KR101730482B1 - Protective shield of bodily tissue - Google Patents

Abstract

A method for manufacturing artificial bodys for body tissue protection and the artificial bodys are provided.
The artificial tissue for body tissue protection,
(1) forming a polyolefin film having two or more layers;
(2) pinning and fixing the fins densely at regular intervals on the edge of the polyolefin film, and then stretching while heating at a temperature of 350 to 380 DEG C to modify the surface while imparting a high density pore size;
(3) a step of superimposing two or more layers of the surface-modified polyolefin film between the jigs of the planar structure and then bonding them under pressure to form a laminated structure.

Description

Protective shield of bodily tissue < RTI ID = 0.0 >

TECHNICAL FIELD The present invention relates to a method of manufacturing artificial bodys for body tissue protection and artificial bodyshells, and more particularly, to artificial bodyshells having a high density pore size and high tensile strength characteristics. The present invention is the result of the research carried out by the Small and Medium Business Administration in cooperation with the Ministry of Education, Culture, Sports, Science and Technology (project number: C0198940).

It is expected that the incidence of neck (spinal disc) patients will increase due to the long time use of smartphone or computer, and the attitude of going to the back of the neck and back among the lifestyle of modern people. In view of the above situation, sheet products for the protection of blood vessels and nerve tissue at the application site, ease of operation, shortening of operation time and recovery time of patient in disc surgery with frequent reoperations in spine special hospitals, .

The sheet product can reduce the foreign body feeling with the surrounding tissues to a maximum extent at the body application site and provide a strong tensile strength that does not tear even when the strong pressure inside and the strong external pressure caused by the post- It can protect the application site.

Accordingly, the sheet product is required to have a high tensile strength and a high pore size while being thin. However, conventional products have a large foreign body feeling due to excessive thickness, It is necessary to develop a sheet product having a high tensile strength while having a uniform thickness and a high density of uniform pores.

The object of the present invention is to provide a method for manufacturing artificial bodys for body tissue protection having a uniform thickness and high density of uniform pores and a high tensile strength, and a method for fabricating the same.

According to an aspect of the present invention,
(1) forming a polyolefin film having two or more layers;
(2) pinning and fixing the fins densely at regular intervals on the edge of the polyolefin film, and then stretching while heating at a temperature of 350 to 380 DEG C to modify the surface while imparting a high density pore size;

(3) preparing a laminate structure by superimposing two or more layers of the surface-modified polyolefin film between jigs having a planar structure, and bonding the laminate structure under pressure.

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The artificial bodyshell according to the present invention can be densified by adjusting the pore size more densely and has a high tensile strength even at a thin thickness, so that it is possible to reduce shrinkage due to external pressure or shear stress. Therefore, it can be effectively used for protecting blood vessels and nerves at the time of surgery, for example, at the time of spinal surgery, and its manufacturing method is simple and economical efficiency is improved, so that mass production at a lower price becomes possible.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a schematic representation of an apparatus for the stretching process of a polyolefin film according to the invention.
Figure 2 shows a schematic view of an apparatus for the lamination process of a polyolefin film according to the invention.
Fig. 3 shows a surface SEM photograph of the polytetrafluoroethylene film surface-modified in Example 1. Fig.
4 is a SEM photograph of the surface of the artificial tissue for protecting body tissue obtained in Example 1. Fig.

Hereinafter, the present invention will be described in more detail.

The artificial bodyshell according to the present invention is obtained by bonding two or more surface-modified polyolefin films with a high density pore size of 1.0 micron or less and a thickness of 0.3 to 1.0 mm and a tensile strength of 500 to 2,000 psi .

The artificial tissue for protecting the body tissue is densified by densely adjusting the pore size to 1.0 micron or less and has a high tensile strength of 500 to 2,000 psi even at a thin thickness of 0.3 to 1.0 mm so that the reduction due to external pressure or shear stress It is possible to reduce the phenomenon. Therefore, it can be usefully used as an artificial tissue for protecting blood vessels or nerves during surgery, for example, in spinal surgery of human beings or animals.

