KR101501383B1 - Nanofiber scaffold with an aligned structure and method thereof - Google Patents

Abstract

The present invention relates to a perpendicularly aligned tube-shaped nanofiber scaffold using conductive wire and to a manufacturing method thereof. The method for manufacturing a nanofiber scaffold according to the present invention comprises the steps of: (a) manufacturing a spinning solution by dissolving polymers in a solvent solely or in mixture; (b) installing conductive wire between a drum-shaped current collector and a collector in an electrospinner; and (c) spraying the polymer solution by using the electrospinner. The perpendicularly aligned tube-shaped nanofiber scaffold provided by the present invention has an effect of regenerating nerves, blood vessels and other tissues rapidly.

Description

Technical Field [0001] The present invention relates to a nanofiber scaffold and a method of manufacturing the same,

[0001] The present invention relates to a method of manufacturing a nanofiber support, and more particularly to a nanofiber support in the form of a tube arranged in an orthogonal shape using electrospinning and conductive wires and a method of manufacturing the same.

Tissue regeneration effectively regenerates tissues by providing cells, drug supports, and the like in an organ or tissue in the human body to lose its function or to perform osteoporosis. At this time, the tissue regeneration support is physically stable at the implant site, And after decomposition in vivo after the formation of new tissue, degradation products should not be toxic.

As such a tissue regeneration support, a porous support using a polymer having a predetermined strength and shape has been produced, and sponge type, fiber type matrix or gel type cell culture support using such a polymer has been produced and used.

Among them, the fibrous matrix support has open pores and has a structure in which cells are well adhered and proliferated because the pore size is large. However, the fibrous matrix scaffold is not widely used at present. When the scaffold is made of a natural polymer, the strength of the scaffold is so low that it can not be disintegrated or shrunk to maintain its shape. Even if a synthetic polymer is used, Dimensional structure rather than a three-dimensional structure. For reference, the three-dimensional structure in the regeneration of tissues is a very important structure for cell activity and regeneration ability. In addition, with such a support alone, there is a limitation in applying all natural polymers having physiological activity by controlled release by enclosing the drug.

In general, nanofibers have a large surface area and high porosity. When these advantages are applied to the nanofiber support for tissue engineering, the support has a structure similar to that of the extracellular matrix, which is easy to adhere to the cells and easy to penetrate and discharge the nutrients and metabolites of the cells. Therefore, it is widely used as a support for tissue engineering for the purpose of rapid regeneration of wound or defective part. These nanofibers can be manufactured by various methods such as superconducting method, synthesis method, phase separation method, electrospinning method, etc. However, since the operation is simple, the cost is low, and the wide range of materials is available, It is mainly used in various fields including the field.

The start of electrospinning was coincidentally discovered by Formhals during the experiment in the 1930s and began with device patents for the production of acetic acid cellulose fibers. At first, however, it was not of industrial importance because of various problems such as low yield, unquantified method, low orientation, irregularity of properties. Since Reneker, a simpler electrospinning device has been developed and is now being studied in various fields as a convenient way to manufacture nanofibers, a global concern. As the magnitude of the electric field increases, the hemispherical solution surface formed at the capillary tube tip is extended into a conical shape known as a Taylor cone. When the electric repulsive force reaches a threshold value that overcomes the surface tension, when the charged solution jets are moved in the air, the solvent evaporates and the charged polymer fibers are accumulated on the surface of the opposite electrode, Woven fabric.

The parameters of electrospinning can be divided into the variables of the spinning solution, the process variables and the environmental variables. The parameters of the spinning solution include the surface tension, viscosity, and conductivity of the polymer solution. Process variables include the potential at the capillary tip, the distance between the tip and the collector, and so on. Environmental variables include temperature, humidity, and vacuum conditions during spinning.

Nanofilm supports produced through electrospinning process are mainly used to produce sheet, tube, or other types of fibrous tissue-based supports. They are manufactured from non-polymeric materials to suit the desired site can do. Sheet-shaped supports using an electrospinning process can be used for skin regeneration, cartilage and other tissue regeneration, and tube-shaped tissue engineering supports are used for revascularization techniques of vascular tissue and bone tissue.

