Polymer tube manufacturing device and polymer tube manufacturing method

Abstract

This polymer tube manufacturing device (1) is provided with: a mandrel collector (13) having long-length; a rotary drive unit (14) that rotates the mandrel collector (13) about a central axis (J1); a head (12) having a head body (121) that stores a spinning liquid inside and a nozzle (123) for discharging the spinning liquid stored inside the head body (121) to the outside of the head body (121); a head drive unit (171) that rotates the head (12) about a rotation axis (J2) extending in the Z-axis direction, thereby causing the nozzle (123) to circulate about the rotation axis (J2); and a high-voltage power supply (18) that applies a voltage to the nozzle (123) such that the nozzle (123) has a higher potential than the mandrel collector (13).

Description

Polymer tube manufacturing apparatus and polymer tube manufacturing method

[0001] The present invention relates to a polymer tube manufacturing apparatus and a polymer tube manufacturing method.

[0002] Some biological tissues, such as cardiac muscle tissue, have a fibrous, spirally oriented structure. In the field of regenerative therapy for such biological tissues, a tubular structure formed from bioabsorbable polymer fibers with sidewalls oriented along the fibrous tissue orientation direction constituting the biological tissue is required as a scaffolding material for biological tissue. To address this issue, a nanofiber production method using electrospinning has been proposed (see, for example, Patent Document 1). This method applies a high voltage between a spinneret and a cylindrical rotating collector, and then sprays and sucks a solution of charged fiber raw material and a solvent toward the rotating collector, thereby accumulating nanofibers on the rotating collector.

[0003] Japanese Patent Application Laid-Open No. 2008-223186

[0004] However, in the tubes produced by the nanofiber manufacturing method described in Patent Document 1, the nanofibers that make up the tube walls are stretched in random directions and lack orientation, which may prevent the tubes from fully functioning as a scaffold for biological tissue.

[0005] The present invention has been made in consideration of the above-mentioned reasons, and aims to provide a polymer tube manufacturing apparatus and a polymer tube manufacturing method that can produce a tube having a tube wall formed from highly oriented polymer fibers.

[0006] The polymer tube manufacturing apparatus of the present invention comprises: a long mandrel collector; a rotation drive unit that rotates the mandrel collector around a central axis along the longitudinal direction of the mandrel collector; a head having a box-shaped head body that stores a spinning solution inside, in which at least one type of polymer is dissolved in at least one type of solvent, and a nozzle that ejects the spinning solution stored inside the head body to the outside of the head body; a head drive unit that rotates the head around a rotation axis that extends in a direction perpendicular to the longitudinal direction of the mandrel collector, thereby causing the nozzle to revolve around the rotation axis; and a first voltage application unit that applies a voltage to the nozzle so that the nozzle has a higher potential than the mandrel collector.

[0007] From another perspective, the method for manufacturing a polymer tube according to the present invention involves rotating a long mandrel collector around a central axis along the longitudinal direction of the mandrel collector, and rotating a box-shaped head having a head body that stores a spinning solution inside, in which at least one type of polymer is dissolved in at least one type of solvent, and a nozzle for ejecting the spinning solution stored inside the head body to the outside of the head body, around a rotation axis that extends in a direction perpendicular to the longitudinal direction of the mandrel collector, thereby causing the nozzle to revolve around the rotation axis and applying a voltage to the nozzle so that the nozzle has a higher potential than the mandrel collector.

[0008] According to the polymer tube manufacturing apparatus and method of the present invention, the mandrel collector is rotated about its central axis along its longitudinal direction, and the head is rotated about a rotation axis extending perpendicular to the longitudinal direction of the mandrel collector, thereby rotating the nozzle of the head around the rotation axis and applying a voltage to the nozzle so that the nozzle has a higher potential than the mandrel collector. This makes it possible to manufacture a tube having a tube wall formed from polymer fibers oriented along the longitudinal direction of the mandrel collector.

[0009] 4A is a schematic diagram of a polymer tube manufacturing apparatus according to an embodiment of the present invention; FIG. 4B is a perspective view of a head according to an embodiment; FIG. 4C is a cross-sectional view of a head according to an embodiment; FIG. 4D is a schematic plan view for explaining the operation of a polymer tube manufacturing apparatus according to an embodiment; FIG. 4E is a schematic side view for explaining the operation of a polymer tube manufacturing apparatus according to an embodiment; FIG. 4F is a photograph showing an example of a polymer tube manufactured by a polymer tube manufacturing method according to an embodiment; FIG. 4G is an SEM photograph of a portion of an inner wall of the polymer tube shown in FIG. 4A; FIG. 4H is an SEM photograph of a portion of an outer wall of the polymer tube shown in FIG. 4A.

