CN115154666A

CN115154666A - Degradable artificial ligament capable of being used for repairing nerve loop and preparation method thereof

Info

Publication number: CN115154666A
Application number: CN202210842965.XA
Authority: CN
Inventors: 师东良; 黄琬芸; 齐燕; 张晓青; 侯成义; 李华; 王晶洁; 丁巧方
Original assignee: Shanghai Yanzhi Rehabilitation Hospital Shanghai Sunshine Rehabilitation Center
Current assignee: Shanghai Yanzhi Rehabilitation Hospital Shanghai Sunshine Rehabilitation Center
Priority date: 2022-07-18
Filing date: 2022-07-18
Publication date: 2022-10-11
Anticipated expiration: 2042-07-18
Also published as: CN115154666B

Abstract

The invention relates to the technical field of medical materials, in particular to a degradable artificial ligament for repairing a nerve loop and a preparation method thereof. The preparation method of the invention is integrated, ensures the internal and external directions of chitosan and PHBV, and reduces the additional interference of chemical solution and the uncontrollable property of the fiber direction of the chemical fixation method. In addition, the invention also carries out grid control corona polarization on the chitosan part of the surface, and the degradable artificial ligament prepared by the invention has stronger current stimulation effect and can better promote ligament tissues and nerve regeneration.

Description

Degradable artificial ligament capable of being used for repairing nerve loop and preparation method thereof

Technical Field

The invention relates to the technical field of medical materials, in particular to a degradable artificial ligament for repairing a neural circuit and a preparation method thereof.

Background

Mechanical stability of Anterior Cruciate Ligament (ACL) decreases after rupture, and proprioceptive afferent dysfunction ^[1] Central nervous system function remodeling (CNSP) ^[2] Abnormal gait and movement posture ^[3-6] Early onset of osteoarthritis of the knee ^[7] The pain caused by the disease seriously affects the movement and the mental health of the patient, and the life quality is greatly reduced. Although the current conventional ACL reconstruction surgery (autologous or allogeneic tendon reconstruction, artificial ligament reconstruction) can increase the mechanical stability of the knee joint ^[8] But it is difficult to restore the proprioceptive afferent function of the ACL at all, and thus difficult to avoid CNSP. This CNSP forms a vicious circle not only as a result of an injury to the ACL, but also as a cause of an injury to the ACL ^[9,10] . Thus, CNSP is critical for the healing of ACL damage ^[11] 。

CNSPs derive from decreased numbers of proprioceptors, morphological and functional abnormalities, and proprioceptive upload disorders following ACL injury, which in turn lead to dysfunction of the central nervous system in the control of the descending motor control system. ACL repair regeneration is the fundamental approach to restore ACL proprioception. The better the ACL tissue regeneration, the better the ability to restore mechanical stability macroscopically, signal pathways microscopically andand (4) feeling the body. ACL preservation reconstruction surgery is the root of ACL repair regeneration. The tissue engineering technologies of stem cells, platelet-rich plasma and the like also play a role in promoting the repair and regeneration of ACL tissues to a certain extent ^[12] . On the basis of the above, the surgical mode of ACL biologic bridging enhanced repair proposed by Murray doctors in the child hospital of Boston in the United states has achieved certain effects in animal research and initial clinical research ^[13] . However, these methods for promoting the repair of the ACL stump itself do not specifically focus on the important issue of regeneration of neural tissue such as receptors in the ACL.

The development of material science opens a door for nerve repair and regeneration. On one hand: various biological and non-biological nerve conduits have gained favorable results in the basic and clinical research related to the regeneration of peripheral nerves, wherein chitosan is an ideal material for constructing artificial nerve graft due to good adsorptivity, permeability, plasticity, biocompatibility and biodegradability ^[14-16] . On the other hand: tissue regeneration requires time, and the reduction in the number of proprioceptors, morphological abnormalities, and functional decline of ACL, and the consequent central nervous system remodeling, in the time waiting for successful tissue regeneration, is inevitable. In the period, the novel material is required to collect mechanical energy along with the movement of the joint and convert the mechanical energy into electric energy, so that the deformation of the knee joint during the movement of the knee joint can be sensed, the electric impulse is generated for uploading, the ACL proprioception is simulated and replaced, and the requirement of the neural circuit is recovered ^[17] . Therefore, the simulation of the function of the proprioceptors of the anterior cruciate ligament is replaced by a transitional approach for the period of time required for regenerative repair.

