(2) Electrospinning: the solution obtained in (1) is injected into a 10 mL injector which is added with a 21 G stainless steel syringe needle. A distance between a spinning nozzle and a roller (mandrel receiving device) is regulated to be 15 cm, and spinning is performed for 10 h under the conditions that the ambient temperature is 40° C., the ambient humidity is 40% RH, the voltage is regulated to be 30 kV, the rotating speed of the roller is 150 rad/min, and the feeding speed of the solution is 1 mL/h to obtain an electrospun inner layer.

(3) A fiber membrane of the electrospun inner layer obtained in (2) is dried for 12 h to remove the excessive residual solvent.

(4) Electric Spray:

a) Set electric spray conditions that the concentration of the polymer solution to be 35% (w/v), the feeding speed to be 3.5 mL/h, the rotating speed of the roller to be 1000 rad/min, the ambient temperature to be 20° C., the ambient humidity to be 10% RH and the voltage to be 5 kV, perform the electric spray for 20 min, stop for 5 min. When a trace amount of electric spray solution is attached to surfaces of fibers on an inner layer and is fused with the fibers, the porosity of the fiber layer is reduced.

b) Perform the electric spray for 20 min again, and then stop for 5 min, so that the electric spray solution is secondarily fused with the fibers, and the porosity is further reduced.

c) Regulate the concentration to be 40% (w/v), the feeding speed to be 2.8 mL/h and the rotating speed of the roller to be 80 rad/min, perform the electric spray for 10 min to eliminate the porosity and form a relatively thin dense electric spray membrane.

d) Regulate the concentration to be 50% (w/v), the feeding speed to be 1.2 mL/h and the rotating speed of the roller to be 200 rad/min, perform the electric spray for 30 min to ensure that the electric spray solution is aggregated on the surface of the relatively thin dense electric spray membrane, and dry to form a dense outer layer with a certain thickness.

By measurement, a thickness of the electrospun inner layer is 100 μm, diameters of the fibers are 2000 nm, and a thickness of the dense outer layer is 80 μm.

Embodiment 4: Preparation Process of Puncture-Resistant Artificial Blood Vessel

(1) Preparation of a Solution:

PU (the weight-average molecular weight is 150000) is dissolved into a mixed solvent of N,N-dimethylacetamide (DMAC) and acetone (a volume ratio is 5/5) and is heated and stirred in a 40° C. water bath for 12 h to obtain a polymer solution with the concentration of 5% w/v for standby application of electrospinning.

PU (the weight-average molecular weight is 150000) is dissolved into a mixed solvent of N,N-dimethylacetamide (DMAC) and acetone (a volume ratio is 5/5) and is heated and stirred in a 35° C. water bath for 12 h to obtain electric spray solutions with concentrations of 25% w/v, 35% w/v and 50% w/v for standby application of electric spray.

(2) Electrospinning: the solution obtained in (1) is injected into a 10 mL injector which is added with a 21 G stainless steel syringe needle. A distance between a spinning nozzle and a roller (mandrel receiving device) is regulated to be 18 cm, and spinning is performed for 8 h under the conditions that the ambient temperature is 45° C., the ambient humidity is 35% RH, the voltage is regulated to be 25 kV, the rotating speed of the roller is 150 rad/min, and the feeding speed of the solution is 1 mL/h to obtain an electrospun inner layer.

(3) A fiber membrane of the electrospun inner layer obtained in (2) is dried for 12 h to remove the excessive residual solvent.

(4) Electric Spray:

a) Set electric spray conditions that the concentration of the polymer solution to be 25% (w/v), the feeding speed to be 0.2 mL/h, the rotating speed of the roller to be 60 rad/min, the ambient temperature to be 30° C., the ambient humidity to be 10% RH and the voltage to be 30 kV, perform the electric spray for 15 min, stop for 10 min. When a trace amount of electric spray solution is attached to surfaces of fibers on an inner layer and is fused with the fibers, the porosity of the fiber layer is reduced.

b) Perform the electric spray for 15 min again, and then stop for 10 min, so that the electric spray solution is secondarily fused with the fibers, and the porosity is further reduced.

c) Regulate the concentration to be 35% (w/v), the feeding speed to be 1.8 mL/h and the rotating speed of the roller to be 150 rad/min, perform the electric spray for 20 min to eliminate the porosity and form a relatively thin dense electric spray membrane.

d) Regulate the concentration to be 50% (w/v), the feeding speed to be 0.5 mL/h and the rotating speed of the roller to be 700 rad/min, perform the electric spray for 30 min to ensure that the electric spray solution is aggregated on the surface of the relatively thin dense electric spray membrane, and dry to form a dense outer layer with a certain thickness.

