JP2002060341A - Hemostatic agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hemostatic agent not disturbing the healing of wound surfaces and exhibiting a rapid coagulation reaction capable of stopping bleeding of arterial blood, adhesive property to tissues and biodegradability. SOLUTION: This hemostatic agent comprises a calcium salt of a nucleic acid such as DNA, or the like, as a main component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

2. Description of the Related Art Surgical operations have been remarkably extended with advances in medicine. Among them, there has been a remarkable progress in techniques related to structure construction such as removal of a lesion, reconstruction of a structure, and introduction of an artificial prosthesis. On the other hand, it is essential to insert a scalpel into a blood vessel in these operations, and it is a major issue how to stop the hemostasis after the operation. For this purpose, various types of hemostatic agents such as fibrin glue, collagen-based hemostatic agents, and oxidized cellulose have been developed and used in practice, but their hemostatic power is weak, and they are almost ineffective at bleeding from the arterial system. It is the present situation that compression bleeding is performed for a long time. In addition to the progress of catheter technology, endovascular treatment and angiography are frequently performed in fields other than surgery. At present, compression hemostasis is performed without any treatment. In artificial dialysis, dialysis treatment is performed after the indwelling needle is punctured in a blood vessel. After the dialysis is completed and the indwelling needle is removed, compression bleeding is also performed. As described above, at present, there is no effective drug capable of reliably stopping bleeding, and the reality is that a primitive method called compression bleeding is used.

[0002]

At present, the most widely used hemostatic agent is fibrin glue, which is used to gel blood-derived fibrin in a bleeding part to stop the bleeding. Hemostatic power is weak because it is in a state,
At present, little effect is observed on hemostasis from arteries. In addition, since human-derived fibrin is used, there is a risk that the risk of infection by an unknown virus is always present. Collagen or gelatin-based hemostatic agents try to obtain a hemostatic effect by utilizing the fact that these proteins have the property of activating platelets, but it is difficult to adapt to hemorrhagic sites. There is also the problem of antigenicity. Hemostatic agents using synthetic polymers include cyanoacrylates and acrylics. Although they can stop bleeding in the short term, they do not essentially stop bleeding and, on the contrary, impede the natural repair of wounds in blood vessels. For this reason, there is a problem that rebleeding occurs after peeling of the polymer. Therefore, it does not hinder the healing of the wound surface as an excellent hemostatic agent,
Quick coagulation reaction that can stop arterial blood, adhesion to tissue,
Biodegradability is also required.

[0003]

Means for Solving the Problems As a result of intensive studies in consideration of the above problems, the present inventors have reached the following invention. That is, the present inventors have found a hemostatic agent which has solved the above-mentioned problems by using a hydrogel material based on a nucleic acid. Specifically, the present invention is achieved by the following contents 1) to 5). 1) A hemostatic agent containing a calcium salt of a nucleic acid as a main component. 2) The hemostatic agent according to 1), wherein the nucleic acid is DNA. 3) The calcium salt of the nucleic acid is 10-100 equivalent% of the counter cation of the nucleic acid is calcium ion.
Or the hemostatic agent according to 2). 4) The hemostatic agent further contains a protein 1) to
The hemostatic agent according to any one of 3). 5) The hemostatic agent according to 4), wherein the protein is at least one selected from the group consisting of protamine, collagen, and gelatin.

[0004]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail. The nucleic acid used in the present invention is D
Both NA and RNA may be used, and those derived from various animals can be used. Although molecular weights of tens of thousands to millions can be used, those having a molecular weight of about 100,000 to 2,000,000 are desirable from the viewpoint of the preparation method and operability of the hemostatic agent. As an animal from which nucleic acids are obtained, DNA extracted from sperm or testis of salmon is preferable in terms of cost, but is not limited thereto. Nucleic acid is a biological component and is a material excellent in biocompatibility without problems such as antigenicity. Further, since it is decomposed in a living body, it does not remain as a foreign substance in the living body unlike a synthetic polymer-based hemostatic agent.

In the present invention, the counter cation of the nucleic acid (counter cation) is desirably calcium ion in the range of 10-100 equivalent%. That is, 10-100 equivalent% of all anions of the nucleic acid is neutralized by the calcium cation. The reason for using calcium ions is that calcium ions can be used together with the effect of promoting blood coagulation. In a medical setting, heparin is administered to a patient at the time of surgery or at the time of catheter operation for anticoagulation. After the operation, an anti-heparin drug is administered to reduce unnecessary bleeding. A specific example is protamine. Protamine is a physiologically active protein, and has already been used as a drug, and is used for neutralization, for example, when heparin is overdosed, and for neutralizing heparin action after extracorporeal blood circulation such as hemodialysis and cardiopulmonary bypass. Protamine is a protein with a molecular weight of 2,000 to 12,000 obtained from the testes of fishes such as salmonids.It has a high content of the basic amino acid arginine, and is a strongly basic protein. It is said to block anticoagulant effects.

