative Example 2 provided by the present invention, wherein: Figure 3 The magnification of the upper row is ×200. Figure 3 The magnification in the lower row is ×1000.

[0024] Figure 4 This is a test result diagram of Test Example 2 provided by the present invention.

[0025] Figure 5 This is a test result diagram of Test Example 3 provided by the present invention.

[0026] Figure 6 This is a test result diagram of Test Example 5 provided by the present invention.

[0027] Figure 7 This is a test result diagram of Test Example 6 provided by the present invention.

[0028] Figures 8-10 This is a test result diagram of Test Example 7 provided by the present invention.

[0029] Figure 11 This is a test result diagram of Test Example 8 provided by the present invention. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0031] The following combination Figures 1 to 11 The invention describes a conjugated electrospun pomegranate peel microcapsule nano yarn core-covered yarn and a preparation method thereof.

[0032] If no specific techniques or conditions are specified in the examples, the experiments were carried out according to the techniques or conditions described in the literature in the field or according to the product instructions. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0033] Chitosan, chemically pure, was purchased from Shanghai MacLean Biochemical Technology Co., Ltd. Gelatin, chemically pure, Shanghai MacLean Biochemical Technology Co., Ltd.; PLA: purchased from Shanghai MacLean Biochemical Technology Co., Ltd., with a purity of Mw 60000 Cotton yarn: 29.5tex.

[0034] Preparation Example 1 A method for preparing PPE (pomegranate peel extract) is as follows: Fresh pomegranate peel was rinsed with running water to remove surface impurities, then dried in a dark, ventilated area at room temperature for 48 h to constant weight. The peel was then processed using a high-speed universal grinder and passed through a 40-mesh standard sieve to obtain a uniform powder. Accurately weigh 100.0 g of the powder was mixed with 4.8 L of an ethanol-water solution (50% by volume, solid-to-liquid ratio of 1:48, w / v). Static extraction was performed in an 80°C water bath for 2 h. The extract was filtered through a Büchner funnel under reduced pressure (0.08 MPa). The filtrate was then subjected to three liquid-liquid extractions with petroleum ether at a 1:3 volume ratio to remove fat-soluble impurities. The aqueous phase was collected, concentrated on a rotary evaporator (40°C, -0.09 MPa), and freeze-dried to obtain a pale yellow PPE powder.

[0035] Preparation Example 2 A method for preparing PPE microcapsules, comprising the following steps: (1) Dissolve a certain amount of chitosan in 1% acetic acid solution to prepare a chitosan solution with a mass concentration of 1%.

[0036] Dissolve a certain amount of gelatin in deionized water to prepare a gelatin solution with a mass concentration of 10%.

[0037] (2) The PPE prepared in Preparation Example 1 was suspended in the gelatin solution of step (1), and Tween 80 was added. The mixture was homogenized in a homogenizer at 6000 rpm for 5 min to completely disperse the PPE to obtain a mixed solution I. The mass of Tween 80 added was half the mass of the PPE added.

[0038] (3) The chitosan solution from step (1) was evenly added dropwise to the mixed solution from step (2) at a rate of 1 mL / min, and the mixture was stirred continuously at 500 rpm to mix the solution evenly, thereby obtaining mixed solution II. The mass ratio of gelatin to chitosan was 15:1, and the mass ratio of the total mass of gelatin and chitosan to PPE was 6.3:1.

[0039] (4) Gradually add 1M sodium hydroxide solution to the mixed solution II, slowly adjust the pH of the system to 5.6, and continue stirring at 500 rpm for 4 hours to induce coagulation. Then continue stirring in an ice bath. When the temperature drops below 5°C, add 0.15 mL of glutaraldehyde (50%) dropwise to the system and stir for 1 hour to generate covalently cross-linked microcapsules. After the solidification is completed, centrifuge at 1500 rpm for 15 minutes, freeze the coagulant at -20°C, and then freeze-dry to obtain PPE microcapsule powder with an inclusion rate of 81.4%. The freeze-dried microcapsules are stored in sealed glass bottles and kept away from light.

[0040] Example 1 A method for preparing a conjugated electrospun pomegranate peel microcapsule nano yarn core-covered yarn, comprising the following steps: (1) Dissolve PLA particles in hexafluoroisopropanol to prepare a PLA solution with a mass fraction of 12%.