By measurement, a thickness of the electrospun inner layer is 200 μm, diameters of the fibers are 1000 nm, and a thickness of the dense outer layer is 100 μm.

Embodiment 5: Preparation Process of Puncture-Resistant Artificial Blood Vessel

(1) Preparation of a Solution:

PLA (the weight-average molecular weight is 200000) and PU (the weight-average molecular weight is 150000) are dissolved into a mixed solvent of N,N-dimethylacetamide (DMAC) and acetone (a volume ratio is 5/5), wherein a weight ratio of the PLA to the PU is equal to 5:95, and the dissolved product is heated and stirred in a 40° C. water bath for 12 h to obtain a polymer solution with the concentration of 12% w/v for standby application of electrospinning.

PU (the weight-average molecular weight is 120000) is dissolved into a mixed solvent of N,N-dimethylacetamide (DMAC) and acetone (a volume ratio is 6/4) and is heated and stirred in a 35° C. water bath for 12 h to obtain electric spray solutions with concentrations of 30% w/v, 40% w/v and 60% w/v for standby application of electric spray.

(2) Electrospinning: the solution obtained in (1) is injected into a 10 mL injector which is added with a 21 G stainless steel syringe needle. A distance between a spinning nozzle and a roller (mandrel receiving device) is regulated to be 12 cm, and spinning is performed for 8 h under the conditions that the ambient temperature is 45° C., the ambient humidity is 35% RH, the voltage is regulated to be 30 kV, the rotating speed of the roller is 150 rad/min, and the feeding speed of the solution is 1 mL/h to obtain an electrospun inner layer.

(3) A fiber membrane of the electrospun inner layer obtained in (2) is dried for 12 h to remove the excessive residual solvent.

(4) Electric Spray:

a) Set electric spray conditions that the concentration of the polymer solution to be 30% (w/v), the feeding speed to be 0.5 mL/h, the rotating speed of the roller to be 1000 rad/min, the ambient temperature to be 30° C., the ambient humidity to be 30% RH and the voltage to be 10 kV, perform the electric spray for 5 min, stop for 10 min. When a trace amount of electric spray solution is attached to surfaces of fibers on an inner layer and is fused with the fibers, the porosity of the fiber layer is reduced.

b) Perform the electric spray for 10 min again, and then stop for 10 min, so that the electric spray solution is secondarily fused with the fibers, and the porosity is further reduced.

c) Regulate the concentration to be 40% (w/v), the feeding speed to be 3.8 mL/h and the rotating speed of the roller to be 550 rad/min, perform the electric spray for 5 min to eliminate the porosity and form a relatively thin dense electric spray membrane.

d) Regulate the concentration to be 60% (w/v), the feeding speed to be 4.5 mL/h and the rotating speed of the roller to be 800 rad/min, perform the electric spray for 5 min to ensure that the electric spray solution is aggregated on the surface of the relatively thin dense electric spray membrane, and dry to form a dense outer layer with a certain thickness.

By measurement, a thickness of the electrospun inner layer is 50 μm, diameters of the fibers are 1500 nm, and a thickness of the dense outer layer is 50 μm.

Embodiment 6: Preparation Process of Puncture-Resistant Artificial Blood Vessel

(1) Preparation of a Solution:

PLA (the weight-average molecular weight is 500000) and PU (the weight-average molecular weight is 600000) are dissolved into a mixed solvent of N,N-dimethylacetamide (DMAC) and acetone (a volume ratio is 5/5), wherein a weight ratio of the PLA to the PU is equal to 10:85, and the dissolved product is heated and stirred in a 40° C. water bath for 12 h to obtain a polymer solution with the concentration of 30% w/v for standby application of electrospinning.

PU (the weight-average molecular weight is 500000) is dissolved into a mixed solvent of N,N-dimethylacetamide (DMAC) and acetone (a volume ratio is 6/4) and is heated and stirred in a 35° C. water bath for 12 h to obtain electric spray solutions with concentrations of 50% w/v, 20% w/v and 35% w/v for standby application of electric spray.

(2) Electrospinning: the solution obtained in (1) is injected into a 10 mL injector which is added with a 21 G stainless steel syringe needle. A distance between a spinning nozzle and a roller (mandrel receiving device) is regulated to be 5 cm, and spinning is performed for 30 h under the conditions that the ambient temperature is 70° C., the ambient humidity is 60% RH, the voltage is regulated to be 40 kV, the rotating speed of the roller is 1000 rad/min, and the feeding speed of the solution is 5.0 mL/h to obtain an electrospun inner layer.

(3) A fiber membrane of the electrospun inner layer obtained in (2) is dried for 12 h to remove the excessive residual solvent.

