JP2001224677A - Photosetting tissue adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive cured on the surface of the tissue of a living body by light to be converted from a solution state to a gel-like state to be bonded to the tissue of a living body. SOLUTION: A protein macromer obtained by introducing a vinyl group into protein, a polysaccharide macromer obtained by introducing a vinyl group into polysaccharides or a mixture of both of them is mixed with an optically reactive compound generating radicals by the irradiation with light to prepare a buffer solution. When the buffer solution is irradiated with light, it is cured to become a gel-like state to be bonded and fixed to the surface of tissue.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biological tissue adhesive for medical use. More specifically, an aqueous solution of a protein macromer or a polysaccharide macromer having a vinyl group is cured into a gel using a photoreactive compound that generates radicals by light, and the photocuring is adhered and fixed to a living tissue. Biological tissue adhesive.

[0002]

2. Description of the Related Art In a surgical operation, the joining of soft tissues such as skin and organs takes about one to two weeks until the damaged tissue is restored to its original form and the wound is healed by its own tissue regeneration and repair function. During the period, it is necessary to withstand the pulsating pressure, contraction force, or external force inherent in the living body, and maintain the bonding force.

[0003] Conventionally, anastomosis using a suture needle and a suture has been generally performed for joining tissues. As an alternative tissue bonding method, a method using an adhesive has been developed for a long time. (1) A cyanoacrylate that utilizes the fact that a liquid cyanoacrylate monomer is polymerized and cured in a short time by moisture. Acrylate adhesive, (2) Fibrin glue utilizing the mechanism of blood coagulation in vivo, in which fibrinogen forms an insoluble fibrin clot by the action of thrombin, (3) Gelatin adhesive, which crosslinks gelatin and resorcinol with formalin The agent has been put to practical use.

[0004]

In the anastomosis using a suture needle and a suture, not only suturing may be difficult depending on the injured part, but also blood flow obstruction, necrosis, or suture of surrounding tissues due to tightening of the suture. There are problems such as bleeding from holes. Cyanoacrylate adhesives have excellent fast-setting properties and high adhesiveness to tissues, but the cured products lack flexibility and are extremely hard compared to living soft tissues, so bonding failure due to stress such as shrinkage of living tissues And may interfere with wound healing. In addition, since decomposition in a living body is as slow as six months to one year, it is easily encapsulated and becomes a foreign substance. Further, there is a problem that some of them form highly toxic formaldehyde upon decomposition. Fibrin glue has insufficient adhesion to living tissue, cannot follow the movement of the tissue, and is easily peeled from the tissue. In addition, since it is a human-derived blood product, infections such as hepatitis and AIDS may be a concern. Furthermore, there is a problem that it is more expensive than other tissue adhesives and is difficult to use in large quantities. It has been pointed out that gelatin-based materials exhibit high tissue adhesiveness, but that formalin, which is a cross-linking agent for gelatin, causes a cross-linking reaction with proteins in the living body and exhibits toxicity.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and can be carried out quickly on a wet living tissue surface by a simple light irradiation operation using inexpensive raw materials without using toxic chemicals. An object of the present invention is to provide a medical tissue adhesive which can be firmly adhered to a living tissue by being cured, the cured product is flexible and biodegradable, and the degraded product does not show toxicity.

[0006]

In order to achieve the above object, a photocurable tissue adhesive according to the present invention comprises a protein macromer or a polysaccharide macromer having a vinyl group introduced into a protein or polysaccharide which is a natural product. , Or an aqueous solution in which a mixture of both is mixed with a photoreactive compound that generates radicals by light irradiation, or a mixed aqueous solution to which a vinyl compound is further added.
It is characterized by being adhered to tissues by being cured into a gel by light.

[0007] The features of the present invention are listed specifically below (1).
It can be quickly cured by light irradiation operation, (2) has adhesive force with tissue in the presence of water such as body fluids and blood, and (3) cured gel has physical flexibility that can follow the movement of living tissue, The flexibility can be easily adjusted by changing the types and contents of the protein macromer and the vinyl compound, and (4) the use of a bio-derived polymer makes it non-toxic and thus has excellent biocompatibility. (5) It has biodegradability, and the degraded product is non-toxic.

