CN109937055A - Biological tissue's reinforcing material and artificial dura mater - Google Patents

Abstract

A kind of biological tissue's reinforcing material is provided, can more reliably enhance reduction tissue in the case where not using blood products Fibrin Glue while preventing air leakage or liquid leakage, the artificial dura mater including biological tissue's reinforcing material is also provided.A kind of biological tissue's reinforcing material including laminar structure is provided, which includes: the film made of biologically absorbable polymer；With fibre structure, cavernous body or film made of the etherified cellulose the etherificate generation the hydroxyl of cellulose.

Description

Biological tissue reinforcement and artificial dura mater

Field of Invention

The present invention relates to a biological tissue reinforcing material capable of reinforcing weakened tissue more reliably without using fibrin glue, a blood product, while preventing air leakage or liquid leakage, and also relates to an artificial tissue comprising the biological tissue reinforcing material Dura mater.

Background technique

The most fundamental problem in the field of surgery is the repair of damaged or weakened organs or tissues.

The dura mater, which lies between the skull and the brain and covers the spinal cord, mainly provides protection for the brain and spinal cord and inhibits the leakage of cerebrospinal fluid. In the field of neurosurgery, defects or contractures of the dura mater need to be filled after the dura mater has been opened during surgery, and a lyophilized product of the human dura mater is used for this filling. However, lyophilized products of human dura mater have various disadvantages, such as low homogeneity and short supply. Also, Non-Patent Document 1 reports that it is possible to transmit Creutzfelt-Jacob disease infection by using human dura mater. Finally, the Japanese Ministry of Health and Welfare banned human dura mater freeze-dried products on April 7, 1997.

An artificial dura mater made of a fluororesin, for example, is available on the market as a filler to replace the human dura mater. Unfortunately, however, fluororesin artificial dura mater may cause granulation or refractory skin fistula due to infection after long-term implantation, as reported in Non-Patent Document 2.

Meanwhile, artificial dura maters made of degradable, absorbable polymers that degrade and absorb after a certain period of use have been proposed. Examples of such artificial dura mater include artificial dura mater made of natural polymers such as collagen reported in Non-Patent Document 3 and gelatin reported in Non-Patent Document 4. However, these artificial dura mater have not been practically used due to various disadvantages, including insufficient suture strength when sutured integrally with living dura mater, and possible infection risk due to natural raw materials.

In order to solve the above-mentioned problems, Patent Document 1 discloses an artificial dura mater made of a biodegradable, bioabsorbable synthetic polymer, specifically, a lactide-ε-caprolactone copolymer. The artificial dura mater has little risk of infection and degrades after a certain period of use, preventing harmful effects from long-term implantation.

Typically, the artificial dura mater is secured to the dura mater at the site of the defect or contracture by sutures using sutures. However, small gaps inevitably form at the edges of the sutures, and part of the cerebrospinal fluid may leak from the gaps.

The use of fibrin glue with artificial dura mater has been investigated to achieve sealing without sutures. However, experts in the field of neurosurgery have doubts about the use of fibrin glue due to the potential for unknown viral infections caused by fibrin glue as a blood product.

Citation List

-Patent literature

Patent Document 1: JP H8-80344A

- Non-patent literature

Non-Patent Document 1: Neurosurgery, 21(2), 167-170, 1993

Non-patent document 2: Japanese Journal of Neurosurgery, 16(7), 555-560 (2007)

Non-Patent Document 3: Journal of Biomedical Materials Research, Vol. 25, 267-276, 1991

Non-Patent Document 4: Brain and Nerve, 21, 1089-1098, 1969

SUMMARY OF THE INVENTION

-technical problem

An object of the present invention is to provide a biological tissue reinforcing material that can more reliably reinforce weakened tissue while preventing air leakage or liquid leakage without using fibrin glue, a blood product, and an artificial dura mater including the biological tissue reinforcing material.

- Solutions to problems

The present invention relates to a biological tissue reinforcement material comprising a laminated structure comprising: a film made of a bioabsorbable polymer; and a film made of etherified cellulose produced by etherification of hydroxyl groups of cellulose formed fibrous structures, sponges or membranes.

The present invention will be described in detail below.

As a result of extensive research, the inventors of the present invention have found that a biomaterial including etherified cellulose (hereinafter, also referred to as "etherified cellulose") produced by etherification of hydroxyl groups of cellulose in place of fibrin glue Tissue reinforcement materials can more reliably strengthen weakened tissue, and in particular, it has also been found that the use of etherified cellulose for attaching the artificial dura mater prevents leakage of fluid. Based on this finding, the inventors have completed the present invention.

Etherified cellulose is a proven very safe compound and gels in a short time, acting as a glue, like fibrin glue. Also, since etherified cellulose has a certain level of adhesion even after it is gelled, if adhesion failure or interfacial peeling occurs due to high pressure, it can adhere again, preventing air leakage or liquid leakage. Etherified cellulose can be processed into various shapes. Therefore, a biological tissue reinforcing material excellent in handling properties can be prepared from a laminated structure in which a fibrous structure, a sponge or a film made of etherified cellulose is stacked on a film made of a bioabsorbable polymer.

The biological tissue reinforcing material of the present invention includes a laminated structure including a film made of a bioabsorbable polymer and a fibrous structure, a sponge made of etherified cellulose produced by etherification of hydroxyl groups of cellulose body or membrane.