[0041] (2) Add the PPE microcapsule powder prepared in Preparation Example 1 to the PLA solution of step (1), mix well, and obtain a spinning solution, wherein the mass ratio of PLA to PPE microcapsule powder is 4:1.

[0042] (3) With cotton yarn as the core yarn, the spinning solution of step (2) was used, and a conjugated electrospinning device was used to continuously prepare the nanofibers formed by the spinning solution under the conditions of positive and negative voltage ±10 kV, propulsion flow rate 0.8 mL / h, and collection roller speed 3° / s. The nanofibers formed by the spinning solution were coated on the surface of the core yarn to obtain conjugated electrospun pomegranate peel microcapsule nano yarn core yarn. The obtained core yarn was recorded as MIC / PLA4, wherein the collection distance was 12 cm, the collection roller diameter was 5 cm, the ambient temperature was 25 °C, and the humidity was 40%.

[0043] The nanofibers in the obtained core-spun yarn account for 45% of the total mass of the core-spun yarn.

[0044] Example 2 The method is basically the same as Example 1, except that the collecting roller rotates at a speed of 2° / s.

[0045] Example 3 The method is basically the same as Example 1, except that the collecting roller rotates at a speed of 4° / s.

[0046] Example 4 The method is basically the same as Example 1, except that the mass fraction of the PLA solution is 10%.

[0047] Example 5 The method is basically the same as Example 1, except that the mass ratio of PLA to PPE microcapsule powder is 6:1, and the obtained core-spun yarn is recorded as MIC / PLA6.

[0048] Comparative Example 1 The method is basically the same as Example 1, except that the mass fraction of the PLA solution is 8%.

[0049] Comparative Example 2 The method is basically the same as Example 1, except that the mass ratio of PLA to PPE microcapsule powder is 2:1, and the obtained core-spun yarn is recorded as MIC / PLA2.

[0050] Comparative Example 3 The method is basically the same as Example 1, except that: there is no step (2), the spinning solution in step (3) is the PLA solution in step (1), and the obtained core-spun yarn is recorded as PLA / cotton or PLA / C.

[0051] Test Example 1 SEM: Scanning electron microscopy was used to characterize the morphology of the samples, and Nano measure software was used to measure the fiber diameters. The average values ​​of the measurement results were taken.

[0052] The nanofibers obtained in Examples 1 to 3 were tested, and the results were as follows: Figure 1 As shown, it can be seen that: The roller receiving speed is the core control parameter in the conjugate electrospinning process. It directly affects the fiber morphology, orientation and functional properties by changing the jet stretching dynamics and fiber solidification behavior.

[0053] When the roller speed is 2° / s, the randomness of fiber deposition is enhanced, and a random network structure is easily formed with low orientation degree.

[0054] When the roller speed is increased to 3° / s, a directional tensile force is generated, which causes the fibers to be highly ordered along the direction of roller rotation, forming a parallel bundle structure, significantly improving the mechanical anisotropy of the yarn.

[0055] When the roller speed is increased to 4° / s, the fiber collection rate decreases, the nanofiber layer is thinner, and the fiber diameter is smaller.

[0056] The nanofibers obtained in Examples 1, 4 and Comparative Example 1 were tested, and the results were as follows: Figure 2 As shown, it can be seen that: Spinning solution viscosity has a significant bidirectional control effect on the electrospinning process. When the viscosity of the spinning solution is below a critical lower limit (8 wt%), the solution jet cannot form a stable Taylor cone structure due to insufficient molecular chain entanglement density. The surface tension of the solution and the electric field cannot achieve a dynamic equilibrium, resulting in difficulty in forming a fiber membrane and preventing continuous spinning. When the solution viscosity is increased to the critical range (10-12 wt%), the system exhibits good spinnability. Under the action of the electric field, the solution jet can produce effective tensile deformation. However, spinning solutions with excessively high viscosities are still not spinnable. First, excessive viscosity can easily clog the spinning solution at the nozzle, resulting in insufficient yarn output and difficulty in forming a continuous core-spun yarn. Second, when the solution concentration is high, the solvent content is low, and the jet is easily affected by airflow, leading to rapid solvent evaporation. The cone membrane formation rate is slow and the nanofibers easily solidify, being dragged into a dry membrane. This makes it difficult for the nanofibers to slide and wrap around the core yarn.