[0008] The photocurable tissue adhesive comprises a protein macromer or polysaccharide macromer and a vinyl compound in a weight ratio of 100: 0 to 1:99, preferably in a weight ratio of 2: 1 to 1: 2. 1-99.9 in combination or in physiological saline solution or balanced salt solution
%, Preferably 30%.
The photoreactive compound is mixed with the protein macromer or polysaccharide macromer contained in the mixed solution at a weight of 0.0001% to 30%, preferably 0.5% of the total weight of the vinyl compound.

The protein and protein of the protein macromer in the present invention are collagen, albumin, fibronectin derived from a living body, and gelatin, which is a denatured form thereof, artificially synthesized synthetic polypeptide, and the like, and preferably gelatin. Further, the polysaccharides and polysaccharides of polysaccharide macromers are those derived from living organisms such as heparin, glycosaminoglycan, cellulose, starch, denatured products thereof, and artificially synthesized synthetic polysaccharides. Preferably heparin. The vinyl group to be introduced into the protein may be any one having a double bond in the molecule, such as an acrylate group or a styrene group, and is preferably a styrene group. Introduction of a vinyl group into a protein can be performed by using 1-ethyl-3-(-dimethylaminopropyl) carbodiimide hydrochloride or 1-ethyl-3-(-dimethylaminopropyl) carbodiimide hydrochloride.
Chemical bonding by an amide bond using a water-soluble carbodiimide-based binding reagent such as cyclohexyl-3- (2-morpholinoethyl) carbodiimide meso-p-toluenesulfonic acid is preferable, but ethyl chloroformate, carbonyldiimidazole and dimethyl Chemical bonding with a bivalent crosslinking reagent such as adipineimidate or disuccinimidyl suberate may be used. In addition, a polyethylene glycol chain or a long-chain alkyl chain may be introduced as a spacer into the bond between the protein and the vinyl group.

The vinyl compound used in the present invention may be any radically polymerizable water-soluble vinyl monomer, oligomer or polymer.
Further, a polyfunctional vinyl compound such as difunctional or trifunctional is preferred. Desirably, it is polyethylene glycol diacrylate having a molecular weight of about 1,000.

The photoreactive compound is an organic compound which generates a radical upon irradiation with light, for example, carbonyl compounds such as camphorquinone, acetophenone, benzophenone, dimethoxyphenylacetophenone and derivatives thereof, dithiocarbamates, xanthates and thiophenols. Sulfur compounds and their derivatives, peroxides and their derivatives such as benzoyl peroxide and butyl peroxide, azobis compounds and their derivatives such as azobisisobutyronitrile and azobisisobutyrate, bromopropane and chloromethylnaphthalene Halogen compounds and their derivatives, azide compounds and their derivatives such as phenylazide, xanthene dyes such as rhodamine, erythrone, fluorescein, and eosin And their derivatives are riboflavin and mixtures prepared by adding a proton donor, such as at least one or amines, selected from the group consisting of their derivatives, preferably camphorquinone alone,
Alternatively, it is a mixed system with dimethylaminoethyl methacrylate. When the photoreactive compound is a photoreactive protein or polysaccharide in which the above photoreactive compound is chemically introduced into a side chain of a protein or polysaccharide, the protein macromer or polysaccharide is used. An aqueous solution comprising a photoreactive protein or a photoreactive polysaccharide without using a macromer can also be used as an adhesive.

The mixed aqueous solution is physiological saline, Ringer's solution,
It is a physiological salt solution such as a lock solution, a phosphate buffer solution, a Tyroth solution, a Hanks solution, an Earle solution, a Hepes solution, or the like, and is preferably a saline solution. The light source for light irradiation is, for example, a halogen lamp, a xenon lamp, an incandescent lamp or a mercury lamp, or an excimer laser or an argon ion laser.
From 500 nm is used. The irradiation time is preferably about 1 minute.