Electrets and piezoelectric electrets in the field of material science can meet this requirement. (1) Electret (also called electret) refers to a dielectric capable of maintaining a state of polarization for a "long period", i.e. a dielectric capable of storing an excess of "real" charge for a long period of time or/and of maintaining an "oriented" electric dipole (i.e. a relative permittivity greater than 1) ^[18] . The chitosan can be polarized to become an "oriented" electret. (2) Piezoelectretes (also called ferroelectrets) refer to microporous-structured electrets with piezoelectric effect containing oriented "macroscopic electric dipoles ^[19] . It removesThe material has the outstanding characteristics of lightness, thinness, low acoustic impedance, ultra-wide response frequency band, low relative dielectric constant, low cost, environmental friendliness and the like besides the strong piezoelectric effect of the traditional piezoelectric ceramic and the high flexibility of the ferroelectric polymer, and is an ideal sensitive material for preparing various flexible light force sensors. Poly-3-Hydroxybutyrate-3-Hydroxyvalerate (PHBV) has biodegradability, biocompatibility and stronger mechanical property ^[20] . PHBV can not only promote the regeneration of spinal cord and peripheral nerve tissues, but also provide better environment for ligament cell adhesion, proliferation and matrix production ^[21] 。

In order to solve the problems of tissue regeneration and proprioception replacement simultaneously, the project team uses PHBV as a substrate and surface modification of chitosan to develop PHBV-CS absorbable nano ACL ^[22,23] . The PHBV-CS can absorb the nano ACL, can promote ligament collagen secretion, improve tissue healing capacity, has good biocompatibility and antibacterial property, good tensile modulus and ultimate tensile stress, and can maintain the mechanical stability of the knee joint; can provide good environment for the growth and adhesion of Schwann cells and promote nerve regeneration; can be successfully degraded by 50 percent in 14 days, and ensures that the ligament is healed for 6 weeks ^[24] 。

The deep molecular mechanism of absorbable nanometer anterior cruciate ligament for regulating central remodeling relates to three levels of brain, spinal cord and ACL ^[25,26] . (1) Brain level: the project group finds out in the national science fund project research undertaken at present: the Ras homologous gene member A is in negative correlation with the nerve growth related protein-43, and the Ras homologous gene member A is reduced and the nerve growth related protein-43 is increased after ACL damage, so that central remodeling is promoted; the opposite is true after ACL repair. (2) Spinal cord level: the expression of spinal cord dorsal root neuron neurotrophin 3 and nerve tyrosine kinase receptor 3 is reduced after the ACL proprioceptive nerve injury, and the expression of the spinal cord dorsal root neuron and the nerve tyrosine kinase receptor 3 is obviously increased after the electrical stimulation intervention of the ACL-popliteal muscle reflex arc ^[27] . (3) ACL levels: ACL injury can reduce mechano-mechanical sensitivity information, promote alpha motor neuron activation, and thus produce effects at the spinal cord level ^[28] . ACL can sense toughnessThe ability to carry mechanical stretch stimuli lies in their proprioceptors. Because the proprioceptors of ACL are dominated by Ruffini corpuscles, ACL proprioception should focus primarily on Ruffini corpuscles. On a microscopic level, the key point is that the Acid-sensing ion channel (ASIC) of the Ruffini corpuscle is a signal channel with dual chemical sensitivity and mechanical sensitivity in nature, and the molecular determinant promoting the dynamic mechanical sensitivity of the proprioceptor ^[29,30] 。

The project group is combined with the invention patent and the earlier stage research result to develop PHBV-CS absorbable nanometer anterior cruciate ligament. Firstly, preparing a PHBV-CS shell-core structure oriented nanofiber scaffold by using a coaxial spinning technology; then, electric polarization is carried out to form a chitosan electret; finally, the PHBV-CS material which is formed into the ACL broken end repairing material suitable for surgical repair can absorb the nano anterior cruciate ligament.

