JPH01110366A - Artificial tubal organ - Google Patents

Abstract

PURPOSE:To improve the bio-compatibility of an artificial tubal organ, by covering a hollow base made of a bio-compatible dense material with collagen fibers with bio-compatibility. CONSTITUTION:A hollow base 2, composed of glass ceramics containing CaO, P2O5, MgO, Al2O3, SiO2, etc., has a recess 2a in the middle thereof which is thermally or mechanically made. The hollow base 2 is bent with heat of oxyhydrogen flame in the direction opposite to the recess 2a, and a short base 2b of the same composition is welded into the recess 2a. After welding, the whole body 2 and 2b is heat-treated at 850 deg.C or above to make a crystalline layer 3 of calcium phosphate (apatite) deposit on the surface of the bases 2 and 2b. The whole body 2 and 2b is further spray-coated with beta-TCP (tricalcium phosphate) layer 4, is sintered at 750 deg.C or above, and is then covered with collagen fibers 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to artificial lumen organs such as an artificial trachea and an artificial esophagus.

[Conventional technology]

Artificial tracheas are made of materials such as Teflon (trade name), Marlex mesh (trade name), Silastic tube (trade name), and stainless steel. Glass tubes, vinyl tubes, and nylon tubes are proposed as nonporous tubes. Good results were not obtained due to deformation and slippage of the hoop tube, but good results were subsequently obtained by using a silicone rubber polyethylene tube with a non-slip layer made of copper wire. As mesh methods for epithelial regeneration, proposals have been made such as stainless steel wire mesh, nylon mesh, and saran polyethylene mesh.

Regarding artificial esophagus, the stomach, colon, skin tube, etc. are transplanted for reconstruction after cervical esophagectomy, and the stomach, colon, and sometimes the small intestine are used for reconstruction after thoracic esophagectomy. The jejunum and stomach are used for reconstruction after volume resection.

By the way, the following conditions are imposed on the artificial trachea. ■
Must be completely airtight. This is because the trachea is a passageway for air, so there must be no air leakage from the material. In particular, because the pressure inside the thoracic cavity is decompressed, even the slightest hole can cause a large amount of air to leak, resulting in pneumomediastinum, which can be fatal. ■It is necessary to maintain the inner cavity by giving the material a certain amount of support.

■The tracheal wall has many secretory glands that serve as a defense mechanism for the airways, and a large amount of secretory fluid flows through ciliary movement, so the material must not impede this flow.

■If the material does not have sufficient tissue affinity, it will be difficult to incorporate it into the tracheal wall and stabilize it.

Like the skin, when artificial materials that are foreign substances are used in areas that face the outside world, a healing mechanism works to remove the foreign substances to the outside world.

[Problem that the invention seeks to solve]

However, artificial tracheas using conventional materials lack one or more of the above requirements. In particular, the above-mentioned condition (1), tissue compatibility, could hardly be satisfied with conventional materials.

Furthermore, conventional materials have poor heat resistance, so they cannot be sterilized using dry heat at temperatures above several hundred degrees.

The present invention has been made to eliminate these drawbacks, and aims to provide an artificial hollow organ that satisfies the above conditions and is particularly compatible with living tissue.

[Means for solving problems]

In order to achieve the above object, the artificial hollow organ of the present invention is one in which the surface of a hollow base body made of a dense material having tissue affinity is coated with collagen fibers having tissue affinity.

[For production]

In such an artificial hollow organ of the present invention, the base itself does not have tissue affinity, and the collagen coated on the outside has strong biocompatibility.
When it comes into contact with living organisms, it can be stabilized with living organisms due to its extremely high affinity for fibers. Furthermore, since the base has a dense structure, airtightness is maintained.

〔Example〕

FIG. 1 shows an embodiment of an artificial lumen organ according to the present invention, and in this example, it is constructed as an artificial trachea. The base of the artificial trachea 1 is a hollow tubular main body 2 made of glass ceramic with a dense structure, an apatite layer 3 having tissue affinity deposited on the surface by heating the glass ceramic main body, and an apatite layer 3 having a tissue affinity formed on the surface. β-T CP (Tr
icalciumPhosphate: Caz(PO
<)z) Consisting of a layer 4, a collagen fiber layer 5 is coated on the surface of this substrate.

A ring 6 is provided at the tips of the three branches of the artificial trachea 1, and this ring is also constructed by covering the surface of a tissue-compatible substrate with a fibrous collagen layer. Such a ring 6 is useful when the artificial trachea l is placed in the body.

As mentioned above, in this example, the substrate 2.3 with high tissue affinity is used.
．． Since the surface of the artificial trachea 4 is coated with a fibrous collagen layer 5 which also has high tissue affinity, the tissue affinity of the artificial trachea 1 is significantly increased, and it is stably retained in the body. Furthermore, since the main body 2 is made of glass ceramic having the same density as artificial bone, sufficient airtightness is obtained, mechanical strength is high, and workability is also good.

Furthermore, since the glass ceramic body 2 has high heat resistance, high temperature sterilization is possible.

