CN110344151B

CN110344151B - Bionic scaffold simulating natural tendon tissue fiber hierarchical structure and preparation method thereof

Info

Publication number: CN110344151B
Application number: CN201910677294.4A
Authority: CN
Inventors: 莫秀梅; 谢宪瑞; 吴晶磊; 陈玉杰
Original assignee: Donghua University
Current assignee: Donghua University
Priority date: 2019-07-25
Filing date: 2019-07-25
Publication date: 2024-04-16
Anticipated expiration: 2039-07-25
Also published as: CN110344151A

Abstract

The invention relates to a bionic scaffold simulating a natural tendon tissue fiber hierarchical structure and a preparation method thereof. The stable continuous primary core spun yarn is prepared by adopting a double-nozzle spinning head, respectively adding positive and negative electric fields, receiving nano fibers through a rotating funnel and twisting the nano fibers on core yarns. And then, stranding a plurality of primary core-spun yarns to be used as core yarns, and carrying out outer electrostatic spinning on the nanofibers, wherein the obtained secondary core-spun yarns are stranded to be used as core layers, and the outer electrostatic spinning on the nanofibers is used for preparing the tertiary core-spun yarns with the fiber multi-layer structure simulating tendon tissues, so that the tertiary core-spun yarns are used for tendon repair brackets. The invention is favorable for tendon repair and normal function recovery, is very suitable for tendon injury repair and medical instrument materials, has good application prospect, and has simple and convenient preparation method and high production efficiency.

Description

Bionic scaffold simulating natural tendon tissue fiber hierarchical structure and preparation method thereof

Technical Field

The invention belongs to the field of bionic materials, and particularly relates to a bionic scaffold simulating a natural tendon tissue fiber hierarchical structure and a preparation method thereof.

Background

With the progress of human civilization and the pursuit of health, outdoor exercises of people have been significantly increased. Due to the continuous occurrence of accidents and the increasingly obvious trend of social aging, sports injuries are also increasing, wherein more than 50% of injuries of tendons and ligaments are caused. Statistics show that there are at least 3000 tens of thousands of tendon-damaged patients each year. Due to the limited regeneration capacity of tendons and ligaments, the healing is often accompanied by the formation of fibrotic scar tissue. At present, tendon injury repair methods mainly include autologous tendon transplantation, xenogeneic tendon transplantation, artificial tendon replacement and the like. In addition to donor scarcity, the use of these grafts presents a number of risks such as tissue rejection, disease transmission, donor site imperfections, inadequate repair, and the like. Bad repair of tendon injury not only affects daily life quality, but also breaks down the career of many top athletes. Therefore, the search for a novel method capable of promoting tendon physiological regeneration and repair has extremely important clinical significance.

At present, studies on tissue engineering artificial tendons mainly report that artificial tendon scaffolds prepared from biodegradable fibers by a weaving, knitting or braiding method, artificial tendon scaffolds prepared from porous materials prepared by a freeze-drying method, and the like are useful. However, most tendon scaffolds prepared by the method cannot simulate the fiber multi-level structure of tendon tissues, the biomechanical function still cannot reach the normal tendon, and the tendon scaffolds are easy to adhere to surrounding tissues in the repairing process, so that tendon healing is delayed, and the normal function of the healed tendon is affected.

In recent years, electrospun nanofibers have been widely used for tissue repair scaffolds, particularly tendon repair, due to their ability to simulate the filamentous structure of tissue extracellular matrix. A great deal of researches show that the nanofiber tissue repair material can remarkably promote the adhesion, proliferation and differentiation of cells, regulate the signal path for controlling the transcriptional activity and gene expression in the cells, guide the directional arrangement of cytoskeletal proteins, and the larger specific surface area of a nanoscale bracket (such as nanofiber) is favorable for adsorbing more proteins, can provide more adhesion sites for receptors on cell membranes, and the adsorbed proteins can also expose more hidden adhesion sites by changing the conformation, thereby being favorable for cell adhesion.

