KR20020083664A - A composit materials for medical implement reinforced by nano fiber, and a process of preparing for the same - Google Patents

Abstract

PURPOSE: A composite material having bio-degradable property and reinforced with nano-fiber to give good bending strength and elasticity is provided to effectively use the material in medical application such as stapler, hook, nails, anchors, clamps, operating implant, etc. CONSTITUTION: The composite material comprises 10-90 volume% of bio-degradable polymer matrix and 90-10 volume% of bio-degradable nano-fibers having particle diameter ranging of 10-500 nanometers as reinforcing material and has 290MPa of bending strength and 17GPa of bending elasticity. The composite material is prepared by a process comprising the steps of (i) electrically spinning the bio-degradable polymer to produce a non-woven cloth consisting of nano-fibers, and then breaking the cloth into the bio-degradable nano-fibers having such particle size; (ii) mixing the bio-degradable polymer matrix and the nano-fibers in a ratio of 10-90 volume% to 90-10 volume% and compression-molding the mixture.

Description

A composite material for medical implement reinforced by nano fiber, and a process of preparing for the same}

The present invention relates to a composite material for medical devices biodegradable and reinforced with nanofibers and a method for producing the same. Medical implants and instruments are orthopedic disposable and surgical instruments such as pins, rods, nails, anchors, screws, plates, staplers, clamps, hooks, clips, etc. Is being used.

Conventional medical implants and instruments made of titanium have been widely used, but they have the disadvantage of requiring a separate secondary procedure for removing them after the bone is completely bonded because they are not biodegradable. In order to solve this problem, various medical implants and instruments made of biodegradable polymers have been proposed.

Specifically, US Pat. No. 4,279,249 proposes a surgical medical device manufactured using poly (lactic acid) or a copolymer thereof as a matrix and poly (glycolic acid) or a copolymer thereof as a reinforcing fiber.

U.S. Patent 4,743,257 proposes a surgical composite material made of the same type of biodegradable polymer using reinforcing fibers or matrices.

U.S. Patent 4,843,112 proposes a bone cement in which a cross-linked biodegradable polymer is used as a matrix, and calcium phosphate ceramic and the like are dispersed therein.

U.S. Patent 4,604,097 proposes a surgical or dental implant made of glass fiber reinforced biodegradable polymer composites.

US Pat. No. 5,108,755 uses ortho esters prepared by the reaction of ketene acetals having two or more functional groups as a matrix, and calcium-sodium metaphosphate fiber as a reinforcing material. It is proposed a biodegradable composite material prepared using.

U.S. Patent 5,468,544 proposes a composite material made of biodegradable polymer reinforced with biocompatible glass fibers or ceramic fibers.

U.S. Patent 5,338,772 proposes a porous composite material for implants in which the matrix of the biodegradable polymer is reinforced with calcium phosphate.

U.S. Patent 5,092,884 proposes a composite material prepared using biodegradable polymers as the matrix and non-degradable fibers.

U.S. Patent 5,578,046 proposes a biodegradable composite material prepared using a biodegradable polymer having a high decomposition rate in a core and a biodegradable polymer having a low decomposition rate in a shell portion.

U. S. Patent 6,171, 338 relates to a cylindrical biodegradable medical device for keeping a tissue cavity open. A helical structure is provided to distribute force evenly in a direction perpendicular to the axial direction. As the reinforcing elements, medical devices using fibers, films, wires, braids, ribbons, nonwoven fabrics, woven fabrics, knitted fabrics, staples, and the like are proposed.

The conventional biodegradable medical instruments described above have the property of naturally decomposing in the human body, but have a lower bending strength and flexural modulus than those of bone and conventional titanium medical instruments.

The present invention seeks to provide a composite material for medical devices that is both excellent in biodegradability, bending strength, and flexural modulus at the same time in order to solve these conventional problems. In addition, the present invention provides an ultra-fine fiber having a diameter of nano-level in the biodegradable matrix (hereinafter " After the nanofibers are mixed with each other, compression molding is performed to provide a composite material for medical devices having excellent biodegradability, bending strength, and flexural modulus at the same time. In another aspect, the present invention is to provide a method for efficiently producing the nanofibers.

1 is a photograph of a nonwoven fabric composed of poly (L-lactide) nanofibers.

FIG. 2 is a photograph of poly (L-lactide) nanofibers (enlarged photograph of FIG. 1)

Figure 3 is a photograph of L-lactide / glycolide copolymer nanofibers

4 is a photograph of a nonwoven fabric composed of cellulose nanofibers

Figure 5 is a photograph of cellulose nanofibers (enlarged photograph of Figure 4)

The composite material for medical devices reinforced with nanofibers of the present invention for achieving the technical problem is a biodegradable nanofibers (reinforcement) of 10 to 90% by volume of the matrix (biotrix) and 10 to 500 nanometers in diameter It is composed of 90 to 10% by volume, the bending strength is 290MPa or more and the flexural modulus is 17GPa or more.

