KR20220055286A - Graft material for blood vessel regeneration and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to a revascularization graft material and, more specifically, to a revascularization graft material comprising: a biodegradable luminal layer in the form of a hollow cylinder which has pores, and openings at both ends; a biodegradable coated layer having pores laminated on an outer surface of the luminal layer; and a biodegradable coil layer which surrounds an outer surface of the coated layer, and which has a biodegradation rate slower than that of the coated layer. According to the present invention, the strength of the graft material can be increased, and blood vessels can be protected from external pressure and the shape thereof can be maintained even when both the luminal layer and the coated layer being degraded before the completion of revascularization.

Description

Graft material for blood vessel regeneration and method for manufacturing thereof

The present invention relates to a graft material for vascular regeneration and a method for manufacturing the same.

Surgical revascularization surgery is often performed to replace damaged or lost blood vessels due to trauma or vascular disease. Many bioengineering researchers are currently developing alternative strategies to combine biofunctional materials for regeneration of living blood vessels.

Polyethylene terephralate (PET) or stretched polytetrafluoroethylene (ePTFE), which has been conventionally used for manufacturing artificial blood vessels for medical use, is not decomposed in vivo, so it cannot be used for tissue engineering to induce regeneration of living tissue. Specifically, when a material that is not biodegradable is used, since cells are formed on the graft material, it is hard compared to the physiological pressure range, so there is a problem in that blood flow is not smooth, so that a thrombus is generated.

In addition, the biodegradable vascular graft material inoculated with patient autologous cells has disadvantages in that its application in cardiovascular surgery is limited due to a long manufacturing time, low mechanical strength, and low flexibility.

Currently, as a tissue engineering technology, clinically applicable vascular graft materials have been limited only to the vena cava and pulmonary arterial systems, which have relatively low blood pressure in vivo, and tissue engineered vascular graft materials that can withstand conditions of hypertension such as the arterial system have not been developed. the current situation. Therefore, there is a demand for the development of a tissue engineered graft material for vascular regeneration with high elasticity and excellent mechanical strength.

Korean Patent No. 1587802

An object of the present invention is to provide a graft material for vascular regeneration.

An object of the present invention is to provide a method for manufacturing a graft material for vascular regeneration.

1. A hollow cylindrical biodegradable lumen layer having pores and openings at both ends;

a biodegradable coating layer having pores laminated on the outer surface of the lumen layer; and

Including; a biodegradable coil layer surrounding the outer surface of the coating layer,

A graft material for regenerating blood vessels in which the biodegradation rate of the coating layer is faster than the biodegradation rate of the coil layer.

2. The graft material for vascular regeneration according to 1 above, wherein the biodegradation rate of the luminal layer is faster than the biodegradation rate of the covering layer.

3. The graft material for vascular regeneration according to the above 1, wherein the coating layer comprises a first polymer included in the lumen layer and a second polymer included in the coil layer.

4. The graft material for revascularization of the above 1, wherein the luminal layer comprises polydioxanone (PDO).

5. The graft material for vascular regeneration according to 1 above, wherein the coil layer comprises polycaprolactone (PCL).

6. The graft material for vascular regeneration according to the above 3, wherein the first polymer is polydioxanone, and the second polymer is polycaprolactone.

7. The graft material for vascular regeneration according to the above 3, wherein the coating layer comprises the first polymer and the second polymer in a weight ratio of 0.5:1 to 1.5:1.

8. The graft material for vascular regeneration according to 1 above, wherein at least one of the luminal layer and the coating layer further contains an antithrombotic agent.

9. The above 1, wherein the diameter of the opening is 2mm to 6mm, a graft material for revascularization.

10. Preparing a hollow cylindrical biodegradable lumen layer by electrospinning the composition for forming a lumen layer on a rotating barrel;

preparing a biodegradable coating layer by electrospinning a composition for forming a coating layer on the outer surface of the lumen layer; and

A method for manufacturing a graft material for blood vessel regeneration, comprising winding a composition for forming a coil layer that biodegrades slower than the composition for forming a coating layer on the outer surface of the coating layer to prepare a coil layer.

11. The method according to the above 10, wherein the composition for forming the coating layer is biodegradable slower than the composition for forming the lumen layer, the method for producing a graft material for vascular regeneration.

12. The method according to 10 above, wherein the manufacturing of the coil layer comprises 3D printing the composition for forming the coil layer and winding the outer surface of the coating layer in a coil shape.