The Chinese patent application: CN104147642B discloses a preparation method of an anti-infective artificial ligament; the method specifically comprises the following steps: carrying out ultrasonic cleaning on the PET artificial ligament to remove surface dirt; performing corona treatment on the PET artificial ligament; preparing a nano-silver surface coating solution; coating the surface of the PET artificial ligament; washed and dried in vacuum. The thickness of the prepared nano silver coating on the surface of the artificial ligament is 50-300 nm, and the coating can improve the biocompatibility and the osteoconductivity of the artificial ligament, so that the artificial ligament has antibacterial and anti-inflammatory properties, and meets the requirements of clinical medicine in the aspects of bioactivity and mechanical properties. The mechanical strength of the artificial ligament described in this patent is yet to be improved.

The prior art is as follows: development of scientific Engineering of biological Engineering, tonekabon Branch, islamic Azaled University, tonekabon, iran,2proteomics Research center, shahid Behcheni University of Medical science, tehran, iran, and 3tissue Engineering Department, school of Advanced technology in medicine, tehran University of Medical science, tehran, and Iran discloses: the aim of The present invention, i.e., the aim of The present invention, is achieved by The aid of The objective tissue wave to product a dental-crosslinked biodegradable poly (3-hydroxybutyrate-co-3-hydroxyvale) (PHBV) neutral component, the objective tissue scan oil wave designed by side electrochemical method, and The aid of The objective tissue by chemical method, the physical, mechanical and chemical industries, and cell culture systems with Schwann cells. Results of analysis and compatibility with graft as a neural graft. Cellular experiments with a beta cell addition and growth inside The crosslinked nanofiber graft with a bound non-crosslinked graft. The nerve conduit seems to have proper tissues to carry out The research of living nerve tissue engineering) but The preparation method disclosed in The document is to cross-link The chitosan by a chemical fixation method on The basis of The original PHBV conduit, while The method of The invention is integrated, can ensure The internal and external directions of The chitosan and The PHBV, the additional interference of chemical solution and the uncontrollable of chemical fixing fiber direction are reduced. The invention relates to a degradable artificial ligament which can be used for repairing a neural circuit and a preparation method thereof, which are not reported at present.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a degradable artificial ligament for repairing a neural circuit and a preparation method thereof.

In order to achieve the purpose, the invention adopts the technical scheme that:

in a first aspect, the invention provides a PHBV-CS core-shell structure nanofiber scaffold material, which is prepared from hydroxybutyrate-hydroxyvalerate copolyester and chitosan, and a preparation method of the degradable artificial ligament comprises the following steps:

(1) Dissolving 8-15 wt% of hydroxybutyrate-hydroxyvalerate in trichloromethane to completely dissolve, and preparing for later use;

(2) Dissolving chitosan with the mass percentage concentration of 4-8% and the deacetylation degree of more than or equal to 95% in a dichloromethane-trifluoroacetic acid mixed solvent until the chitosan is completely dissolved, and preparing for later use;

(3) Respectively injecting the solutions obtained in the step (1) and the step (2) into an injector, and preparing the PHBV-CS core-shell fiber film according to an electrostatic spinning method;

(4) Vacuum drying the PHBV-CS core-shell fiber film obtained in the step (3) at room temperature for 1-3 days to remove the solvent, and obtaining the PHBV-CS core-shell structure nano fiber scaffold material;

(5) Polarizing the PHBV-CS shell-core structure nanofiber scaffold material by adopting a grid-control corona polarization method;

(6) And (3) rolling the polarized PHBV-CS shell-core structure nanofiber scaffold material by taking the chitosan layer as the inner surface to obtain the PHBV-CS shell-core structure nanofiber scaffold material.

Preferably, the mass percentage concentration of the hydroxybutyrate-hydroxyvalerate in step (1) is 15%.

Preferably, the chitosan concentration in the step (2) is 8% by mass.

Preferably, the experimental conditions in the electrospinning method in step (3) are: the inner diameter of the inner pipe of the coaxial spinning nozzle is 0.5mm, and the inner diameter of the outer pipe is 1.2mm; the spray head is connected with a positive voltage, and the receiving plate is connected with a negative voltage; the spinning conditions were: the size of the injector is 17mm, the rotating speed of the collector is 1500rpm, the flow rate of the outer tube is 0.04mm/min, the flow rate of the inner tube is 0.02mm/min, the distance between the head of the injector and the collector is 14cm, the positive voltage is 20kv, the negative voltage is 2kv, the temperature is 25 ℃, and the relative humidity is 30-40%.