The human tendon is a fiber bundle composed of a large number of nano collagen fibers, and the fibers are arranged in parallel and are basically consistent with the axial direction of the tendon, so that the human tendon bears certain stretching force, and the stretching strength in the axial direction is 200-500 times of that in the radial direction. The nanofiber yarn with certain orientation arrangement can simulate collagen fiber bundles in natural tendons, and the ordered arrangement of nanofibers can increase the axial tensile strength. The prior study shows that the nanofiber yarn is a very ideal tendon tissue regeneration bracket.

CN 103445884A discloses an intelligent tendon repair device with a two-way shape memory function and a preparation method thereof, but the intelligent tendon repair device cannot simulate the fiber hierarchical structure of natural tendon tissue and the preparation method is complex, and the invention fills the blank of simulating the artificial tendon scaffold of the fiber hierarchical structure of natural tendon tissue.

Disclosure of Invention

The invention aims to provide a bionic bracket simulating a natural tendon tissue fiber hierarchical structure and a preparation method thereof, and overcomes the defect that the natural tendon tissue fiber hierarchical structure cannot be bionic in the prior art. The invention adopts a double-nozzle spinning head, positive and negative electric fields are respectively added, and the nano fibers are received through a rotating funnel and twisted on the core layer yarn to prepare the stable and continuous primary core-spun yarn. And then stranding a plurality of primary core-spun yarns to obtain a core-spun yarn, and spinning the nanofiber on the outer layer to obtain the secondary core-spun yarn which is still used as the core-spun yarn after continuous stranding, wherein the nanofiber is spun on the outer layer to prepare the tertiary core-spun yarn simulating the hierarchical structure of the natural tendon tissue fibers and is used for the tissue engineering artificial tendons.

The invention relates to a material simulating a natural tendon tissue fiber structure, which is a multi-layer structure simulating tendon tissue fibers, and the multi-layer structure comprises: the polymer yarn is used as a primary structure, and the outer layer of the polymer yarn wraps the electrospun nanofiber to form a core-spun yarn which is used as a secondary structure; ply-bonding the secondary structure to form a fiber bundle, and wrapping the electrospun nanofiber on the outer layer to form a core-spun yarn as a tertiary structure; the three-stage structure is stranded to form a fiber bundle, the outer layer wraps the electrospun nano fibers to form a core spun yarn which is stranded to form cellulose as an n-1 stage structure with the same four-stage structure …, and the outer layer comprises the electrospun nano fibers to form an n-stage structure, wherein n is a positive integer more than or equal to 3.

The diameter of the secondary structure is 0.1-0.2mm; the diameter of the tertiary structure is 0.3mm-0.6mm;2-10 secondary structures are stranded to form fiber bundles; 4-8 tertiary structures are stranded to form cellulose.

The diameter of the material is 1-12mm; the number of layers of the multilayer structure is 3-6 (i.e., the multilayer structure is 3-6).

The appearance of the material simulating the natural tendon tissue fiber structure comprises, but is not limited to, a cylinder, a flat shape and a cuboid.

The fiber bundles in the material are consistent with the axial direction of the material, and the core spun yarns in the fiber bundles are arranged in parallel.

The polymer yarn is one or more of polyethylene terephthalate yarn, polylactic acid yarn, polycaprolactone yarn, polylactic acid-glycolic acid copolymer yarn and silk fibroin yarn.

Further, the polymer yarn is a yarn with the diameter of 0.03-0.1mm formed by combining and drawing single fibers with the diameter of 20-50 micrometers.

The electrospun nanofiber is an electrospun nanofiber comprising a polymer and a natural polymer; wherein preferably, the polymer comprises one or more of lactic acid-caprolactone copolymer P (LLA-CL), polycaprolactone and polylactic acid-glycolic acid copolymer; the natural polymer comprises one or more of silk fibroin, collagen and gelatin.

Further, the electrospun nanofiber is a silk fibroin-P (LLA-CL) composite nanofiber having a silk fibroin content of 25%.