[0057] In summary, when the PLA solution concentration was 12wt%, the spinning jet was relatively stable, and a full, uniform tapered fiber membrane was formed. Nanofiber core-spun yarns were produced consistently and continuously, initially achieving a tightly wrapped, uniformly thick yarn. The nanofibers were aligned along the yarn axis, and as the solution viscosity increased, the nanofiber coating on the core yarn became more complete, while the amount of loose fibers on the surface gradually decreased.

[0058] The nanofibers obtained in Examples 1, 4 and Comparative Example 1 were tested, and the results were as follows: Figure 3 As shown, it can be seen that: Nanofibers can be formed using spinning solutions of varying ratios, but the resulting core-spun yarns exhibit distinct morphologies. Comparison of yarn morphologies (×200) obtained with different spinning solutions reveals that increasing the microcapsule loading to a microcapsule / PLA ratio of 1:2 or higher results in significant changes in the fiber surface morphology, primarily manifested by heterogeneous microcapsule aggregation. This is likely due to stress concentration generated by the spinning solution during electric field stretching, which promotes heterogeneous nucleation of microcapsules on the fiber surface.

[0059] It can be seen from the above tests that the average diameter of the nanofibers in the present invention is 600-700 nm.

[0060] Test Example 2: Sustained Release Performance Weigh 100 mg of core-spun yarn, cut it into pieces and put it into a centrifuge tube. Add 5 mL of PBS and shake it at 37°C for a sustained release test. Take 1 mL of the solution every 8 hours, centrifuge it at 5000 rpm for 10 minutes, take the supernatant, and measure the content of PPE released using a UV spectrophotometer.

[0061] Dynamic release experiments were used to evaluate the controlled-release properties of the core-spun yarn, revealing a three-stage release curve. The initial rapid release phase (0-24 hours) was primarily driven by the rupture of microcapsules adsorbed on the fiber surface and diffusion through the pores. The mid-term sustained release phase (24-64 hours) involved the diffusion of PPE through permeation channels formed by the swelling of the polymer matrix. Finally, the plateau phase (>64 hours) revealed that the residual amount of PPE was limited by the PPE concentration difference inside and outside the microcapsules.

[0062] The experimental results are as follows Figure 4 As shown in the figure, it shows that the core-spun yarn loaded with PPE microcapsules can slowly release the PPE therein. The release rate is positively correlated with the microcapsule content. The nano yarn sustained-release system has the characteristics of high loading rate, stability and slow release.

[0063] Test Example 3 Mechanical Properties The prepared yarns were tested using the YG061FQ electronic single yarn strength tester according to the standard "GB / T 3916-2013 Test method for tensile properties of chemical fiber filaments". 20 yarns of each type were randomly selected and the test results were averaged. Figure 5 As shown, *** indicates that there is a highly significant difference between the data, and **** indicates that there is a clear difference between the data. The specific values ​​are shown in the following table:

[0064] The breaking strength of cotton yarn is 324.34 ± 11.27 cN / dtex, while the average breaking strength of PLA / cotton is 419.93 ± 5.69 cN / dtex. The yarn strength and elongation at break are increased after nanofiber coating. When the nanofiber core-spun yarn is subjected to external tension, the surface nanofibers tend to fall off and the nanofibers tend to slip and break apart, causing the nanofibers to break first. The core-spun yarn only breaks completely after the external force exceeds the breaking strength of the core yarn.

[0065] Test Example 4 Hairiness Index and Sliver Unevenness The hairiness index of the prepared yarn was tested according to the standard FZ / T 01086 “Determination of Hairiness of Textile Yarns - Projection Counting Method”. The length of the test yarn segment was 10 m, the test speed was set at 30 m / min, 10 yarns were randomly selected from each yarn, and the test results were averaged.

[0066] The standard: GB / T 3292.1-2008 “Test method for unevenness of textile yarns - Part 1: Capacitance method” was used to test the unevenness of the prepared yarns. The length of the tested yarn segment was 100 m, the unwinding speed was set at 50 m / min, 10 yarns of each yarn were randomly selected, and the test results were averaged.