The artificial bodyshell according to the present invention is obtained by bonding two or more surface-modified polyolefin films to a usable polyolefin film. For example, the polyolefin film is mixed with the polymer at the melting temperature of the mixture, Melting the polyolefin with the resulting additive, cooling the formed layer at the rate and temperature at which non-equilibrium separation is initiated from the mixed solution, and cooling and solidifying the layer.

The polyolefin used for producing the polyolefin film is preferably a polymer of ethylene and propylene, and may be a polymer such as 1-octene, 1-butene, 1-methyl-4-pentene or styrene, Specific mixtures of the above polymers, such as copolymers or mixtures of two or more of the above olefins containing segments, and mixtures of isotactic polypropylene with atactic polypropylene, isotactic polystyrene and atactic polystyrene, And polytetrafluoroethylene is more preferable.

The additive to be mixed with the polyolefin is a material capable of forming a solution having a thermoplastic polymer when heated to a temperature above the melting temperature of the polymer, and a material that is separated from the polymer upon cooling can be used.

In one embodiment of the present invention, the polyolefin film may have a thickness of about 0.01 to 0.02 mm and may have an average pore size of about 0.1 to 0.3 microns. Such a polyolefin film can be stretched in at least one direction as required.

In one embodiment of the present invention, the polyolefin film may be purchased by using a film having a predetermined pore size and thickness. For example, the polyolefin film may have an average pore size of 0.1 to 0.3 microns and a thickness of 0.01 to 0.02 mm A polyolefin film of polytetrafluoroethylene can be used. Such a polyolefin film may be purchased from, for example, PTFE Membrane (IPE, USA).

The artificial tissue for protecting a body tissue according to the present invention is obtained by bonding two or more layers of the above-mentioned polyolefin film, and the surface modification treatment is performed for such bonding.

The surface modification process is performed by sintering the polyolefin film at a temperature of about 350 to 380 ° C, for example, performing corona treatment or the like. By such a heat treatment, the polyolefin film can be given adhesiveness required for lamination. Such a corona treatment process may be carried out under a voltage of, for example, 15 to 50 V, or 25 to 30 V for about 1 to 10 minutes, or about 3 to 4 minutes, and if necessary, repeated 2 to 5 times . (The numerical range above is further expanded.)

In the surface modification step, an expansion process may be performed together to increase the porosity of the polyolefin film. As shown in Fig. 1, the stretching treatment is performed by densely pinning the edges of the polyolefin film at regular intervals, for example, at intervals of about 3 to 10 mm, or 5 to 6 mm, To give a desired pore size, and it is possible to uniformly give an average pore size of, for example, 1.0 micron or less, or 0.1 to 0.5 micron, or 0.1 to 0.7 micron.

By the surface modification described above, the polyolefin film can be imparted with an adhesive force, and the polyolefin film having two or more layers can be laminated. Such a lamination process can be performed by applying a mechanical external pressure, and a laminated structure having a constant thickness is obtained by giving a uniform adhesive force between the films. In such a lamination step, as shown in Fig. 2, a polyolefin film having two or more layers, for example, 5 to 50 layers, or 20 to 30 layers, is disposed between jigs having a planar structure, It is possible to uniformly press the jig to maintain uniform adhesive force and tensile strength on each film.

The laminating step may be performed at a temperature of, for example, about 250 to 350 DEG C, or 270 to 300 DEG C for about 15 to 20 minutes, and the pressure applied by the pressure holding device may be, for example, 0.1 to 0.2 kPa Stainless steel or the like may be used as the jig, but the present invention is not limited thereto.

The artificial tissue for protection of the body tissue obtained by the laminating step may have a thickness of, for example, 1 mm or less, or 0.1 to 0.5 mm, depending on the number of polyolefin films used and the magnitude of external pressure applied .