13. The blood vessel of the above 10, wherein in the step of preparing the coating layer, a composition for forming a coating layer comprising a first polymer and a composition for forming a coating layer comprising a second polymer are respectively electrospinning on the outer surface of the luminal layer A method for manufacturing a regenerative graft material.

14. In the above 13, the first polymer is included in the composition for forming a lumen layer, and in the step of preparing the coating layer, the second polymer is included in the composition for forming a coil layer, and the first polymer and the second polymer is electrospun on the outer surface of the lumen layer in a weight ratio of 0.5:1 to 1.5:1, a method for manufacturing a graft material for vascular regeneration.

15. The method according to 10 above, wherein the composition for forming the lumen layer contains polydioxanone.

16. The method according to 10 above, wherein the composition for forming the coating layer contains polycaprolactone.

17. The method according to 13 above, wherein the first polymer is PDO, and the second polymer is PCL.

18. The method of manufacturing a graft material for vascular regeneration according to the above 10, wherein the rotary tube has a diameter of 2 mm to 6 mm.

The graft material for vascular regeneration of the present invention includes a luminal layer and a coating layer having a different biodegradation rate, so that the strength of the graft material can be maintained during vascular regeneration, and blood leakage from the graft material can be prevented.

The graft material for vascular regeneration of the present invention can increase the strength of the graft material by including a coil layer having a different biodegradation rate from the coating layer, and protects blood vessels from external pressure even when both the lumen layer and the coating layer are decomposed before all blood vessels are regenerated. shape can be maintained.

1 is a schematic diagram of the overall structure of a graft material 1000 for revascularization according to an embodiment.
2 is a cross-sectional view of the graft material 1000 for revascularization according to an embodiment.
3 is an enlarged photograph of the luminal layer having high porosity of the graft material 1000 for revascularization according to an embodiment.
4 is a flowchart illustrating a manufacturing process of a graft material for vascular regeneration according to an embodiment.
5 shows the results of confirming the strength of the graft material for vascular regeneration according to the presence or absence of the coil layer.
6 shows the results of a comparative experiment confirming the degree of vascular patency by transplanting a commercialized artificial blood vessel and a graft material for vascular regeneration according to an embodiment.
7 shows the results of a comparative experiment confirming the level of generation of factors that help early blood vessel formation by transplanting a graft material for vascular regeneration and a commercialized artificial blood vessel according to an embodiment.
8 shows the results of measuring the distance between the diameter and the coil of the graft material for revascularization according to an embodiment.

The present invention provides a graft material for vascular regeneration.

The graft material for vascular regeneration of the present invention will be described with reference to FIG. 1 . However, FIG. 1 is only a graft material for vascular regeneration according to an embodiment, and the present invention is not limited to FIG. 1 .

The present invention graft material for revascularization 1000 includes a hollow cylindrical biodegradable luminal layer 100 having openings 101 at both ends; a biodegradable coating layer 200 having pores laminated on the outer surface of the lumen layer 100; and a biodegradable coil layer 300 surrounding the outer surface of the coating layer 200, wherein the biodegradation rate of the coating layer 200 is faster than the biodegradation rate of the coil layer 300. Graft material for vascular regeneration (1000) am.

The lumen layer 100 has a hollow cylindrical structure located at the innermost side of the graft material 1000 for revascularization.

The lumen layer 100 may include openings 101 at both ends.

The diameter of the opening 101 may be 0.01 mm to 20 mm, 0.1 mm to 15 mm, 1 mm to 10 mm, or 2 mm to 6 mm.

The graft material 1000 for regenerating blood vessels according to the present invention may be used for small-diameter blood vessels. For example, the graft material 1000 for revascularization of the present invention may be used as a graft material for a coronary artery or a peripheral artery, but is not limited thereto.

The lumen layer 100 may include a biodegradable polymer.

The biodegradable polymer included in the lumen layer 100 is Under the condition, it may be a polymer having a faster biodegradation rate than the polymer included in the coating layer 200 and the coil layer 300 .

The biodegradable polymer included in the lumen layer 100 may be polydioxanone (PDO) or a polymer having a biodegradation rate similar thereto. For example, the biodegradable polymer included in the lumen layer 100 is polydioxanone (PDO), polyglycolic acid (PGA), poly-d,l-lactic-co-glycolic acid (85:15) (PLGA 85:15), ethylglycinate polyphosphazene, polyurethane caprolactone or polyglycolide-co-γ-caprolactone (PGCL), and the like.

The biodegradable polymer included in the lumen layer 100 is It may be a polymer that decomposes within a period of 1 week to 15 weeks, 2 weeks to 14 weeks, or 3 weeks to 12 weeks under conditions.

