JPH0497753A - Prosthetic material for medical treatment - Google Patents

Abstract

PURPOSE:To reduce possibility of obstruction inside vessels and bacterial infection as caused by leakage of blood in an artificial blood vessel and an artificial trachea by forming a prosthetic material for medical treatment from an unwoven cloth of a biologically absorbable high polymer yarn and a non-biologically absorbable high polymer yarn immediately after the implantation in vivo or onto the surface of a body. CONSTITUTION:A prosthetic material for medical treatment is made up of an unwoven cloth of a biologically absorbable high polymer yarn 2 and a non-biologically absorbable high polymer yarn 1. A yarn 2 as shown by the black line comprising the biologically absorbable high polymer yarn and a yarn 1 as shown by the white line comprising a non-biologically absorbable high polymer yarn are entangled mutually and fixed partially at intersections thereof. A pore of the unwoven cloth which is formed by the non-biologically absorbable high polymer yarn, left after the biologically absorbable high polymer yarn is decomposed to be absorbed in vivo, is at least 110mum, for example, in an average pore diameter at the shaded part, preferably 150-400mum. This allows a granulation tissue to enter into gaps between yarns and forms a tissue in vivo swiftly, thus preferably for the solidification of the prosthetic material for medical treatment in vivo.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to medical prosthetic materials, and more specifically, to the use of body tissues such as the trachea, blood vessels, or heart, and surface tissues such as the skin that have been removed due to lesions, injuries, etc. Related to medical prosthetic materials for repair and repair.

[Conventional technology]

Gauze has been used as a medical prosthetic material for a long time to absorb exudate from the wound surface and prevent the invasion of bacteria from the outside. There was a drawback of giving. There are also cloth-like or tubular medical prosthetic materials made by weaving or knitting polyester or fluororesin threads, but when stopping bleeding after surgery, blood leaks through the weave or stitches. It was necessary to seal the weaves or stitches with blood clots.

In addition, Japanese Patent Application Publication No. 501118/1993 discloses that by using a tubular body of woven fabric with a new weaving pattern of alternating plain weave and twill weave as a medical prosthetic material, it can be made flexible without blood clotting on the surface. Artificial blood vessels with flexibility and flexibility have been introduced.

Furthermore, JP-A-57-1 was used as a medical prosthetic material for artificial trachea to be transplanted after removing the affected area due to laryngeal cancer, bronchial tumor, etc.
No. 15250 describes coagulation on the wall surface of a tubular artificial organ.
Immobilized factor I has been introduced, and by increasing the rate of organization after implantation in the body, an artificial organ without the risk of thrombotic occlusion, ulcer formation, or stenosis has been formed. In addition, artificial tracheas made of silicone are commercially available, which use fiber cloth as a medical prosthetic material on the wall of the spiral wire to prevent the leakage of exhaled air. Japanese Patent Publication No. 60-43981 introduces a method of making an artificial blood vessel using a tubular fibrous body made of a molded nonwoven fabric.

(Problems to be Solved by the Invention) However, medical prosthetic materials for artificial tracheas made of knitted fabrics and non-woven fabrics are low-density products that take flexibility into account, and therefore have insufficient airtightness, making it difficult for outside air to escape from inside the tubular body. There is a high risk of passing through medical prosthetic materials and invading body tissues, causing bacterial infection and inflammation.Also, increasing the density of knitted fabrics and non-woven fabrics, and surface coating can improve airtightness and liquidtightness. If it is raised, it becomes rigid and remains in the body tissue for a long time.There is no invasion of endothelial cells, and it causes damage to surrounding tissues.-1 Silicone artificial trachea emphasizes flexibility, airtightness, and liquidtightness. However, the granulation tissue does not penetrate into the interior of the medical prosthetic material, and the artificial trachea does not integrate with the surrounding body tissues and may deviate from the artificial trachea.

Furthermore, artificial blood vessels made of woven or non-woven fabrics with new patterns have improved flexibility and are easier to handle before being implanted in the body, but once they adhere to the granulation tissue after being implanted in the body, they become less flexible. It is lost, cannot be linked to body movements, does not integrate with surrounding tissues, and is at risk of inflammation.

An object of the present invention is to provide a flexible medical prosthetic material that has a lumen retention force and is airtight immediately after implantation into the body, and which integrates and adheres to living tissue after implantation.