[0010] An apparatus and a method for manufacturing a polymer tube according to an embodiment of the present invention will be described below with reference to the drawings. The apparatus for manufacturing a polymer tube according to this embodiment includes a long mandrel collector, a rotation driver for rotating the mandrel collector around a central axis along the longitudinal direction of the mandrel collector, a head, a head driver, and a first voltage application unit. The head has a box-shaped head body that stores a spinning solution containing at least one polymer dissolved in at least one solvent, and a nozzle for ejecting the spinning solution stored inside the head body to the outside of the head body. The head driver rotates the head about a rotation axis extending in a direction perpendicular to the longitudinal direction of the mandrel collector, thereby causing the nozzle to orbit around the rotation axis. The first voltage application unit applies a voltage to the nozzle so that the nozzle has a higher potential than the mandrel collector.

[0011] 1 , the polymer tube manufacturing apparatus 1 according to this embodiment includes a long, cylindrical mandrel collector 13, a rotation drive unit 14 that rotates the mandrel collector 13 about a central axis along the longitudinal direction, a head 12, and a head drive unit 171. The polymer tube manufacturing apparatus 1 also includes a high-voltage power supply 172 that applies a voltage to the shaft 122 of the head 12 via a power line L1, and a high-voltage power supply 18 that applies a voltage to the mandrel collector 13.

[0012] 2A , the head 12 includes a head main body 121, a shaft 122 that is long and cylindrical and has one end in the longitudinal direction connected to approximately the center of the head main body 121 on the +Z direction side, a nozzle 123, and a conductive wire 124. The head main body 121 is hollow and disk-shaped, and as shown in FIG. 2B , includes a box-shaped housing 1212 that is circular in plan view, a partition wall 1211 that has a hexagonal outer shape in plan view and that defines a first region S1 that is circular in plan view inside, and that is disposed approximately in the center of the housing 1212, and a partition wall 1213 that separates the region between the partition wall 1211 and the inner wall of the housing 1212 to form a second region S2 around the partition wall 1211. A spinning solution obtained by dissolving at least one type of polymer in at least one type of solvent is stored in each of the first region S1 and the second region S2. The head body 121 also has two discharge pipes 125, each of which is elongated and extends from two opposing locations across the center of the partition wall 1211 in a direction perpendicular to the Z-axis direction, has one longitudinal end communicating with the first region S1, and discharges the spinning solution stored in the first region S1 from the other end. The other longitudinal end of each of the two discharge pipes 125 is arranged inside a discharge hole 123a of a nozzle 123, which will be described later.

[0013] The shaft 122 is rotatably supported by a shaft support portion 173. Here, the shaft support portion 173 supports the shaft 122 while maintaining electrical insulation from the shaft 122, for example, via an insulating bearing (not shown). A pulley 1741 is fitted into the other end of the shaft 122 opposite to the one end connected to the head main body 121.

[0014] The nozzles 123 are disposed at two opposing locations on the side wall of the housing 1212, sandwiching the center of the nozzle 123. The nozzles 123 are formed from a conductive material such as metal and include a rectangular plate-shaped base 1232 embedded in the side wall of the housing 1212, and a nozzle main body 1231 erected on the surface of the base 1232 opposite the side embedded in the housing 1212 in the thickness direction. The nozzle main body 1231 and the base 1232 have discharge holes 123a formed therethrough. The discharge holes 123a communicate with a second region S2 formed inside the housing 1212.

[0015] As shown in FIG. 2A, the conductive wire 124 is long and extends along the outer wall of the housing 1212, with one longitudinal end connected to the shaft 122 and the other end continuing to the base portion 1232 of the nozzle 123.

[0016] 1 , the head driver 171 rotates a shaft 1711 having a pulley 1743 fitted at its tip. The pulleys 1741 and 1743 are connected by a belt 1742 made of an electrically insulating material. The head driver 171 rotates the shaft 1711 and the pulley 1743, thereby rotating the head 12 about the rotation axis J2 via the belt 1742 and the pulley 1741, as indicated by the arrow AR2.

