JPH09299477A - Cholesterol adsorptive material, cholesterol removing filter and method for removing cholesterol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an adsorbent with which useful components in blood are not adsorbed and cholesterol can be selectively removed by incorporating polypropylene glycol and/or its derivatives. SOLUTION: Polypropylene glycol and/or polypropylene glycol derivatives are incorporated in a cholesterol adsorbent. In this case, polypropylene glycol and polypropylene glycol derivatives may be fixed on a carrier by heat treatment and/or radiation treatment or it may be applied on the carrier by coating. As the carrier, fibrous, sheet-like, cotton-like and granulated substances are pref. and e.g. an ultrafine fiber with a mean fiber diameter of 0.5-5μm is used. In addition, this cholesterol adsorbent is used by making it as a shape of a cholesterol removing filter and filling it in a container.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an adsorbent for removing harmful components in blood. For more information,
The present invention relates to an adsorbent for selectively adsorbing and removing cholesterol (including lipoprotein, particularly very low density lipoprotein (VLDL) and / or low density lipoprotein (LDL)) from blood.

[0002]

2. Description of the Related Art Cholesterol is abundant in lipoproteins (VLDL-LDL) existing in blood and is known to cause arteriosclerosis. In particular, in hyperlipidemia such as familial hyperlipidemia and hypercholesterolemia, VLDL and / or LDL values are several times higher than the normal value, causing hardening of coronary arteries and the like. Although diet therapy, drug therapy, and the like are used to treat these diseases, their effects are limited and side effects are also a concern. Especially for familial hyperlipidemia, the blood of the patient is collected to collect cholesterol (VLDL-LD
After separating plasma containing a large amount of L), replace it with normal plasma or a replacement solution containing albumin as a component to VLDL.
So-called plasmapheresis, which lowers the LDL and LDL levels, is currently the only effective treatment.

However, as is well known in the plasmapheresis treatment method, (1) it is necessary to use expensive fresh plasma or plasma preparation, (2) there is a risk of infection with hepatitis virus, and (3) only harmful components. Not only useful components (eg high density lipoprotein (HDL)) are removed at the same time,
It has disadvantages such as.

For the purpose of eliminating the above drawbacks, selective removal of harmful components by a membrane has been attempted. However, its selectivity is still unsatisfactory.

For the purpose of solving the above-mentioned drawbacks, an adsorbent based on the so-called affinity chromatography principle, which uses a substance having a specific affinity for the substance to be removed, has been attempted. For example, an attempt to use a so-called immunoadsorbent on which an antigen or an antibody is immobilized, or an affinity chromatography in which a substance (ligand) having a specific affinity for a substance to be removed other than the antigen and the antibody is immobilized on a carrier. Attempts have been made to use graphy.

The above-mentioned affinity chromatography is almost satisfactory in terms of selectivity. However, the antigen, antibody or ligand used in this method is often a substance derived from a living body. Therefore, there is a drawback that the stability against sterilization operation is low. Further, antigens and antibodies are difficult to obtain, and ligands are easier to obtain than antigens and antibodies, but they are difficult to obtain and expensive. Therefore, the use of affinity chromatography for extracorporeal circulation therapy is not sufficient in terms of safety and cost.

On the other hand, Japanese Examined Patent Publication No. 63-19214 and Japanese Patent Laid-Open No. 4-2
No. 27268 describes that dextran sulfate and / or a salt thereof is immobilized on a water-insoluble porous body via a covalent bond and used as a ligand of an adsorbent for the treatment of extracorporeal circulation of cholesterol.

However, dextran sulfate and /
Alternatively, its salt is insufficient as a material for adsorbing and removing cholesterol (including lipoprotein). The reason is that dextran sulfate contains cholesterol (including lipoproteins)
However, since it has a negative charge, it also adsorbs proteins having a positive charge (for example, cytochrome C and β2-microglobulin). Therefore, it is insufficient as a specific adsorption / removal material for cholesterol (including lipoprotein).