Next, the manufacturing process of such an artificial tube 1 will be explained with reference to FIGS. 2 to 7. First, a hollow main body 2 as shown in FIG. 2 is prepared. The main body 2 is made of a glass ceramic material on which calcium phosphate crystals are deposited on the surface by heat treatment. This glass ceramic is Ca
b, Pz05* MgO+A j! toz, Si
When heat-treated at 850° C. or higher and subjected to X-ray diffraction, it was confirmed that abaphyte crystals were precipitated. FIG. 7 is an enlarged cross-sectional view showing the surface structure after heat treatment, in which minute irregularities are formed on the outer surface of the main body 2 made of glass ceramics, and an apatite crystal layer 3 is deposited on the surface.

Next, as shown in FIG. 3, the intermediate portion 26 is removed thermally and mechanically, and the opposite side is heated with an oxyhydrogen flame burner and bent to form another short body 2b having the same structure as shown in FIG. Weld it to the shape shown in Figure 5.

After welding, the entire body is heat-treated to deposit a calcium phosphate (apatite) crystal layer 3 on the surfaces of the bodies 2, 2b. FIG. 6 shows the state in which a β-TCP (recalcium phosphate) layer 4 was further spray-coated on the surface of the apatite N3 precipitated in this manner and bonded by firing at a high temperature of 750° C. or higher. In the experiment, good results were obtained when β-TCP powder was emulsified with ammonium polyacrylate salt and water, coated with a spray gun, and baked at 800 degrees for 2 hours.

The surface of the base thus constructed is covered with a fibrous collagen layer 5 or the like. In experiments, good results were obtained when collagen was coated with a dilute solution of 7% polyphosphoric acid.

After having been constructed in this way, a ring 6 for coupling with the biological trachea is attached to each branch tip of the artificial trachea l. This is to serve as a locking part when the biological trachea is placed over the tip of the branch and then tied up, or to be used as a binding part if the ring surface is formed to prevent slipping. Needless to say, collagen must be adhered and fixed to the surface.

When the artificial trachea of the present invention was compared with one using a conventional silicone tube, the latter was found to be of size 16III1.
1. A device configured with a length of 40 mm was successively sutured and transplanted to the cervical trachea of two adult mongrel dogs where 6 tracheal rings had been removed.
Endoscopic observation was performed every month, and from the second month onwards, granulation formation in the lumen, ulcer formation, and deformation due to lack of support force were observed. At the fourth month, the granulation rate increased, and good results could not be obtained as an artificial trachea.

On the other hand, no abnormality was observed in the cells according to the present invention that had passed for 6 months or more after transplantation.

The artificial luminal organ of the present invention can also be configured as an artificial esophagus. In this case, after mirror-finishing the inner surface, a collagen layer is adhered and fixed to the base surface in the same manner as in the case of the artificial trachea described above. When the artificial esophagus of the present invention and the conventional silicone rubber tube were compared in the esophagus of a rabbit, the latter fell off after 3 weeks, but the artificial esophagus of the present invention showed no abnormality even after 6 months. It matched with living tissue.

The present invention is not limited to the embodiments described above, but can be modified in many ways. For example, the material of the substrate and the surface structure of the substrate before collagen attachment may be appropriately selected, and the glass ceramics need not be heat-treated to precipitate calcium phosphate. Additionally, a β-702 layer was deposited on top of the calcium phosphate layer, but this is also not necessary.

〔Effect of the invention〕

As described above, according to the present invention, the tissue affinity can be dramatically improved by forming the base surface of the artificial hollow organ from a calcium phosphate material such as β-TCP or hydroxyapatite.

Furthermore, by coating the top with collagen fibers, we were able to achieve stability with living organisms without causing antigen-antibody reactions. Furthermore, by forming the base body from glass ceramics, it is not only airtight, but also has workability similar to that of metal, and can be dry heat sterilized at temperatures of several hundred degrees or higher.

[Brief explanation of the drawing]

FIG. 1 is an overall view showing an embodiment of the artificial trachea of the present invention, FIGS. 2 to 6 are views showing the manufacturing process thereof, and FIG. 7 is an enlarged sectional view showing the surface structure of the base body. 1...Artificial trachea 2...Glass ceramic body (substrate) 3...Apatite crystal layer (substrate) 4...β-702 layer (substrate) 5...Collagen layer Patented Izushiojin Olympus Optical Industry Co., Ltd. Procedures Amendment Book January 9, 1986 Director General of the Patent Office Kunio Ogawa 1. Indication of the case 1988 Patent Application No. 268124 2. Name of the invention Artificial luminal organ 3. Person making the amendment Relationship to the case Patent applicant (037) Olympus Optical Industry Co., Ltd. 4, Agent 5, Subject of amendment 1, “Stabilizing” on page 3, line 3 of the specification is “stabilizing” Correct to. 2. "Artificial tube 1" on page 5, line 17 of the same page is replaced with "artificial trachea 1."
Correct to. 3. Change "middle part 26" on page 6, line 10 to "middle part 2a".
” is corrected. 4. In the 19th line of page 8, correct the phrase "you should do it again" to "you should do it again."

Claims (1)

[Scope of Claims] 1. An artificial hollow organ characterized in that the outer surface of a tubular base body made of a dense material having tissue affinity is coated with fibrous collagen. 2. The artificial hollow organ according to claim 1, wherein the base body contains a calcium phosphate type material.