Membranes made of bioabsorbable polymers are designed to exhibit tissue-enhancing effects, air-leakage-preventing effects, and fluid-leakage-preventing effects when attached to damaged or weakened organs. Specifically, when the biological tissue-enhancing material of the present invention is used as an artificial dura mater, the artificial dura mater plays an important role in protecting the brain and spinal cord, and preventing leakage of cerebrospinal fluid.

A fibrous structure, sponge or membrane made of etherified cellulose absorbs moisture, gels, and acts as a glue to connect the membrane made of bioabsorbable polymers with biological tissue.

Non-limiting examples of bioabsorbable polymers include: synthetic absorbable polymers, eg, alpha-hydroxy acid polymers, eg, polyglycolide, polylactide (D, L, DL isomers), glycolide Ester-lactide (D, L, DL isomer) copolymer, glycolide-ε-caprolactone copolymer, lactide (D, L, DL isomer)-ε-caprolactone copolymer polymers, poly(p-dioxanone) or glycolide-lactide (D, L, DL isomers)-ε-caprolactone copolymers; and natural absorbable polymers such as collagen Protein, gelatin, chitosan or chitin. Any of these polymers may be used alone, or two or more of them may be used in combination. For example, in the case of using a synthetic absorbable polymer as the bioabsorbable polymer, a natural absorbable polymer may be used therewith. Specifically, α which is a homopolymer or copolymer of at least one monomer selected from the group consisting of glycolide, lactide, ε-caprolactone, dioxanone and trimethylene carbonate is preferably used - Hydroxy acid polymers because of their high strength. It is more preferable to use the alpha-hydroxy acid polymer as a homopolymer or copolymer of the glycolide-containing monomer because the polymer exhibits suitable decomposition behavior.

In the case of using the biological tissue reinforcing material of the present invention as an artificial dura mater, the bioabsorbable material is preferably a lactide (D, L, DL isomer)-ε-caprolactone copolymer. Films made from lactide (D, L, DL isomers)-ε-caprolactone copolymers are highly flexible and strong, allowing them to conform to the site of application along the delicate curvature of the site , therefore, suitable for artificial dura mater. Also, the material breaks down after a certain period of use, preventing problems that can occur after long-term implantation.

The lactide (D, L, DL isomer)-ε-caprolactone copolymer preferably contains at least 40 mol % and at most 60 mol % of lactide. When the lactide (D, L, DL isomer)-ε-caprolactone copolymer contains more than 60 mol% of lactide or ε-caprolactone, the resulting biological tissue reinforcement may have high crystallinity, becomes rigid so that it cannot achieve sufficient flexibility. More preferably, the lactide (D, L, DL isomer)-ε-caprolactone copolymer contains at least 45 mol % and at most 55 mol % lactide.

The weight average molecular weight of the lactide (D, L, DL isomer)-ε-caprolactone copolymer is preferably not less than 100,000 and not more than 500,000. A lactide (D, L, DL isomer)-ε-caprolactone copolymer having a weight average molecular weight of less than 100,000 may not have sufficient strength. When a lactide (D, L, DL isomer)-ε-caprolactone copolymer having a weight average molecular weight of more than 500,000 is used, the resulting film may have poor formability due to high melt viscosity. More preferably, the weight average molecular weight of the lactide (D, L, DL isomer)-ε-caprolactone copolymer is preferably not less than 150,000 and not more than 450,000.

The thickness of the film made of the bioabsorbable polymer is not particularly limited, and a preferable lower limit thereof is 10 μm, and a preferable upper limit thereof is 800 μm. Films made of bioabsorbable polymers with a thickness of less than 10 μm have poor strength and may not produce sufficient tissue reinforcement. Films made of bioabsorbable polymers with a thickness greater than 800 μm may not adequately adhere to and fix tissue. The more preferable lower limit of the thickness of the film made of the bioabsorbable polymer is 20 μm, and the more preferable upper limit thereof is 300 μm.

Membranes made from bioabsorbable polymers can be hydrophilized. Membranes that have been hydrophilized quickly absorb water on contact, such as saline, and are therefore easy to handle.

Non-limiting examples of hydrophilization include plasma treatment, glow discharge treatment, corona discharge treatment, ozone treatment, surface graft treatment, and ultraviolet irradiation treatment. In particular, plasma treatment is preferred because the treatment significantly increases the water absorption rate without changing the appearance of the film.

Etherified cellulose is produced by etherification of the hydroxyl groups of cellulose. Specific examples thereof include: hydroxyalkylated cellulose represented by the following formula (1), for example, hydroxyethylated cellulose in which the hydroxyl group of cellulose has been replaced by hydroxyethyl, or in which the hydroxyl group of cellulose has been replaced by hydroxypropyl hydroxypropylated cellulose; and carboxyalkylated cellulose, eg, carboxymethylated cellulose in which the hydroxyl groups of the cellulose have been replaced by carboxymethyl groups. Specifically, hydroxyethyl cellulose, which has been proven to be very safe, is preferred.

In formula (1), n represents an integer, R represents hydrogen or -R'OH, wherein R' represents an alkylene group.