[Means to solve the problem]

The present invention is a medical prosthetic material made of a nonwoven fabric formed by intertwining bioabsorbable polymer threads and non-bioabsorbable polymer threads with each other.

Furthermore, in the medical prosthetic material, the present invention provides pores in which the average pore diameter of the nonwoven fabric formed by the non-bioabsorbable polymer threads remaining after the bioabsorbable polymer threads are absorbed in the body is at least 110μ. is at least 20 in the nonwoven fabric.
% of medical prosthetic materials.

Furthermore, the present invention provides a medical prosthetic material, in which the surface of the nonwoven fabric is coated with protein.

[Effect]

Immediately after implantation into the body, the medical prosthetic material of the present invention is made of a non-woven fabric composed of a bioabsorbable polymer system and a non-bioabsorbable polymer thread, which requires relatively airtightness and liquidtightness, so it is free from bacteria. Although the passage of fine substances through the nonwoven fabric is suppressed,
The bioabsorbable polymer system is gradually decomposed and absorbed within the body, and granulation tissue bites into the threads of the non-bioabsorbable polymer threads of the non-woven fabric, filling in the parts of the threads that have been decomposed and absorbed, forming living tissue. Eventually, a coarse-density nonwoven fabric made only of non-bioabsorbable polymer threads will form a tight composite with biological tissue.

〔Example〕

The present invention will be explained below with reference to Examples.

FIG. 1 is an enlarged plan view of a nonwoven fabric showing an example of the medical prosthetic material of the present invention, and FIG. 2 is a perspective view of an artificial blood vessel formed using the medical prosthetic material of the present invention.

In the figure, the white line 1 indicates a bioabsorbable polymer thread, and the black line indicates a bioabsorbable polymer thread.

FIG. 1 is an enlarged plan view of a medical prosthetic material made of a nonwoven fabric of bioabsorbable polymer threads and non-bioabsorbable polymer threads.

In other words, it is made of a bioabsorbable polymer system! The four-wire thread 2 and the white-line thread 1 made of non-bioabsorbable polymer thread are intertwined with each other and partially immobilized at their intersections.

Nonwoven fabrics are produced by spinning bioabsorbable polymers and non-bioabsorbable polymers through different nozzles with static electricity, air currents, or liquid streams, and then dispersing the fibers on a conhair or on the surface of a rotating cylindrical or cylindrical mandrel. Then, the fibers dispersed in a plane are partially fixed in the cross-sectional direction by a physical method such as a kneeling method or a water jet method. As a method for bonding the fibers, the intertwined points of the fibers can also be fixed by attaching the intertwined points between the fibers by heat, or by a chemical method such as chemical treatment or solvent treatment. Further, the nonwoven fabric dispersed on the surface of the mandrel becomes a tubular nonwoven fabric by removing the mandrel.

In the first section, the structure of the nonwoven fabric was explained using long fibers, but a nonwoven fabric made of short fibers may also be used, and the nonwoven fabric may be formed into a tubular or planar shape.

The average pore diameter of the pores of the non-woven fabric formed by the non-bioabsorbable polymer threads remaining after the bioabsorbable polymer threads are decomposed and absorbed in the body, for example, the shaded area in FIG. 1, is preferably at least 110 μ-1. It is preferable that the amount is 150 to 400 μm in order for the granulation tissue to invade the spaces between the threads to quickly form body tissue and to fix the medical prosthetic material in the body.

At least 20 pores with an average pore diameter of at least 110 μm are formed by non-bioabsorbable polymer threads in the nonwoven fabric.
%, preferably 40 to 70%, the medical prosthetic material is firmly fixed to the body tissue. If the average pore diameter formed by the non-bioabsorbable polymer thread is less than 110 μ-, it becomes difficult for granulation tissue to penetrate between the fibers, making it difficult for the fibrous tissue to be immobilized in the body.

Monofilaments are usually used as bioabsorbable polymer threads and non-bioabsorbable polymer threads, but multifilaments may also be used.

Non-bioabsorbable polymer threads include polyesters such as polyethylene terephthalate, polyolefins such as polypropylene and polyethylene, polyamides such as nylon 6 and nylon 66, and fluorine-based polymers such as polyethylene fluoride and polyvinylidene fluoride. , chlorine-based resins such as polyvinyl chloride and polyvinylidene chloride, threads made of polyurethane, cellulose-based semi-synthetic fibers, and natural fibers.