As described above, in the conventional adsorption / removal material, cholesterol (lipoprotein, particularly very low density lipoprotein (VLDL))
And / or low density lipoprotein (LDL)) could not be selectively adsorbed and removed.

[0010]

DISCLOSURE OF THE INVENTION The present invention provides cholesterol (including lipoprotein) in patients with familial hyperlipidemia and the like without adsorbing useful components in blood. It is an object of the present invention to provide an adsorbent that is selectively adsorbed and removed to be used as an adsorbent for extracorporeal circulation treatment.

[0011]

Means for Solving the Problems As a result of intensive studies to solve these problems, the inventors of the present invention have surprisingly found that a carrier (for example, ultrafine fibers or polymer particles) is used.
The inventors have found that cholesterol (lipoprotein) is selectively adsorbed and removed by immobilizing or coating polypropylene glycol and / or a polypropylene glycol derivative, which is an uncharged neutral molecule, on the above, and completed the present invention.

The present invention relates to a cholesterol adsorbent containing polypropylene glycol and / or a polypropylene glycol derivative.

Further, the present invention relates to a cholesterol adsorbent in which polypropylene glycol and / or polypropylene glycol derivative is fixed or coated on a carrier.

The present invention also relates to a cholesterol adsorbent in which polypropylene glycol and / or polypropylene glycol derivative is fixed or coated on a carrier by heat treatment and / or radiation treatment.

In a preferred embodiment, the carrier is fibrous, sheet-like, cotton-like or particle-like.

[0016] In a preferred embodiment, the fibrous carrier is ultrafine fibers, and more preferably, the average fiber diameter of the ultrafine fibers is 0.5 µm to 5 µm.

Furthermore, in a preferred embodiment, the ultrafine fibers are cotton-like or sheet-like.

[0018] In a preferred embodiment, the carrier is a particulate resin.

The present invention also relates to a cholesterol removal filter in which the above cholesterol adsorbent is loaded in a container.

In a preferred embodiment, the container is a cylindrical container.

[0021] In a further preferred embodiment, the cholesterol adsorbent is polypropylene glycol and
/ Or ultrafine fibers coated with a polypropylene glycol derivative, which are loaded in the tubular container in a cotton or sheet shape.

The present invention also relates to a method for producing a cholesterol adsorbent, which comprises a step of fixing or coating a carrier by heat treatment or radiation treatment of polypropylene glycol and / or a polypropylene glycol derivative.

Furthermore, the present invention includes the step of bringing the cholesterol removal filter into contact with blood.
It relates to a method of removing cholesterol in blood.

As described above, only cholesterol is selected by using a filter in which a cholesterol adsorbent obtained by fixing or coating polypropylene glycol and / or a polypropylene glycol derivative on a carrier is loaded in a (cylindrical) container. Provided is a filter for selectively adsorbing and removing. This filter can be used for extracorporeal circulation therapy for hyperlipidemia / hypercholesterolemia patients such as familial hyperlipidemia.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The cholesterol adsorbent of the present invention contains polypropylene glycol and / or a polypropylene glycol derivative.

When cholesterol is referred to in the present invention,
Not only cholesterol, but also lipoproteins containing cholesterol, particularly very low density lipoprotein (VLDL) and / or low density lipoprotein (LDL) are included.

The polypropylene glycol (hereinafter sometimes referred to as PPG) and the PPG derivative used in the present invention are not particularly limited. For example, PPG having various molecular weights such as average molecular weights of 200, 400, 1000, 2000 and 4000 are commercially available, but any of them can be used. Further, various structural formulas such as diol type and triol type are commercially available, but these can also be used. As the PPG derivative, one having a terminal group modified with methacrylate, alkylate or the like can be used. Further, as the surfactant, a derivative polymerized with ethylene oxide or the like can also be used. These PPG
Although there is no great difference in the cholesterol adsorption ability of the derivatives, it is preferable to use PPG and PPG derivatives having a large molecular weight in order to widen the adsorption area.

As the adsorbent, a water-insoluble carrier can be preferably used. The carrier may be fibrous, sheet-like, cotton-like or particle-like, and any carrier having such a shape or capable of constituting such a shape may be used. For example, polymer fiber,
Polymer particles may be mentioned. The polymer fiber may be used in the form of sheet or cotton.

