JP2717666B2 - Blood purification adsorbent, method for producing the same, and blood purification apparatus using the same - Google Patents

Description

The present invention relates to an adsorbent for purifying blood by adsorbing and removing harmful components in blood, a method for producing the adsorbent, and a blood purification apparatus using the adsorbent. About. More specifically, the present invention relates to a blood purification adsorbent obtained by treating a carrier having a silanol group on the surface with a silane compound.

[Conventional technology]

The technology to remove harmful substances in blood using a porous adsorbent is first to use activated carbon, and then to use low-density lipoproteins, immune complexes, γ-globulins, immunosuppressants, etc. Various organic and inorganic porous materials have been studied in order to remove pathogenic substances. Among these, many proposals have been made with respect to those using a porous body having a silanol group on the surface, such as porous glass and porous silica. For example, JP-A-58-38562,
58-61753,58-166582,59-139935,60-150833 and 60
Japanese Patent Publication No. 242862 discloses a blood purification adsorbent using such a porous material as it is.
56038,57-56039,57-75141,57-122875,57-170263,58
In each of the publications −10056, 58-54961 and 58-173553, a silanol group-containing carrier is treated with a silane coupling agent to bind the silane compound to the carrier, and further has an affinity for a substance to be adsorbed on the silane compound. A selective adsorbent having a compound (ligand) bound thereto is disclosed. In addition,
JP-A-59-44266 also proposes an adsorbent in which a part of a silanol group of a carrier is blocked with a silane compound to improve adsorption characteristics.

[Problems to be solved by the invention]

The adsorbent using such a silanol group-containing carrier has a problem that a part of the carrier component is gradually eluted. Therefore, when used in a living body, this eluted component may be mixed into blood, which is not preferable. It is considered that this eluted component is generated by dissolving a part of the carrier, and it has been considered that it is impossible to produce an adsorbent with a small amount of eluted matter by simply washing.

Therefore, in Japanese Patent Application Laid-Open No. 61-58664, a porous glass is treated with a silane coupling agent having three lower alkoxy groups such as γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane. In addition, a method has been proposed in which a crosslinked layer is formed on the surface to suppress the elution of eluted substances. According to this method, the elution of the eluate can be suppressed to some extent, but it is not sufficient. The reason is that such a method merely reduces the elution rate and because the adsorbent still contains a large amount of eluted components, which elute gradually through the crosslinked layer. The blood purification adsorbent is usually used after steam sterilization at a temperature of about 115 ° C. According to the results of tests performed by the present inventors, a large amount of eluted components during sterilization were obtained after the above cross-linking treatment. Was found to elute. In addition, when a ligand is bound to a silane coupling agent, it is necessary to wash and remove unreacted ligand that has not been bound later, but this takes a lot of time, and washing is insufficient. It turned out that there was also a problem that the compound leaked into the blood.
Therefore, there was a problem in terms of safety.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a highly safe adsorbent with a small amount of eluate.

[Means for solving the problem]

According to the results of a detailed study by the present inventors, the carrier having a silanol group contains a water-soluble component in the production process, and most of the eluted substance is this water-soluble component, and if the carrier is sufficiently washed, It was found that the soluble component was removed to obtain a product with almost no eluate. As a result of further study, when a silane compound having three lower alkoxy groups that react with a silanol group is used as in the prior art when treated with a silane coupling agent, sufficient elution occurs even after long-time washing. While it is difficult to reduce the amount of the substance, when a silane compound having two lower alkoxy groups is used, washing is efficiently performed,
It was found that unreacted ligand could be easily removed.

That is, the present invention is a blood purification adsorbent obtained by treating a carrier having a silanol group on the surface with a silane compound, wherein the silane compound has a structure in which two lower alkoxy groups are bonded to a silicon atom, And the adsorbent is 115
An adsorbent for blood purification, characterized in that the amount of eluted material after extraction with hot water at 30 ° C. for 30 minutes is 500 μg / g or less. And the manufacturing method, the carrier having a silanol group on the surface,
The method comprises treating with a silane compound having a structure in which two lower alkoxy groups are bonded to a silicon atom, reacting the silane compound with the silanol group, and then washing with water or an aqueous solution. Further, the present invention is a blood purification apparatus characterized in that the above-mentioned adsorbent is filled in a vessel having an inlet and an outlet for blood and sterilized by high-pressure steam.