The biodegradable polymer included in the lumen layer 100 may be decomposed into a non-toxic material.

The biodegradable polymer or its decomposition product included in the lumen layer 100 may not cause an immune response or allergy in the body.

The biodegradable polymer included in the lumen layer 100 may be a homopolymer or a copolymer.

The biodegradable polymer included in the lumen layer 100 may be a state in which two or more polymers are simply mixed.

The biodegradable polymer included in the lumen layer 100 may be a hydrophobic polymer.

The lumen layer 100 may have a structure obtained by electrospinning a biodegradable polymer.

The lumen layer 100 is made of microfibers and/or nanofibers manufactured by electrospinning, and may have a structure showing voids.

Cells may be attached to the pores of the luminal layer 100 , and the attached cells may proliferate.

The pore size of the lumen layer 100 may be 1 μm to 50 μm, 1 μm to 40 μm, 1 μm to 30 μm, 1 μm to 20 μm, or 1 μm to 10 μm.

The thickness of the lumen layer 100 may be 1 μm to 1000 μm, 10 μm to 900 μm, 50 μm to 800 μm, 100 μm to 700 μm, 200 μm to 600 μm, or 300 μm to 500 μm.

An antithrombotic agent may be included in the lumen layer 100 .

The antithrombotic agent may be coated on the inner or outer surface of the lumen layer, or may be mixed with a biodegradable polymer during electrospinning and spun.

For example, antithrombotic agents include dipyridamole, clopidogrel, ticagrelor, ticlopidine, prasugrel, abciximab, and eptifibatide. , tirofiban (Tirofiban), cilostazol (Cilostazol) or heparin may be, but is not limited thereto.

The biodegradable polymer and the antithrombotic agent included in the lumen layer 100 may be included in a weight ratio of 5:1 to 20:1, 5:1 to 15:1, or 5:1 to 10:1.

The coating layer 200 has a structure laminated on the outer surface of the lumen layer 100 .

The coating layer 200 may include a biodegradable polymer.

The biodegradable polymer included in the coating layer 200 may be a polymer having a slower biodegradation rate than the polymer included in the lumen layer 100 under in vivo conditions.

The biodegradable polymer included in the coating layer 200 may be a polymer having a faster biodegradation rate than the polymer included in the coil layer 300 under in vivo conditions.

The biodegradable polymer included in the coating layer 200 may be one type of polymer, may be a copolymer in which two or more polymers are polymerized, or two or more polymers may be simply mixed and mixed.

The biodegradable polymer included in the coating layer 200 may include a first polymer and a second polymer.

The first polymer included in the coating layer 200 may be a polymer included in the lumen layer 100 , and the second polymer may be a polymer included in the coil layer 300 . If the coating layer 200 includes the polymer included in the lumen layer 100 and the polymer included in the coil layer 300 , a graft material can be economically manufactured using a small amount of polymer.

The coating layer 200 may include the first polymer included in the lumen layer 100 and the second polymer included in the coil layer 300 in a weight ratio of 0.001:1 to 10:1, for example, the coating layer 200 ) may include the first polymer and the second polymer in a weight ratio of 0.001:1 to 10:1, 0.01:1 to 5:1, 0.1:1 to 3:1, or 0.5:1 to 1.5:1.

The coating layer 200 may include the first polymer included in the lumen layer 100 and the second polymer included in the coil layer 300 in a weight ratio of 1:0.001 to 1:10, for example, the coating layer 200 . Silver may include the first polymer and the second polymer in a weight ratio of 1:0.001 to 1:10, 1:0.01 to 1:5, 1:0.1 to 1:3, or 1:0.5 to 1:1.5.

By including the first polymer and the second polymer in the coating layer 200 in a ratio in the above-mentioned range, the coating layer 200 and the coil layer 300 can effectively interact, so that the graft material for vascular regeneration has high stability and strength in the body. can be produced.

The biodegradable polymer included in the coating layer 200 is polydioxanone (PDO) or a polymer having a similar biodegradation rate; and polycaprolactone (PCL) or a polymer having a biodegradation rate similar thereto.

The biodegradable polymer included in the coating layer 200 may be decomposed into a non-toxic material.

The biodegradable polymer or its decomposition product included in the coating layer 200 may not cause an immune response or allergy in the body.

The biodegradable polymer included in the coating layer 200 may be a hydrophobic polymer.

The coating layer 200 may have a structure obtained by electrospinning a biodegradable polymer.

