Tissue reinforcing material

Abstract

To provide a tissue reinforcement material capable of reinforcing more surely the tissue weakened by following the shape of the tissue, and having high adhesion to the tissue.SOLUTION: There is provided a tissue reinforcement material comprising a bioabsorbable nonwoven fabric. The tissue reinforcement material has such open holes penetrating the bioabsorbable nonwoven fabric in a thickness direction, that the average major axis is 500 μm or more and 3,500 μm or less, the average minor axis is 400 μm or more and 2,500 μm or less, and the density is one / cm2 or more and 10 / cm2 or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a tissue reinforcing material that can more reliably reinforce a weakened tissue following the shape of the tissue and has high adhesion to the tissue.

Background Art

[0002] In surgery, a reinforcing material may be used to reinforce tissue for the purpose of protecting the resection surface at the surgical site, preventing body fluid leakage, and reinforcing the suture site. In order to suppress peeling from the tissue and obtain a high reinforcing effect, it is necessary to firmly adhere the tissue reinforcing material to the tissue. As a measure for firmly adhering the tissue reinforcing material to the tissue, for example, a method of improving stretchability by making cuts in the tissue reinforcing material has been proposed (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, although conventional tissue reinforcing materials are excellent in stretchability, their adhesion to tissues has not yet been considered sufficient. When the adhesion of the tissue reinforcing material to the tissue is poor, the tissue regeneration promoting effect of the tissue reinforcing material also decreases, and thus a tissue reinforcing material with higher adhesion has been demanded.

[0005] An object of the present invention is to provide a tissue reinforcing material that can more reliably reinforce a weakened tissue following the shape of the tissue and has high adhesion to the tissue.

Means for Solving the Problems

[0006] The present invention relates to a tissue reinforcing material made of a bioabsorbable nonwoven fabric, wherein the tissue reinforcing material has through-holes with an average major axis of 500 μm or more and 3500 μm or less and an average minor axis of 400 μm or more and 2500 μm or less penetrating in the thickness direction of the bioabsorbable nonwoven fabric, at a density of 2 1 or more and 10 or less per cm 2 The following is a detailed description of the present invention. The present invention will be described in detail below.

[0007] As a result of intensive studies by the present inventors, by providing through-holes with specific major and minor diameters and density in a bioabsorbable nonwoven fabric, it is possible to follow the shape of the tissue and more reliably reinforce the weakened tissue, and a tissue reinforcing material with high adhesion to the tissue is obtained. The present invention has been completed.

[0008] The tissue reinforcing material of the present invention is made of a bioabsorbable nonwoven fabric (hereinafter also simply referred to as a nonwoven fabric). By using a bioabsorbable nonwoven fabric as the tissue reinforcing material, it is gradually absorbed by the living body after transplantation, and eventually disappears and is replaced by self-tissue. Therefore, the risk of reducing the foreign body reaction in the chronic phase and becoming a breeding ground for infection is reduced.

[0009] Examples of the bioabsorbable material constituting the nonwoven fabric include synthetic absorbable polymers such as polyglycolide, polylactide (D, L, DL forms), glycolide-lactide (D, L, DL forms) copolymer, glycolide-ε-caprolactone copolymer, lactide (D, L, DL forms)-ε-caprolactone copolymer, poly(p-dioxanone), and glycolide-lactide (D, L, DL forms)-ε-caprolactone copolymer. These may be used alone or in combination of two or more. Among them, polyglycolide, polylactide (L form), and lactide (D, L, DL forms)-ε-caprolactone copolymer are preferred because they can exhibit appropriate strength and flexibility and can cause an appropriate biological reaction to promote tissue repair. Polyglycolide is more preferred because it exhibits appropriate degradation behavior. In addition, as the above-described bioabsorbable material, natural absorbable polymers such as silk fibroin, collagen, gelatin, chitin, chitosan, fibrin, etc. can also be used. Furthermore, the above synthetic absorbable polymer and the above natural absorbable polymer may be used in combination.

[0010] When using polyglycolide (a homopolymer or copolymer of glycolide) as the above bioabsorbable material, the preferable lower limit of the weight average molecular weight of polyglycolide is 30,000, and the preferable upper limit is 1,000,000. When the weight average molecular weight of the above polyglycolide is 30,000 or more, sufficient strength as a tissue reinforcing material can be exhibited, and when it is 1,000,000 or less, it causes an appropriate biological reaction to promote tissue repair, and by decomposing, there is no remaining as a foreign substance for a long time and it is quickly replaced by living tissue. The more preferable lower limit of the weight average molecular weight of the above polyglycolide is 50,000, and the more preferable upper limit is 300,000.