[Action]

According to the present invention, the reason why the washing is carried out efficiently to obtain an adsorbent with a small amount of eluted material is not clear, but it is presumed that the reason may be as follows. That is, when a carrier is treated with a silane compound in which three lower alkoxy groups are bonded to a silicon atom, the silane compound not only reacts with the silanol group of the carrier but also has three reaction sites,
The silane compounds react with each other to form a three-dimensional cross-linking layer composed of several molecular layers, and the permeation of the eluted material is prevented and the elution is delayed. Since a monolayer that hardly affects the permeation of the eluate is formed, it is considered that washing is performed efficiently. For the same reason, it is considered that removal of the unreacted ligand becomes easy.

〔Example〕

The carrier having a silanol group on the surface used in the present invention is a carrier having a silanol group -Si-OH on the surface, and a porous carrier is preferably used. Examples of such carriers include porous silica,
Examples thereof include porous silica-alumina and porous glass. Since these porous bodies have different optimum ones depending on the substance to be adsorbed, the silanol group concentration, pore diameter, pore volume, surface area and the like should be appropriately selected for use.

The silane compound used to treat the carrier has two lower alkoxy groups bonded to a silicon atom and the other two
One bond is a compound in which a group other than an alkoxy group is bonded, It is a compound represented by these. Here, R ₁ is a lower alkyl group such as a methyl group or an ethyl group, and R ₂ and R ₃ are the same or different lower alkyl groups. A is preferably a group whose main chain is composed of an alkyl group and has a reactive group at the terminal for binding a ligand. Examples of the reactive group for binding the ligand include an epoxy group and an amino group. Preferred examples of the silane compound include γ-glycidoxypropylmethyldiethoxysilane and N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane. Since these are commercially available as silane coupling agents,
Can be used easily.

When the silane compound is brought into contact with the silanol group-containing carrier in the presence of water, the lower alkoxy group reacts with the silanol group and binds to the carrier. Generally, a method in which an aqueous solution of a silane compound is prepared and a carrier is immersed in the aqueous solution is preferable. The bond between the silane compound and the ligand is performed by a known method using an epoxy group or an amino group. As the ligand, there are various ones described in the above-mentioned prior art documents. In addition, as a ligand for adsorbing hemoglobin, it has a phenol group or a phenyl group exemplified by tyramine, tyrosine, phenylalanine, aminophenol and the like. Compounds can be used.

The carrier treated with the silane compound and, if necessary, to which the ligand has been bound is then washed with water or an aqueous solution to remove eluates. As the water, distilled water or water purified by a method such as membrane filtration is preferably used. As a washing method, there are a method of repeating immersion in water many times and a method of exposing to running water. However, it is preferable to use a Soxhlet extractor because long-time washing can be performed easily and efficiently. Washing usually needs to be performed for several hours or more, so that the amount of eluate after extraction with hot water at 115 ° C. for 30 minutes is 5 hours.
It can be less than 00 μg / g. On the other hand, when a silane compound in which three lower alkoxy groups are bonded is used, elution occurs forever even if the washing time is extended, and it is difficult to reduce the amount of eluted material to 500 μg / g or less. . In the washing, it is preferable to wash the carrier after it is immersed in an acid such as hydrochloric acid or acetic acid in advance to transfer the carrier to the acidic side, in order to reduce the eluted material.

The adsorbent thus washed is filled in a container having an inlet and an outlet for blood. The container has filters at both ends for holding the adsorbent, and is made of a material that can withstand steam sterilization. In the case of performing steam sterilization, it is preferable to fill an adsorbent with an aqueous solution such as water or a physiological saline solution. Steam sterilization temperature is 100
A range of ~ 130 ° C is appropriate.

In order to remove the pathogenic substance in blood using the adsorbent of the present invention, the blood may be directly contacted with the adsorbent, or the blood may be separated into blood cells and plasma once and only the plasma is contacted with the adsorbent. You may make it do. Such methods are well-known to those skilled in the art.

Hereinafter, the present invention will be described in more detail with reference to specific examples.