The coating layer 200 may have a structure obtained by electrospinning the first polymer and the second polymer on the outer surface of the lumen layer 100 , respectively.

The coating layer 200 may have a structure obtained by mixing the first polymer and the second polymer and then electrospinning.

The coating layer 200 is made of microfibers and/or nanofibers manufactured by electrospinning, and may have a structure showing voids.

Cells may be attached to the pores of the coating layer 200 , and the attached cells may proliferate.

The pore size of the coating layer 200 may be 1 μm to 50 μm, 1 μm to 40 μm, 1 μm to 30 μm, 1 μm to 20 μm, or 1 μm to 10 μm.

The thickness of the coating layer 200 may be 50 μm to 1200 μm, 100 μm to 1100 μm, 200 μm to 1000 μm, 300 μm to 900 μm, or 400 μm to 800 μm.

The coating layer 200 may be laminated on all or part of the outer surface of the lumen layer 100 .

When the term "a component" is referred to as being "stacked" on another component or "surrounding" another component, it is said to be directly stacked on or directly surrounding another component. It may be interpreted, but an additional third element may be further included between a certain element and another element.

The coating layer 200 may include an antithrombotic agent.

The antithrombotic agent may be coated on the inner or outer surface of the coating layer 200, or may be mixed with a biodegradable polymer during electrospinning and spun.

For example, antithrombotic agents include dipyridamole, clopidogrel, ticagrelor, ticlopidine, prasugrel, abciximab, and eptifibatide. , tirofiban (Tirofiban), cilostazol (Cilostazol) or heparin may be, but is not limited thereto.

For example, antithrombotic agents include dipyridamole, clopidogrel, ticagrelor, ticlopidine, prasugrel, abciximab, and eptifibatide. , tirofiban (Tirofiban), cilostazol (Cilostazol) or heparin may be, but is not limited thereto.

At least one of the polymers included in the coating layer 200 and the antithrombotic agent may be included in a weight ratio of 5:1 to 20:1, 5:1 to 15:1, or 5:1 to 10:1.

The coil layer 300 has a biodegradable structure surrounding the outer surface of the coating layer 200 .

The coil layer 300 may have a structure in which a biodegradable polymer surrounds the outer surface of the coating layer 200 in a coil shape.

The coil layer 300 may have appropriate strength and flexibility for use as a vascular graft material by enclosing the outer surface of the coating layer in a coil shape. For example, the coil layer 300 surrounds the outer surface of the coating layer in the form of a coil, so that the graft material for vascular regeneration can be effectively transplanted into a body region where there is a curve or fold that needs to be bent.

On the other hand, when the outer surface of the coating layer is laminated with general chain fibers instead of being surrounded by coils, the strength of the grafting agent is too high, so it may not be easily bent. That is, in this case, there is a disadvantage in that it is difficult to implant in a curved or folded body region.

The coil layer 300 may have a structure in which a biodegradable polymer surrounds the outer surface of the coating layer 200 in a coil shape using 3D printing.

The coil layer 300 may include a biodegradable polymer.

The biodegradable polymer included in the coil layer 300 may be a polymer having a slower biodegradation rate than the polymer included in the lumen layer 100 and the coating layer 200 under in vivo conditions.

The biodegradable polymer included in the coil layer 300 may be polycaprolactone (PCL) or a polymer having a biodegradation rate similar thereto. For example, the second polymer may be selected from polycaprolactone (PCL), polylactic acid (PLA), or poly-d,l-lactic acid (PDLLA).

The biodegradable polymer included in the coil layer 300 may be a polymer that is decomposed under in vivo conditions within a period of 1 month to 2 years, 2 months to 1 year and 6 months, or 3 months to 1 year.

The biodegradable polymer included in the coil layer 300 may be decomposed into a non-toxic material.

The biodegradable polymer or its decomposition product included in the coil layer 300 may not cause an immune response or allergy in the body.

The biodegradable polymer included in the coil layer 300 may be a homopolymer or a copolymer.

The biodegradable polymer included in the coil layer 300 may be a simple mixture of two or more polymers.

The biodegradable polymer included in the coil layer 300 may be a hydrophobic polymer.

The coil layer 300 may surround all or a part of the outer surface of the coating layer 200 .

The biodegradation rate of the coating layer 200 of the graft material 1000 for revascularization of the present invention is faster than the biodegradation rate of the coil layer 300 .

The difference in decomposition rate between the coating layer 200 and the coil layer 300 of the graft material 1000 for revascularization of the present invention may be indicated by different polymers constituting the coating layer 200 and the coil layer 300 .