[0017] The high-voltage power supply 172 is a voltage application unit that applies a voltage to the nozzle 123 so that the nozzle 123 has a higher potential than the mandrel collector 13. The high-voltage power supply 172 applies a voltage to the shaft 122 of the head 12 via a power supply line L1 having a brush contact (not shown) at its tip, for example, to maintain the potential of the shaft 122 and the nozzle 123 at a potential higher than the ground potential. Here, the high-voltage power supply 172 applies a voltage of, for example, about 10 kV to the shaft 122.

[0018] The mandrel collector 13 is formed from metal, ceramic, glass, polymer, or the like, and its end on the +Y direction side is connected to the shaft 141 of the rotation drive unit 14 via a coupling member 19, while its end on the -Y direction side is connected to a long, cylindrical support shaft 20 via a coupling member 22 made of metal. The support shaft 20 is supported by a support member 15 so as to be rotatable about a central axis J1 along the longitudinal direction of the mandrel collector 13. Each coupling member 19 has a structure in which the shaft 141 is connected to a main body 191 made of metal, and holds the end of the mandrel collector 13 via an insulating member 192. The support member 15 is placed on a base 23 made of an electrically insulating material. As a result, the mandrel collector 13 is electrically insulated from the shaft 141 of the rotation drive unit 14 via the insulating member 192 and also via the base 23. 3A, the mandrel collector 13 is disposed at a position spaced apart from the head 12 in the X-axis direction. The shortest distance W1 between the trajectory OB1 of the tip of the nozzle 123 and the mandrel collector 13 shown in FIG. 3B is set to be 50 mm or more and 500 mm or less.

[0019] The rotation drive unit 14 has a motor that rotates a shaft 141, and as shown by an arrow AR1, rotates the mandrel collector 13 about the central axis J1 via a coupling member 19. The rotation drive unit 14 operates based on a control signal input from the control unit 21.

[0020] The high-voltage power supply 18 is a second voltage application unit that applies a voltage to the mandrel collector 13 so that the mandrel collector 13 has a negative potential relative to the ground potential. The high-voltage power supply 18 applies a voltage to the mandrel collector 13 via a power supply line L2 having a brush contact (not shown) at its tip, for example, to maintain the potential of the mandrel collector 13 at a potential lower than the ground potential. Here, the high-voltage power supply 18 applies a voltage of, for example, about −5 kV to the mandrel collector 13.

[0021] The control unit 21 has, for example, a PLC (Programmable Logistic Controller) and controls the rotation drive unit 14 to rotate the mandrel collector 13 about the central axis J1. The control unit 21 also controls the head drive unit 171 so that the head 12 rotates at a preset rotation measurement. Here, the control unit 21 controls the head drive unit 171 so that the head 12 rotates at a rotation speed of, for example, 1000 rpm. Furthermore, the control unit 21 controls the high-voltage power supplies 172 and 18 so that the shaft 122 and nozzle 123 of the head 12 are maintained at a potential higher than ground potential and the mandrel collector 13 is maintained at a potential lower than ground potential.

[0022] Next, a method for manufacturing a polymer tube using the polymer tube manufacturing apparatus 1 according to this embodiment will be described. First, a spinning solution is prepared by dissolving at least one type of polymer in an organic solvent. The polymer may be a highly bioabsorbable polymer with shape-memory function, such as polyglycolic acid (PGA), a copolymer of glycolic acid and L-lactic acid (PGLA), a copolymer of glycolic acid and DL-lactic acid (PGDLLA), poly-L-lactic acid (PLLA), poly-D-lactic acid (PDLA), poly-DL-lactic acid (PDLLA), a copolymer of L-lactic acid and ε-caprolactone (LCL), or poly-p-dioxanone (PDO). The organic solvent may be dichloromethane, trichloromethane (CHCl 3 ), or the like. ３ ), dichloroethane, N,N-dimethylformamide, tetrahydrofuran, toluene, pyridine, acetonitrile, formamide, benzene, dimethylacetamide, N-methylpyrrolidone, hexane, 1,4-dioxane, acetone, methanol, ethanol, etc. The concentration of the polymer contained in the spinning solution may be 5 wt % or more and 15 wt % or less, and preferably 6 wt % or more and 8 wt % or less.

[0023] Next, the prepared spinning solution is poured into the first region S1 and the second region S2 inside the head body 121 of the head 12. Here, spinning solutions containing different types of polymers dissolved therein may be poured into the first region S1 and the second region S2. In this case, a polymer tube having a tube wall formed from polymer fibers having a so-called core-sheath structure can be produced.