The material of the polymer fiber used in the present invention is not particularly limited, and examples thereof include polyester, nylon and polypropylene. Of these, hydrophobic polypropylene and polyester polymers, which have low complement activity and excellent biocompatibility, are preferable.

In the present invention, ultrafine fibers can be preferably used as the polymer fiber used for the carrier. The shape of the ultrafine fibers is not particularly limited, and examples thereof include a sheet shape, a cotton shape, a non-woven cloth shape, a woven cloth shape, and a knitted cloth shape. Formability, processability, easiness of handling, and difficulty of channeling and uneven flow after forming, it is preferable to use a non-woven fabric or cotton obtained by a usual ultrafine fiber spinning method such as melt blow, and it is preferable to use a non-woven fabric. More preferable.

The average fiber diameter of the ultrafine fibers used in the present invention is preferably 0.5 μm-5.0 μm, and more preferably,
It is 1.5 μm-3.5 μm. Here, the average fiber diameter of the ultrafine fibers is the diameter of 50 ultrafine fibers randomly selected from the photograph of the ultrafine fiber aggregate taken with an electron microscope at a magnification of 2000, and the diameter is measured with a caliper or scale loupe. It is the average of the calculated values.

When ultrafine fibers are loaded into a container as an adsorbent and used as a filter, when the loading amount is the same, the smaller the average fiber diameter of the ultrafine fibers, the larger the surface area per unit volume and the greater the adsorption amount of cholesterol. Become. However, the smaller the average fiber diameter of the ultrafine fibers,
The fiber length per unit volume of the ultrafine fiber assembly becomes longer,
The number of entangled portions of the fibers per unit volume is increased, the fiber gap is reduced, and white blood cells and platelets are easily adsorbed. Furthermore, when the fiber gap becomes small, blood cells are likely to be clogged, and the blood cells remain in the filter. The average fiber diameter of the ultrafine fibers is preferably 0.5 μm-5.0 μm, and more preferably, in order to maintain the cholesterol adsorbing ability without the blood cell components remaining in the filter.
l.5 μm-3.5 μm. The ultrafine fibers can be produced by a method well known to those skilled in the art, for example, a melt blow method.

As the particulate carrier used in the present invention,
Particles of polymers can be used. As the polymer, polyethylene, polyethylene terephthalate, polypropylene, polyethylene and other polymers can be preferably used. The particle size of the polymer particles is not particularly limited, but the smaller the particle size, the larger the surface area and the larger the amount of cholesterol adsorbed. However, if the particle diameter is too small, the gap between particles becomes small when the filter is used, and blood cells are likely to be clogged, and the blood cells remain in the filter.
On the contrary, when the particle size is increased, the gap between particles is increased and blood cells are less likely to be clogged, but the surface area is decreased and the amount of cholesterol adsorbed is decreased. The particle size of the polymer particles is 5-200 in order to maintain the cholesterol adsorption capacity without the blood cell components remaining in the filter.
μm is preferred.

For fixing or coating the PPG and / or PPG derivative on the carrier, a method well known to those skilled in the art can be used. For example, it may be fixed or coated by heat treatment, radiation treatment or chemical bonding. Here, fixed means P
It refers to fixing the PG or PPG derivative to the carrier, and includes the case of covering the entire surface of the carrier. When covering the entire surface of the carrier, it is called coating. Although the heat treatment of PPG differs depending on the treatment concentration, the treatment temperature, etc., for example, PPG or PPG
0.001% to 50% by weight of the derivative, preferably 0.05% to 10% by weight, particularly preferably 0.0
It is carried out by immersing the carrier in an aqueous solution having a concentration of 1% by weight to 1% by weight and heating it in the range of 30 ° C to 200 ° C, preferably 70 ° C to 130 ° C for 5 minutes to 2 hours. Thereby, the PPG and / or the PPG derivative is fixed or coated on the carrier.