The polylactic acid yarn is preferably used as an inner core, and has good biodegradability, good biocompatibility and good tensile strength and extensibility because polylactic acid is nontoxic. The combination of natural materials and synthetic materials can obtain new materials with optimal mechanical properties and optimal biocompatibility, and it has been found that the mechanical properties and the biological properties of the materials are optimal when the combination ratio of silk fibroin and P (LLA-CL) is 25:75, so that silk fibroin-P (LLA-CL) composite nanofiber yarns with 25% silk fibroin content can be prepared.

The electrospun nanofiber also contains one or more of drugs and growth factors.

The invention relates to a preparation method of a material simulating a natural tendon tissue fiber structure, which comprises the following steps:

the stable continuous primary core spun yarn is prepared by adopting a double-nozzle spinning head, respectively adding positive and negative electric fields, receiving nano fibers through a rotating funnel and twisting the nano fibers on core yarns. And then, stranding a plurality of primary core-spun yarns to obtain core-spun yarns, and carrying out outer electrostatic spinning on the obtained yarns to obtain the yarns which are still used as the core-spun yarns after being continuously strapped, wherein the outer electrostatic spinning on the nano-fibers can be repeated to prepare the bionic scaffold with the fiber multi-layer structure for simulating the tendon tissue, and the bionic scaffold is used for tissue engineering artificial tendons.

Further, the preparation method specifically comprises the following steps:

(1) Preparing spinning solution: dissolving a polymer and a natural polymer in a solvent to obtain a spinning solution;

(2) Preparing continuous primary core-spun yarn:

coating (twisting) the polymer yarn inner core by adopting the nanofiber subjected to electrostatic spinning by adopting the spinning solution in the step (1) to obtain primary core-spun yarn;

the method is characterized by further comprising the following steps: placing the polymer yarn into an electrospinning nanofiber yarn preparation device as an inner core, and carrying out the following steps

(1) Performing electrostatic spinning on the nanofiber by using the medium spinning solution to prepare primary core-spun yarns;

(3) The primary core spun yarn in the step (2) is twisted to form a bundle of yarn which is used as an inner core, and the nanofiber which is subjected to electrostatic spinning by adopting the spinning solution in the step (1) is wrapped (twisted) on the inner core to obtain the secondary core spun yarn;

the method is characterized by further comprising the following steps: stranding the primary core spun yarn obtained in the step (2) to form a bundle of yarn, placing the stranded yarn into electrospun nanofiber yarn preparation equipment to serve as an inner core, and carrying out electrospun nanofiber on the spinning solution in the step (1) to prepare secondary core spun yarn;

(4) And (3) stranding the two-stage core spun yarns to form a bundle of yarns serving as an inner core, and wrapping (twisting) the inner core by adopting the nanofiber subjected to electrostatic spinning by adopting the spinning solution in the step (1) to obtain the three-stage core spun yarns.

The method is characterized by further comprising the following steps: and (3) stranding the secondary core spun yarn obtained in the step (3) to form a bundle of yarn, placing the stranded yarn into electrospun nanofiber yarn preparation equipment to serve as an inner core, and carrying out electrostatic spinning on the spinning solution in the step (1) to obtain the three-stage core spun yarn which is used for simulating the bionic scaffold of the natural tendon tissue fiber hierarchical structure.

The mass ratio of the polymer to the natural polymer in the step (1) is 90:10-10:90; further, the mass ratio of polymer to natural polymer is 90:10, 80:20, 70:30, 75:25, 60:40, 50:50, 40:60, 25:75, 30:70, 20:80, or 10:90, etc. The mass fraction of the polymer and natural polymer in the spinning solution is 5% -20%, preferably 6%, 8%, 9% or 10.5%, etc., more preferably 8%.

The solvent in the step (1) is one or more of hexafluoroisopropanol, trifluoroethanol, dichloromethane and trifluoroacetic acid.