The process of regenerating blood vessels by attaching and proliferating cells to the luminal layer 100 and the coating layer 200 by including the coil layer 300 having a slower biodegradation rate than the coating layer 200 in the present invention. Even if both the luminal layer 100 and the covering layer 200 are decomposed before the blood vessels are completely regenerated, the structure of the regenerated blood vessels can be maintained.

Since the graft material 1000 for revascularization of the present invention includes the coil layer 300 having a slower biodegradation rate than the coating layer 200, it is possible to maintain the rigidity of the arterial wall in the process of regenerating blood vessels and prevent the occurrence of diseases such as aneurysms. can be suppressed

The biodegradation rate of the lumen layer 100 of the graft material for revascularization 1000 of the present invention is faster than that of the coating layer 200 .

The graft material 1000 for revascularization of the present invention can prevent the outflow of blood by including the coating layer 200 on the outside of the lumen layer 100 .

In the coil layer 300 of the graft material for vascular regeneration according to the present invention, the number of turns per cm of the graft material for vascular regeneration is 0.5 times/cm to 8 times/cm, 1 time/cm to 7 times/cm, 2 times/cm to 6 times/cm or 3 times/cm to 5 times/cm.

The diameter of the opening 101 of the graft material 1000 for revascularization of the present invention and the length between the coils are 0.5:1 to 3:1, 1:1 to 2.5:1, 1.5:1 to 2:1, or 1.3:1 to 2: It may be a ratio of 1 (see FIG. 8).

In addition, the present invention provides a method for manufacturing the graft material for vascular regeneration described above.

The method for manufacturing a graft material for revascularization of the present invention comprises the steps of: preparing a hollow cylindrical biodegradable lumen layer by electrospinning a composition for forming a lumen layer on a rotary tube; preparing a biodegradable coating layer by electrospinning a composition for forming a coating layer on the outer surface of the lumen layer; and winding the composition for forming a coil layer, which biodegrades more slowly than the composition for forming the coating layer, on the outer surface of the coating layer to prepare a coil layer.

Since the contents of the lumen layer, the coating layer, the coil layer, and the graft material for revascularization have been described above, a detailed description thereof will be omitted.

The term “rotating drum” is an electrospinning collector, which serves to collect electrospun micro and/or nanofibers. The rotating barrel can also be represented as a rotating mandrel.

The diameter of the rotary tube may be 0.01mm to 20mm, 0.1mm to 15mm, 1mm to 10mm, or 2mm to 6mm, but is not limited thereto.

In the step of manufacturing the lumen layer, the rotary tube may be rotated faster than the rotation speed of the rotary tube in the step of manufacturing the coil layer.

For example, in the step of preparing the lumen layer, the rotary tube may rotate at 100 rpm to 2500 rpm, 500 rpm to 2000 rpm, and 1000 rpm to 1700 rpm.

The composition for forming a lumen layer may include a biodegradable polymer.

The composition for forming a lumen layer may be a polymer having a faster biodegradation rate than the polymer included in the composition for forming the coating layer and the composition for forming the coil layer under in vivo conditions.

The composition for forming a lumen layer may include polydioxanone (PDO) or a polymer having a biodegradation rate similar thereto. The composition for forming a lumen layer is polydioxanone, polydioxanone (PDO), polyglycolic acid (PGA), poly-d,l-lactic-co-glycolic acid (85:15) (PLGA 85) :15), ethyl glycinate polyphosphazene, polyurethane caprolactone, or polyglycolide-co-γ-caprolactone (PGCL).

The composition for forming a lumen layer may further include an antithrombotic agent. Since the antithrombotic agent has been described above, a detailed description thereof will be omitted.

The composition for forming the coating layer may include a biodegradable polymer.

The composition for forming a coating layer may be biodegradable more slowly than the composition for forming a lumen layer under in vivo conditions.

The manufacturing of the coating layer may include electrospinning a composition for forming a coating layer including a first polymer and a composition for forming a coating layer including a second polymer on the outer surface of the lumen layer, respectively.

When the composition for forming a coating layer including the first polymer and the composition for forming a coating layer including the second polymer are separately electrospun in the step of preparing the coating layer, the composition for forming a coating layer including the first polymer and the second polymer Compared with the case of mixing a composition for forming a coating layer containing a mixture and electrospinning at one time, polymer fibers having relatively slow decomposition remain, thereby maintaining the shape of the coating layer.

