JPS63122463A - Adsorbing body and method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an adsorbent for removing harmful components from body fluids. More specifically, the present invention relates to an adsorbent for selectively adsorbing and removing amyloid precursors contained in body fluids.

[Problems to be solved by the prior art and the invention] Amyloidosis is a phenomenon in which β-fibrillar proteins called amyloid substances are deposited in blood vessels, tissues, and organs, leading to organ failure such as heart and kidney, cardiac impulse conduction disorder, It is a disease that causes serious disorders such as progressive dementia, cerebrovascular disorders, and neurological disorders.
There are currently no established treatments.

It is known that amyloidosis has disease types such as primary, secondary, familial, and senile, but in all disease types, deposited amyloid substances produce green polarized light when stained with Congo red. , its structure is a β-sheet structure.

In recent years, a disease called carpal bone syndrome has been occurring frequently in patients who have undergone artificial dialysis for a long period of time, and it has recently become clear that amyloid substances with the above-mentioned characteristics are deposited in the affected areas in these cases as well.

However, its protein composition differs depending on the disease type; primary disease is composed of a protein called AL, continuous disease is composed of a protein called AA, and senile disease is composed of a protein called As. In addition, in amyloidosis caused by long-term dialysis, β2-microglobulin-like protein is
As for familial occurrence, it varies depending on the family, but proteins similar to prealbumin are deposited.

It is becoming clear that precursor substances corresponding to amyloidosis substances deposited in each disease type exist in patient blood. Familial amyloidosis, in which immunoglobulin light chain (SAL) is deposited in primary cases, SAA protein, a type of apoliboprotein, is deposited in secondary cases, and β2-microglobulin and prealbumin-like protein are deposited in long-term dialysable cases. It is said that abnormal prealbumin is a precursor substance.

As mentioned above, amyloidosis is a serious disease with a high mortality rate, so treatments for it have been actively researched, but so far no effective treatment, especially drug therapy, has been found. .

On the other hand, attempts have been made to treat amyloidosis using blood purification methods using extracorporeal circulation, which have become popular in recent years, especially plasmapheresis. It has been reported that symptoms can be alleviated and the progression of lesions can be halted by replacing it with

Blood purification through extracorporeal circulation, especially plasmapheresis, is currently the most effective treatment, but it requires the use of large amounts of expensive and valuable normal plasma or plasma preparations, and it requires the use of precursors other than those contained in the patient's plasma. Since useful components are also discarded at the same time, there is a strong desire to develop a method for more selectively removing precursors.

A separation method using an ultrafiltration membrane is known as a method for selectively separating components in plasma depending on their size, but the amyloid precursors mentioned above are proteins such as albumin and gamma globulin that are useful components in plasma. This method is not suitable for removing amyloid precursors because these useful proteins are also lost at the same time when the precursors are separated and disposed of because they are similar in size to amyloid precursors.

Therefore, a selective removal method other than membrane separation is desired, but no practical method for removing amyloid precursors has been developed so far.

[Means for Solving the Problems] The present invention relates to an adsorbent for amyloid precursor protein, which is a porous body containing polystyrene as a main component.

The present invention also relates to a method for removing amyloid precursor protein from a body fluid, which comprises filling the adsorbent into a container having a fluid inlet and an outlet, and then circulating the body fluid containing the amyloid precursor protein.

[Example] In this specification, body fluids refer to those containing blood, plasma, serum, ascites, lymph fluid, intraarticular fluid, fractionated components obtained therefrom, and other biologically derived humoral components.

The adsorbent of the present invention is an adsorbent suitable for selectively and efficiently removing amyloid precursor protein from body fluids, and is particularly suitable for a method of removing amyloid precursor protein by extracorporeal circulation.

Adsorbents for extracorporeal circulation are required to have various properties compared to general adsorbents.

The required properties are: (1) Since it is necessary to process body fluids at a certain high speed, there is little pressure loss when body fluids are distributed in columns etc., and there is no clogging due to deformation of adsorbent particles. (2) It has high mechanical strength and does not shatter due to vibration impact and does not produce fine powder; (3) It does not undergo chemical or physical and (4) low toxicity.

The present inventors have conducted extensive research on adsorbents that meet the above conditions and can selectively and efficiently remove amyloid precursor protein from body fluids, and have discovered that a porous material whose main component is polystyrene is superior. This led to the invention.

Although it is not necessarily clear why a porous material whose main component is polystyrene selectively and efficiently adsorbs amyloid precursor protein, it is thought that it is because the polystyrene chains have a moderate interaction with the hydrophobic sites of amyloid precursor protein. It will be done.