The artificial bodyshell of the present invention as described above can be densified by adjusting the pore size more densely and has a high tensile strength even at a thin thickness so as to reduce shrinkage due to external pressure or shear stress It is possible. Therefore, it can be usefully used in various fields such as surgery for a human or animal body, for example, protection of blood vessels or nerves during spinal surgery, substitution of peritoneum, artificial blood vessels, implants for cosmetic molding, Since the economical efficiency is improved by this simple method, it becomes possible to mass-produce at a lower price.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but it should be understood that the technical scope of the present invention is defined by the appended claims.

Example 1

- polyolefin film

A polytetrafluoroethylene film (PTFE Membrane, manufactured by IPE) having an average pore size of 0.1 micron, a size of 150 X 150 mm, and a thickness of 0.0125 mm was purchased and used.

Surface Modification and Stretching Process

As shown in Fig. 1, the fins were fixed to the edges of the polytetrafluoroethylene film at intervals of 6 mm, and then stretched in both directions with a tensile force of 5 to 10 psi while being heated at a temperature of 370 DEG C for 15 minutes.

An SEM photograph of the formed polytetrafluoroethylene film is shown in Fig. As can be seen from FIG. 3, the average pore size of the film is about 1 micron.

- bonding process

Using the apparatus as shown in Fig. 2, the surface-modified polytetrafluoroethylene film layers 25 to 30 were superimposed on each other, placed in a stainless steel filament, and the external pressure of the film itself was adjusted to 15 Min at < RTI ID = 0.0 > 300 C < / RTI > to form the artificial tissue for body tissue protection.

A photograph of the surface SEM of the formed artificial tissue protective body is shown in Fig.

Experimental Example 1

The apparent density, average pore size and tensile strength of the artificial bodys for body tissue protection obtained in Example 1 were measured as follows, and the results are shown in Table 1 below.

- Apparent density

KS M ISO 845: 2012.

- average pore size

ASTM F 316: 2003.

- The tensile strength

ASTM D 412: 2006.

division Apparent density
(g / cm ³⁾ Average pore size
(탆) The tensile strength
(psi) MD CD Example 1 0.952 0.4 1640 910

As shown in Table 1, the artificial bodyshell according to the present invention has a small average pore size of 0.4 micron, a high density, and a very high tensile strength.

Experimental Example 2

The artificial respiration protection agent obtained in Example 1 was tested for toxicity for ensuring biological safety and for ensuring effectiveness against aseptic test as follows.

- Biosafety test according to ISO 10993 and aseptic test according to the Korean Pharmacopoeia (Korea Food and Drug Administration, 2013-64, 2013. 4. 5)

- Cytotoxicity test, skin sensitization test, skin irritation test, systemic toxicity (acute) test and genotoxicity test (return mutation test, micronucleus test and chromosome aberration test)

- cytotoxicity test

A test for determining the effect on the cell based on the degree of cell lysis (cell death) and the inhibition rate of cell growth by using the cell culture technique

- intradermal reaction test

Test for confirming intradermal reaction of the finished product and raw materials or their eluates to the experimental animals (rabbits).

- systemic toxicity (acute) test

Tests to assess the potential for adverse systemic reactions to occur in finished products and raw materials or their eluents

- exothermic test

Tests to determine the presence of pyrogenic substances in experimental animals (rabbits) subject to finished products and raw materials or their eluates

- skin irritation test

Tests to determine the potential for irritation of the skin of finished products and raw materials or their effluents to laboratory animals (rabbits).

- Skin sensitization test

Tests to determine the potential of allergy to the finished product and raw materials or their eluates for experimental animals (guinea pig)

- Genotoxicity test (microbial return mutation test)

Tests for evaluating gene mutations, chromosome structure and number changes, DNA or genotoxicity by finished products and raw materials or their eluents

- Aseptic test

The Korean Pharmacopoeia (10th revision) This is a test for evaluating the suitability of sterilization for finished products and raw materials according to the aseptic test method. The test substance is immersed and cultured directly in the medium to confirm whether or not the bacteria are produced.