The radiation treatment of PPG varies depending on the concentration of PPG to be treated and the like. For example, 0.001 to 50% by weight of PPG or a PPG derivative, preferably 0.
The carrier is immersed in an aqueous solution having a concentration of from 05% by weight to 10% by weight, particularly preferably from 0.01% by weight to 1% by weight, and 1
It is performed by irradiation with a radiation dose of not less than kGy, preferably 10 kGy to 100 kGy. This gives P
The PG and / or PPG derivative is fixed or coated on the carrier.

As another method of fixing or coating the PPG and / or PPG derivative on the carrier, a method of chemically bonding the PPG and / or PPG derivative can be used.

The adsorbent fixed or coated by the above method is washed with water and dried, and then loaded into a container to form a filter. As the drying, natural drying or heat drying at 30 ° C. to 150 ° C. can be used.

If the operating conditions are the above-mentioned heating temperature, heating time, radiation irradiation conditions (strength, time), and drying conditions,
There is no significant difference in cholesterol adsorption capacity.

The shape of the container in the cholesterol removing filter of the present invention is not particularly limited. A cylindrical container is preferable from the viewpoint of strength and handling. When the same volume of ultrafine fibers is loaded, the cross-sectional area decreases as the inner diameter decreases, and the blood passage amount per unit area increases, so that blood cells are likely to be clogged at the entangled portions of the fibers. Therefore, it is not preferable to use a cylindrical container having an inner diameter of 2 mm or less.

A cholesterol-removing filter in which a cylindrical container is loaded in the form of cotton or a sheet and using ultrafine fibers coated with polypropylene glycol and / or a polypropylene glycol derivative as an adsorbent is preferable.

As a method of removing cholesterol in blood according to the present invention, there is a method of supplying blood to a cholesterol removing filter and applying a constant pressure. Generally, a pressure comparable to blood pressure is preferred.

The operation and effect of the present invention will be described below with reference to examples and comparative examples.

[0043]

EXAMPLES In the following examples, ultrafine fibers spun by the melt-blowing method or polyethylene particles are used as a carrier, and the carrier is heat-treated or irradiated with PPG to fix or coat PPG on the carrier. Used as a material.

A 20 ml plastic syringe was filled with ultrafine fibers little by little to prepare a cholesterol adsorption filter having a constant bulk density in the syringe. The filter (adsorbent) was evaluated using fresh bovine blood to which an appropriate amount of ACD (acid citrate dextrose) solution was added as an anticoagulant. A fixed amount of ACD-added fresh bovine serum was added to the cholesterol adsorption filter, a fixed pressure was applied to collect blood after passing through the filter, and the concentration of cholesterol was compared with the blood before passing through the filter. In addition, in order to analyze the performance of the filter (to confirm the specificity), the albumin / total protein / urea nitrogen concentration, which is usually performed as a biochemical analysis, was measured. Furthermore, as a hemolysis test, the concentration of free hemoglobin in the obtained blood was measured. The albumin, total protein, urea nitrogen and cholesterol were measured using "Test Wako (manufactured by Wako Pure Chemical Industries)". Hemoglobin was measured for UV absorption at wavelengths of 570 nm and 700 nm, and was measured by the difference in UV absorption between the two (570 nm-700 nm).

Example 1 Polyethylene terephthalate ultrafine fibers having an average fiber diameter of 1.8 μm were made into a non-woven fabric to form P
It was immersed in a 1% aqueous solution of PG4000. After irradiating with γ-ray at 20KGy, it was washed with water and dried to obtain an adsorbent. Fill the syringe with dried non-woven microfibers (adsorbent) little by little,
Finally, 1.5 g of the adsorbent was filled to a volume of 10 ml to prepare a cholesterol adsorption filter having a bulk density of 0.15 g / cm ³ .

10 ml of fresh bovine blood to which an ACD solution was added as an anticoagulant was passed through the cholesterol adsorption filter to collect blood, and the blood components before and after the permeation were analyzed.