[0011] When the tissue reinforcing material of the present invention is made of polyglycolide, the preferable upper limit of the melt flow rate of polyglycolide is 15 g / 10 min, and the preferable lower limit is 2 g / 10 min. When the melt flow rate of the above polyglycolide is within this range, sufficient strength as a tissue reinforcing material can be exhibited, and at the same time, an appropriate biological reaction is caused to promote tissue repair, and by decomposing, there is no remaining as a foreign substance for a long time and it is quickly replaced by living tissue. The more preferable upper limit of the melt flow rate of the above polyglycolide is 10 g / 10 min, and the more preferable lower limit is 4 g / 10 min.

[0012] The basis weight of the above nonwoven fabric is not particularly limited, but the preferable lower limit is 5 g / m 2 and the preferable upper limit is 300 g / m 2 . When the basis weight of the above nonwoven fabric is less than 5 g / m 2 , the strength as a biological tissue reinforcing material may be insufficient and it may not be able to reinforce fragile tissues. When it exceeds 300 g / m 2 , the adhesiveness to the tissue may deteriorate. The more preferable lower limit of the basis weight of the above nonwoven fabric is 10 g / m 2 , and the more preferable upper limit is 100 g / m 2 .

[0013] The porosity of the nonwoven fabric is not particularly limited, but the preferred lower limit is 20% and the preferred upper limit is 90%. When the porosity of the nonwoven fabric is within this range, sufficient strength as a tissue reinforcing material and adhesiveness to living tissue and invasion of regenerated tissue can be achieved simultaneously. The more preferred lower limit of the porosity of the nonwoven fabric is 60%, and the more preferred upper limit is 80%.

[0014] The method for manufacturing the nonwoven fabric is not particularly limited. For example, conventionally known methods such as electrospinning deposition method, meltblowing method, needle punching method, spunbond method, flash spinning method, hydroentanglement method, airlaid method, thermal bonding method, resin bonding method, and wet method can be used.

[0015] The tissue reinforcing material of the present invention has through holes with an average major axis of 500 μm or more and 3500 μm or less and an average minor axis of 400 μm or more and 2500 μm or less penetrating in the thickness direction of the bioabsorbable nonwoven fabric. Conventional tissue reinforcing materials may entrap air during pasting, and the entrapped air remains as bubbles, so the part with bubbles floats up and the adhesion decreases. In the present invention, by providing through holes in the tissue reinforcing material, the bubbles generated during pasting of the tissue reinforcing material can be released to the outside, so that floating can be suppressed and high adhesion can be exhibited. As a result, it becomes difficult for the tissue reinforcing material to peel off, and it becomes difficult to accumulate body fluid. In addition, by increasing the adhesion, the tissue regeneration promoting effect of the tissue reinforcing material can be fully exerted. Furthermore, when the average major axis and average minor axis of the through holes are within the above ranges, the bubbles can be reliably released to the outside while maintaining the performance as a tissue reinforcing material.

[0016] The average major diameter of the above through-holes is preferably 550 μm or more, more preferably 1000 μm or more, preferably 3300 μm or less, and more preferably 3000 μm or less. Further, the average minor diameter of the above through-holes is preferably 450 μm or more, more preferably 800 μm or more, preferably 2400 μm or less, and more preferably 2000 μm or less. Here, the average major diameter and the average minor diameter refer to the average of the major diameters and minor diameters of the 10 above through-holes. Further, when the above through-holes are perfect circles, the average major diameter and the average minor diameter become the average diameter.

[0017] The above through-holes are 1 piece / cm 2 or more and 10 pieces / cm 2 or less in density. When the density of the above through-holes is within the above range, the number of bubbles can be sufficiently reduced, and high adhesiveness can be exhibited. The density of the above through-holes is preferably 2 pieces / cm 2 or more, more preferably 3 pieces / cm 2 or more, preferably 8 pieces / cm 2 or less, and more preferably 7 pieces / cm 2 or less.