[0024] Next, a voltage is applied to the nozzle 123 of the head 12 so that the nozzle 123 has a higher potential than the mandrel collector 13, and a negative voltage is applied to the mandrel collector 13 so that the mandrel collector 13 has a lower potential than the ground potential.

[0025] Then, the mandrel collector 13 is rotated about the central axis J1, and the head 12 is rotated about the rotation axis J2, thereby orbiting the nozzle 123 around the rotation axis J2. As a result, a polymer generated from the spinning solution discharged from the nozzle 123 is deposited on the side wall of the mandrel collector 13. As a result, a polymer tube having a tube wall formed from a nonwoven polymer fabric, as shown in FIG. 4A, for example, is formed on the side wall of the mandrel collector 13. The polymer fibers constituting the tube wall of this polymer tube are oriented in the axial direction of the polymer tube, i.e., along the longitudinal direction of the mandrel collector 13, as shown in FIGS. 4B and 4C, for example.

[0026] Thereafter, the polymer tube formed on the side wall of the mandrel collector 13 is removed from the mandrel collector 13 .

[0027] As described above, according to the polymer tube manufacturing apparatus 1 and polymer tube manufacturing method of this embodiment, the mandrel collector 13 is rotated about the central axis J1, and the head 12 is rotated about the rotation axis J2 extending in a direction perpendicular to the longitudinal direction of the mandrel collector 13, thereby causing the nozzle 123 of the head 12 to revolve around the rotation axis J2 and applying a voltage to the nozzle 123 so that the nozzle 123 has a higher potential than the mandrel collector 13. This makes it possible to manufacture a tube having a tube wall formed from polymer fibers oriented along the longitudinal direction of the mandrel collector 13.

[0028] However, conventional electrospinning methods using a rotating collector, known as the fiber winding method, have only produced polymer tubes with nonwoven fabric-like walls, with the polymer fibers constituting the wall only being short, with the length of the polymer tube being 30 mm or less in the axial direction. Furthermore, production efficiency has been low. In contrast, the polymer tube manufacturing method according to the present embodiment combines the electrospinning method and centrifugal spinning methods. By applying both centrifugal force and an elongation force due to an electric field to the polymer molecular chains constituting the polymer fibers, the polymer fibers constituting the wall of the polymer tube can be highly oriented along the axial direction of the polymer tube and have a length of more than 30 mm in the axial direction.

[0029] Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the above-described embodiments. For example, a plurality of types of discharge pipes with different diameters may be coaxially arranged inside the discharge hole 123a of the nozzle 123, and the other ends of the respective discharge pipes may be connected to different regions formed inside the head body 121.

[0030] In the embodiment, an example has been described in which the rotation axis J2 of the head 12 is perpendicular to the central axis J1 of the mandrel collector 13. However, the relative orientation of the mandrel collector 13 with respect to the head 12 is not limited to this, and for example, the mandrel collector 13 may be disposed so that the central axis J1 of the mandrel collector 13 is inclined with respect to the rotation axis J2 of the head 12 when viewed from the X-axis direction.

[0031] In an embodiment, the head 12 may include a heater (not shown) for heating and melting a solid polymer-containing composition containing at least one type of polymer that is poured into the first region S1 and the second region S2 inside the head body 121. This polymer-containing composition can be prepared, for example, as follows: First, at least one type of polymer is dissolved in an organic solvent to prepare a polymer solution, and the polymer solution is maintained at room temperature or a temperature higher than room temperature to remove most of the organic solvent. Thereafter, the polymer-containing composition obtained after removing most of the organic solvent is heated to the crystallization temperature of the polymer or higher to crystallize it and dry it, thereby preparing a solid polymer-containing composition. The polymer may be selected from, for example, polyglycolic acid (PGA), copolymer of glycolic acid and L-lactic acid (PGLA), copolymer of glycolic acid and DL-lactic acid (PGDLLA), poly-L-lactic acid (PLLA), poly-D-lactic acid (PDLA), poly-DL-lactic acid (PDLLA), copolymer of poly-L-lactic acid and ε-caprolactone (PLCL), and poly-p-dioxanone (PDO). In particular, polymers with a relatively high melting point are preferred.