The nucleic acid used in the present invention is a kind of polyanion having a large amount of a phosphate group in a side chain, as can be seen from its chemical structure. For this reason, proteins having physiological activity, or proteins such as protamine which contain a large amount of basic amino groups among polypeptides, or polypeptides form complexes due to ionic interaction with phosphate groups of nucleobases. It is expected. For this reason, complexing with protamine is suitable for the hemostatic agent used in the present invention, particularly for hemostasis of heparinized blood. The platelet system also plays a major role in hemostasis, and it is important to use this system. That is, it is important to add a protein or polypeptide that activates platelets. Among them, it is desirable to use collagen and / or gelatin. Further, among collagen, atelocollagen or low-molecular-weight gelatin having reduced antigenicity is desirable. The amount of these proteins and / or polypeptides to be added is preferably in the range of 0 to 90% by weight based on the nucleic acid. If it exceeds 90%, the function as a so-called DDS carrier, which is an advantage of nucleic acids, is reduced.

As the dosage form of the hemostatic agent of the present invention and the method of use, a method of sprinkling it locally as a powder, a method of applying it as a film to a bleeding site, and a method of spraying or applying it to a bleeding site as a liquid can be used.

[0008]

EXAMPLES The present invention will be described more specifically with reference to the following examples. Experimental Example 1 (DNA-Ca film) 500 mg of salmon DNA-Na salt powder (derived from testis, manufactured by Wako Pure Chemical Industries, Ltd.) in water, 40 m
to give a clear, viscous solution. This was cast on a petri dish and air-dried at room temperature to obtain a transparent DNA-Na film. The film is immersed for 24 hours in 40 g of a mixed solution of methanol / water (25:75 wt / wt) in which calcium chloride corresponding to 60 mol% of Na ion of the film is dissolved, thereby ion-exchanging the DNA-Ca salt film. Was prepared.

Experimental Example 2 (DNA-Na / protamine complex film) 500 mg of salmon DNA-Na salt powder (derived from testis, manufactured by Wako Pure Chemical Industries, Ltd.) was added to water, 40 m
to give a clear, viscous solution. By adding 10 ml of an aqueous protamine solution (containing 10 mg / ml of protamine) to this solution, a complex suspension in which an insoluble gel was partially precipitated was formed. This suspension was cast on a petri dish and air-dried to prepare a DNA-Na / protamine composite film.

Experimental Example 3 (DNA-Ca / protamine complex film) 500 mg of salmon DNA-Na salt powder (derived from testis, manufactured by Wako Pure Chemical Industries, Ltd.) was mixed with 40 m of water.
to give a clear, viscous solution. This was cast on a petri dish and air-dried at room temperature to obtain a transparent DNA-Na film. 10 ml of an aqueous protamine solution (containing 10 mg / ml of protamine) was added to 40 g of a methanol / water (25:75 wt / wt) mixed solution in which calcium chloride corresponding to 60 mol% of Na ions in the film was dissolved. A DNA-Ca / protamine composite film was prepared by immersing in a / protamine mixed solution for 24 hours.

Example 1-3, Comparative Example 1 Using the samples obtained in Experimental Example 1-3, the following blood coagulation properties were evaluated. Heparinized arterial blood (heparin
2.4 U / mL) was dropped at room temperature in a windless state on a sample placed in a 25 mm dish, and the sample was tilted every 30 seconds.
The fluidity of the blood was observed. No change was observed even after 25 minutes with the heparinized arterial blood of the comparative example alone, but a blood clot was formed after 5 minutes with each sample, and the fluidity was reduced. The sample becomes semi-lysed and forms a blood clot,
In the film obtained in Experimental Example 2, coagulation was confirmed in 5-10 minutes. In the film of Experimental Example 1, solidification was confirmed after 15 minutes. From these results, the product of the present invention was confirmed to have coagulation ability.

Example 4-6, Comparative Example 2 The hemostatic effect of the film obtained in Experimental Example 1-3 was evaluated by the following method using animals. The exposed rabbit femoral artery (heparin 200U / BWiv) was punctured with a 23G injection needle,
Immediately, each sample was pressed against the bleeding site, and hemostasis was observed. In Comparative Example 2, it took approximately 10 minutes to stop the bleeding with mere compression bleeding, but the bleeding was completed in 3 minutes when each sample was used. According to this example, the product of the present invention showed hemostasis superior to compression hemostasis by applying to the bleeding hole of the artery under pulsation.

[0013]

As described in detail above, the present invention is a hemostatic agent containing a calcium salt of a nucleic acid as a main component, so that there is no risk of infection by unknown virus caused by human-derived material, It is possible to provide a hemostatic agent which can be applied to many sites and has no antigenicity problem. Further, according to the present invention, it is possible to provide a hemostatic agent which promotes natural repair of a wound formed in a blood vessel and hardly causes rebleeding from the wound. That is, according to the present invention,
It is possible to provide a hemostatic agent having a rapid coagulation reaction capable of stopping arterial blood without inhibiting the healing of a wound surface, and having both adhesiveness to tissue and biodegradability.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) A61P 7/04 A61K 37/08 // C07H 21/00 37/12

Claims (5)

[Claims] 1. A hemostatic agent comprising a calcium salt of a nucleic acid as a main component. 2. The hemostatic agent according to claim 1, wherein said nucleic acid is DNA. 3. The hemostatic agent according to claim 1, wherein the calcium salt of the nucleic acid is 10-100 equivalent% of the counter cation of the nucleic acid is a calcium ion. 4. The hemostatic agent according to claim 1, wherein the hemostatic agent further contains a protein. 5. The hemostatic according to claim 4, wherein said protein is at least one selected from the group consisting of protamine, collagen, and gelatin.