[0018] The method for forming the above through-holes is not particularly limited, and examples thereof include a method of piercing needles into the above nonwoven fabric, a method of heating the nonwoven fabric after making cuts (slits), and the like.

[0019] Here, a photograph of the through-holes of the present invention is shown in FIG. 1. The through-holes in FIG. 1 are formed by a method of making slits in a nonwoven fabric and then heating. Since the tissue reinforcing material of the present invention has through-holes as shown in FIG. 1 having the size and density within the above range, the bubbles generated during the attachment of the tissue reinforcing material can escape to the outside, so that floating can be suppressed and high adhesiveness can be exhibited.

[0020] The thickness of the tissue reinforcing material of the present invention is not particularly limited, but is preferably 30 μm or more and 300 μm or less. By having the thickness of the tissue reinforcing material within the above range, a tissue reinforcing material excellent in the balance between strength and adhesion can be obtained. The thickness of the above tissue reinforcing material is more preferably 50 μm or more, and more preferably 200 μm or less.

[0021] The tissue reinforcing material of the present invention is used for hemostasis, prevention of air leakage, and prevention of body fluid leakage of damaged or weakened organs and tissues in the surgical field. In particular, it can be preferably used for the respiratory organs. The tissue reinforcing material of the present invention can be easily attached, for example, by simply immersing the tissue reinforcing material in physiological saline and then applying it to the affected area. Also, when there is blood or body fluid in the affected area, the adhesive force can be expressed by absorbing these. Further, since the tissue reinforcing material of the present invention has the above through-holes, even if air is entrapped when the tissue reinforcing material is attached to the tissue, the air can escape through the through-holes, so that the tissue reinforcing material can be sufficiently adhered and the tissue can be more reliably reinforced.

Advantages of the Invention

[0022] According to the present invention, it is possible to more reliably reinforce a weakened tissue following the shape of the tissue, and to provide a tissue reinforcing material with high adhesion to the tissue.

Brief Description of the Drawings

[0023]

Figure 1

Modes for Carrying Out the Invention

[0024] Examples will be given below to explain the aspects of the present invention in more detail, but the present invention is not limited only to these examples.

[0025] (Example 1) A non-woven fabric (Neo Balunano (NV-1010-D10G), manufactured by Gunze Ltd.) made of polyglycolide with a thickness of 70 μm was provided with 10 slits of 1 mm per cm 2It was inserted so as to have a density of [density value]. Then, by performing a heat treatment at 80°C for 10 minutes, a tissue reinforcing material having elliptical through-holes with an average major axis of 0.55 mm and an average minor axis of 0.46 mm was obtained.

[0026] (Examples 2 to 7) Slits with the lengths shown in Table 1 were made in the non-woven fabric made of polyglycolide, and a tissue reinforcing material was obtained in the same manner as in Example 1 except that through-holes with the sizes and densities shown in Table 1 were formed.

[0027] (Comparative Example 1) A tissue reinforcing material was obtained in the same manner as in Example 1 except that no slits were made and no through-holes were provided.

[0028] <Evaluation> The following evaluations were performed on the tissue reinforcing materials obtained in the examples and comparative examples.

[0029] (Evaluation of Adhesion) A 50 mm × 30 mm sample was cut out from the center of the tissue reinforcing material to prepare an evaluation sample. Then, the evaluation sample was placed on the pig liver, and it was gently pressed several times from above with a moistened gauze or the like to wet the sample and make it adhere. The tissue reinforcing material after adhesion was visually observed, and when no floating due to air bubbles was seen in the tissue reinforcing material, it was evaluated as "○", and when floating due to air bubbles was seen in the tissue reinforcing material, it was evaluated as "×" for adhesion.

[0030]

Table 1

Industrial Applicability

[0031] According to the present invention, it is possible to more reliably reinforce a tissue that has become vulnerable following the shape of the tissue, and to provide a tissue reinforcing material with high adhesion to the tissue.

Claims

【Claim 1】 A tissue reinforcing material made of a non-woven fabric of a bioabsorbable material, wherein the bioabsorbable material is a synthetic absorbable polymer, The tissue reinforcing material has through holes that penetrate the nonwoven fabric in the thickness direction, with an average major axis of 500 μm or more and 3500 μm or less, and an average minor axis of 400 μm or more and 2500 μm or less, at a density of 1 piece / cm ２ or more and 10 pieces / cm ２ or less tissue reinforcing material.

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