Preferably, the experimental conditions for said polarization in step (5) are: the electrode spacing is 4cm, the corona voltage is-8 kv, the gate voltage is-1 kv, the polarization temperature is room temperature, the polarization humidity is 0-40%, and the polarization time is 5min.

Preferably, the preparation method in the step (6) is as follows: and (3) cutting the material obtained after polarization in the step (5) into a rectangle, taking the fiber arrangement direction as the width, taking a metal rod as an axis, and rolling the material along the width of the rectangle by taking the chitosan layer as an inner layer to obtain the chitosan/chitosan composite material.

In a second aspect, the invention provides a preparation method of a PHBV-CS shell-core structure nanofiber scaffold material, which comprises the following steps:

(1) Dissolving the hydroxybutyrate-hydroxyvalerate with the mass percentage concentration of 8-15% in trichloromethane to be completely dissolved, and preparing for standby;

(3) Respectively injecting the solutions obtained in the step (1) and the step (2) into an injector, and preparing a PHBV-CS core-shell fiber film according to an electrostatic spinning method;

(4) Vacuum drying the PHBV-CS core-shell fiber film obtained in the step (3) at room temperature for 1-3 days to remove the solvent, so as to obtain a PHBV-CS shell-core structure nanofiber scaffold material;

(5) Adopting a grid-control corona polarization method to polarize the PHBV-CS shell-core structure nanofiber scaffold material;

(6) And (3) rolling the polarized PHBV-CS shell-core structure nano fiber scaffold material by taking the chitosan layer as the inner surface to obtain the nano fiber scaffold material.

Preferably, the mass percentage concentration of the hydroxybutyrate-hydroxyvalerate in step (1) is 15%; the mass percentage concentration of the chitosan in the step (2) is 8%.

Preferably, the experimental conditions in the electrospinning method in step (3) are: the inner diameter of the inner pipe of the coaxial spinning nozzle is 0.5mm, and the inner diameter of the outer pipe is 1.2mm; the spray head is connected with a positive voltage, and the receiving plate is connected with a negative voltage; the spinning conditions were: the size of the injector is 17mm, the rotating speed of the collector is 1500rpm, the flow rate of the outer tube is 0.04mm/min, the flow rate of the inner tube is 0.02mm/min, the head distance of the injector is 14cm from the collector, the positive voltage is 20kv, the negative voltage is 2kv, the temperature is 25 ℃, and the relative humidity is 30-40%; the experimental conditions for the polarization in step (5) are: the electrode spacing is 4cm, the corona voltage is-8 kv, the gate voltage is-1 kv, the polarization temperature is room temperature, the polarization humidity is 0-40%, and the polarization time is 5min; the preparation method in the step (6) specifically comprises the following steps: and (3) cutting the material obtained after polarization in the step (5) into a rectangle, taking the fiber arrangement direction as the width, taking a metal rod as an axis, and rolling the material along the width of the rectangle by taking the chitosan layer as an inner layer to obtain the chitosan/chitosan composite material.

In a third aspect, the invention provides an application of the PHBV-CS core-shell structure nanofiber scaffold material as described above as a degradable artificial ligament.

At present, how the PHBV-CS can absorb nano anterior cruciate ligament acts on Ruffini corpuscle makes the Ruffini corpuscle feel tension stimulation, and how ASIC in the Ruffini corpuscle generates proprioception deep molecular mechanism is unknown. Combining domestic and foreign literature reports and preliminary results of the national science fund project, the research team of the invention proposes the hypothesis that the PHBV-CS absorbable nano material repairs the anterior cruciate ligament and generates the proprioceptive mechanism (see figure 3): the PHBV-CS absorbable nano material promotes regeneration of ACL nervous tissue and maintains ACL tension, knee joint movement stretch ACL, collagen resisting pressure, shearing force and tension and proteoglycan keeping cell firmness exist in extracellular matrix (ECM), and the like can transmit mechanical signals to cell membranes and extracellular H while maintaining cell stability ⁺ And other regulating substances activate ASIC channels. For cation (mainly Na) ⁺ And to a lesser extent Ca ²⁺ ) The permeable ASIC generates an inward current that depolarizes the cell membrane, activating voltage-gated Ca ²⁺ Channels and Na ⁺ Channels, and possibly by releasing voltage-dependent Mg ²⁺ Blocking may promote NMDA receptor activation. Voltage-gated Ca ²⁺ Channels and Na ⁺ The channels can promote generation of dendritic spines and action potential, ca ²⁺ Calponin-dependent protein kinase II activation and possibly influence other second messenger pathways. Thus, the current signal is conducted through afferent nerves, through the dorsal root ganglia to the spinal cord to form thin tracts, which are conducted to the brain.