In another aspect, the present invention is to produce a biodegradable nanofibers (reinforcement) of 10 to 500 nanometers in diameter by producing a non-woven fabric composed of nanofiber by electrospinning the biodegradable polymer (ⅰ) the composite material for medical devices. Then, (ii) 10 to 90% by volume of the matrix (Matrix) which is a biodegradable polymer and 90 to 10% by volume of the nanofibers, and then characterized in that the compression molding.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The composite material for a medical device of the present invention has a diameter of 10 to 500 nanometers in a matrix which is a biodegradable polymer and has a composition in which nanofibers made of a biodegradable polymer are mixed as a reinforcing material. At this time, the mixing ratio of the matrix: nanofibers is 10 to 90%: 90 to 10%, more preferably 30 to 70%: 70 to 30% by volume. When the volume ratio of the nanofibers is lower than the above range, the bending strength and the flexural modulus of the composite material may decrease, and when the volume ratio exceeds the above range, the moldability may deteriorate.

In order to improve physical properties and molding processability of the composite material, it is preferable that the aspect ratio of the nanofibers is in the range of 10 ⁴ to 10 ⁸ .

The biodegradable polymers constituting the matrix and the nanofibers are polyglycolide, copolymers of glycolide, glycolide-lactide copolymers, glycolide-trimethylene carbonate aerials. Glycolide-trimethylene carbonate copolymers, Polylactides, Poly-L-lactide, Poly-D-lactide, Poly-DL-lactide (Poly-DL-lactide), L-lactide / DL-lactide copolymer, L-lactide / D-lactide copolymer, polylactide copolymer, lactide-trimethylene glycolide copolymer, lactide -Trimethylene carbonate copolymer, lactide / δ-valerolactone copolymer, lactide / ε-caprolactone copolymer, polydepsipeptide (glycine-DL-lactide copolymer) [Polydepsipeptides ( glycine-DL-lactide copolymer)], polylactide / ethylene oxide copolymer, Asymmetrically 3,6-substituted poly-1,4-dioxane-2,5-diones, poly- β-hydroxybutyrate, poly-β-hydroxybutylate / β-hydroxyvalerate copolymer, poly-β-hydroxypropionate (Poly-β -hydroxypropionate), poly-p-dioxone, poly-δ-valerolactone, poly-ε-caprolactone, copolymers thereof, or blends thereof.

Since the composite material of the present invention is made of a biodegradable polymer, it has biodegradability, and because the ultrafine nanofiber is contained as a reinforcing material, the bending strength and the flexural modulus are very excellent.

Specifically, the bending strength of the human bone is 80 to 120 MPa, the bending strength of the steel is 280 MPa level, but the bending strength of the composite material of the present invention is 290 MPa or more. In addition, the bending elastic modulus of the human bone is 10-17 GPa, but the bending elastic modulus of the composite material of the present invention is 17 GPa or more.

As a result, the composite material of the present invention is molded into various forms such as staplers, hooks, clamps, rods, pins, etc., and is used as hard / soft tissue connective prosthetics, surgical implants, and the like.

Next, a method of manufacturing the composite material of the present invention will be described in detail.

First, after dissolving the biodegradable polymer in a solvent, it is electrospun to prepare a non-woven fabric consisting of nanofibers, and then crushed it to a diameter of 10 to 500 nanometers, shape deformation ratio of 10 ⁴ ~ 10 ⁸ level Biodegradable nanofibers (reinforcements) are prepared.

Next, the composite material of the present invention is manufactured by mixing and compressing the nanofibers prepared as described above and the biodegradable polymer (metrics) described above in a compression molding machine. In this case, the mixing ratio (volume%) of the nanofibers: matrix is 10 to 90%: 90 to 10%, more preferably 30 to 70%: 70 to 30%.

1 is an enlarged photograph of the surface of a nonwoven fabric prepared by dissolving poly (L-lactide) in methylene chloride solvent at 5% and electrospinning at a high pressure of 10 kV at room temperature. FIG. 2 is an enlarged photograph of FIG. 1 with a fiber diameter of about 180 nanometers. 3 is a photograph of nanofibers prepared by dissolving an L-lactide / glycolide copolymer at 12% in methylene chloride solvent and electrospinning at a high pressure of 8 kV at room temperature. FIG. 4 is a photograph of a nonwoven fabric by dissolving cellulose with N-methyl morpholine N-oxide and electrospinning. FIG. 5 is an enlarged photograph of FIG. 4 to show cellulose nanofibers. .