(Example 2) Ultrafine fibers of polyethylene terephthalate having an average fiber diameter of 3.5 μm were made into a non-woven fabric to form P
It was immersed in a 1% aqueous solution of PG4000. After irradiating with γ-ray at 20KGy, it was washed with water and dried to obtain an adsorbent. Fill the syringe with dried non-woven microfibers (adsorbent) little by little,
Finally, 1.5 g of the adsorbent was filled to a volume of 10 ml to prepare a cholesterol adsorption filter having a bulk density of 0.15 g / cm ³ .

10 ml of fresh bovine blood to which an ACD solution was added as an anticoagulant was passed through the cholesterol adsorption filter to collect blood, and the blood components before and after the permeation were analyzed.

(Embodiment 3) Ultrafine fibers of polyethylene terephthalate having an average fiber diameter of 1.8 μm are made into a non-woven fabric to form P
It was immersed in a 1% aqueous solution of PG200. After irradiating with γ-ray at 20KGy, it was washed with water and dried to obtain an adsorbent. The dried non-woven fabric ultrafine fibers (adsorbent) are packed into a syringe little by little, and finally 1.5 g of adsorbent is filled to a volume of 10 m1,
A cholesterol adsorption filter having a bulk density of 0.15 g / cm ³ was prepared.

10 ml of fresh bovine blood to which an ACD solution was added as an anticoagulant was passed through the cholesterol adsorption filter to collect blood, and the blood components before and after the permeation were analyzed.

Example 4 Ultrafine fibers of polyethylene terephthalate having an average fiber diameter of 1.8 μm were made into a non-woven fabric to form P
It was immersed in a 1% aqueous solution of PG4000. After heat treatment at 121 ° C. for 1 hour, it was washed with water and dried to obtain an adsorbent. Small portions stuffed dry nonwoven microfine fiber (adsorbent) in a syringe and finally adsorbent 1.5g was filled so that the capacity of 10M1, bulk density cholesterol absorption filter of 0.15 g / cm ³ It was made.

10 ml of fresh bovine blood to which an ACD solution was added as an anticoagulant was passed through the cholesterol adsorption filter to collect blood, and the blood components before and after permeation were analyzed.

Example 5 Polyethylene terephthalate ultrafine fibers having an average fiber diameter of 1.8 μm were made into a non-woven fabric to form P
It was immersed in a 1% aqueous solution of PG4000. After heat treatment at 70 ° C. for 20 minutes, it was washed with water and dried to obtain an adsorbent. Small portions stuffed dry nonwoven microfine fiber (adsorbent) in a syringe and finally adsorbent 1.5g was filled so that the capacity of 10M1, bulk density cholesterol absorption filter of 0.15 g / cm ³ It was made.

10 ml of fresh bovine blood to which an ACD solution was added as an anticoagulant was passed through the cholesterol adsorption filter to collect blood, and the blood components before and after permeation were analyzed.

Example 6 Ultrafine fibers of polyethylene terephthalate having an average fiber diameter of 1.8 μm were made into a non-woven fabric,
It was immersed in a 1% aqueous solution of a PPG derivative having an acrylic group at the end. After irradiating with γ-ray at 20KGy, it was washed with water and dried to obtain an adsorbent. Fill the syringe with dried non-woven microfibers (adsorbents) little by little, and finally fill 1.5g of adsorbents to a volume of 10m1, with a bulk density of 0.15g / cm ³
The cholesterol adsorption filter of was prepared.

10 ml of fresh bovine blood to which an ACD solution was added as an anticoagulant was passed through the cholesterol adsorption filter to collect blood, and the components of the blood before and after permeation were analyzed.

(Embodiment 7) PPG is prepared by forming ultrafine fibers of polyethylene terephthalate having an average fiber diameter of 1.8 μm into a cotton shape.
It was immersed in 4000 1% aqueous solution. After irradiating with γ-ray at 20KGy, it was washed with water and dried to obtain an adsorbent. Fill the syringe with dry cotton-like ultrafine fibers (adsorbent) little by little, and finally
A cholesterol adsorption filter having a bulk density of 0.15 g / cm ³ was prepared by filling 1.5 g of the adsorbent so as to have a volume of 10 ml.