In the case where the etherified cellulose is hydroxyethylated cellulose, in the hydroxyethylated cellulose, the molar ratio of diethylene glycol groups to ethylene glycol groups (diethylene glycol groups/ethylene glycol alcohol group) is preferably 0.1-1.0, and the molar ratio of triethylene glycol group to ethylene glycol group (triethylene glycol group/ethylene glycol group) is preferably 0.1-0.5. Etherified cellulose having a molar ratio within the above range yields excellent initial adhesion when the film made of bioabsorbable polymer adheres to biological tissue through a fibrous structure, sponge or membrane made of etherified cellulose Adhesion and maintain high adhesion after adhesion. Even if adhesion failure or interfacial peeling occurs due to high pressure, the film can be re-adhered to prevent air leakage or liquid leakage.

For example, the number of moles of ethylene glycol, diethylene glycol and triethylene glycol groups in hydroxyethylcellulose can be measured by NMR or thermal decomposition GC-MS.

In the case where the etherified cellulose is hydroxyethylated cellulose, the preferred lower limit of the average number of molecules (molar substitution degree, MS) of alkylene oxides bound to the anhydroglucose unit is 1.0, which is preferably is capped at 4.0. Etherified cellulose with MS in this range can gel in a short time with high gel strength, and adhere tightly to and fix tissue. When the MS is less than 1.0, the gelled hydroxyethyl cellulose tends to be less viscous. When the MS is greater than 4.0, gelation tends to take longer. A more preferable lower limit of MS is 1.3, and a more preferable upper limit thereof is 3.0.

In the case where the etherified cellulose is hydroxyethylated cellulose, the preferred lower limit of the average degree of substitution (DS) of the alkylene oxide with respect to the hydroxyl groups at the 2-, 3-, and 6-positions of the anhydroglucose unit is 0.2 , its preferred upper limit is 2.5. Etherified cellulose with DS in this range can gel in a short time with high gel strength, and adhere tightly to and fix tissue. When DS is less than 0.2, gelation may take a long time. When the DS is greater than 2.5, the wet strength may decrease. A more preferable lower limit of DS is 0.3, and a more preferable upper limit thereof is 1.5.

MS and DS can be calculated by measuring the NMR spectrum of an aqueous solution of hydroxyethylcellulose and measuring the intensities of the signals belonging to the carbon atoms of the anhydroglucose ring and the carbon atoms of the substituents in the spectrum (see, for example, JP H6-41926 B).

Specifically, for example, 0.2 g of the sample, 30 mg of the enzyme (cellulase) and the internal standard material are dissolved in 3 mL of heavy water. The resulting solution was sonicated for 4 hours, and its NMR spectrum was measured using an NMR measurement apparatus (eg, JNM-ECX400P available from JEOL) under the conditions of a scan number of 700, a pulse width of 45°, and an observation frequency of 31,500 Hz.

The etherified cellulose may be cellulose produced by etherification and carboxylation of hydroxyl groups of cellulose such that partially unetherified hydroxyl groups are carboxylated (hereinafter, also referred to as "etherified and carboxylated cellulose") . The use of etherified and carboxylated cellulose enables strong adhesion to damaged sites with particularly large surface irregularities.

Etherified and carboxylated cellulose is produced by etherification and carboxylation of cellulose hydroxyl groups. Specific examples thereof include hydroxyalkylated and carboxylated cellulose, such as hydroxyethylated and carboxylated cellulose in which the hydroxyl groups of cellulose have been replaced by hydroxyethyl and carboxyl groups, or in which the hydroxyl groups of cellulose have been replaced by hydroxyethyl and carboxyl groups. Hydroxypropyl and carboxy-substituted hydroxypropylated and carboxylated cellulose. Hydroxyethylated and carboxylated celluloses are particularly preferred since they have proven to be very safe.

For example, hydroxyalkylated and carboxylated celluloses represented by the following formula (2) are preferred:

wherein n represents an integer, R represents hydrogen or -R'OH, wherein R' represents an alkylene group.

Moles of diethylene glycol groups to ethylene glycol groups in the hydroxyethylated and carboxylated cellulose where the etherification used to produce the etherified and carboxylated cellulose is hydroxyethylated The ratio (diethylene glycol group/ethylene glycol group) is preferably 0.1-1.5, and the molar ratio of triethylene glycol group to ethylene glycol group (triethylene glycol group/ethylene glycol group) It is preferably 0.1-1.0.

The lower limit of the average molecular number (molar substitution degree, MS) of the alkylene oxide bound to the anhydroglucose unit is preferably 1.0, and the upper limit thereof is preferably 4.0. The lower limit of the average degree of substitution (DS) of the alkylene oxide with respect to the hydroxyl groups at the 2-, 3-, and 6-positions of the anhydroglucose unit is preferably 0.2, and the upper limit is preferably 2.5.

The average number of molecules (MS), the average degree of substitution (DS) and the number of moles of ethylene glycol groups, diethylene glycol groups and triethylene glycol groups can be measured, for example, by NMR or thermal decomposition GC-MS.

Hydroxyethylated cellulose can be produced, for example, by the reaction of ethylene oxide with alkali cellulose produced by treating cellulose with an aqueous alkali solution.

Specifically, for example, alkali cellulose is produced from a fibrous structure by treating a fibrous structure made of cellulose as a raw material with an aqueous solution of an alkali such as sodium hydroxide. A certain amount of ethylene oxide and a reaction solvent are added to the produced alkali cellulose to carry out the reaction.

Etherified and carboxylated cellulose can be produced, for example, by carboxylating and then etherifying cellulose.