However, due to the nature of the electrospinning process, the rotation of the jet will result in a stack of nanofibers with a random arrangement for accumulation on the collecting plate, and the random nanofiber support has a limitation of slower regeneration than the aligned nanofiber support.

Korean Patent Publication No. 10-2005-0014033

In order to solve the above problems, it is an object of the present invention to provide a nanofiber support body in the form of a tube arranged in an orthogonal shape.

Another object of the present invention is to provide a method of manufacturing a tube-shaped nanofiber support which is arranged in an orthogonal shape.

Accordingly, the present invention provides a method for producing a spinning solution, comprising: (a) preparing a spinning solution by dissolving the polymer alone or in a solvent; (b) providing a conductive wire between the rotating drum-shaped current collector plate and the collector of the electrospinning apparatus; And (c) spinning the polymer solution using an electrospinning apparatus.

In one embodiment of the present invention, the polymer of (a) is at least one selected from the group consisting of polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone, diol / diacid aliphatic polyester, polyester- Biodegradable aliphatic polyesters such as polyester-urethane, or one or more natural polymers selected from the group consisting of chitosan, chitin, alginic acid, collagen, gelatin and hyaluronic acid .

In one embodiment of the present invention, the solvent of (a) is water; Lower alcohols such as methanol, ethanol, propanol and butanol; Acetone; Trifluoroethanol; Tetrahydrofuran; Dichloromethane; And a mixed solvent thereof.

In one embodiment of the present invention, (b) is characterized in that a conductive wire is installed horizontally at an interval of 1 to 7 cm from the collector.

In one embodiment of the present invention, the conductive wire of (b) can be used as long as it is electrically conductive, and preferably a metal rod (thick wire) is used as a wire and installed on the left side of the collector, The wire can be charged at the same time, and the position of the wire can be anywhere on the left or right of the collector.

In one embodiment of the present invention, the electrospinning apparatus of (c) is used to apply a voltage of 5 to 30 kV during spinning.

In one embodiment of the present invention, (c) is characterized in that the discharge part of the polymer solution is spun in the form of vertical spinning after a motor is wound between the collector and the conductive wire.

In one embodiment of the present invention, the speed of the motor is set to 25 to 300 rpm.

In one embodiment of the present invention, the flow rate of the polymer solution is 0.01 to 0.1 ml / h.

In one embodiment of the present invention, the diameter of the discharge portion is characterized by using a syringe needle having a diameter of 0.45 to 0.55 mm.

The present invention also provides a nanofiber support formed in the form of an orthogonal aligned tube made according to the above process.

The present invention has the effect of rapidly regenerating nerve regeneration, vascular regeneration, and other tissue regeneration in a tubular nanofiber scaffold that is arranged in an orthogonal fashion using a wire.

Figure 1 a is a schematic representation of a method of making a nanofiber support.
FIG. 1B is an illustration of an arrangement of nanofiber supports constructed in an orthogonal configuration.
2 is a SEM (Scanning Electronic Microscope) photograph of the nanofiber support of the present invention.
3A is a graphical representation of nanofiber array angles of a nanofiber support produced by conventional electrospinning.
FIG. 3B shows the arrangement angle of the nanofibers of the nanofiber support of the present invention as an application.
FIG. 4A is a result of measuring the young's modulus of the nanofiber support.
4B shows the result of measuring the tensile strength of the nanofiber support.

The present invention is characterized by providing a tubular nanofiber support that is arranged in an orthogonal fashion using conductive wires in the manufacture of nanofiber supports using electrospinning.

The first feature of the present invention is a support for tissue engineering comprising nanofibers. In the case of the support for tissue engineering using nanofibers, it has a high porosity which is advantageous for the penetration of nutrients necessary for cells, a discharge of metabolites, and a large surface area which facilitates cell adhesion. It has properties similar to natural extracellular matrix. When applied to supporters composed of nanofibers in defects or damaged areas, it facilitates adhesion, growth and differentiation of cells as a supporter, thereby accelerating wound and tissue regeneration.