10 ml of fresh bovine blood to which an ACD solution was added as an anticoagulant was passed through the cholesterol adsorption filter to collect blood, and the blood components before and after the permeation were analyzed.

Example 8 Polyethylene beads having an average particle size of 1.8 μm were immersed in a 1% aqueous solution of PPG4000. After irradiating with γ-ray at 20KGy, it was washed with water and dried to obtain an adsorbent of polyethylene peas. A syringe was filled with 3 g of dried polyethylene beads (adsorbent) to a volume of 10 ml to prepare a cholesterol adsorption filter having a bulk density of 0.3 g / cm ³ .

10 ml of fresh bovine blood to which an ACD solution was added as an anticoagulant was passed through the cholesterol adsorption filter to collect blood, and the blood components before and after the permeation were analyzed.

(Comparative Example) Ultrafine fibers of polyethylene terephthalate having an average fiber diameter of 1.8 μm were made into a non-woven fabric and packed into a syringe little by little, and finally 1.5 g of the adsorbent was filled to a volume of 10 ml, A cholesterol adsorption filter having a bulk density of 0.15 g / cm ³ was prepared.

10 ml of fresh nocturnal blood to which an ACD solution was added as an anticoagulant was passed through this cholesterol adsorption filter to collect blood, and the components of the blood before and after permeation were analyzed.

The results of each Example and Comparative Example are shown in Tables 1 and 2. It is clear that the adsorbent of the present invention fixed or coated with PPG and / or PPG derivative selectively adsorbs cholesterol.

[0064]

[Table 1]

[0065]

[Table 2]

[0066]

According to the present invention, as is clear from Tables 1 and 2, cholesterol could be selectively adsorbed and removed without adsorbing other components in blood.

Claims (16)

[Claims] 1. A cholesterol adsorbent containing polypropylene glycol and / or a polypropylene glycol derivative. 2. A cholesterol adsorbent in which polypropylene glycol and / or polypropylene glycol derivative is immobilized on a carrier. 3. A cholesterol adsorbent in which a carrier is coated with polypropylene glycol and / or a polypropylene glycol derivative. 4. A polypropylene glycol and / or a polypropylene glycol derivative is heat treated and / or
Alternatively, a cholesterol adsorbent fixed on a carrier by radiation treatment. 5. A polypropylene glycol and / or a polypropylene glycol derivative is heat treated and / or
Alternatively, a cholesterol adsorbent coated on a carrier by radiation treatment. 6. The cholesterol adsorbent according to claim 1, wherein the carrier is fibrous, sheet-like, cotton-like or particle-like. 7. The cholesterol adsorbent according to claim 6, wherein the fibrous carrier is an ultrafine fiber. 8. The average fiber diameter of the ultrafine fibers is 0.5 μm.
To 5 μm, the cholesterol adsorbent according to claim 7. 9. The cholesterol adsorbing material according to claim 7, wherein the ultrafine fibers are cotton-shaped or sheet-shaped. 10. The cholesterol adsorbent according to claim 6, wherein the particulate carrier is a resin. 11. A cholesterol removal filter in which a container is loaded with the cholesterol adsorbent according to any one of claims 1 to 10. 12. The container according to claim 1, wherein the container is a cylindrical container.
The cholesterol removal filter described in 1. 13. The method according to claim 12, wherein the cholesterol adsorbent is an ultrafine fiber coated with polypropylene glycol and / or a polypropylene glycol derivative, and is loaded in the tubular container in a cotton shape or a sheet shape. Cholesterol removal filter. 14. A method for producing a cholesterol adsorbent, which comprises a step of heat-treating or irradiating polypropylene glycol and / or a polypropylene glycol derivative to fix it on a carrier. 15. A method for producing a cholesterol adsorbent, which comprises a step of coating a carrier by heat treatment or radiation treatment of polypropylene glycol and / or polypropylene glycol derivative. 16. A method for removing cholesterol in blood, comprising the step of bringing the cholesterol removal filter according to claim 11, 12 or 13 into contact with blood.