The diameter of the primary core-spun yarn in the step (2) is 0.1-0.2mm.

2-10 primary core-spun yarns in the step (3) are combined into a bundle; the diameter of the secondary core-spun yarn is 0.3mm-0.6mm.

And (3) combining 4-8 secondary core-spun yarns into one bundle in the step (4).

The specific electrostatic spinning processes in the steps (2) - (4) are as follows: adding spinning solution into an injector, respectively connecting spinning nozzles at the left end and the right end of the yarn, respectively applying positive and negative high voltage of 9KV, applying positive and negative high voltage, and applying positive and negative high voltage, wherein the speed of a push pump is 1.2mL/h, the receiving distance is 10cm, the rotating speed of a rotating funnel is 400 turns/min, and the receiving roller is 10 turns/min, so as to perform electrostatic spinning of the nanofiber, receive the nanofiber through the rotating funnel and twist the nanofiber onto a core layer yarn, and prepare the core spun yarn.

The invention discloses a fiber structure material simulating natural tendon tissue, which is prepared by the method.

The invention also provides a device adopted by the preparation method, which comprises: positive and negative high-voltage power supply devices, a double spray head, a hollow rotary funnel, a receiving roller and the like, wherein the hollow rotary funnel is vertically arranged above the receiving roller, positive and negative electric fields are respectively applied to the double spray heads, when the two spray heads spray nanofibers upwards onto the middle rotary funnel, the rotary funnel twists the nanofibers into yarns, and the continuous nanofibers are obtained by rotating the yarn receiving roller.

The method comprises the following steps: the first-stage core spun yarn is prepared by adopting a double-nozzle spinning head, respectively adding positive and negative electric fields, receiving nano fibers through a rotating funnel and twisting the nano fibers on the core yarn. And then, the primary core spun yarn is stranded to be used as a core yarn, the outer layer is subjected to electrostatic spinning of nano fibers to obtain the secondary core spun yarn, the secondary core spun yarn is stranded to be used as the core yarn, and the outer layer is subjected to electrostatic spinning of nano fibers to prepare the tertiary core spun yarn simulating the hierarchical structure of the natural tendon tissue fibers, and the tertiary core spun yarn is used for tissue engineering artificial tendons.

The material simulating the natural tendon tissue fiber structure is applied to a bionic scaffold, such as a human tendon injury repair scaffold and a medical instrument material.

Preferably, the bionic scaffold is prepared to have a diameter of 1-12mm in consideration of tendon size when repairing human tendon tissue.

Advantageous effects

(1) The bionic scaffold simulating the fiber hierarchy of the natural tendon tissue provided by the invention can simulate the complex fiber hierarchy of the natural tendon tissue, spans a plurality of length scales from nano-scale to macro-scale, and better simulates the shape of the natural tendon tissue;

(2) The bionic bracket simulating the fiber hierarchical structure of the natural tendon tissue provided by the invention is provided with nanofiber yarns which are arranged in a certain orientation, and fiber bundles formed by parallel arrangement of fibers, wherein the fiber bundles are consistent with the axial direction of a material, so that the bionic bracket bears certain tensile force, and the ordered arrangement of the nanofibers can increase the axial tensile strength;

(3) The bionic bracket simulating the fiber hierarchical structure of the natural tendon tissue provided by the invention has adjustable mechanical properties, can be matched with the mechanical requirements of tendons at different parts of a human body, can simulate the stress-strain curve of the natural tendon, is a nonlinear toe region at low strain and is a linear region at high strain, and the thickness of nanofiber yarns can be adjusted according to the number of yarns in a core layer and the number of stranding;

(4) According to clinical requirements, the bionic scaffold simulating the natural tendon tissue fiber hierarchical structure can be added with anti-inflammatory and tissue adhesion preventing drugs or growth factors in different layers of materials in the preparation process, so that inflammatory reaction is reduced, tissue adhesion is avoided, tendon repair and normal function recovery are promoted, and a drug slow release effect is achieved;

(5) The bionic scaffold simulating the fiber hierarchical structure of the natural tendon tissue has a three-dimensional structure, can induce cells and blood vessels to grow in, gradually degrades from outside to inside while new tissue grows in, finally forms complete tendon healing, has no residual toxicity in the biodegradation process, and has good biocompatibility;

(6) The tendon bionic scaffold has the mechanical properties matched with natural tendons, avoids tissue adhesion, is beneficial to tendon repair and normal function recovery, and has the advantages of simple and convenient manufacturing method and high production efficiency.