In the step of preparing the coating layer, the first polymer and the second polymer may be electrospun onto the outer surface of the lumen layer in a weight ratio of 0.001:1 to 10:1. For example, the first polymer and the second polymer may be used in a weight ratio of 0.001:1 to 10:1, 0.01:1 to 5:1, 0.1:1 to 3:1, or 0.5:1 to 1.5:1 outside the luminal layer. Electrospinning can be done on the side.

In the step of preparing the coating layer, the first polymer and the second polymer may be electrospun onto the outer surface of the lumen layer in a weight ratio of 1:0.001 to 1:10. For example, the first polymer and the second polymer are used in a weight ratio of 1:0.001 to 1:10, 1:0.01 to 1:5, 1:0.1 to 1:3, or 1:0.5 to 1:1.5 in a weight ratio of the outside of the luminal layer. Electrospinning can be done on the side.

In the step of manufacturing the coating layer, the rotary tube may be rotated faster than the rotation speed of the rotary tube in the step of manufacturing the coil layer.

For example, in the step of preparing the coating layer, the rotary cylinder may be rotated at 100 rpm to 2500 rpm, 500 rpm to 2000 rpm, and 1000 rpm to 1700 rpm.

In the step of preparing the lumen layer or the coating layer, the coil layer may be manufactured from nano-sized fibers by rotating the rotary tube at the aforementioned speed.

The composition for forming the coating layer may include an antithrombotic agent.

Since the antithrombotic agent has been described above, a detailed description thereof will be omitted.

For example, the composition for forming a coating layer including the first polymer may include an antithrombotic agent.

For another example, the composition for forming a coating layer including the second polymer may include an antithrombotic agent.

Voltage conditions for the electrospinning in the step of preparing the steel lumen layer and the step of preparing the coating layer may be 5kV to 50Kv, 10kV to 40kV, 13kV to 30kV.

The pump flow rate conditions for the electrospinning in the step of preparing the lumen layer and the step of preparing the coating layer may be 0.1ml/h to 15ml/h, 0.2ml/h to 10ml/h, 0.5ml/h to 5ml/h. .

The distance between the nozzle tip and the rotary tube used for electrospinning in the step of preparing the lumen layer and the step of preparing the coating layer may be 1 cm to 30 cm, 5 cm to 25 cm, or 10 cm to 20 cm.

The manufacturing of the coil layer may be 3D printing the composition for forming the coil layer and winding the outer surface of the coating layer in the form of a coil.

The composition for forming a coil layer may include polycaprolactone (PCL) or a polymer having a biodegradation rate similar thereto. For example, the composition for forming the coil layer may be selected from polycaprolactone (PCL), polylactic acid (PLA), or poly-d,l-lactic acid (PDLLA).

In the step of manufacturing the coil layer, the rotary tube may be rotated slower than the rotation speed of the rotary tube in the step of manufacturing the lumen layer or the coating layer.

For example, in the step of preparing the coil layer, the rotary tube may rotate at 5 rpm to 40 rpm, 8 rpm to 30 rpm, or 10 rpm to 20 rpm.

In the step of preparing the coil layer, the coil layer may be made of micro-sized fibers by rotating the rotary tube at the above-described speed.

The method of manufacturing a graft material for revascularization of the present invention may further include separating the graft material including the lumen layer, the coating layer, and the coil layer from the rotary tube.

The method of manufacturing a graft material for vascular regeneration of the present invention may further include sterilizing the graft material separated from the rotary tube. For example, sterilization may be performed using ethylene oxide.

production example

Preparation Example 1. Preparation of graft material for vascular regeneration including a lumen layer, a coating layer and a coil layer

The lumen layer and the coating layer were prepared by electrospinning, and a coil layer surrounding the outer surface of the coating layer was prepared by 3D printing (see FIG. 2 ).

First, PDO and dipyridamole (DY), an antithrombotic agent, are loaded in an electrospinning machine at a weight ratio of 10:1, and PDO is sprayed at a pressure that can show the pump flow rate of a specific condition in a rotary tube to which a voltage is applied. A lumen layer was prepared (see Stage ① in FIG. 2). After that, using an electrospinning machine loaded with PDO and an electrospinning machine loaded with polycaprolactone (PCL) in a weight ratio of 10:1 to dipyridamole, PDO and PCL were applied to the outer surface of the lumen layer existing on the rotary tube. The outer steel layer was prepared by co-electro spinning. PDO and PCL were sprayed in a 1:1 weight ratio (see Stage ② in FIG. 2).

Electrospinning was performed under the following conditions: a voltage of 13 kV to 30 kV, a pump flow rate of 0.5 ml/h to 5 ml/h, a distance between the nozzle tip and the rotary tube 10 cm to 20 cm, and a rotation speed of the rotary tube 1000 rpm to 1700 rpm.