For example, cellulose can be carboxylated as follows. The hydroxyl groups of cellulose are oxidized to aldehydes by reaction with 2,2,6,6-tetramethylpiperidine-1-oxide (TEMPO) and sodium hypochlorite as oxidizing agents (TEMPO oxidation step). Subsequently, the cellulose is reacted with sodium chlorite to carboxylate the aldehyde (carboxylation step).

The resulting carboxylated cellulose is treated with an aqueous base such as sodium hydroxide (alkali treatment step) and then reacted with ethylene oxide for etherification (hydroxyethylation) (hydroxyethylation step). In this way, etherified and carboxylated cellulose (hydroxyethylated and carboxylated cellulose) can be prepared.

In the hydroxyethylated and carboxylated cellulose obtained by this method, the carboxyl group is mainly introduced into the 6-position of the cellulose, and the hydroxyethyl group is mainly introduced into the 2-position and the 6-position of the cellulose.

The preferable lower limit of the water absorption of the fibrous structure, sponge or film made of etherified cellulose is 200%, and the preferable upper limit thereof is 1,000%. A fibrous structure, sponge, or membrane made of etherified cellulose having a water absorption rate within this range can be gelled with high gel strength in a short time, and closely adhere to and fix tissue. When the water absorption rate is lower than 200%, gelation may take a long time. When the water absorption rate is higher than 1,000%, the gel strength tends to become lower. The more preferable lower limit of the water absorption rate is 400%, and the more preferable upper limit thereof is 800%.

The water absorption rate here can be measured by the following method.

Specifically, the initial weight of the sample is measured, and the sample is placed in a petri dish. Distilled water was slowly added dropwise to the sample. The weight of the sample that absorbed the distilled water to the greatest extent (under the condition that the sample no longer absorbed the distilled water, and the excess distilled water leaked from the sample if the distilled water was continuously added dropwise) was determined as the maximum water absorption weight. The water absorption rate can be determined from the initial weight and the maximum water absorption weight based on the following formula.

Water absorption rate (%)=(maximum water absorption weight-initial weight)/initial weight×100

The preferable lower limit of the moisture absorption rate of the fibrous structure, sponge or film made of etherified cellulose is 7%, and the preferable upper limit thereof is 50%. A fibrous structure, sponge, or film made of etherified cellulose having a moisture absorption rate within this range can be gelled with high gel strength in a short time, and closely adhere to and fix tissue. When the moisture absorption rate is lower than 7%, gelation may take a long time. When the moisture absorption rate is higher than 50%, the gel strength tends to be lower. The more preferable lower limit of the moisture absorption rate is 10%, and the more preferable upper limit thereof is 35%.

The moisture absorption rate used here can be measured by the following method.

Specifically, the sample was heated at 105°C for 2 hours. The weight of the resulting sample was determined as absolute dry weight. Next, the absolutely dried samples were placed in an atmosphere of 20°C and 65% Rh for 7 hours to control the moisture content of the samples. The weight of the sample was determined as the weight after moisture control. The moisture absorption rate can be calculated from the absolute dry weight and the weight after moisture control based on the following formula.

Moisture absorption rate (%)=(weight after moisture control-absolute dry weight)/absolute dry weight×100

The fibrous structure made of etherified cellulose can be in any form including non-woven fabric, knitted fabric, woven fabric, gauze or yarn form or these combination of forms. Specifically, the form of a non-woven fabric is preferred.

In the case where the fibrous structure made of etherified cellulose is in the form of a nonwoven fabric, the weight per unit area of the nonwoven fabric is not particularly limited, a preferred lower limit is 20 g/m ² , and a preferred upper limit is 700 g/m ² . Non-woven fabrics with a weight per unit area of less than 20 g/m ² may not be able to attach the biological tissue reinforcing material to biological tissue with sufficient adhesion. When the weight per unit area of the nonwoven fabric is more than 700 g/m ² , the gelation of the etherified cellulose takes a long time. The more preferable lower limit of the weight per unit area of the nonwoven fabric is 50 g/m ² , and the more preferable upper limit thereof is 500 g/m ² .

The nonwoven fabric may be produced by any method, and examples of the method include conventionally known methods such as electrospinning deposition, melt blowing, needle punching, spun bonding, Flash spinning, hydroentanglement, air laying, thermal bonding, resin bonding or wet processing.

The weight per unit area of the sponge body made of etherified cellulose is not particularly limited, and a preferable lower limit thereof is 15 g/m ² , and a preferable upper limit thereof is 1,200 g/m ² . Spongies with a weight per unit area of less than 15 ^g /m are not strong enough to be used as biological tissue reinforcement materials and may not reinforce weakened tissue. Spongies with a weight per unit area greater than 1,200 ^g /m2 may result in poor adhesion to tissue. A more preferable lower limit of the weight per unit area of the sponge is 30 g/m ² , and a more preferable upper limit thereof is 500 g/m ² .

The thickness of the fibrous structure or sponge body made of etherified cellulose is not particularly limited, and a preferable lower limit thereof is 50 μm, and a preferable upper limit thereof is 10 mm. Fibrous structures or sponges made of etherified cellulose with a thickness of less than 50 μm may not be able to attach the biological tissue reinforcement material to the biological tissue with sufficient adhesion. A fibrous structure or sponge body made of etherified cellulose with a thickness of more than 10 mm is less likely to absorb water and has poor texture, thereby deteriorating handling properties. A more preferable lower limit of the thickness of the fibrous structure or sponge body made of etherified cellulose is 50 μm, and a more preferable upper limit thereof is 5 mm.