[0067] The test results are as follows:

[0068] It can be seen that compared with traditional cotton yarn, nanofiber core-spun yarn has made breakthrough progress in core weaving performance indicators through electrospinning process.

[0069] Yarn hairiness is a key quality indicator of yarn appearance and style, significantly impacting weaving efficiency, fabric style, and dyeing results. Experimental data shows that nanofiber core-spun yarn exhibits a significantly lower hairiness index compared to cotton yarn. This is primarily due to the electric field, which uniformly wraps the cotton core yarn with the nanofibers. Furthermore, the roller receiving device improves fiber orientation, reducing the likelihood of exposed fiber ends.

[0070] Yarn unevenness is a core quality indicator that characterizes the uniformity of yarn thickness along its length. It is defined as the degree of variation in the yarn's cross-sectional area (or diameter) over a specified length range and is typically quantified as the coefficient of variation (CV%) or Uster unevenness (U%). Experimental results show that the nanofiber coating process can significantly improve yarn uniformity. Compared with traditional ring-spun yarn, the CV% value of nanofiber core-spun yarn has been reduced from 12.94% to below 9.85%. Overall, compared with traditional cotton yarn, nanofiber core-spun yarn has significantly lower hairiness index and yarn unevenness, which helps reduce end-down rates, improve yarn tension balance, enhance weaving stability, and reduce costs across the entire supply chain. It represents a key technological breakthrough in the transformation of textile materials towards high-end and functionalized textiles.

[0071] Test Example 5 Antibacterial Performance The antibacterial properties of nano yarns against E. coli, S. aureus, MRSA and CA were tested by co-culture method. After sterilization by UV irradiation, the nano yarns were placed in a 5 mL centrifuge tube, and 2 mL PBS and 0.1 mL bacterial solution (10 6 ~10 7 CFU / mL), cultured at 37℃ for 24h, the bacterial solution with nano yarn added was recorded as the experimental group, and the original bacterial solution without nano yarn was recorded as the blank control group. After 100-fold dilution of the blank control group and the experimental group, 0.1mL of bacterial solution was evenly spread on the culture medium and cultured at 37℃ for 24h before colony count. Y The calculation method of (%) is as follows: Where, Y 0 is the colony count of the blank control group, Y 1 is the colony number of the experimental group.

[0072] Test structure such as Figure 6 As shown in the figure, neither the blank control group nor the PLA / cotton group showed significant antibacterial activity. However, nanofiber membranes loaded with different concentrations of PPE microcapsules showed antibacterial activity against E. coli, S. aureus, MRSA, and CA, with inhibition rates significantly higher than those of the PLA control group. Furthermore, the inhibition rate of the nanofiber yarn increased with increasing PPE microcapsule content.

[0073] Test Example 6 Cytotoxicity The CCK-8 assay was used to detect the cell viability of L929 and RAW 264.7 cells after incubation with nanoyarns containing different microcapsule contents. The test process was as follows: no cells were inoculated in the blank group, and cells were inoculated in 96-well culture plates in the control and experimental groups. The L929 cell inoculation amount was 8,000 cells / well, and the RAW 264.7 cell inoculation amount was 20,000 cells / well. The cells were incubated in a 37°C, 5% CO2 incubator for 24 hours. After treatment with yarn extract at a concentration of 1,000 μg / mL for 24 hours, the supernatant was removed, and 100 μL of 10% CCK-8 solution was added. The cells were incubated in a 37°C, 5% CO2 incubator for a certain period of time (L929 cells were incubated for 1.5 hours, and RAW 264.7 cells were incubated for 1 hour). The absorbance at 450 nm was measured to evaluate cell viability. The calculation formula for cell viability C (%) is as follows: Where A s For experimental wells at OD 450 The absorbance at A c For the control wells, the OD 450 The absorbance at A b For blank holes at OD 450 The absorbance at .

[0074] The test results are as follows Figure 7 As shown, ns indicates "not significant," meaning the difference between the two data sets was not statistically significant. * indicates a statistically significant difference, and ** indicates a highly significant difference. It can be seen that compared with the control group, the yarns in the experimental groups all exhibited good biocompatibility, and the addition of PPE microcapsules improved biocompatibility. The MIC / PLA4 group had the highest cell viability, while the MIC / PLA2 group had the lowest.