The invention has the advantages that:

1. the chitosan used in the invention has excellent nerve protection effect, can promote good bracket of nerve regeneration, and the PHBV used has piezoelectric biopolymer with biodegradability, biocompatibility and stronger mechanical property, can generate micro-current in pressure change, and has better capability of promoting cell proliferation and differentiation. In the research process, the inventor finds that chitosan has low mechanical strength and is mechanically unstable in a physiological environment due to the structure, PHBV has high surface hydrophobicity to reduce the proliferation and adhesion of cells, and the crystal degree is high to show high brittleness. However, when the artificial material is prepared, PHBV is used as a substrate, and chitosan surface modification can make up for deficiencies of others, and simultaneously meets the functions of repairing an anterior cruciate ligament proprioceptor and cell adhesion and the strength requirement of the artificial ACL ligament.

2. The invention uses coaxial electrostatic spinning technology to prepare PHBV-CS shell-core structure oriented nanofiber bracket, adopts oriented spinning in the spinning process, and considers the unique tensile ductility, fiber axial arrangement, porosity and other characteristics of ligament. The preparation method of the invention is integrated, ensures the internal and external directions of chitosan and PHBV, reduces the additional interference of chemical solution and the uncontrollable property of the fiber direction of the chemical fixation method.

3. The invention also carries out grid-control corona polarization on the chitosan part on the surface, so that the chitosan surface has electric charges, and the current stimulation effect of the artificial ligament is enhanced, thereby better promoting ligament tissues and nerve regeneration.

4. The mechanical property and the biological property of the material prepared by the experimental conditions of the invention achieve unexpected technical effects.

Drawings

FIG. 1 is a flow chart of preparation of PHBV-CS absorbable nano anterior cruciate ligament.

FIG. 2 is a degradable artificial ligament which can be used for repairing a neural circuit and is prepared by the preparation method of the invention.

FIG. 3 is a schematic diagram of a hypothesis that PHBV-CS absorbable nano anterior cruciate ligament regulates ASIC signaling pathway mechanism.

FIG. 4a shows the tensile test results of sample 1.

FIG. 4b shows the tensile test results for sample 2.

Figure 4c is the tensile test result for sample 3.

Figure 4d is the tensile test result for sample 4.

FIG. 4e shows the tensile test results for sample 5.

FIG. 4f shows the tensile test results for sample 6.

FIG. 4g shows the tensile test results for sample 7.

Detailed Description

The invention will be further illustrated with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that various changes and modifications can be made by those skilled in the art after reading the disclosure of the present invention, and equivalents fall within the scope of the appended claims.

Example 1

1 materials and instruments

Hydroxybutyrate-hydroxyvalerate (PHBV), nibotianan biomaterial ltd.

Chitosan (CS), degree of deacetylation is more than or equal to 95%, MW is approximately equal to 100000, powder, kuer bioengineering Co., ltd, anhui.

Chloroform, dichloromethane, trifluoroacetic acid, and the reagent Aladdin, shanghai, inc.

Coaxial electrospinning equipment, SS-2535H, beijing yongkangle scientific and technological development ltd.