The thickness of the film made of etherified cellulose is not particularly limited, and a preferable lower limit thereof is 10 μm, and a preferable upper limit thereof is 800 μm. Membranes made of etherified cellulose with a thickness of less than 10 μm are less strong and may not produce sufficient tissue reinforcement. Membranes made of etherified cellulose with a thickness greater than 800 μm may not be sufficient to adhere to and fix tissue. The more preferable lower limit of the thickness of the film made of etherified cellulose is 20 μm, and the more preferable upper limit thereof is 300 μm.

Preferably, a membrane made of bioabsorbable polymer and a fibrous structure, sponge or membrane made of etherified cellulose are integrated to improve handling properties.

As used herein, the term "integrated" refers to a state in which two structures laminated to each other can be handled as one structure and cannot be easily separated.

Non-limiting examples of ways of integration include ways in which a portion of a fibrous structure or sponge made of etherified cellulose is incorporated into a portion of a membrane made of a bioabsorbable polymer.

The biological tissue augmentation material of the present invention is used in the surgical field to prevent bleeding from damaged or weakened organs or tissues, or to prevent air leakage or fluid leakage. In particular, biological tissue-enhancing materials are advantageously used as artificial dura mater in the field of neurosurgery.

Another aspect of the present invention is an artificial dura mater comprising a biological tissue augmentation material.

The biological tissue reinforcing material of the present invention can be easily attached to the affected area simply by applying the material pre-soaked in physiological saline to the affected area. Also, the biological tissue augmentation material absorbs blood or fluid from the affected area so that it can exhibit adhesion.

Description of drawings

FIG. 1 is a view schematically showing a water pressure resistance tester used in the water pressure resistance test performed in the examples.

- Beneficial effects of the invention

The present invention can provide a biological tissue reinforcing material capable of reinforcing weakened tissue more reliably without using a blood product fibrin glue while preventing air leakage or liquid leakage, and an artificial dura mater including the biological tissue reinforcing material.

Detailed ways

Examples are described below in order to more specifically illustrate the embodiments of the present invention. The present invention is not limited to these examples.

(Example 1)

(1) Preparation of fibrous structures made of hydroxyethylated cellulose

A 280 μm-thick single knit made of 80-count cellulose yarn as a raw material was bleached by hydrogen peroxide bleaching.

A 3.55 g amount of bleached knitted fabric was soaked in 140 mL of 10% aqueous sodium hydroxide solution at 15°C for 30 minutes to alkalize the cellulose. A load of 2.5-3.0 kg was applied to the alkalized knit for padding.

Next, 12.25 g of the resulting knitted fabric made of alkali cellulose was soaked in 50 mL of a 0.8 mol/L hexane solution of ethylene oxide at 25°C, and reacted at 50°C for 3 hours. The reacted knitted fabric was washed by soaking in 70 mL of a mixture of methanol and methyl isobutyl ketone (methanol: methyl isobutyl ketone = 35:35) at 25°C for 5 minutes, followed by washing at 25°C at 72.6 It was neutralized by soaking in a mixture of methanol, methyl isobutyl ketone and acetic acid (methanol: methyl isobutyl ketone: acetic acid = 35:35:2.6) for 10 minutes. The neutralized knit fabric was soaked in 70 mL of a mixture of isopropanol and water (isopropanol:water=63:7) at 25°C for 3 minutes, followed by 70 mL of acetone at 25°C for 5 minutes. The resulting knitted fabric was dried at 40°C for 24 hours to prepare a fibrous structure prepared from hydroxyethylated cellulose.

Analysis of the resulting fiber-structured hydroxyethylcellulose using thermal degradation GC-MS revealed that the molar ratio of diethylene glycol groups to ethylene glycol groups (diethylene glycol groups/ethylene glycol groups) ) was 0.20, and the molar ratio of triethylene glycol group to ethylene glycol group (triethylene glycol group/ethylene glycol group) was 0.21.

(2) Manufacture of biological tissue reinforcement materials

L-lactide/ε-caprolactone copolymer (molar ratio: 50/50, weight average molecular weight by GPC: 220,000, hereinafter also referred to as "P(L-LA/CL) (molar ratio)" : 50/50)") was dissolved in chloroform and filtered to remove unmelted material to prepare a 5 wt% solution. The solution was cast on a glass plate and air-dried, followed by vacuum drying at 50° C. for 12 hours, resulting in a 100 μm-thick film made of P(L-LA/CL) (molar ratio: 50/50).

The fibrous structures made of hydroxyethylated cellulose were partially dissolved by soaking in 1,4-dioxane. A partially dissolved fibrous structure made of hydroxyethyl cellulose was stacked on one surface of a film made of P(L-LA/CL) (molar ratio: 50/50) and uniformly pressed, and then Dry at 23°C for 3 hours. In this way, a biological tissue reinforcing material was prepared comprising a laminated structure in which a fibrous structure made of hydroxyethyl cellulose was stacked on top of P(L-LA/CL) (molar ratio: 50/50 ) on one surface of the film.

The biological tissue reinforcing material was punched into a circle with a diameter of 11 mm to obtain a test sample for measurement.