Bioabsorbable polymer threads include polylactide, polyglycolic acid, polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, polyamino acids, polycaprolactone, polydioxanone and copolymers thereof, ethylene-carbon oxide copolymers, cellulose derivatives or their Examples include threads made of copolymers, vinyl acetate and unsaturated carboxylic acid copolymers, and the like.

The fiber diameter of the non-bioabsorbable polymer yarn is 0.1-80μ, preferably 1.0-40μ. Fiber M diameter is 80
If it exceeds μ, the nonwoven fabric becomes stiff and tends to cause inflammation when implanted into the body, and if it is less than 0.1μ, it tends to be difficult to mold the fiber. The bulk density of the non-woven fabric made of non-absorbable polymer yarn is 0.
．． 0.005 to 0.60 g/am. In general, the bulk density of nonwoven fabrics varies depending on the use, and for artificial blood vessels and artificial tracheas, the bulk density is 0. ] 0-0.6 h nod 0.005-0.
It is 15g/d. Bulk density of non-woven fabric is 0.60g/cd
If the nonwoven fabric exceeds this amount, the nonwoven fabric tends to become stiff and tends to cause inflammation when implanted into the body. Bulk density is 0.005
If it is less than g/c4, the mechanical properties of the nonwoven fabric tend to deteriorate.

The thickness of the nonwoven fabric is at least 0.1 brocade, preferably 1 to 1
It is 0 kaku. If the thickness of the nonwoven fabric is less than 0.1 m, durability tends to deteriorate.

By coating the surface of a nonwoven fabric made of bioabsorbable polymer threads and non-bioabsorbable polymer threads with protein, it is possible to promote bioadhesion on the surface of a medical prosthetic material and maintain airtightness.

Examples of proteins include collagen, gelatin, albumin, fibrinogen, globulin, and fibronectin.

To coat the surface of a nonwoven fabric with a protein coating, the nonwoven fabric is immersed in a protein solution, rinsed several times with water at room temperature, and dried to form a coating.

The nonwoven fabric has a tensile elongation of at least 5%, preferably from 10 to
It is 25%. In particular, cylindrical objects that are subject to internal pressure, such as artificial blood vessels and artificial tracheas, have a certain degree of elongation and have different characteristics from medical prosthetic materials made of textiles.

FIG. 2 shows an artificial blood vessel formed using the medical prosthetic material of the present invention, in which, for example, a bioabsorbable polymer thread and a non-bioabsorbable polymer thread are placed together with a fluid from the outside of a rotating cylindrical support. A tubular body made of a non-woven fabric of bioabsorbable polymer threads and non-biobitable polymer threads is produced by spraying from a nozzle on the outer surface of the support.

The outer surface of the tubular body may be coated with a coating of protein such as collagen or gelatin, and the inner surface may be coated with a coating of antithrombotic material.

When such an artificial blood vessel is incorporated into the body, the bioabsorbable polymer thread, which is one of the constituents of the nonwoven fabric that makes up the tubular body, breaks down the main chain of the polymer over time, decomposes, and is absorbed by the living body. At the same time, the granulation tissue bites into the voids of the non-bioabsorbable polymer threads, and the artificial blood vessel is tightly fixed to the living tissue.

Artificial blood vessels, which were initially required to be airtight and liquid-tight, had a high density and were rather rigid, but as the bioabsorbable polymer thread was absorbed within the body, the artificial blood vessels became flexible. Disorders caused by foreign substances entering the body are alleviated, and inflammation does not occur.

In addition, for example, the skeleton has an inner diameter of 20 to 30 mm and a length of 10 mm.
~50 kaku, thickness 0. An artificial trachea is formed by covering the outer surface and/or inner surface of the body of the porous cylindrical body made of fluororesin bw with the medical prosthetic material of the present invention. For example, an artificial trachea is formed by covering the skeleton of the artificial trachea with a tubular body made of a nonwoven fabric of bioabsorbable polymer threads and non-bioabsorbable polymer threads. The external surface of the nonwoven may be coated with a protein coating such as collagen or gelatin.

The artificial trachea originally transplanted into the body is made of high-density non-woven fabric, so it maintains an airtightness to prevent exhaled air and air from escaping, and it works effectively as an artificial trachea and has good liquid-tightness, so it can prevent external bacteria from escaping. will not pass through the nonwoven fabric and cause bacterial infection. Gradually, the bioabsorbable polymer threads that make up the nonwoven fabric are decomposed and absorbed within the body, and granulation and
The No. 11 weave bites into the voids of the remaining non-bioabsorbable polymer threads and is tightly fixed to the living tissue, forming a flexible composite.

