KR20010027252A - A biodegradable bone fixing device, and a process for preparing the same - Google Patents

Abstract

PURPOSE: Provided is an osteosynthesis apparatus made of biodegradable high polymer naturally decomposed in the living body, which can join fractured or cracked bones to another well. There is no need for another operation to remove the apparatus. CONSTITUTION: The apparatus is composed of multilayered compound materials of biodegradable high polymer matrix(1) and biodegradable high polymer nonwoven fabric, blade, knitting or fabrics(2) those are heat compressed. The osteosynthesis apparatus is produced by the steps of:(i) getting undrawn fiber by spinning the biodegradable high polymer at a rate of 500-3500m/min; (ii) making nonwoven fabric, blade, knitting or fabrics by using the undrawn fiber; (iii) getting matrix by melting and forming the biodegradable high polymer; (iv) producing a multilayered compound material by heat compressing the resulting matrix, the nonwoven fabric, blade, knitting or fabrics; and then (v) drawing the compound material under high pressure and cutting. The apparatus is made into various types such as a pin, staple, screw or plate type.

Description

Biodegradable bone fixing device and method for manufacturing the same {A biodegradable bone fixing device, and a process for preparing the same}

The present invention relates to a bone joining mechanism and a method of manufacturing the same for fixing them firmly until the bones of the human body are broken or cracked.

If fine cracks are generated in the bone, the bone bonding apparatus of the present invention may be firmly fixed to both bones with the bone bonding apparatus of the present invention through surgery to ensure that they are bonded more quickly. Bone joining devices are manufactured and used in the form of screws, pins, plates, staples and the like.

Until now, a bone bonding device composed of metals such as stainless steel and titanium, which does not have a natural decomposition property (hereinafter referred to as "biodegradability") in the human body, has been mainly used. There was a problem that hassle has to be removed by surgery.

Recently, in order to solve this problem, a bone bonding apparatus composed of a biopolymer such as polylactic acid has been developed and used.

Specifically, Japanese Patent Application Laid-Open No. 196,617 describes a method of manufacturing a molded body by melt molding and stretching a high molecular weight polylactic acid-based polymer, and cutting the same to produce a bone bonding mechanism such as a bone screw.

U.S. Patent 5,275,601 describes a special design of the screw made of biodegradable polymers, and U.S. Patents 5,250,049, U.S. Patent 5,324,307, U.S. Patent 5,227,412 and the like also describe bone bonding devices composed of biodegradable polymers.

The prior arts have limitations in providing physical properties such as flexural strength and flexural modulus required for the bone bonding mechanism because the bone bonding mechanism is manufactured by cutting only the molded body melt-molded and stretched the biodegradable polymer.

It is an object of the present invention to provide a bone bonding apparatus having biodegradability and good mechanical properties at the same time.

The present invention is to provide a bone bonding device and a method of manufacturing the same having excellent mechanical properties, such as compressive flexural strength, so that the biodegradability does not require reoperation to remove the bone bonding mechanism after the bone is completely bonded.

1 is an enlarged exemplary view showing a cross section of the composite material of the present invention.

2 is a photographic copy of the present invention of the screw type (Screw).

3 is a photographic copy of the present invention of plate type.

4 is a photographic copy of the present invention of staple type.

5 is a process schematic diagram of manufacturing a multilayer composite material of the present invention.

6 is a schematic diagram of a high-pressure stretching apparatus for producing a multilayer composite material of the present invention.

※ Code explanation for main part of drawing

1: matrix which is a biodegradable polymer

2: non-woven, braid, knit or woven of biodegradable polymer

3: Supply Roller 4: Pressed Calender Roller

5: multilayer composite material roll 6: pressure piston

7: heating tube 8: stretching detention

9: stretched multilayer composite material 10: pressurization device

The present invention relates to a bone bonding device having a biodegradability and excellent mechanical properties and a method of manufacturing the same.

Specifically, the present invention relates to a biodegradable bone bonding apparatus, characterized in that the matrix (1) of the biodegradable polymer and the nonwoven, braid, knit or woven fabric (2) of the biodegradable polymer are composed of a thermocompressed multilayer composite material.

In the present invention, biodegradable polymers include polyglycolide, polylactide, polyglycolic acid, polylactic acid, polydioxane source, polytrimethylene carbonate, polycaprolactone, poly (ortho ester), poly (anhydro), One polymer selected from the group consisting of poly (phosphazene), poly (amino acid), cellulose derivative, poly (saccharide), poly (hydroxy butylate) or copolymers or blends thereof is used. .

The matrix 1 and the nonwoven fabric, braid, knitted fabric or woven fabric 2 may be composed of the same kind of polymer, or may be made of a different kind of polymer.

The bone bonding apparatus of the present invention can be made in the type of pins, staples, screws or plates and the like.