(3) Water pressure test

The water pressure test was performed using the water pressure tester 1 shown in FIG. 1 .

Collagen membranes (obtained from Nippi. Inc.) approximately 130 μm thick were punched into rectangles 5.5 cm in length and 5.0 cm in width, and the membranes were washed with 70% ethanol and the liquid was wiped off. The resulting membrane was mounted on a filter holder 2 (Swinnex (registered trademark) 25, available from Merck Millipore). A hole of 3 mm in diameter was formed in the center of the collagen membrane mounted on the filter holder 2 with a punch. A 20 mL syringe 3 (Terumo Syringe SS-20ESZ, available from Terumo Corporation) containing phosphate buffer, and a pressure gauge 5 (digital pressure gauge FUSO-8230, available from Fusorika Co., Ltd.) were placed via a three-way valve 4. downstream of the filter holder. In this way, a water pressure resistance tester is manufactured.

Purified water was added dropwise to the surface of the test sample on one side of the fibrous structure made of hydroxyethyl cellulose. The resulting test sample was placed in the center of the collagen membrane mounted in the filter holder so that the surface was in contact with the collagen membrane. After allowing the test sample to stand for 1 minute, phosphate buffer was delivered by syringe. The maximum pressure before peeling of the test sample was measured with a manometer for evaluation of water pressure resistance.

Table 1 shows the results.

(Example 2)

(1) Preparation of fibrous structures made of hydroxyethylated and carboxylated cellulose

A 280-μm-thick single-jersey knitted fabric made of 80-count cellulose yarn as a raw material was bleached by hydrogen peroxide bleaching.

Bleached knitted fabrics were incubated at 25°C in a 1:30 bath of TEMPO oxidation solution (TEMPO concentration: 20% owf, 5% sodium hypochlorite concentration: 180% owf, sodium bromide: 17.5% owf, pH 10 aqueous solution) Than soak for 10 minutes for oxidation. The oxidized knitted fabric was washed 3 times with water, then at 80°C in sodium chlorite solution (25% sodium chlorite concentration: 20% owf, CG1000 concentration: 1.0 g/L, pH 3.8 aqueous solution) at 1 :15 bath ratio for 90 minutes for carboxylation. The resulting knitted fabric was washed with hot water, then water, and at 70°C in a hydrogen peroxide/sodium borohydride solution (30% hydrogen peroxide concentration: 1% owf, sodium borohydride concentration: 5% owf, PCL7000 Concentration: 0.4 g/L, pH 10.5 aqueous solution) for 20 minutes at a liquor ratio of 1:20 for dechlorination and reduction of partially formed ketones to hydroxyl groups. The resulting knitted fabric was further washed with hot water, neutralized, and washed with water. Thereby, a carboxylated knitted fabric was prepared.

The obtained carboxylated knitted fabric was soaked in a 20% aqueous sodium hydroxide solution for 30 minutes at 15°C in a liquor ratio of 1:40 for alkalization. A load of 2.5-3.0 kg was applied to the resulting knitted fabric for full padding. The knitted fabric after the whole pad was soaked in 0.8 mol/L hexane solution of ethylene oxide at a liquor ratio of 1:15 at 50° C. for 30 minutes for hydroxyethylation. The knitted fabric after the reaction was immersed in 70 mL of a mixture of methanol and methyl isobutyl ketone (methanol:methyl isobutyl ketone=35:35) at 25°C for 5 minutes at a liquor ratio of 1:30 for washing, It was then immersed in 70 mL of a mixture of methanol, methyl isobutyl ketone and acetic acid (methanol: methyl isobutyl ketone: acetic acid = 35:35:2.6) at 25°C for 10 minutes at a liquor ratio of 1:30. and. The neutralized knitted fabric was soaked in 70 mL of a mixture of isopropanol and water (isopropanol:water = 63:7) at 25°C for 3 minutes in a liquor ratio of 1:30 (2 times), then at 25°C immersed in acetone at a liquor ratio of 1:60 for 5 minutes, and then dried at 40°C for 24 hours to obtain a medical fiber structure including a fiber structure made of hydroxyethylated and carboxylated cellulose.

Analysis of hydroxyethylated and carboxylated cellulose of the resulting fibrous structures using thermal degradation GC-MS revealed that the molar ratio of diethylene glycol groups to ethylene glycol groups (diethylene glycol groups/ethylene glycol) glycol group) was 0.18, and the molar ratio of triethylene glycol group to ethylene glycol group (triethylene glycol group/ethylene glycol group) was 0.15.

(2) Manufacture of biological tissue reinforcement materials

As in Example 1, a 100 μm-thick film made of P(L-LA/CL) (molar ratio: 50/50) was prepared.

The fibrous structures made of hydroxyethylated and carboxylated cellulose were partially dissolved by soaking in 1,4-dioxane. A partially dissolved fibrous structure made of hydroxyethylated and carboxylated cellulose was stacked on one surface of a film made of P(L-LA/CL) (molar ratio: 50/50) and uniformly Pressed and then dried at 23°C for 3 hours. In this way, a biological tissue reinforcement material comprising a laminated structure in which a fibrous structure made of hydroxyethylated and carboxylated cellulose is stacked on a : 50/50) on one surface of the film.

The biological tissue reinforcing material was punched into a circle with a diameter of 11 mm to obtain a test sample for measurement.