The porous body mainly composed of polystyrene used in the present invention means that among the polymer chains constituting the porous body, monomer units represented by (in the formula, R+ is a hydrogen atom or a methyl group) constitute the polymer. 50 mol% or more of the total monomer units contained in the monomer. A portion of the hydrogen atoms on the benzene ring in the monomer unit is substituted with an alkyl group having 1 to 6 carbon atoms, an amino group, a carboxyl group, a sulfone group, a sulfuric acid ester group, or a substituent containing these functional groups. You can leave it there.

The porous body containing polystyrene as a main component used in the present invention may consist entirely of the above-mentioned monomer units, or may contain less than 50 mol% of other monomer units. Other monomer units include trifunctional vinyl or allyl compounds such as divinylbenzene and diallyl phthalate, ethylene, propylene, vinyl acetate, vinyl alcohol, vinyl chloride, acrylic acid, methacrylic acid,
Examples include, but are not limited to, vinyl compounds such as methyl acrylate and methyl methacrylate, and diene compounds such as butadiene and isoprene.

A porous material whose main component is polystyrene may or may not be crosslinked, but if it is crosslinked, it has relatively high strength, and in particular, it has better heat resistance and chemical resistance. preferable.

The porous body containing polystyrene as a main component used in the present invention preferably has a large number of continuous pores with appropriate diameters.

Methods for measuring the pore diameter, pore volume, and pore distribution of porous materials include a method using a mercury porosimeter, and a nitrogen gas adsorption method (BE).
T method) is typical. These methods measure porous materials in a dry state, and although the pore state of porous materials is generally different from that in solution, there is little change in porous materials whose main component is polystyrene. The value is considered to reflect the pore state in solution well.

The preferred pore volume of the porous body used in the present invention is 0.2 ml.
/g or more, more preferably 0.5ml/g or more. If the pore volume is less than 0.2 ml/g, the effective surface area for adsorption of the adsorbed protein is small and a sufficient amount of adsorption cannot be achieved.

The average pore diameter of the porous body mainly composed of polystyrene used in the present invention is preferably 50 Å or more, and 10 Å or more.
More preferably, the thickness is 0 Å or more. If the average pore diameter is less than 50, the diffusion of amyloid precursor protein into the pores is slow and a sufficient amount of adsorption cannot be achieved. In particular, when the proteins are associated, the substantial molecular weight of the proteins becomes large, so that the diffusion rate becomes lower.

In addition, if the average pore diameter is too large, the surface area of the adsorbent becomes small and the adsorption capacity decreases.
This is not preferable because so-called non-specific adsorption increases and selectivity decreases. Furthermore, if the pore size is too large, the adsorbent becomes brittle and is likely to be crushed by impact to produce fine powder, which is not preferable as an adsorbent for extracirculation therapy. A preferred average pore diameter is 1500 Å or less.

Therefore, the average pore diameter of the porous body mainly composed of polystyrene used in the present invention is preferably 50 or more and 1500 Å or less.

Next, it is preferable that the pore distribution of the porous body containing polystyrene as the main component used in the present invention be narrower because the selectivity will be improved. do not have. As a guideline for preferred pore distribution, 50% or more of the total pore volume is 50 or more and 1500 Å.
It can be mentioned that the pores are occupied by pores with the following pore diameters. If the ratio of the pore volume occupied by pores with a pore diameter of 50 to 1500 Å to the total pore volume is less than 5θ%, if there are many pores with a diameter of 1500 Å or more, the surface area is small and a sufficient amount of adsorption may not be achieved. Alternatively, there are disadvantages such as a large amount of non-specific adsorption. Also, if there are many pores with a small pore size, it is not preferable because a sufficient amount of adsorption cannot be obtained, as in the case where the average pore size is small.

Further, even if the pore distribution is too wide and it is difficult to determine the average pore diameter, it is suitable for the present invention as long as the pore distribution meets the above criteria.

The surface area of the porous body mainly composed of polystyrene used in the present invention is an important factor determining the saturated adsorption amount of the adsorbent, and is preferably at least 50 d1g or more.

Next, the particle diameter of the porous body mainly composed of polystyrene used in the present invention is preferably 10 or more and 3000 or less. 1
If it is less than 0, it is difficult to filter out the adsorbent, and the pressure loss when filling a column or the like and distributing body fluid is undesirable. Moreover, if the number of printings exceeds 3,000, it takes time for the amyloid precursor protein, which is the object to be adsorbed, to diffuse into the particles, so the adsorption rate decreases, which is not preferable. A more preferable particle size is 4 oum or more and 1500 rho or less.