In addition, a second feature of the present invention resides in the manufacture of a tube-shaped tissue engineering support having nanofibers arranged in an orthogonal configuration by providing wires around the current collector. Generally, in the case of manufacturing a nanofiber support by an electrospinning process, the nanofibers constitute a support in a random arrangement due to the characteristics of the electrospinning process. However, by arranging the conductive wires, the arrangement of the nanofibers is aligned in an orthogonal form, which is because in the regeneration of the tissue, the aligned nanofiber array induces the direction of differentiation of the cells, The reproduction speed of the recording medium is increased.

In a third aspect of the present invention, the diameter of the nanofibers constituting the support may be controlled by controlling the rotation speed of the current collector plate. This is because the nanofibers that are radiated in the electrospinning process are wound on the rotating collecting plate to form a tube-shaped support, which can speed up the rotation speed of the collecting plate to produce thinner nanofiber supports. Alternatively, To make relatively thick nanofibers.

According to a fourth aspect of the present invention, the rotation speed of the current collector plate is varied to adjust the angle of the nanofibers constituting the support. In the case of a nanofiber support without a conductive wire, the arrangement of the nanofibers constituting the support is random, and the frequency of the nanofibers forming the orthogonal shape is high even though the rotation speed of the current collector is increased. However, Nanofibers are made at random angles.

The present invention can control the arrangement angles of the nanofibers constituting the support by arranging the conductive wires around the current collector plate and adjusting the rotation speed of the current collector plate by arranging the nanofibers in an orthogonal shape or by slowing them and arranging them in a nonorthogonal arrangement.

Specifically, (a) preparing a spinning solution by dissolving the polymer in a solvent, alone or in combination; (b) providing a conductive wire between the rotating drum-shaped current collector plate and the collector of the electrospinning apparatus; And (c) spinning the polymer solution using an electrospinning machine to produce a nanofiber support.

In one embodiment of the present invention, the polymer of (a) is selected from the group consisting of polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone, diol / diacid aliphatic polyester, polyester- Ester-urethane and the like, or at least one natural polymer selected from the group consisting of chitosan, chitin, alginic acid, collagen, gelatin and hyaluronic acid, characterized in that it is at least one natural polymer selected from the group consisting of typical biodegradable aliphatic polyesters And may preferably be polycaprolactone.

Further, in one embodiment of the present invention, the solvent of (a) is water; Lower alcohols such as methanol, ethanol, propanol and butanol; Acetone; Trifluoroethanol; Tetrahydrofuran; Dichloromethane; And a mixed solvent thereof. Preferably, trifluoroethanol can be used.

Further, in an embodiment of the present invention, a conductive wire is placed between the collector and the rotating drum-shaped current collecting plate of the electric radiator of step (b) horizontally with the collector.

A constant current is flowed in the voltage generating device to form an electric field between the nozzle and the collector. The polymer solution filled in the spinning liquid reservoir is radiated to the collector by the force of the electric field and the dry pressure in the syringe pump. Factors affecting radiation include voltage, flow rate, distance between the nozzle and collector, temperature, and humidity.

The condition of the electric radiator is a radiation range of 10 to 20 cm, preferably 15 cm. A voltage of 5 to 30 kV, a discharge speed of 0.01 to 0.1 ml / h, and a motor rotation speed of 25 to 300 rpm, but is not limited thereto.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are only the preferred embodiments of the present invention, and the present invention is not limited by the following Examples.

< Example  1>

Manufacture of nanofiber supports in the form of tubes in orthogonal alignment

<1-1> Polycaprolactone  Preparation of polymer solution

1 g of polycaprolactone (epsilon -caprolactone; PCL, Sigma-Aldrich, 440744-500G, Mn 70,000-90.000) and 8 g of chloroform (Sigma-Aldrich, 288306-2L) And 2 g of 2,2,2-trifluoroethanol (TFE, T63002-500G) were dissolved to prepare a polycaprolactone polymer solution.