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited only to the following examples.

Example 1

Using a capillary viscometer at 25 ° C using a chloroform solvent, poly (L-lactide) with an intrinsic viscosity of 3.2 was dissolved in methylene chloride to obtain a 4.5% solution. Manufacture. Then, it was electrospun under a high voltage of 10 kV using a nozzle having a nozzle diameter of 1 mm to prepare a nonwoven fabric composed of fibers having an average diameter of 200 nanometers. The prepared nonwoven fabric was pulverized in a press mill (freez mill) under liquid nitrogen and dried at 120 ° C. under vacuum for 12 hours to prepare nanofibers. The nanofibers produced had a length / diameter ratio of 6.5 × 10 ⁵ . Next, poly (p-dioxone) polymer having an intrinsic viscosity of 2.3 measured at 25 ° C. in a hexafluoroisopropanol solvent was ground to a particle size of 300 μm using a freeze mill. Next, a poly (L-lactide) nano reinforced fiber and a matrix of poly (p-dioxanaone) polymer are mixed (nano fiber / matrix = 30 /). 70: by volume ratio), and compression molding under a pressure of 2.5 tons and a temperature of 110 ℃ and then quenched to prepare a composite material. The flexural strength of the manufactured composite material was 320 MPa, the flexural modulus was 18 GPa.

Example 2

Using a capillary viscometer at 25 ° C. with chloroform solvent, poly (L-lactide) with an intrinsic viscosity of 4.5 was dissolved in methylene chloride to give a 3.6% solution. Manufacture. Then, it was electrospun under a high voltage of 8 kV using a nozzle having a nozzle diameter of 0.8 mm to prepare a nonwoven fabric composed of fibers having an average diameter of 160 nanometers. The prepared nonwoven fabric was pulverized in a press mill (freez mill) under liquid nitrogen and dried at 120 ° C. under vacuum for 12 hours to prepare nanofibers. The prepared nanofibers had a length / diameter ratio of 7.5 × 10 ⁵ . Next, poly (p-dioxone) polymer having an intrinsic viscosity of 2.3 measured at 25 ° C. in a hexafluoroisopropanol solvent was ground to a particle size of 300 μm using a freeze mill. Next, a poly (L-lactide) nano reinforced fiber and a matrix of poly (p-dioxanaone) polymer are mixed (nano fiber / matrix = 30 /). 70: by volume ratio), and compression molding under a pressure of 2.5 tons and a temperature of 110 ℃ and then quenched to prepare a composite material. The flexural strength of the manufactured composite material was 340 MPa and the flexural modulus was 19.5 GPa.

Example 3

D, L-lactide-glycolide copolymer [poly (D, L-lactide-co-glycolide), molar ratio: 50 /, having an intrinsic viscosity of 3.8 as measured by a capillary viscometer at 25 ° C. using a chloroform solvent 50] is dissolved in methylene chloride to prepare a 1.2% solution. Then, it was electrospun under a high voltage of 10 kV using a nozzle having a nozzle diameter of 1 mm to prepare a nonwoven fabric composed of fibers having an average diameter of 80 nanometers. The prepared nonwoven fabric was pulverized in a press mill (freez mill) under liquid nitrogen and dried at room temperature under vacuum for 24 hours to prepare nanofibers. The prepared nanofibers had a length / diameter ratio of 8.0 × 10 ⁵ . Next, the particle size of D, L-lactide / glycolide copolymer [poly (D, L-lactide-co-glycolide), molar ratio: 50/50] with an intrinsic viscosity of 0.7 was obtained from a freeze mill. It was ground to 350 μm. Next, poly (L-lactide) was mixed with the nano-reinforced fiber and the matrix (nano fiber / matrix = 25/75: volume ratio), followed by a pressure of 2.5 tons and a temperature of 50 ° C. After compression molding under the temperature was quenched to prepare a composite material. The flexural strength of the manufactured composite material was 300 MPa and the flexural modulus was 18 GPa.