Thereafter, after injecting PCL into the 3D printer, the filament was heated to 150-180° C. and pressurized, and the PCL was sprayed on the outer surface of the coating layer existing on the rotating barrel, and laminated in the form of a coil to prepare a coil layer. In the step of spraying PCL using 3D printing, the rotary cylinder was rotated at 10 rpm to 20 rpm (see Stage ③ in FIG. 2).

The graft material including the lumen layer, the coating layer and the coil layer was separated from the rotary tube, and the separated graft material was left in a vacuum condition at 40° C. for one day. Thereafter, it was sterilized with ethylene oxide to obtain a graft material for vascular regeneration of the present invention.

Preparation Example 2. Preparation of a graft material for vascular regeneration including a lumen layer and a coating layer, some regions including the coil layer and the remaining region not including the coil layer

In order to compare the effects according to the presence or absence of the coil layer, the first region including the lumen layer, the coating layer, and the coil layer (the left region of FIG. 3A) and the second region including only the lumen layer and the coating layer without the coil layer (the right side of FIG. 3A) The graft material further comprising an area) was prepared. Specifically, the steps of electrospinning in Preparation Example 1 (Stages ① and ② in FIG. 2) are the same, but in the first region, a coil layer is manufactured using 3D printing as in Preparation Example 1, and in the second region, Preparation Example 1 did not perform 3D printing.

Confirmation of strength of graft material for vascular regeneration

Water was poured into the cylindrical graft material having a diameter of 4 mm prepared in Preparation Example 2, and external pressure was applied to the first region (left in FIG. 3A) and the second region (right in FIG. 3A) of the graft material. Thereafter, by checking whether the flow of water inside the implanted material is smooth, the strength against external pressure according to the inclusion of the coil layer was confirmed.

As a result of the experiment, the water flow inside the graft material was smooth even when pressure was applied to the first area having the coil layer (see FIG. 3B ). On the other hand, in the second region not having the coil layer, when pressure was applied, the water flow inside the graft material was not smooth (see FIG. 3C ). Through this, it was confirmed that when the PCL coil layer was further included on the PDO+PCL coating layer, the resistance to external pressure was excellent and the strength was large.

Confirmation of patency of graft material for vascular regeneration

Vascular patency confirmation experiments were performed using the graft material for vascular regeneration prepared in Preparation Example 1 (see FIG. 4A) and the commercially available expanded PTFE (ePTFE) vascular graft material (see FIG. 4B). This experiment was conducted with the approval of the Chonnam National University Hospital Animal Experiment Ethics Committee. A total of 7 male pigs weighing 30-40 kg were used, and 100 mg aspirin was orally administered as an antithrombotic agent the day before the procedure. Prior to the procedure, anesthesia was performed with xylazine (3 mg/kg, Rompun ®Bayer AG, Leverkusen, Germany), Ketamine (0.3ml/kg), and azaperone (6 mg/kg, Strensil ®), followed by mechanical ventilation with Isoflurane. Respiratory anesthesia was performed. After exposing both sides of the carotid artery surgically, a 20 mm excision was made, one side was transplanted with a commercially available expanded PTFE (ePTFE) vascular graft material, and the other side was transplanted with this vascular graft material. During the experiment, 200 IU/Kg of heparin was injected intravenously to prevent thrombosis. After transplantation, the incision site was sealed and disinfected, and the condition of the graft material was checked using ultrasound and the pig was moved to the cage. Aspirin 100 mg and clopidogrel 75 mg were orally administered once a day as antithrombotic agents to prevent acute thrombosis until 2 days after the procedure. After transplantation, the blood flow in the anterior and posterior junctions of the graft material and the graft material was checked through pulse wave mode and color doppler using an ultrasound device every week after transplantation. One month after transplantation, the graft material was separated under the same anesthesia as above.

As a result of ultrasound analysis, blood flow was observed in the graft material prepared in Preparation Example 1, and patency was also observed in the tissue photograph at the lower right (see FIG. 4C). On the other hand, blood flow was not observed in the commercialized graft material, and it was observed that a thrombus (pink in the lower right photograph of Fig. 4D) formed and the patency disappeared in the tissue photograph at the lower right (see Fig. 4C). That is, it was confirmed that the graft material of the present invention has excellent patency and is suitable for use as a vascular graft material.