(4) Electric Spray:

a) Set electric spray conditions that the concentration of the polymer solution to be 50% (w/v), the feeding speed to be 2.5 mL/h, the rotating speed of the roller to be 800 rad/min, the ambient temperature to be 30° C., the ambient humidity to be 30% RH and the voltage to be 10 kV, perform the electric spray for 40 min, stop for 20 min. When a trace amount of electric spray solution is attached to surfaces of fibers on an inner layer and is fused with the fibers, the porosity of the fiber layer is reduced.

b) Perform the electric spray for 40 min again, and then stop for 15 min, so that the electric spray solution is secondarily fused with the fibers, and the porosity is further reduced.

c) Regulate the concentration to be 20% (w/v), the feeding speed to be 0.5 mL/h and the rotating speed of the roller to be 100 rad/min, perform the electric spray for 25 min to eliminate the porosity and form a relatively thin dense electric spray membrane.

d) Regulate the concentration to be 35% (w/v), the feeding speed to be 5.0 mL/h and the rotating speed of the roller to be 1000 rad/min, perform the electric spray for 20 min to ensure that the electric spray solution is aggregated on the surface of the relatively thin dense electric spray membrane, and dry to form a dense outer layer with a certain thickness.

By measurement, a thickness of the electrospun inner layer is 200 μm, diameters of the fibers are 800 nm, and a thickness of the dense outer layer is 120 μm.

Embodiment 7: Preparation Process of Puncture-Resistant Artificial Blood Vessel

(1) Preparation of a Solution:

PLA (the weight-average molecular weight is 50000), PCL (the weight-average molecular weight is 60000) and PU (the weight-average molecular weight is 100000) are dissolved into HFIP, wherein a weight ratio of the PLA:PCL:PU=5:10:85, and the dissolved product is heated and stirred in a 40° C. water bath for 10 h to obtain a polymer solution with the concentration of 12% w/v for standby application of electrospinning.

PU (the weight-average molecular weight is 100000) is dissolved into a mixed solvent of N,N-dimethylformamide (DMF) and acetone (a volume ratio is 6/4) and is heated and stirred in a 40° C. water bath for 10 h to obtain electric spray solutions with concentrations of 35% w/v, 40% w/v and 50% w/v for standby application of electric spray.

(2) Electrospinning: the solution obtained in (1) is injected into a 10 mL injector which is added with a 21 G stainless steel syringe needle. A distance between a spinning nozzle and a roller (mandrel receiving device) is regulated to be 25 cm, and spinning is performed for 8 h under the conditions that the ambient temperature is 20° C., the ambient humidity is 20% RH, the voltage is regulated to be 8 kV, the rotating speed of the roller is 10 rad/min, and the feeding speed of the solution is 0.5 mL/h to obtain an electrospun inner layer.

(3) A fiber membrane of the electrospun inner layer obtained in (2) is dried for 12 h to remove the excessive residual solvent.

(4) Electric Spray:

a) Set electric spray conditions that the concentration of the polymer solution to be 35% (w/v), the feeding speed to be 5.0 mL/h, the rotating speed of the roller to be 1000 rad/min, the ambient temperature to be 20° C., the ambient humidity to be 10% RH and the voltage to be 5 kV, perform the electric spray for 20 min, stop for 5 min. When a trace amount of electric spray solution is attached to surfaces of fibers on an inner layer and is fused with the fibers, the porosity of the fiber layer is reduced.

b) Perform the electric spray for 20 min again, and then stop for 5 min, so that the electric spray solution is secondarily fused with the fibers, and the porosity is further reduced.

c) Regulate the concentration to be 40% (w/v), the feeding speed to be 2.8 mL/h and the rotating speed of the roller to be 80 rad/min, perform the electric spray for 10 min to eliminate the porosity and form a relatively thin dense electric spray membrane.

d) Regulate the concentration to be 50% (w/v), the feeding speed to be 1.2 mL/h and the rotating speed of the roller to be 200 rad/min, perform the electric spray for 30 min to ensure that the electric spray solution is aggregated on the surface of the relatively thin dense electric spray membrane, and dry to form a dense outer layer with a certain thickness.

By measurement, a thickness of the electrospun inner layer is 100 μm, diameters of the fibers are 1800 nm, and a thickness of the dense outer layer is 10 μm.

Testing of Intensity and Water Leakage Performance After Repeated Puncture

The intensities and water leakage performance of the puncture-resistant artificial blood vessel prepared in embodiment 1, a Nicast AVflo artificial blood vessel and a single-layer electrospun artificial blood vessel which are repeatedly punctured at the same time are measured. The intensities (an instrument is shown in