Furthermore, the medical prosthetic material of the present invention can be used as a cultured skin that permanently engrafts on a patient with a skin defect using the patient's own skin cells.

When a planar nonwoven fabric made of bioabsorbable polymer threads and non-bioabsorbable polymer threads is applied to the wound surface, it is possible to absorb exudate from the wound surface and prevent the invasion of bacteria from the outside. Then, the bioabsorbable polymer threads that make up the nonwoven fabric are decomposed and bioabsorbed, and the granulation tissue bites into the voids of the non-bioabsorbable polymer threads, making it a flexible artificial skin that is closely fixed to the living tissue. is formed. An antibacterial agent may be applied to the wound side of the planar nonwoven fabric to prevent bacterial growth.

Examples 1 to 5 Polyethylene terephthalate (hereinafter referred to as PET) and polyglycolic acid (hereinafter referred to as PGA) were spun using a water jet from different nozzles, and the diameter of the PET fiber was 4.
PGA fibers with a diameter of 1.3 μm and a diameter of 38.4 μm were collected on a conveyor and formed into a nonwoven fabric with a thickness of 1.6 μm and a bulk density of 0.12 g/cd by needling.

The mixing sound of PET fibers and PGA fibers was variously changed so that the average pore diameters formed by PET fibers were as shown in Table 1. Colladev 10% by weight was applied to the surface of the obtained nonwoven fabric.
An aqueous solution was applied and dried, and the nonwoven fabric was implanted subcutaneously on the back of a dog for 6 weeks, and the embedding status of the nonwoven fabric was visually evaluated as described below.

The results are shown in Table 1.

O The granulation tissue has penetrated well into the voids of the non-woven fabric and the non-woven fabric is fixed to the body tissues Δ The granulation tissue has invaded the voids of the non-woven fabric, but the non-woven fabric is easily peeled × To the voids of the non-woven fabric of the granulation & Il fabric Comparative Example 1 in which no intrusion was observed Using only the PET fibers used in Example 1 with the nonwoven fabric shown in Figure 1, the average pore diameter formed by the PET fibers was 92 μm.
The nonwoven fabric shaped into a shape of m was implanted subcutaneously on the back of a dog in the same manner as in Example 1, and the implantation status after 6 weeks is shown in Table 1.

Table 1 As is clear from Table 1, in the nonwoven fabric of Comparative Example 1 in which the pore diameter formed by the PET fibers was less than 100 μm, no intrusion of granulation &i1m was observed in the fiber pores, and the pore diameter was 1
In the nonwoven fabric of Example 5 with a thickness of 0.8 μm, intrusion of granulation tissue into the fiber pores was observed, but it seems that a long period of time is required for the nonwoven fabric to be fixed to body tissues.

〔effect〕

Immediately after implantation into the body or on the body surface, the medical prosthetic material of the present invention is made of a non-woven fabric of bioabsorbable polymer threads and non-bioabsorbable polymers, so it has a high density and absorbs the pores of the fibers into blood, tissue cells, etc. The passage of bacteria is suppressed, and for example, in artificial blood vessels and artificial tracheas, concerns about intraductal blockage and bacterial infection due to blood leakage are significantly reduced.

Then, as time passes, the bioabsorbable polymer threads are broken down in the body and absorbed into the body, and are replaced by granulation &
The fabric penetrates into the spaces between the bioabsorbable polymer threads and is tightly fixed to the living tissue, so that the medical prosthetic material is incorporated into the living body tissue and stabilized.

[Brief explanation of drawings]

Claims (3)

[Claims] (1) A medical prosthetic material made of a nonwoven fabric formed by intertwining bioabsorbable polymer threads and non-bioabsorbable polymer threads with each other. (2) A claim that at least 20% of the pores in the nonwoven fabric, which are formed by non-bioabsorbable polymer threads remaining after the bioabsorbable polymer threads are absorbed in the body, have an average pore diameter of at least 110 μm. The medical prosthetic material according to item 1. (3) Claim 1, wherein the surface of the nonwoven fabric is coated with protein.
Or the medical prosthetic material according to 2.