<1-2> Rotary drum type House front  Conductive around wire  install

A motor (12V DC motor, custom-made) was installed on a 0.404 mm diameter collector plate (0.45 mm diameter syringe needle, custom made) of an electric radiator, and a metallic wire was installed horizontally at a distance of 4 cm from the collector. Specifically, as shown in Fig. 1, the position of the metallic wire was set on the left side of the collector using a metallic rod (coarse wire) as a wire, and electric charges were simultaneously applied to the collector and the wire.

Further, in the present invention, a wire usable as a conductive wire can be used as long as it can be electrically conductive, and preferably a metal rod can be used, and the position of the wire can be anywhere on the left or right of the collector. However, it can preferably be placed in the form described in Fig.

&Lt; 1-3 > Fabrication of nanofiber scaffolds in the form of tubes arranged in an orthogonal shape

The polymer solution prepared in Example 1-1 was directed vertically downward in the discharge part of the electrospinning device, and the motor was turned on at a distance of 15 cm between the collector and the wires. At this time, the flow rate of the polymer solution was set at 0.01 to 0.1 ml, and a syringe needle having a diameter of 0.511 mm was used as the discharging portion. A nanofiber support was prepared using an electrospinning device at an application voltage of 5 to 30 kV and a motor speed of 250 rpm (see FIG. 1).

< Experimental Example  1>

Identification of tubular nanofiber scaffolds in orthogonal alignment

Scanning Electron Microscope (SEM) was taken to confirm the shape of the nanofiber support. As a result, it was confirmed that the shape of the nanofiber support according to the present invention was aligned in parallel with the nanofiber support without spinning the conductive wire as shown in FIG. 2 (see FIG. 2).

As a result of measuring the arrangement angle of the nanofibers, in the case of the nanofiber support without the conductive wire, the arrangement of the nanofibers constituting the support increases the rotation speed of the current collector, and the frequency of the nanofibers forming the orthogonal structure is high However, it was found that the nanofibers were formed at a random angle rather than the support using the conductive wire (see FIG. 3).

< Experimental Example  2>

Of a tubular nanofiber support arranged in an orthogonal shape Young's modulus  And The tensile strength  Confirm

As a result of measuring the Young's modulus (length elastic modulus) of the nanofiber support of the present invention, it was found that as the rotation speed of the motor increases as shown in FIG. 4A, the nanofiber support prepared by installing the conductive wire is a conventional nanofiber It was found that the modulus of elasticity was higher than that of the support.

As a result of measurement of the tensile strength of the nanofiber support of the present invention, it was found that the tensile strength of the nanofiber support of the present invention was high as the rotation speed of the motor increased as shown in FIG. 4B.

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is indicated by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims (9)

(a) preparing a spinning solution containing at least one polymer;
(b) providing a conductive wire between the rotating drum-shaped current collector plate and the collector of the electrospinning apparatus; And
(c) vertically spinning the spinning solution prepared in the step (a) using an electrospinning device, the method comprising the steps of:
Wherein the spinning solution containing the polymer of step (a) is characterized in that polycaprolactone, chloroform and trifluoroethanol are in a mass ratio of 1: 8: 2;
Wherein the conductive wire of step (b) is installed horizontally at an interval of 1 cm to 7 cm from the collector.
Wherein the conductive wire of step (b) is a metallic conductive wire of iron or aluminum;
The vertical spinning in the step (c) is carried out by using an electrospinning device in a voltage range of 5 to 30 kV during the spinning, and the ejection part of the spinning solution using a syringe needle having a diameter of 0.45 to 0.55 mm, Downward;
Wherein the vertical spinning in step (c) is performed by rotating at a speed of 250 rpm, and the flow rate of the polymer solution is set at 0.01 to 0.1 ml / h. Way. delete delete delete delete delete delete delete A nanofiber support, in the form of a tube, arranged in an orthogonal shape, produced according to the method of claim 1.

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