As in Example 1, the test samples were subjected to the hydrostatic pressure test.

(Example 3)

(1) Preparation of film made of hydroxyethyl cellulose

By mixing commercially available hydroxyethylated cellulose (available from Wako Pure Chemical Industries, Ltd., the molar ratio of diethylene glycol group to ethylene glycol group (diethylene glycol group/ethylene glycol group) ): 1.06, the molar ratio of triethylene glycol group to ethylene glycol group (triethylene glycol group/ethylene glycol group): 4.01) was dissolved in distilled water so that the solid content of the solution was 7.5wt% , to prepare a sol solution of hydroxyethylated cellulose.

The sol solution of hydroxyethylcellulose was cast on a petri dish and dried at 30° C. for 24 hours to obtain a 50 μm-thick film made of hydroxyethylcellulose.

(2) Manufacture of biological tissue reinforcement materials

As in Example 1, a 100 μm-thick film made of P(L-LA/CL) (molar ratio: 50/50) was prepared. The membrane made of hydroxyethylated cellulose was partially dissolved by soaking in 1,4-dioxane. A partially dissolved film made of hydroxyethyl cellulose was stacked on one surface of a film made of P(L-LA/CL) (molar ratio: 50/50), and pressed uniformly, and then at 23 Dry at °C for 3 hours. In this way, a biological tissue reinforcing material was prepared including a laminated structure in which a film made of hydroxyethyl cellulose was stacked on top of P(L-LA/CL) (molar ratio: 50/50) on one surface of the film made.

The biological tissue reinforcing material was punched into a circle with a diameter of 11 mm to obtain a test sample for measurement. As in Example 1, the test samples were subjected to the hydrostatic pressure test.

(Example 4)

(1) Preparation of film made of carboxymethylated cellulose

A sol solution of carboxymethylated cellulose was prepared by dissolving commercially available carboxymethylated cellulose (available from Wako Pure Chemical Industries, Ltd.) in distilled water so that the solid content of the solution was 7.5 wt%.

The sol solution of carboxymethylated cellulose was cast on a petri dish and dried at 30° C. for 24 hours to obtain a film made of carboxymethylated cellulose with a thickness of 80 μm.

(2) Manufacture of biological tissue reinforcement materials

As in Example 1, a 100 μm-thick film made of P(L-LA/CL) (molar ratio: 50/50) was prepared.

The membrane made of carboxymethylated cellulose was partially dissolved by soaking in 1,4-dioxane. A partially dissolved film made of carboxymethylated cellulose was stacked on one surface of a film made of P(L-LA/CL) (molar ratio: 50/50) and pressed uniformly, and then at 23 Dry at °C for 3 hours. In this way, a biological tissue-enhancing material including a laminated structure in which a film made of carboxymethylated cellulose is stacked on top of P(L-LA/CL) (molar ratio: 50/50) is prepared. on one surface of the film made.

The biological tissue reinforcing material was punched into a circle with a diameter of 11 mm to obtain a test sample for measurement. As in Example 1, the test samples were subjected to the hydrostatic pressure test.

(Comparative Example 1)

The water pressure resistance of the case of using fibrin glue in combination with a fibrous structure made of a bioabsorbable polymer was evaluated by the following method.

Circular sheets with a diameter of 11 mm were punched out of a 150 μm thick non-woven fabric made of polyglycolide (NEOVEIL Type NV-M015G, GUNZELIMITED).

The collagen membrane prepared as in Example 1 was mounted on the filter holder of the hydrometer used in Example 1. Then, 20 μL of Beriplast P, consisting of solution A (mixture of fibrinogen powder and aprotinin solution) and solution B (mixture of thrombin powder and calcium chloride solution) of fibrin glue, obtained from CSL Behring K.K.) was dropped in the center of the collagen film in a manner avoiding the holes in the collagen film, and spread to a shape of about 11 mm in diameter. Next, the non-woven fabric impacted into a circle with a diameter of 11 mm was placed on the spread solution A and impregnated with the solution A. Subsequently, 20 μL of the solution A was dropped on the nonwoven fabric, and the nonwoven fabric was sufficiently impregnated with the solution A. After that, 20 μL of solution B was dropped on the non-woven fabric.

5 minutes after the dropwise addition of solution B, phosphate buffer was delivered by syringe. The maximum pressure before peeling of the test sample was measured with a manometer for evaluation of water pressure resistance. Table 1 shows the results.

(Comparative Example 2)

A biological tissue reinforcement was obtained in the same manner as in Example 1, except that a fiber structure made of oxidized cellulose (Surgicel, available from Johnson & Johnson K.K.) was used instead of fibers made of hydroxyethylated cellulose structure.

The biological tissue reinforcing material was punched into a circle with a diameter of 11 mm to obtain a test sample for measurement. As in Example 1, the test samples were subjected to the hydrostatic pressure test.

(Comparative Example 3)

(1) Preparation of film made of oxidized cellulose

A sol solution of oxidized cellulose was prepared by dissolving a fibrous structure made of oxidized cellulose (Surgicel, available from Johnson & Johnson K.K.) in distilled water so that the solids content of the solution was 7.5 wt%.

The sol solution of oxidized cellulose was cast on a petri dish and dried at 30°C for 24 hours, resulting in a 130 μm-thick film made of oxidized cellulose.