Example 4

Using a capillary viscometer at 25 ° C using a chloroform solvent, poly (DL-lactide) with an intrinsic viscosity of 3.2 was dissolved in methylene chloride to obtain a 5% solution. Manufacture. Then, it was electrospun under a high voltage of 10 kV using a nozzle having a nozzle diameter of 0. mm to prepare a nonwoven fabric composed of fibers having an average diameter of 180 nanometers. The prepared nonwoven fabric was pulverized in a press mill (freez mill) under liquid nitrogen and dried at 120 ° C. under vacuum for 12 hours to prepare nanofibers. The prepared nanofibers had a length / diameter ratio of 7.0 × 10 ⁵ . Next, poly (p-dioxone) polymer having an intrinsic viscosity of 2.3 measured at 25 ° C. in a hexafluoroisopropanol solvent was pulverized in a freeze mill so as to have a particle size of 200 μm. Next, a poly (DL-lactide) nano reinforced fiber and a matrix of poly (p-dioxanaone) polymer are mixed (nano fiber / matrix = 35 /). 65: volume ratio), and then compression molded under a pressure of 2.5 tons and 110 ℃ temperature to quench the composite material. The flexural strength of the manufactured composite material was 325 MPa and the flexural modulus was 19.7 GPa.

Example 5

Using a capillary viscometer at 25 ° C using a chloroform solvent, poly (L-lactide) with an intrinsic viscosity of 3.2 was dissolved in methylene chloride to obtain a 4.5% solution. Manufacture. Then, it was electrospun under a high voltage of 10 kV using a nozzle having a nozzle diameter of 1 mm to prepare a nonwoven fabric composed of fibers having an average diameter of 190 nanometers. The prepared nonwoven fabric was pulverized in a press mill (freez mill) under liquid nitrogen and dried at 120 ° C. under vacuum for 12 hours to prepare nanofibers. The prepared nanofibers had a length / diameter ratio of 6.5 × 10 ⁵ . Next, poly (p-dioxionone) polymer having an intrinsic viscosity of 2.5 measured at 25 ° C. in a hexafluoroisopropanol solvent was pulverized so as to have a particle size of 200 μm using a freeze mill. Next, a poly (L-lactide) nano reinforced fiber and a P-dioxone / glycolide copolymer [poly (p-dioxanone / glycolide), molar ratio = 80/20)] was mixed. (Nano fiber / matrix = 40/60: volume ratio), and then compression molded under a pressure of 2.5 tons and a temperature of 108 ℃ and quenched to prepare a composite material. The flexural strength of the manufactured composite material was 325 MPa and the flexural modulus was 18 GPa.

The composite material for a medical device of the present invention is excellent in biodegradability, bending strength and bending elastic modulus at the same time. In addition, the manufacturing method of the present invention can more efficiently produce nanofibers and the composite material for medical devices.

Claims (6)

It is composed of 10 ~ 90% by volume of matrix, biodegradable polymer, and 90 ~ 10% by volume of biodegradable nanofiber (reinforcement material) with diameter of 10 ~ 500 nanometers. A composite material for medical instruments reinforced with nanofibers. The composite material for a medical device reinforced with nanofibers according to claim 1, wherein the volume% of the biodegradable nanofibers is 30 to 70%. The composite material according to claim 1, wherein the shape ratio of the biodegradable nanofibers is 10 ⁴ to 10 ⁸ . The method according to claim 1, wherein the biodegradable polymers constituting the matrix and nanofibers are polyglycolide, copolymers of glycolide, glycolide-lactide copolymers, glycolide- Glycolide-trimethylene carbonate copolymers, Polylactides, Poly-L-lactide, Poly-D-lactide, Poly- DL-Lactide, L-Lactide / DL-Lactide Copolymer, L-Lactide / D-Lactide Copolymer, Polylactide Copolymer, Lactide-Trimethylene Glycolide Air Copolymer, lactide-trimethylene carbonate copolymer, lactide / δ-valerolactone copolymer, lactide / ε-caprolactone copolymer, polydepeptide (glycine-DL-lactide copolymer Polydepsipeptides (glycine-DL-lactide copolymer), polylactide / ethylene oxide aerial Asymmetrically 3,6-substituted poly-1,4-dioxane-2,5-diones , Poly-β-hydroxybutyrate, poly-β-hydroxybutylate / β-hydroxyvalerate copolymer, poly-β-hydroxypropionate ( Poly-β-hydroxypropionate), poly-p-dioxone, poly-δ-valerolactone, poly-ε-caprolactone, copolymers thereof or blends thereof Composite materials for medical devices reinforced with nanofibers. (Iii) electrospinning the biodegradable polymer to prepare a nonwoven fabric composed of nanofibers, and then grinding it to produce a biodegradable nanofiber (reinforcement agent) having a diameter of 10 to 500 nanometers, and (ii) Matrix (10) to 90% by volume and the nanofibers 90 to 10% by volume, and then compression molding the method for producing a composite material for medical devices. The method for producing a composite material for a medical device according to claim 5, wherein the matrix: volume% of the nanofibers is 30 to 70%: 70 to 30%.