Confirmation of the generation effect of angiogenic factors in graft materials for vascular regeneration

An experiment was conducted to confirm the effect of generating angiogenesis factors using the graft material for vascular regeneration prepared in Preparation Example 1 (see FIG. 5A) and the commercially available expanded PTFE (ePTFE) vascular graft material (see FIG. 5B). The graft tissue isolated in the patency confirmation experiment was fixed in 10% formalin solution. After that, the tissue was made into a paraffin block, cut to a thickness of 4-6 μm, and fixed on a slide. Tissue sections were deparaffinized, followed by Hematoxylin & Eosin (H&E) staining, Safranin-O staining, Msson trichrome staining, and Verhoeff's staining.

As a result of analyzing the tissue fluorescence staining photos, in the tissue of the pig transplanted with the graft material prepared in Preparation Example 1, glycosaminoglycan (refer to FIG. 5D red arrow), collagen (FIG. 5E), factors that help early blood vessel formation Red arrow) and elastin (see FIG. 5F red arrow) were observed. On the other hand, it was confirmed that factors (vascular endothelial cells, GLYCOSAMINOGLYCAN, COLLAGEN, etc.) that help early angiogenesis were hardly present in the tissues of pigs transplanted with commercially available graft materials (FIGS. 5I, 5J, 5K, 5L) reference). That is, compared to other graft materials, the graft material of the present invention may exhibit the effect of generating factors that help early blood vessel formation.

1000: graft material for vascular regeneration
100: lumen layer
200: coating layer
300: coil layer
101: opening

Claims (18)

a hollow cylindrical biodegradable lumen layer having pores and openings at both ends;
a biodegradable coating layer having pores laminated on the outer surface of the lumen layer; and
Including; a biodegradable coil layer surrounding the outer surface of the coating layer;
A graft material for regenerating blood vessels in which the biodegradation rate of the coating layer is faster than the biodegradation rate of the coil layer.
The graft material for vascular regeneration according to claim 1, wherein the biodegradation rate of the luminal layer is faster than the biodegradation rate of the covering layer.
The graft material for vascular regeneration according to claim 1, wherein the coating layer comprises a first polymer included in the lumen layer and a second polymer included in the coil layer.
The graft material for revascularization of claim 1, wherein the lumen layer comprises polydioxanone.
The graft material for blood vessel regeneration according to claim 1, wherein the coil layer comprises polycaprolactone.
The graft material of claim 3, wherein the first polymer is polydioxanone, and the second polymer is polycaprolactone.
The graft material for vascular regeneration according to claim 3, wherein the coating layer comprises the first polymer and the second polymer in a weight ratio of 0.5:1 to 1.5:1.
The graft material for vascular regeneration according to claim 1, wherein at least one of the luminal layer and the coating layer further contains an antithrombotic agent.
The method according to claim 1, The diameter of the opening is 2mm to 6mm, vascular regeneration graft material.
Preparing a hollow cylindrical biodegradable lumen layer by electrospinning the composition for forming a lumen layer on a rotating barrel;
preparing a biodegradable coating layer by electrospinning a composition for forming a coating layer on the outer surface of the lumen layer; and
A method for manufacturing a graft material for blood vessel regeneration, comprising winding a composition for forming a coil layer that biodegrades slower than the composition for forming a coating layer on the outer surface of the coating layer to prepare a coil layer.
The method according to claim 10, wherein the composition for forming the coating layer is biodegradable slower than the composition for forming the lumen layer, the method for producing a graft material for vascular regeneration.
The method according to claim 10, wherein the manufacturing of the coil layer comprises winding the outer surface of the coating layer in a coil shape by 3D printing the composition for forming the coil layer.
The method according to claim 10, wherein in the step of preparing the coating layer, the composition for forming the coating layer comprising the first polymer and the composition for forming the coating layer including the second polymer are electrospinning to the outer surface of the luminal layer, respectively, for vascular regeneration A method for manufacturing a graft material.
The method according to claim 13, wherein the first polymer is included in the composition for forming the lumen layer, and in the step of preparing the coating layer, the second polymer is included in the composition for forming the coil layer, and the first polymer and the The second polymer is electrospun on the outer surface of the luminal layer in a weight ratio of 0.5:1 to 1.5:1, a method for manufacturing a graft material for vascular regeneration.
The method of claim 10, wherein the composition for forming the lumen layer comprises polydioxanone.
The method according to claim 10, wherein the composition for forming the coating layer contains polycaprolactone.
The method according to claim 13, wherein the first polymer is polydioxanone, and the second polymer is polycaprolactone.
The method of claim 10, wherein the diameter of the rotary tube is 2mm to 6mm.

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