The curing of the photocurable tissue adhesive proceeds by the following mechanism. First, when a photoreactive compound is irradiated with light, radicals are generated. The generated radical initiates the polymerization reaction of the vinyl group contained in the protein macromer or polysaccharide macromer. When a vinyl compound is present, a copolymerization reaction with a protein macromer or a polysaccharide macromer occurs. By these polymerization reactions, cross-linking occurs between proteins or polysaccharides, and further between vinyl compounds, to give a gel-like cured product.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described specifically with reference to examples. Synthesis Example 1 Synthesis of Gelatin Macromer FIG. 1 shows a synthesis route of a styrenated gelatin having a styrene group in a side chain as a gelatin macromer. 50 ml of an aqueous solution containing 0.57 g (3.4 mmol) of 4-vinylbenzoic acid was cooled to 0 ° C., and 1.48 g (7.7 mmol) of 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride was added thereto.
After stirring at 0 ° C. for 1 hour, 50 ml of a phosphate buffer solution in which 1 g (0.01 mmol) of gelatin was dissolved was added, and stirring was continued at room temperature overnight. After dialysis under running water for 3 days using a cellulose tube, freeze-drying was performed to obtain 0.99 g of a white flocculent gelatin macromer. The amount of styrene group introduced was determined by absorbance measurement, and was about 24 per gelatin molecule. Synthesis Example 2 Preparation of photocurable tissue adhesive 200 mg of styrenated gelatin of Synthesis Example 1 and a molecular weight of about 100
The photocurable tissue adhesive was prepared by mixing 100 mg of polyethylene glycol diacrylate (0) with 700 μl of physiological saline. Example 1 Photocurability of photocurable tissue adhesive 10 mg of the photocurable material prepared in Synthesis Example 2 was measured and irradiated with a halogen lamp. FIG. 2 shows the yield of the gel and the degree of swelling of the formed gel with respect to the irradiation time. Gel yield increased and swelling decreased with irradiation time. That is, it was found that a gel having high strength was produced in a high yield with the irradiation time. Test Example 1 Degradability of Photocured Tissue Adhesive The degradability of the photocured tissue adhesive was evaluated by enzymatic degradation using collagenase. 2mg of 20mg of cured product in dry state
l of phosphate buffer solution and swell, collagenase 1
000unit was added. After shaking at 30 ° C. for a predetermined time, the reaction solution was filtered with a filter to remove undecomposed solids. The total organic carbon concentration of the decomposition product dissolved in the filtrate was measured by a TOC measuring device. The results are shown in FIG. The TOC concentration in the solution increased with the passage of the shaking time. Degradation was accelerated for materials with a higher gelatin content. Example 2 Conjugation of Canine Aorta A breed dog (body weight about 14 kg) was exposed to the thoracic aorta under anesthesia, clamped at intervals of about 5 cm, and cut. Knots were sutured at intervals of about 3 to 4 mm with a polypropylene 7-0 suture. 20 μm of the photocurable tissue adhesive of Synthesis Example 2 on the wound
l was added dropwise. Ultraviolet light guided by a quartz fiber was irradiated for 1 minute. Application and light irradiation of the material were repeated several times. After releasing the peripheral clamp and confirming that no blood leaked, the central clamp was released approximately 1 minute later. Test Example 2 Verification of Tissue Adhesion Ability of Example 2 FIG. 4 shows a photograph of the incision wound of the canine thoracic aorta after joining the vascular tissues. It can be seen that it is quickly cured by irradiation for one minute and covers the wound. After resuming the blood flow, no bleeding was observed from the incision wound, and the artery started pulsating, indicating that the sclerosed body had the flexibility to follow the movement of the living body. The hardened tissue adhesive was adhered to the wound without being detached from the wound surface even after washing with physiological saline.

FIG. 5 shows an optical microscope photograph of the structure immediately after bonding. It can be seen that the hardened tissue adhesive is closely adhered to the vascular tissue surface. Example 3 Hemostasis of Hemorrhage of Hemorrhage from Rat Liver Surface Wistar male rats (average body weight 250 g) were laparotomized under Nembutal anesthesia, and 200 units were injected from the rat tail vein.
/ kg of heparin was administered. The liver was exposed, and an incision wound about 2 mm in diameter and about 2 mm deep was made using trepan and bled. 10 μl of the photocurable tissue adhesive of Synthesis Example 2 was dropped. Ultraviolet light induced by a quartz fiber was irradiated for 1 minute to cure at the wound and adhere to liver tissue. Test Example 3 Verification of Tissue Adhesion Ability of Example 3 FIG. 6 shows a photograph of a rat liver after hemostasis for bleeding from an incision wound. No bleeding from the incision was observed, indicating that adhesion was possible even on the tissue surface where blood was present. The hardened tissue adhesive adhered without peeling off from the wound surface even after washing with physiological saline, and maintained a hemostatic effect.