(2) Manufacture of biological tissue reinforcement materials

A 100 μm thick commercial film made of lactide-ε-caprolactone copolymer (SEAMDURA, available from GUNZELIMITED) was used as the film made of bioabsorbable polymer.

The membrane made of oxidized cellulose was partially dissolved by soaking in 1,4-dioxane. The partially dissolved film made of oxidized cellulose was stacked on one surface of the film made of lactide-ε-caprolactone copolymer, and pressed uniformly, and then dried at 23° C. for 3 hours. In this way, a biological tissue reinforcement material is prepared comprising a laminated structure in which a film made of oxidized cellulose is stacked on one surface of a film made of lactide-ε-caprolactone copolymer .

The biological tissue reinforcing material was punched into a circle with a diameter of 11 mm to obtain a test sample for measurement. As in Example 1, the test samples were subjected to the hydrostatic pressure test.

(Comparative Example 4)

A 100 μm thick commercial film made of lactide-ε-caprolactone copolymer (SEAMDURA, available from GUNZELIMITED) was used as the film made of bioabsorbable polymer.

The film was punched into a circle with a diameter of 11 mm to obtain a test sample.

The water pressure test was performed using the water pressure tester 1 shown in FIG. 1 .

Collagen membranes (obtained from Nippi. Inc.) approximately 130 μm thick were punched into rectangles 5.5 cm in length and 5.0 cm in width, and the membranes were washed with 70% ethanol and the liquid was wiped off. The resulting membrane was mounted on a filter holder 2 (Swinnex (registered trademark) 25, available from Merck Millipore). A hole of 3 mm in diameter was formed in the center of the collagen membrane mounted on the filter holder 2 with a punch. The test sample was placed on the collagen film in such a way that the center of the test sample overlapped with the center of the hole of the collagen film. The test sample and the collagen membrane were sutured together using a suture made of polyglycolide of suture size No. 4-0 (Monodiox (registered trademark), available from Alfresa Pharma Corporation). The distance between the sutures is 7.0mm. The 11 mm diameter circular test sample used for the measurement had 5 sutures. A 20 mL syringe 3 (Terumo Syringe SS-20ESZ, available from Terumo Corporation) containing phosphate buffer, and a pressure gauge 5 (digital pressure gauge FUSO-8230, available from Fusorika Co., Ltd.) were placed via a three-way valve 4. downstream of the filter holder. In this way, a water pressure resistance tester is manufactured.

Phosphate buffer is delivered via syringe. The maximum pressure before peeling of the test sample was measured with a manometer for evaluation of water pressure resistance.

[Table 1]

Pressure resistance (mmHg) Example 1 53.6 Example 2 60.7 Example 3 146.5 Example 4 71.3 Comparative Example 1 52.1 Comparative Example 2 4.8 Comparative Example 3 6.2 Comparative Example 4 6.6

Industrial applicability

The present invention can provide a biological tissue reinforcing material that can more reliably strengthen weakened tissue while preventing air leakage or liquid leakage without using fibrin glue, a blood product, and can also provide an artificial dura mater including the biological tissue reinforcing material.

List of reference signs

1 Water pressure tester

2 filter holder

3 syringes

4 Three-way valve

5 Pressure gauge

6 Collagen membrane with holes

Claims (9)

1. A biological tissue augmentation material comprising a laminated structure comprising: membranes made of bioabsorbable polymers; and Fibrous structures, sponges or membranes made of etherified cellulose produced by etherification of the hydroxyl groups of cellulose. 2. The biological tissue enhancing material according to claim 1, wherein the etherified cellulose produced by etherification of the hydroxyl group of cellulose is a hydroxyalkylated cellulose represented by the following formula (1): where n represents an integer, R represents hydrogen or -R'OH, where R' represents an alkylene group. 3. The biological tissue enhancing material according to claim 1, wherein the etherified cellulose produced by etherification of the hydroxyl groups of cellulose is hydroxyethylated cellulose. 4. The biological tissue enhancing material according to claim 1, 2 or 3, The etherified cellulose produced by etherification of hydroxyl groups of cellulose is cellulose produced by etherification and carboxylation of hydroxyl groups of cellulose such that partially non-etherified hydroxyl groups are carboxylated. 5. The biological tissue enhancing material according to claim 4, Among them, cellulose produced by etherification and carboxylation of hydroxyl groups of cellulose is cellulose produced by hydroxyalkylation and carboxylation of hydroxyl groups of cellulose represented by the following formula (2): where n represents an integer, R represents hydrogen or -R'OH, where R' represents an alkylene group. 6. The biological tissue enhancing material according to claim 1, 2, 3, 4 or 5, Wherein the fibrous structure made of the etherified cellulose produced by the etherification of the hydroxyl groups of the cellulose is in the form of a nonwoven fabric, a woven fabric, a woven fabric, a gauze or a yarn. 7. The biological tissue enhancing material according to claim 1, 2, 3, 4 or 5, wherein the bioabsorbable polymer is a lactide (D, L, DL isomer)-ε-caprolactone copolymer. 8. The biological tissue enhancing material according to claim 7, wherein the lactide (D, L, DL isomer)-ε-caprolactone copolymer contains 40-60 mol % of lactide, and has a weight average molecular weight of 100,000 to 500,000. 9. An artificial dura mater comprising the biological tissue enhancing material according to claim 1, 2, 3, 4, 5, 6, 7 or 8.