Example 1 Silica gel (MB-5D manufactured by Fuji Devison Chemical Co., Ltd.)
Is immersed in a 0.5% aqueous solution of methanol (30% methanol concentration) of γ-glycidoxypropylmethyldiethoxysilane (KBE402 manufactured by Shin-Etsu Chemical Co., Ltd.), and the pressure is reduced to remove air bubbles. The silane compound was reacted with the silanol groups of the silica gel. Then, after lifting up from the silane solution, water adhering to the surface was removed, and vacuum drying was performed overnight. Next, after heat treatment at 160 ° C. for 2 hours, it was immersed in a 1% aqueous solution of tyramine, shaken at 60 ° C. for 3 hours, and allowed to stand at room temperature overnight to react the tyramine with the epoxy group of the silane compound. . Then, after washing with water and treating in an autoclave at 120 ° C. for 2 hours, it was washed with a 2N aqueous hydrochloric acid solution and further washed with water. Then, the adsorbent was put into a Soxhlet extractor, and washed for a predetermined time using water to obtain an adsorbent having tyramine bonded to the surface.

Next, for the measurement of the eluate, the adsorbent was treated in an autoclave at 115 ° C. for 30 minutes in a state of being immersed in 50 ml of water, the adsorbent and the liquid were separated by filtration, and 20 ml of the filtrate was evaporated to dryness. The weight of the solid precipitated was measured. Table 1 shows the results
Shown in The weight of the eluate in Table 1 is a value converted per 1 g of the adsorbent.

From the results shown in Table 1, it can be seen that the amount of eluted material becomes 500 μg / g or less after washing for 16 hours or more.

To test the adsorption capacity of the adsorbent, the adsorbent washed with a Soxhlet extractor for 19 hours was filled into a polypropylene container with blood inlet and outlet, and hemoglobin was added.
Plasma containing 230 mg / dl was allowed to flow for 70 minutes, and the hemoglobin concentration in the outflowing plasma was measured. As a result, 75% of hemoglobin in the treated plasma was adsorbed, and had excellent hemoglobin adsorption ability.

Comparative Example 1 As a silane compound, instead of γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane (KBM40 manufactured by Shin-Etsu Chemical Co., Ltd.) was used.
An adsorbent was prepared in the same manner as in Example 1 except that 3) was used as a 0.5% aqueous solution, and the amount of eluted material was measured. Table 2 shows the results.

As is apparent from the result of the vapor, when a silane compound in which three alkoxy groups are bonded to a silicon atom is used,
Washing does not significantly reduce the amount of eluate. Also,
As a result of performing a hemoglobin adsorption test in the same manner as in Example 1, the adsorption rate was 73%.

Example 2 An adsorbent was prepared in the same manner as in Example 1 except that washing with a 10% aqueous acetic acid solution was performed instead of washing with hydrochloric acid before washing with a Soxhlet extractor, and the amount of eluted material was determined. Was measured. Table 3 shows the results.

Comparing the results in Table 3 with the results in Table 1, it can be seen that the use of acetic acid can more easily remove the eluate than the use of hydrochloric acid. The hemoglobin adsorption rate was measured and found to be 71%.

Comparative Example 2 An adsorbent was prepared in the same manner as in Example 2 except that γ-glycidoxypropylmethyldiethoxysilane was used instead of γ-glycidoxypropylmethyldiethoxysilane as a silane compound. The measurement was performed. Table 4 shows the results.

[Effects of the Invention] According to the present invention, an adsorbent with a small amount of eluate can be obtained using a carrier having a silanol group on the surface. Therefore, it is excellent in terms of safety. Moreover, the adsorption capacity is the same as that of the conventional one, and various ligands can be bound by using a silanol group and a silane compound.By selecting various ligands, various pathogens in blood can be selectively selected. Can be adsorbed and removed. Therefore, the blood processing apparatus of the present invention is useful for removing free hemoglobin in blood and treating various diseases such as rheumatoid arthritis, systemic lupus erythematosus, myasthenia gravis, familial hypercholesterolemia, and cancer.

Claims (3)

(57) [Claims] 1. A blood purification adsorbent obtained by treating a carrier having a silanol group on the surface with a silane compound, wherein the silane compound has a structure in which two lower alkoxy groups are bonded to a silicon atom. An adsorbent for blood purification, wherein the amount of eluted material when the adsorbent is extracted with hot water at 115 ° C. for 30 minutes is 500 μg / g or less. 2. A carrier having a silanol group on its surface is treated with a silane compound having a structure in which two lower alkoxy groups are bonded to a silicon atom, and the silane compound is reacted with the silanol group. The method for producing an adsorbent for blood purification according to claim 1, wherein the adsorbent is washed with water. 3. A blood purification apparatus, wherein the adsorbent according to claim 1 is filled in a vessel having an inlet and an outlet for blood and sterilized by high-pressure steam.