Drawings

FIG. 1 is a schematic diagram of an apparatus for preparing electrospun nanofiber yarns;

FIG. 2 is a physical diagram of a tendon bionic scaffold;

FIG. 3 is a surface scanning electron microscope image of a tendon bionic scaffold;

FIG. 4 is a cross-sectional scanning electron microscope view of the tendon bionic scaffold;

FIG. 5 is a stress-strain diagram of a tendon biomimetic scaffold;

FIG. 6 is a graph of water contact angle of a tendon biomimetic scaffold;

FIG. 7 is a scanning electron microscope image of the effect of a tendon biomimetic scaffold on NIH3T3 cells at various time points (1 day, 4 days, 7 days, 14 days).

Detailed Description

The invention will be further illustrated with reference to specific examples. It is to be understood that these examples are illustrative of the present invention and are not intended to limit the scope of the present invention. Further, it is understood that various changes and modifications may be made by those skilled in the art after reading the teachings of the present invention, and such equivalents are intended to fall within the scope of the claims appended hereto.

Example 1

(1) Silk fibroin extraction: cutting off cocoon, removing pupa, peeling to obtain layers, boiling in 0.5% sodium bicarbonate water solution for 30 min, repeating twice to remove surface sericin, washing with deionized water, and air drying to obtain pure silk fibroin fiber. Placing silk fibroin fibers into CaCl ₂ /H ₂ Dissolving in O/absolute ethanol (molar ratio of 1:8:2) ternary solvent, heating to 70deg.C, dissolving for 40 min, dialyzing at room temperature in dialysis bag with molecular weight cutoff of 14000Da for 3 days, filtering to obtain pure silk fibroin aqueous solution, and lyophilizing to obtain spongy silk fibroin.

(2) Preparing spinning solution: 0.6g of P (LLA-CL) (75:25) (available from Gerania, biotech Co., ltd.) having a molecular weight of about twenty-thousand and 0.2g of silk fibroin were weighed out into 10mL of hexafluoroisopropanol (available from Shanghai Dairy Fine chemical Co., ltd.) to prepare a spinning solution having a mass concentration of 8%.

(3) Preparing continuous primary core-spun yarn:

placing polylactic acid yarn into a rotating funnel of electrospun nanofiber yarn preparation equipment to serve as an inner core layer, adding the spinning solution in the step (1) into a syringe, then respectively connecting spinning spray heads at the left end and the right end of the yarn, respectively applying positive and negative high voltage of 9KV, pushing the pump at a speed of 1.2mL/h, receiving the distance of 10cm, rotating the rotating funnel at a speed of 400 rpm, receiving the roller at a speed of 10 rpm, carrying out electrospun nanofiber, receiving the nanofiber through the rotating funnel, and twisting the nanofiber onto the yarn of the core layer, thereby preparing continuous primary core-spun yarn.

(4) And (3) stranding 4-6 primary core-spun yarns obtained in the step (2) to form a bundle of yarns, placing the bundle of yarns into a rotating funnel of electrospun nanofiber yarn preparation equipment to serve as an inner core, and repeating the spinning process in the step (2) to prepare the secondary core-spun yarns.

(5) And (3) stranding 8 secondary core-spun yarns obtained in the step (3) to form a bundle of yarns, placing the bundle of yarns into a rotating funnel of electrospun nanofiber yarn preparation equipment to serve as an inner core, and repeating the spinning process in the step (2) to prepare the three-stage core-spun yarns, wherein the three-stage core-spun yarns are used for simulating the bionic scaffold of the natural tendon tissue fiber hierarchical structure.