Bone bonding mechanism of the present invention is usually excellent in mechanical properties compared to the product produced in the conventional single molded body having a flexural strength of 200Mpa or more, flexural modulus of 10Gpa or more. Normal cortical bones of humans have a tensile strength of 80 ~ 120Mpa, flexural strength is 100 ~ 200Mpa, flexural modulus is 10 ~ 15Gpa.

In addition, the present invention (i) to produce a non-drawn yarn by spinning the biodegradable polymer at a spinning speed of 500 ~ 3500m / min, and (ii) to produce a nonwoven fabric, braid, knitted fabric or woven fabric (2). (Iii) On the other hand, the biodegradable polymer is melt-molded in a molding machine to prepare the matrix 1. (Iii) thermocompression bonding the matrix (1) of the biodegradable polymer (1) and the nonwoven fabric, braid, knitted fabric or fabric (2) under a nitrogen atmosphere to produce a composite material (5), and (iii) the composite material (5) The present invention relates to a method for producing a biodegradable bone bonding apparatus characterized by cutting after stretching under high pressure.

Hereinafter will be described in detail the manufacturing method of the present invention.

First, a non-stretched yarn is manufactured by melt spinning a biodegradable polymer in a conventional melt spinning machine. At this time, the spinning speed is 500 to 3500 m / min, more preferably 500 to 2000 m / min.

Next, the non-drawn yarn is cut and needle punched to produce a nonwoven fabric, or weaving or knitting to prepare a woven fabric, knitted fabric or braid. On the other hand, the biodegradable polymer is melt-molded by a conventional method in a molding machine to prepare the matrix (1).

The matrix 1 thus prepared and the nonwoven fabric, braid, knitted fabric or woven fabric 2 are thermocompressed at high temperature to produce a multilayer composite material.

As a specific example, the matrix 1 and the nonwoven fabric 2 are supplied to the supply roller 3 at a high temperature as shown in FIG. 5 and laminated thereon, and then pressed by a calender roller 4 for compression. 5) can be manufactured. At this time, the temperature is adjusted above the melting point of the biodegradable polymer.

Next, the multilayer composite material is stretched under high pressure, and then cut to prepare a bone bonding apparatus of a desired type. At this time, the stretching is preferably 5 to 20 times, and more preferably 5 to 12 times.

The multilayer composite material 5 is specifically drawn under high pressure by the high-pressure stretching device as shown in FIG. The composite material 5 is moved to the stretching area by the pressure piston 6, the pressure piston 6 is operated by a high pressure of about 50 ~ 400kg / ㎠ by the pressure device (10).

The multi-layered composite material that has been moved to the stretching region is heated to a temperature lower than the melting point of the biodegradable polymer by the heating tube 7, and then stretched at a high magnification while being extruded through the stretching mold 8 installed at the bottom thereof.

The multilayered composite material 9 thus stretched is cut and processed into a pin, screw, plate, staple or the like in a conventional cutting device to produce the bone joining device of the present invention.

The bone joining mechanism of the present invention has excellent durability against external stress in any direction because the unstretched matrix 1 and the nonwoven fabric 2 are made of a composite material which is thermally compressed and stretched together. In addition, it is composed of biodegradable polymers and decomposes naturally in the human body.

The present invention is described in detail through the following examples. However, the present invention is not limited only to the following examples.

Example 1

Poly-L-lactic acid having a viscosity average molecular weight of 450,000 was melt blown at 225 ° C. at a spinning speed of 800 m / min to prepare a nonwoven fabric composed of undrawn yarn. On the other hand, poly-L-lactic acid having a viscosity average molecular weight of 450,000 is prepared in a sheet-like matrix by a conventional method using an extruder.

Next, the nonwoven fabric and the matrix are laminated in the same manner as in FIG. 5, and then thermocompressed in a heat compression roller to prepare a multilayer composite material having a width of 20 mm and a thickness of 2.8 mm.

Subsequently, the multilayer composite material is stretched at high magnification in the high-pressure stretching apparatus of FIG. 6. At this time, the multi-layered composite material is preheated in a heating barrel 7 at 150 ° C. for 20 minutes and then stretched at a draw ratio of 10 times through the drawing tool 8 heated at 155 ° C. The pressure of the pressurized piston 6 is adjusted to 150 kg / cm 2.

The stretched multilayer composite material had a tensile strength of 140 Mpa, a flexural strength of 220 Mpa, a flexural modulus of 11 Gpa, a thickness of 1.8 mm, and a width of 15 mm. The elongated multilayered composite material was cut on a lathe to prepare a plate having a width of 4.5 mm, a thickness of 1.6 mm and a length of 22 mm.

Example 2

Poly-L-lactic acid having a viscosity average molecular weight of 450,000 was spun at 225 ° C. at a spinning speed of 1500 m / min to prepare unstretched yarn, and a knitted knitting machine was manufactured using the circular knitting machine. On the other hand, poly-L-lactic acid having a viscosity average molecular weight of 450,000 is prepared in a sheet-like matrix by a conventional method using an extruder.