[0032] In an embodiment, the polymer contained in the spinning solution may be a thermoplastic resin, i.e., polylactic acid, poly(lactic acid), poly(lactic acid), poly(glycolic acid), poly(dioxane), copolymers of the monomers constituting these, polypropylene, polystyrene, polyethylene, polyvinyl chloride, or a photocurable resin, i.e., an acrylic, epoxy, polyester, urethane acrylate, silicone, olefin, vinyl ether, etc. Alternatively, the polymer contained in the spinning solution may be a natural material that is liquid at room temperature or a natural material dissolved in an inorganic solvent such as water or an organic solvent such as alcohol, i.e., a photocurable resin containing plant-derived components, a resin derived from soybean oil, a natural resin containing cellulose nanofibers, a polyamide such as collagen, gelatin, or fibroin, a polysaccharide such as cellulose, chitosan, or agarose, a polyterpene such as polyisoprene, a phenolic aromatic polymer such as lignin, or a polyester such as polyhydroxyalkanoic acid, shellac, or suberin.

[0033] The present invention allows various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to illustrate the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

[0034] This application is based on Japanese Patent Application No. 2024-055474, filed on March 29, 2024. The entire specification, claims and drawings of Japanese Patent Application No. 2024-055474 are incorporated herein by reference.

[0035] The present invention is suitable for the manufacture of bioabsorbable scaffolds having vessel walls formed from highly oriented polymeric fibers.

[0036] 1: polymer tube manufacturing apparatus, 12: head, 13: mandrel collector, 14: rotation drive unit, 15: support member, 18, 172: high-voltage power supply, 19, 22: coupling member, 20: support shaft, 21: control unit, 23: base, 121: head main body, 122, 1711: shaft, 123: nozzle, 123a: discharge hole, 124: electric wire, 125: discharge pipe, 141: shaft, 171: head drive unit, 173: shaft support unit, 191: main body, 192: insulating member, 1211, 1213: partition wall, 1212: housing, 1231: nozzle main body, 1232: base, 1741, 1743: pulley, 1742: belt, J1: central axis, J2: rotation axis, L1, L2: power line, OB1: locus

Claims

1. A polymer tube manufacturing device comprising: a long mandrel collector; a rotation drive unit that rotates the mandrel collector around a central axis along the longitudinal direction of the mandrel collector; a box-shaped head having a head body that stores a spinning solution inside, the spinning solution being prepared by dissolving at least one type of polymer in at least one type of solvent, and a nozzle that ejects the spinning solution stored inside the head body to the outside of the head body; a head drive unit that rotates the head around a rotation axis that extends in a direction perpendicular to the longitudinal direction of the mandrel collector, thereby causing the nozzle to orbit around the rotation axis; and a first voltage application unit that applies a voltage to the nozzle so that the nozzle has a higher potential than the mandrel collector.

2. The polymer tube manufacturing apparatus according to claim 1, further comprising a second voltage application unit that applies a voltage to the mandrel collector so that the mandrel collector has a potential that is more negative than the ground potential.

3. The polymer tube manufacturing apparatus according to claim 1 or 2, wherein the shortest distance between the trajectory of the nozzle tip and the mandrel collector is set to be 50 mm or more and 500 mm or less.

4. The polymer tube manufacturing apparatus according to claim 1 or 2, wherein the head main body comprises: a box-shaped housing; a partition wall disposed inside the housing and defining a first region therein and defining a second region between the outer wall and the inner wall of the housing; and a thin discharge pipe extending from the partition wall, one end of which in the longitudinal direction communicates with the first region and the other end of which discharges the spinning solution stored in the first region; and the nozzle has a discharge hole on the inside that communicates with the second region, and the other end of the discharge pipe is disposed inside the discharge hole.

5. The polymer tube manufacturing apparatus according to claim 1 or 2, wherein the spinning solution is an organic solvent having dissolved therein at least one polymer selected from polyglycolic acid, a copolymer of glycolic acid and L-lactic acid, a copolymer of glycolic acid and DL-lactic acid, poly-L-lactic acid, poly-D-lactic acid, poly-DL-lactic acid, a copolymer of L-lactic acid and ε-caprolactone, and poly-p-dioxanone.

6. A method for manufacturing a polymer tube, comprising: rotating a long mandrel collector around a central axis along the longitudinal direction of the mandrel collector; and rotating a box-shaped head having a head body inside which is stored a spinning solution in which at least one type of polymer is dissolved in at least one type of solvent, and a nozzle for ejecting the spinning solution stored inside the head body to the outside of the head body, around a rotation axis extending in a direction perpendicular to the longitudinal direction of the mandrel collector, thereby orbiting the nozzle around the rotation axis and applying a voltage to the nozzle so that the nozzle has a higher potential than the mandrel collector.

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