(6) The specific process of the electrostatic spinning in the steps (2) - (4) comprises: adding the spinning solution into an injector, respectively connecting spinning nozzles at the left end and the right end of the yarn, respectively applying positive and negative high voltage of 9KV, and performing electrostatic spinning on the nanofibers by a push pump with the speed of 1.2mL/h, the receiving distance of 10cm, the rotating speed of a rotating funnel of 400 rpm and the receiving roller of 10 rpm.

The tendon bionic scaffold obtained in the above example 1 was transected to obtain a cross section, and the surface and cross section were subjected to metal spraying and then observed for morphology by a scanning electron microscope. The scaffold is cylindrical, has a diameter of about 1-2mm, and can be customized according to the size of the actual damaged tendon when repairing human tendon tissue. The diameter of the fibers on the surface of the bracket is uniformly distributed, and the fibers are aligned along the axial direction (figure 3). The core layer yarns are wrapped by nano fibers to form primary core-spun yarns; the outer layer of the primary core spun yarn after stranding is wrapped with nano fibers to obtain secondary core spun yarn; after the secondary core spun yarn is plied, the outer layer electrospun nanofibers result in a tertiary core spun yarn simulating the fiber hierarchy of natural tendon tissue (fig. 4).

The tendon bionic scaffold obtained in example 1 was placed on a universal tester for mechanical tensile test, the cross-sectional diameter of the specimen was 1.5mm, the gauge length of the specimen was 2.0cm, and the tensile rate was 20.0mm/min. The stress-strain curve is shown in figure 5, and the result shows that the maximum tensile strength of the bracket is 105.08MPa, the elongation at break is 79.66 percent, and the Young modulus 326.85MPa mechanical property is better.

The tendon scaffold obtained in example 1 was measured for the water contact angle on the surface thereof using a contact angle meter (DSA 100). The support was horizontally placed on a stage of a contact angle meter, the size of a distilled water droplet (diameter: 6. Mu.L) was adjusted, the distilled water droplet was dropped on a flat surface of a sample, the contact angle was measured within 5 seconds after dropping, and data were recorded. The surface water contact angle of the tendon bionic scaffold is shown in figure 6, the contact angle is 63.8 degrees and is smaller than 90 degrees, and the tendon bionic scaffold is hydrophilic, so that the tendon bionic scaffold is favorable for cell adhesion growth.

The morphology and growth of mouse embryonic fibroblasts (NIH 3T 3) were observed by scanning electron microscopy on tendon biomimetic scaffolds of example 1 for 1, 4, 7 and 14 days, respectively. From the graph, on the 1 st day, NIH3T3 cells are in good growth state on the surface of the bionic scaffold, the morphology is kept complete and the cells adhere to the scaffold, and as the cells are inoculated to a new environment, the growth of the cells is affected to a certain extent, the cells do not grow into the fibrous membrane at the moment, and the quantity of the cells is not large. The cell growth and proliferation are obvious on days 4 and 7, the cell stretches and spreads out and grows to the periphery, and the antenna of the cell extends to the lower part of the fiber, has a trend of growing deep under the fiber, can be tightly adhered to the fiber, and shows that the cell has good growth activity. The cells are in a spread state on day 14, and are connected into a piece in a prolonged way, so that a single cell layer is formed on the surface of the bracket, and the high specific surface area and the high void ratio of the electrospun nanofiber provide favorable conditions for the growth and proliferation of the cells.