FIG. 7 shows an optical micrograph of the liver tissue immediately after hemostasis. It can be seen that the hardened tissue adhesive is tightly coated on the liver surface and suppresses bleeding. FIG. 8 shows an optical micrograph of the liver tissue one month after hemostasis. The cured material is fragmented and reduced, indicating that the cured product has biodegradability. No damage such as degeneration or necrosis of the surrounding tissue was observed.

[0017]

Industrial Applicability According to the present invention, a protein macromer having at least a portion of a vinyl group, a polysaccharide macromer, or a mixture of both thereof is mixed with a photoreactive compound in an aqueous solution to be cured in a gel state by light to form a biological tissue. A medical tissue adhesive characterized by being adhered can be provided. With this tissue adhesive, it can quickly adhere to living tissue only by irradiating light, without causing serious damage to living tissue,
Alternatively, tissue can be joined. Further, there is an advantage that the components, the cured product and the decomposed product of the tissue adhesive are all non-toxic. The use of this tissue adhesive not only simplifies the operation and shortens the operation time, but also stops hemorrhage from bleeding from adhesion detachment sites, parenchymal organs such as the liver and spleen or microvessels, and filling the dead space. ,
A new technique that could not be performed by the suturing method can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a synthetic route of a styrenated gelatin which is a kind of a protein macromer.

FIG. 2 is a graph showing curability by light irradiation on a photocurable tissue adhesive.

FIG. 3 is a graph showing the enzymatic degradability of a photocured material.

FIG. 4 is an explanatory diagram showing the joining of a dog thoracic aorta using a photocurable tissue adhesive.

FIG. 5 is an explanatory diagram showing a tissue cross section of a joined dog thoracic aorta.

FIG. 6 is an explanatory diagram showing hemostasis against bleeding from rat liver.

FIG. 7 is an explanatory view showing a tissue section of a rat liver after hemostasis.

FIG. 8 is an explanatory diagram showing the in vivo degradability of a material cured on the liver surface.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takehisa Matsuda 1-16 Ao Gaien, Minoh City, Osaka Prefecture Minoh East Corpora A-501 (72) Inventor Yasuhide Nakayama 4-6-5-504, Nyoinya, Minoh City, Osaka Prefecture (72) Inventor Norimasa Tsutsui 611 Tokugawacho, Higashi-ku, Nagoya-shi, Aichi Pref.

Claims (8)

[Claims] An aqueous solution in which a protein macromer in which a vinyl group is bonded to at least a part of a protein and a photoreactive compound is hardened into a gel by light irradiation and adheres to a living tissue. Medical photocurable tissue adhesive. 2. An aqueous solution in which a polysaccharide macromer having a vinyl group bonded to at least a part of a polysaccharide and a photoreactive compound is cured into a gel by light irradiation and adheres to a living tissue. Characteristic photocurable tissue adhesive. 3. The medical photocurable tissue adhesive according to claim 2, wherein the aqueous solution further contains a protein macromer having a vinyl group bonded to at least a part of the protein. 4. The photocurable tissue adhesive for medical use according to claim 1, wherein the aqueous solution is further mixed with a vinyl compound. 5. An aqueous solution containing a compound in which the photoreactive compound is chemically bound to at least one of a protein macromer, a polysaccharide macromer, or a protein and a polysaccharide, or an aqueous solution obtained by mixing them. A photocurable tissue adhesive for medical use, which is cured into a gel by light irradiation and adheres to a living tissue. 6. The photocurable tissue adhesive for medical use according to claim 5, wherein the aqueous solution is further mixed with a vinyl compound. 7. The photocurable tissue adhesive for medical use according to claim 1, wherein the photoreactive compound is a compound that generates a radical upon irradiation with light. 8. The medical photocurable tissue adhesive according to claim 1, wherein the aqueous solution includes a physiological salt aqueous solution or a balanced salt aqueous solution.