2 preparation method

Referring to fig. 1, hydroxybutyrate-hydroxyvalerate with a mass percentage concentration of 15% is dissolved in chloroform and completely dissolved, and is prepared for standby; dissolving chitosan with the mass percentage concentration of 8% and the deacetylation degree of more than or equal to 95% in a dichloromethane-trifluoroacetic acid mixed solvent until the chitosan is completely dissolved, and preparing for later use; the chitosan spinning solution and the PHBV spinning solution are injected into an injector with 5ml of an inner layer, a coaxial spinning nozzle (the inner diameter of an inner pipe is 0.5mm, the inner diameter of an outer pipe is 1.2 mm) is selected, the nozzle is connected with a positive voltage, and a receiving plate is connected with a negative voltage. The spinning conditions were: the size of the injector is 17mm, the rotating speed of the collector is 1500rpm, the flow rate of the outer tube is 0.04mm/min, the flow rate of the inner tube is 0.02mm/min, the distance between the head of the injector and the collector is 14cm, the positive voltage is 20kv, the negative voltage is 2kv, the temperature is 25 ℃, and the relative humidity is 30-40%. Finally, the PHBV-CS core-shell fiber film spun by static electricity is carefully separated from the collector, and is dried for 2 days under vacuum at room temperature to completely remove solvent molecules, and the PHBV-CS core-shell structure nano-fiber support material with the outer layer of chitosan and the inner layer of PHBV is obtained. And (3) polarizing the PHBV-CS nano-fibers by adopting a grid-control corona polarization method. The fibrous membranes were placed on the electrodes at a distance of 4cm. Corona voltage-8 kv, gate voltage-1 kv. The polarization temperature is room temperature, the polarization humidity is less than 40%, and the polarization time is 5min. The polarization enables the chitosan on the outer layer to have the capacity of storing polarization and space charge for a long time, the surface of the chitosan carries negative charges, the chitosan is kept stand in a phosphate buffer solution for 9 days, and the surface potential is more than 52%. Cutting the polarized PHBV-CS shell-core structure nanofiber scaffold into a rectangle, wherein the length of the rectangle is determined according to the length of ligament defect by taking the fiber arrangement direction as width; the metal rod is used as an axis, the diameter of the metal rod is selected according to the diameter of the ligament of the operation object, and the bracket is rolled up along the wide side of the rectangle by taking the chitosan layer as the inner surface to form the chitosan artificial neural prosthesis ACL enhanced cable-1 (see figure 2).

Example 2

1 detection method

1.1 grouping

Group one: the mass fraction of the chitosan is 4 percent, and the content of 2ml/2g of glacial acetic acid is in the stirring process; PHBV mass fraction of 8%, trichloromethane: anhydrous ethanol 9:1, dissolving, and spinning to a thickness of 0.14mm; the spinning conditions were: the size of the injector is 17mm, the rotating speed of the collector is 250rpm, the flow rate of the inner tube and the outer tube is 0.7ml/h, the distance between the head of the injector and the collector is 14cm, the positive voltage is 18kv, the negative voltage is-6 kv, the temperature is 25 ℃, and the relative humidity is 30-40%.

And a second group: the mass fraction of the chitosan is 4 percent, and the content of 2ml/2g of glacial acetic acid is in the stirring process; PHBV mass fraction is 8%, trichloromethane: absolute ethyl alcohol 9:1 dissolving and spinning at a thickness of 0.05mm

The spinning conditions were: the size of the injector is 17mm, the rotating speed of the collector is 500rpm, the flow rate of the inner tube and the outer tube is 0.7ml/h, the distance between the head of the injector and the collector is 14cm, the positive voltage is 18kv, the negative voltage is-6 kv, the temperature is 25 ℃, and the relative humidity is 30-40%.

And (3) group III: the mass fraction of the chitosan is 4 percent, and the ratio of the chitosan to the glacial acetic acid is 2ml/2g in the stirring process; PHBV mass fraction is 8%, trichloromethane: anhydrous ethanol 9:1 dissolving and spinning at a thickness of 0.3mm

The spinning conditions were: the size of the injector is 17mm, the rotating speed of the collector is 250rpm, the flow rate of the inner tube and the outer tube is 0.7ml/h, the head of the injector is 14cm away from the collector, the positive voltage is 18kv, the negative voltage is-6 kv, the temperature is 25 ℃, and the relative humidity is 30-40%.

Group four: the mass fraction of the chitosan is 2 percent, and the content of 2ml/2g of glacial acetic acid is in the stirring process; PHBV mass fraction of 8%, trichloromethane: anhydrous ethanol 9:1 dissolving and spinning at a thickness of 0.14mm

1.2, performing a tensile test on each group of materials, wherein the detection method is uniformly a universal tensile testing machine.

2 results

The results of each group are:

group one: as a result: the maximum load was 16.42957N, the tensile stress was 17.00784MPa, and the Young's modulus was 662.56768MPa. (see FIGS. 4c-4d, i.e., sample 3 and sample 4)

Group two: as a result: the maximum load is 1.86248N, the tensile stress is 2.12855MPa at the maximum load, and the Young modulus is 72.60026MPa. (see FIG. 4g, sample 7)

And (4) group III: as a result: the maximum load was 3.12669N, the tensile stress was 3.4741MPa, and the Young's modulus was 111.8411MPa. (see FIGS. 4e-f, i.e., sample 5 and sample 6)

Group four: as a result: the maximum load is 9.74288N, the tensile stress is 10.08579MPa, and the Young's modulus of elasticity is 564.46442MPa. (see FIGS. 4a-b, i.e., sample 1 and sample 2)

TABLE 1

TABLE 2

TABLE 3

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and additions can be made without departing from the principle of the present invention, and these modifications and additions should also be regarded as the protection scope of the present invention.