Claims

1. A material simulating a natural tendon tissue fiber structure, wherein the material is a multi-layered structure simulating tendon tissue fibers, comprising: the polymer yarn is used as a primary structure, and the outer layer of the polymer yarn wraps the electrospun nanofiber to form a core-spun yarn which is used as a secondary structure; ply-bonding the secondary structure to form a fiber bundle, and wrapping the electrospun nanofiber on the outer layer to form a core-spun yarn as a tertiary structure; forming fiber bundles by three-stage structure ply, and wrapping electrospun nanofibers on the outer layer to form core spun yarns as a four-stage structure; ply-bonding the n-1 level structure in the same way to form a fiber bundle, wherein the outer layer comprises electrospun nano fibers to form an n level structure, wherein n is a positive integer more than 3; wherein the fiber bundles are formed by parallel arrangement of fibers, and the fiber bundles are consistent with the axial direction of the material, and core spun yarns in the fiber bundles are arranged in parallel;

wherein the simulated natural tendon tissue fibrous structure material is prepared by the following method: a double-nozzle spinning head is adopted, positive and negative electric fields are respectively added, and the nano fibers are received through a rotating funnel and twisted on the core layer yarns to prepare first-stage core-spun yarns; and then stranding the primary core-spun yarn to be used as a core yarn, wrapping the electrospun nanofiber on the outer layer, continuously stranding the obtained secondary core-spun yarn to be used as the core yarn, wrapping the electrospun nanofiber on the outer layer, and repeating to prepare the simulated natural tendon tissue fiber structure material.

2. The material of claim 1, wherein the polymer yarn is 0.03-0.1mm; the diameter of the secondary structure is 0.1-0.2mm; the diameter of the tertiary structure is 0.3mm-0.6mm;2-10 secondary structures are stranded to form fiber bundles; 4-8 tertiary structures are plied to form a fiber bundle.

3. The material of claim 1, wherein the material has a diameter of 1-12mm; the multi-level structure is a 3-6 level structure.

4. The material according to claim 1, wherein the polymer yarn is one or more of polyethylene terephthalate yarn, polylactic acid yarn, polycaprolactone yarn, polylactic acid-glycolic acid copolymer yarn, silk fibroin yarn; the electrospun nanofiber is an electrospun nanofiber comprising a polymer and a natural polymer; wherein the polymer comprises one or more of lactic acid-caprolactone copolymer, polycaprolactone and polylactic acid-glycolic acid copolymer; the natural polymer comprises one or more of silk fibroin, collagen and gelatin.

5. The material of claim 4, wherein the electrospun nanofibers further comprise one or more of a drug and a growth factor.

6. A method of preparing a simulated natural tendon tissue fibrous structure material of claim 1, comprising: a double-nozzle spinning head is adopted, positive and negative electric fields are respectively added, and the nano fibers are received through a rotating funnel and twisted on the core layer yarns to prepare first-stage core-spun yarns; and then stranding the primary core-spun yarn to be used as a core yarn, wrapping the electrospun nanofiber on the outer layer, continuously stranding the obtained secondary core-spun yarn to be used as the core yarn, and wrapping the electrospun nanofiber on the outer layer to prepare the fiber structure material simulating the natural tendon tissue.

7. The preparation method according to claim 6, which comprises the following steps:

dissolving a polymer and a natural polymer in a solvent to obtain a spinning solution;

twisting the nanofiber subjected to electrostatic spinning by adopting the spinning solution in the step (1) to the inner core of the polymer yarn to obtain primary core spun yarn;

twisting the primary core spun yarn in the step (2) to form a bundle of yarn serving as an inner core, and twisting the nanofiber subjected to electrostatic spinning by adopting the spinning solution in the step (1) to the inner core to obtain a secondary core spun yarn;

and (3) twisting the two-stage core spun yarns to form a bundle of yarns serving as an inner core, and twisting the nanofiber subjected to electrostatic spinning by adopting the spinning solution in the step (1) to the inner core to obtain the three-stage core spun yarns.

8. The method according to claim 7, wherein the mass ratio of the polymer to the natural polymer in the step (1) is 90:10 to 10:90; the mass fraction of the polymer and the natural polymer in the spinning solution is 5% -20%.

9. Use of the simulated natural tendon tissue fibrous structure material of claim 1 as a biomimetic scaffold.