(1) Testing for biological safety

Specimen thickness and shape Surface area (both sides) or weight Extraction solvent amount Elution condition Less than 0.5 mm 120 cm ² 20 mL 35 to 39 占 폚, 70 to 74 hours

Test Items Test basis Test Methods Aseptic test It shall be suitable for testing according to the test method. It shall be tested according to the aseptic test method in the General Test Methods of KIPO. Cytotoxicity test
(Elution method) It shall be suitable for testing according to the test method. It is tested according to ISO 10993-5, cytotoxicity test (elution conditions: MEM 37 ° C, 24 hours) Intradermal reaction test It shall be suitable for testing according to the test method. Test according to ISO 10993-10, Intracutaneous (Intradermal) Reactivity test. Acute toxicity test It shall be suitable for testing according to the test method. Test according to ISO 10993-11, Tests for systemic toxicity. Pyrogenicity test It shall be suitable for testing according to the test method. Test according to ISO 10993-11, Pyrogen test. Skin irritation test It shall be suitable for testing according to the test method. Test according to ISO 10993-10, Animal imitation test. (Direct application) Skin Sensitization Test It shall be suitable for testing according to the test method. Test according to ISO 10993-10, Maximization sensitization test. Genotoxicity test
(Microbial return mutation test) It shall be suitable for testing according to the test method. Test according to ISO 10993-10, Test for genotoxicity.
According to OECD Guideline 471.

(2) Test results

Test Items Reference value Results Judgment Aseptic test fitness fitness fitness Cytotoxicity test (elution method) fitness Grade 0
(Noncytotoxic) fitness Intradermal reaction test fitness (a) fitness Acute toxicity test fitness (b) fitness Pyrogenicity test fitness (c) fitness Skin irritation test fitness (d) fitness Skin Sensitization Test fitness (e) fitness Genotoxicity test
(Microbial return mutation test) fitness voice fitness

Specimen preparation conditions

Cytotoxicity ^{test: 120 cm 2/20 mL,} 37 ℃, 24 sigan

Biological ^{test: 120 cm 2/20 mL,} 37 ℃, 72 sigan

(a) As a result of the intradermal test, no erythema or edema was observed in NZW rabbits, the difference between the test substance and the control substance was calculated to be less than 1.0 "".

(b) As a result of acute toxicity test of this sample to ICR mouse, no systemic toxicity change was observed within 72 hours after administration.

(c) As a result of exothermicity test of this specimen for NZW rabbit, no animal showing a rise in body temperature of 0.5 ° C or higher was observed, and it was evaluated as a pyrogenic substance negative.

(d) Skin irritation test of this sample against NZW rabbit did not induce erythema, scarring and edema, and it is judged to be non-stimulant.

(e) Sensitization test results of Dunkin Hartley guinea pigs were evaluated as a weak skin sensitizer because they did not cause skin reaction after sensitization.

Claims (9)

delete delete delete delete delete delete (1) forming a polyolefin film having two or more layers;
(2) pinning and fixing the fins densely at regular intervals on the edge of the polyolefin film, and then stretching while heating at a temperature of 350 to 380 DEG C to modify the surface while imparting a high density pore size;
(3) a step of superposing the surface-modified polyolefin film in two or more layers between jigs having a planar structure and then bonding the laminate structure under pressure to form a laminated structure; and 8. The method of claim 7,
While the polyolefin film is mixed with the polymer at the melting temperature of the mixture, the polyolefin is melt mixed with the additives causing phase separation upon cooling, and the layer formed at the rate and temperature at which non-equilibrium separation is initiated from the mixed solution is cooled And then solidifying the layer by cooling the layer. The method for producing a human body protective fabric 9. The artificial tissue for body tissue protection as claimed in claim 7 or 8.

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