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Claims

1. the PHBV-CS core-shell structure nanofiber scaffold material is characterized in that the material is prepared from hydroxybutyrate-hydroxyvalerate and chitosan, and the preparation method of the degradable artificial ligament comprises the following steps:

2. The PHBV-CS core-shell structured nanofiber scaffold material as claimed in claim 1, wherein the concentration of hydroxybutyrate-hydroxyvalerate in step (1) is 15% by mass.

3. The PHBV-CS shell-core structured nanofiber scaffold material according to claim 1, characterized in that the concentration of chitosan in mass percentage in step (2) is 8%.

4. The PHBV-CS shell-core structured nanofiber scaffold material according to claim 1, characterized in that the experimental conditions in the electrospinning process in step (3) are: the inner diameter of the inner pipe of the coaxial spinning nozzle is 0.5mm, and the inner diameter of the outer pipe is 1.2mm; the nozzle is connected with a positive voltage, and the receiving plate is connected with a negative voltage; the spinning conditions were: the size of the injector is 17mm, the rotating speed of the collector is 1500rpm, the flow rate of the outer tube is 0.04mm/min, the flow rate of the inner tube is 0.02mm/min, the distance between the head of the injector and the collector is 14cm, the positive voltage is 20kv, the negative voltage is 2kv, the temperature is 25 ℃, and the relative humidity is 30-40%.

5. The PHBV-CS core-shell structured nanofiber scaffold material according to claim 1, characterized in that the experimental conditions of the polarization in step (5) are: the electrode spacing is 4cm, the corona voltage is-8 kv, the gate voltage is-1 kv, the polarization temperature is room temperature, the polarization humidity is 0-40%, and the polarization time is 5min.

6. The PHBV-CS shell-core structured nanofiber scaffold material according to claim 1, wherein the preparation method in step (6) is as follows: and (3) cutting the material obtained after polarization in the step (5) into a rectangle, taking the fiber arrangement direction as the width, taking a metal rod as an axis, and rolling the material along the width of the rectangle by taking the chitosan layer as an inner layer to obtain the chitosan/chitosan composite material.

7. A preparation method of a PHBV-CS core-shell structure nanofiber scaffold material is characterized by comprising the following steps:

8. The preparation method according to claim 7, wherein the mass percentage concentration of the hydroxybutyrate-hydroxyvalerate in step (1) is 15%; the mass percentage concentration of the chitosan in the step (2) is 8%.

9. The method of claim 7, wherein the experimental conditions in the electrospinning method in step (3) are: the inner diameter of the inner pipe of the coaxial spinning nozzle is 0.5mm, and the inner diameter of the outer pipe is 1.2mm; the spray head is connected with a positive voltage, and the receiving plate is connected with a negative voltage; the spinning conditions were: the size of the injector is 17mm, the rotating speed of the collector is 1500rpm, the flow rate of the outer tube is 0.04mm/min, the flow rate of the inner tube is 0.02mm/min, the head distance of the injector is 14cm from the collector, the positive voltage is 20kv, the negative voltage is 2kv, the temperature is 25 ℃, and the relative humidity is 30-40%;

the experimental conditions for the polarization in step (5) are: the electrode spacing is 4cm, the corona voltage is-8 kv, the gate voltage is-1 kv, the polarization temperature is room temperature, the polarization humidity is 0-40%, and the polarization time is 5min;

the preparation method in the step (6) specifically comprises the following steps: and (3) cutting the material obtained after polarization in the step (5) into a rectangle, taking the fiber arrangement direction as the width, taking a metal rod as an axis, and rolling the material along the width of the rectangle by taking the chitosan layer as an inner layer to obtain the chitosan/chitosan composite material.

10. The use of the PHBV-CS shell-core structured nanofiber scaffold material as defined in any one of claims 1 to 6 as a degradable artificial ligament.