Next, the knitted fabric and the matrix are laminated in the same manner as in FIG. 5, and thermally compressed in a heat compression roller to prepare a multilayer composite material having a width of 20 mm and a thickness of 3.5 mm.

Subsequently, the multilayer composite material is stretched at high magnification in the high-pressure stretching apparatus of FIG. 6. At this time, the multi-layered composite material is preheated in a heating tube 7 at 145 ° C. for 20 minutes, and then stretched at a draw ratio of 10 times through the drawing tool 8 heated at 150 ° C. The pressure of the pressurized piston 6 is adjusted to 200 kg / cm 2.

The stretched multilayer composite material had a tensile strength of 138 Mpa, a flexural strength of 218 Mpa, a flexural modulus of 10.5 Gpa, a thickness of 2.3 mm, and a width of 15 mm. The stretched multilayered composite material was cut on a lathe to prepare a screw having a total length of 16 mm, a diameter of 2.0 mm and a diameter of a valley of 1.6 mm.

Example 3

1,1,2,2-tetrachloroethane solvent and polydioxane source having an intrinsic viscosity of 3.7 at 35 ° C. were spun at 170 ° C. at a spinning speed of 1500 m / min to produce undrawn yarn, which was used as warp and weft yarn. To weave in a narrow loom to produce a 10 cm wide fabric.

Meanwhile, the polydioxane source is extruded at 160 ° C. in an extruder to prepare a sheet-like matrix having a width of 10 cm.

Next, the fabric and the matrix are laminated in the same manner as in FIG. 5 and thermally compressed in a heat compression roller to prepare a multilayer composite material having a width of 20 mm and a thickness of 3.5 mm. Subsequently, the multilayer composite material is stretched at high magnification in the high-pressure stretching apparatus of FIG. 6. At this time, the multi-layered composite material is preheated in a heating barrel 7 at 90 ° C. for 20 minutes, and then stretched at a draw ratio of 9.8 times through the drawing die 8 heated at 93 ° C. The pressure of the pressurized piston 6 is adjusted to 200 kg / cm 2.

The stretched multilayer composite material had a tensile strength of 135 Mpa, a flexural strength of 215 Mpa, a flexural modulus of 10.4 Gpa, a thickness of 2.3 mm, and a width of 15 mm. The stretched multilayered composite material was cut on a lathe to prepare a screw having a total length of 16 mm, a diameter of 2.0 mm and a diameter of a valley of 1.6 mm.

Since the present invention is composed of a biodegradable polymer and is naturally decomposed in the human body, there is no need for a reoperation for removing the bone bonding apparatus after the bone is completely bonded.

In addition, the present invention has excellent mechanical properties such as flexural strength because the matrix 1 and the nonwoven fabric, braid, knitted fabric or woven fabric 2 have a thermocompression-bonded and stretched structure.

Claims (6)

A biodegradable bone bonding apparatus, characterized in that the matrix (1) of the biodegradable polymer and the nonwoven, braid, knit or woven fabric (2) of the biodegradable polymer are composed of a thermocompressed multilayer composite material. The method of claim 1, wherein the biodegradable polymer is selected from polyglycolide, polylactide, polyglycolic acid, polylactic acid, polydioxane source, polytrimethylene carbonate, polycaprolactone, poly (ortho ester), poly (anhydro), It is characterized in that it is one polymer selected from the group consisting of poly (phosphazene), poly (amino acid), cellulose derivative, poly (saccharide), poly (hydroxy butylate) or copolymers or blends thereof. Biodegradable bone bonding apparatus. The biodegradable bone bonding apparatus according to claim 1, wherein the biodegradable bone bonding apparatus is homogeneous or heterogeneous with the polymer constituting the nonwoven fabric, the braid, the knitted fabric or the woven fabric (2, 2 ') constituting the matrix (1). The biodegradable bone bonding device of claim 1, wherein the bone bonding device is of the pin, staple, screw, or plate type. (Iii) A non-drawn yarn is produced by spinning a biodegradable polymer at a spinning speed of 500 to 3500 m / min, and (ii) a nonwoven fabric, a braid, a knitted fabric or a fabric (2) is produced from the undrawn yarn. (Iii) On the other hand, the biodegradable polymer is melt-molded in a molding machine to prepare the matrix 1. (Iii) thermocompression bonding the matrix of the biodegradable polymer and nonwoven fabric, braid, knit fabric or fabric (2) to produce a multilayer composite material (5), and (iii) stretching the composite material (5) under high pressure. A method for producing a biodegradable bone bonding apparatus, characterized in that the cutting process. The method according to claim 5, wherein the biodegradable polymer is selected from polyglycolide, polylactide, polyglycolic acid, polylactic acid, polydioxane source, polytrimethylene carbonate, polycaprolactone, poly (ortho ester), poly (anhydro), It is characterized in that it is one polymer selected from the group consisting of poly (phosphazene), poly (amino acid), cellulose derivative, poly (saccharide), poly (hydroxy butylate) or copolymers or blends thereof. Method for producing a biodegradable bone bonding apparatus.