There are various methods for adsorbing and removing amyloid precursor protein from body fluids using the adsorbent according to the present invention. A typical method is to remove body fluids and store them in a bag etc.
A method in which an adsorbent is mixed with this to adsorb and remove amyloid precursor protein, and then the adsorbent is filtered to obtain a body fluid from which amyloid precursor protein has been removed. One method is to fill a container with a filter that does not allow the adsorbent to pass through, and then pour body fluids through the container. Either method may be used, but the latter method is easy to operate, and by incorporating it into an extracorporeal circulation circuit, it is possible to efficiently remove amyloid precursor protein from a patient's body fluids, especially blood or plasma, online. As already mentioned, the adsorbent of the present invention is most suitable for this method.

The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited to the following Examples.

Example 1 Diaion IPIO, a styrene-divinylbenzene copolymer (manufactured by Mitsubishi Kasei ■, specific surface area 500n? 7g)
, pore volume 0.89 m17g, 50 or more 1500Å
The following pore volumes are 80% of the total pore volume), Diaion llP2O (manufactured by Mitsubishi Kasei ■, specific surface area 720rrl')
7g.

Pore volume 1.1 ml/g, 70% of pore volume of 50 to 1500 Å), Diaion HP50 (manufactured by Mitsubishi Kasei ■, specific surface area 590 nf/g, pore volume 0.87
Diaion SP 20B (manufactured by Mitsubishi Kasei ■, specific surface area 180 rrr 7 g, pore volume 0.
4ml/g, the pore volume of 50 to 1500 Å is 55% of the total pore volume), and the particle size range is 50 to 40.
0ta, and Amberlite XAD-2 (manufactured by Rohm and Haas, specific surface area 300nf 7g, pore volume 0
．． ff5 m17g, average pore diameter 90), Amberlite XAD-4 (manufactured by Rohm and Haas, specific surface area 7)
80rrr 7g, pore volume 1, 0ml 11g, average pore diameter 50 people) All particle sizes 100 to 500, co,
Each was thoroughly washed with pure water, and then washed with physiological saline in an amount 10 times the amount of the adsorbent.

Next, take 1 ml of each adsorbent into a test tube and add β-
2 Serum from long-term dialysis patients containing high amounts of microglobulin 4
ml and incubated for 2 hours at 37°C with shaking. As a control, 4 ml of the same serum was added to 1 ml of physiological saline instead of the adsorbent and incubated in the same manner.

After the incubation, each test tube was centrifuged to separate the adsorbent and serum, and the concentration of β-2 microglolin, albumin, total protein, and immunoglobulin AS in the serum was determined.
G and M were measured.

Table 1 shows the results.

[Example 2: Styrene-divinylbenzene copolymer Diaion HP2Q, HP50, HP2MG (manufactured by Mitsubishi Kasei ■, specific surface area 480rrr 7g, pore volume 1.2ml)
/g, most frequent pore radius 100-1000 people, 50 or more1
Serum of a patient with multiple myeloma complicated by amyloidosis, containing a large amount of immunoglobulin light chain (λ type) using Amberlite XAD-4 An adsorption experiment was conducted in the same manner as in Example 1, except that .

The results are shown in Table 2.

[Left below] Example 3 Diaion lP2O, HP50, IIP2MG, which are styrene-divinylbenzene copolymers, and Annoku-Lite An adsorption experiment was conducted in the same manner as in Example 1, except that serum from amyloidosis patients was used. The adsorption rate of abnormal prealbumin was determined from the difference from the results of an adsorption experiment using normal serum containing approximately the same concentration of prealbumin.

The results are shown in Table 3.

[Margins below] [Effects of the Invention] The amyloid forwarding protein adsorbent of the present invention can selectively and efficiently remove amyloid precursor protein from body fluids without removing other active ingredients. Furthermore, the adsorption method of the present invention is easy to operate, and by incorporating it into an extracorporeal circulation circuit, it is possible to efficiently remove amyloid precursor protein from a patient's body fluids, particularly blood or plasma, online. Therefore, the present invention contributes to the treatment of amyloidosis by removing amyloid precursors.

Claims (1)

[Scope of Claims] 1. An adsorbent for amyloid precursor protein, which is a porous material whose main component is polystyrene. 2. The adsorbent according to claim 1, which is a porous body containing crosslinked polystyrene as a main component. 3. The adsorbent according to claim 1, wherein the porous body has a pore volume of 0.2 ml/g or more and a specific surface area of 50 m^2/g or more. 4 50% or more of the pore volume of the porous body has a pore diameter of 100
The adsorbent according to claim 1, characterized in that the adsorbent is filled with pores having a diameter of 1,500 angstroms or more. 5. A method for adsorbing and removing amyloid precursor protein from a body fluid, which comprises filling the adsorbent according to claim 1 into a container having a fluid inlet and outlet, and then flowing the body fluid containing the amyloid precursor protein. .