[0075] Test Example 7 Anti-inflammatory activity RAW 264.7 was inoculated into 96-well plates at a seeding volume of 2 × 10 4 Cells were incubated at 37°C, 5% CO₂ in an incubator for 24 hours. After treatment with 1000 μg / mL yarn extract for 2 hours and 10 μg / mL LPS for 24 hours, the cell supernatants were collected. NO levels in the cell supernatants were determined using the Griess method, IL-6 and TNF-α secretion was measured using ELISA kits, and ROS release was measured using a DCFH-DA assay.

[0076] The test results are as follows Figures 8-10 As shown in the figure, ns indicates "not significant," meaning the difference between the two data sets was not statistically significant, and **** indicates a significant difference between the data sets. It can be seen that, compared with the LPS-treated group, 24 hours of pretreatment with nanoyarns containing different concentrations of PPE microcapsules significantly decreased the levels of NO, IL-6, and TNF-α secreted by RAW 264.7 cells. This result suggests that PPE microcapsule nanoyarns can significantly inhibit the secretion of inflammatory factors and mediators by RAW 264.7 cells, demonstrating their potential to suppress inflammatory responses in wounds.

[0077] Test Example 8 The antioxidant capacity of the nanofiber membrane was detected by DPPH free radical scavenging method.

[0078] The test results are as follows Figure 11 As shown, the DPPH radical scavenging rates of cotton yarn and PLA / cotton were below 10%, indicating no antioxidant activity. However, the DPPH radical scavenging rates of MIC / PLA6, MIC / PLA4, and MIC / PLA2 all exceeded 40%, demonstrating excellent antioxidant properties. Furthermore, the DPPH radical scavenging rate of the nanofiber membranes gradually increased with increasing PPE microcapsule content, with MIC / PLA2 exhibiting the highest DPPH radical scavenging rate, reaching 63.46 ± 0.40%. This may be due to the antioxidant activity of polyphenols in PPE, which effectively scavenges free radicals, making it a potential candidate for use in medical dressings.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A core-spun yarn, characterized in that: include: A core yarn, and nanofibers coated on the surface of the core yarn; The nanofibers are mainly composed of PLA and composite microcapsules; The shell layer of the composite microcapsule is mainly composed of chitosan and gelatin, and the core layer of the composite microcapsule is mainly composed of pomegranate peel extract.

2. The core-spun yarn according to claim 1, characterized in that: The mass ratio of the PLA to the composite microcapsules is 4-6:

1.

3. The core-spun yarn according to claim 1 or 2, characterized in that: The average diameter of the nanofibers is 600-700 nm.

4. The core-spun yarn according to any one of claims 1 to 3, characterized in that: The nanofibers account for 40-50% of the total mass of the core-spun yarn.

5. The core-spun yarn according to any one of claims 1 to 4, characterized in that: The mass ratio of chitosan to gelatin is 10-20:

1.

6. The core-spun yarn according to any one of claims 1 to 5, characterized in that: The inclusion rate of the composite microcapsules is above 80%.

7. The core-spun yarn according to any one of claims 1 to 6, characterized in that: The core yarn is selected from cotton yarn, polyester filament, nylon filament or spandex filament, preferably cotton yarn.

8. The core-spun yarn according to any one of claims 1 to 7, characterized in that: The core-spun yarn has a breaking strength of 440 cN / dtex or more, a hairiness index of 70 or less, and an evenness CV% value of 9.85% or less.

9. The method for preparing the core-spun yarn according to any one of claims 1 to 8, characterized in that: include: A PLA solution comprising dissolving PLA in a solvent; The composite microcapsules are mixed with the PLA solution to obtain a spinning solution; the shell layer of the composite microcapsules is mainly composed of chitosan and gelatin, and the core layer of the composite microcapsules is mainly composed of pomegranate peel extract; Cotton yarn is used as core yarn, and a conjugate electrostatic spinning process is adopted to make the spinning solution form nanofibers on the surface of the core yarn to obtain the core-spun yarn.

10. The method for preparing core-spun yarn according to claim 9, characterized in that: The collecting roller has a rotational speed of 2-4° / s; and / or the mass fraction of the PLA solution is 10-12%.

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