JP3193819B2 - Artificial organ - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial organ. More specifically, the present invention relates to an artificial organ such as an artificial kidney, an artificial lung, and a blood separation device which suppresses activation of leukocytes or platelets and has excellent biocompatibility.

[0002]

2. Description of the Related Art Conventionally, artificial organs such as artificial kidneys, artificial lungs, and plasma separators have been used, and synthetic polymer membranes have been widely used in dialysis membranes, gas exchange membranes, blood component separation membranes, and the like. . However, for example, in an artificial kidney,
Frequent hemodialysis causes the activation of white blood cells or platelets, resulting in complications and a serious problem for dialysis patients. In particular, a decrease in antioxidant activity in blood and a high level of lipid peroxide have been confirmed in patients undergoing long-term hemodialysis, and as a result, arteriosclerotic diseases in long-term dialysis patients have increased.

On the other hand, in order to solve this problem, an artificial organ in which the surface of a dialysis membrane is coated with a vitamin E film having various physiological actions such as an antioxidant action in a living body, a biomembrane stabilizing action and a platelet aggregation inhibiting action. Has been proposed.
-41738). However, when vitamin E is coated on the surface of the hydrophilic material, elution to blood is observed at the time of blood inflow, and it is confirmed that about 90% of vitamin E elutes into blood 30 minutes after blood circulation. The persistence of the effects of vitamin E is a problem.

Further, the higher the solubility parameter δ, the stronger the hydrophilicity. When the dialysis membrane is a hydrophilic material, the affinity for vitamin E, which is a fat-soluble vitamin, is poor.
The solubility parameter δ is 15.65 (cal / cm ³ ) ^1/2
The problem with regenerated cellulose is that it is eluted into the blood when it flows into the blood.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an artificial organ which has a good affinity for vitamin E which is a fat-soluble vitamin, suppresses elution into blood, and has few side effects on the living body. It is in.

[0006]

[MEANS FOR SOLVING THE PROBLEMS]
The artificial organ of the present invention is an artificial organ having a body fluid permeable membrane.
Wherein the body fluid permeable membrane has a solubility parameter δ of 13
(Cal / cm^Three)^1/2BelowFrom polysulfone
And may further contact at least the bodily fluid of the bodily fluid permeable membrane.
Characterized by a vitamin E coating on the surface of the
I do.Further, the artificial organ of the present invention contacts at least body fluid.
Body fluid permeability with vitamin E coated on the surface of the touchable area
An artificial organ having a perfusion membrane, wherein the body fluid permeable membrane is dissolved.
Degree parameter δ is 13 (cal / cm ^Three ) ^1/2 Below
That the amount of vitamin E eluted in plasma is 0%
Features.

[0007] The artificial organ of the present invention is preferably formed by coating vitamin E on at least the surface of a part of the artificial organ that comes into contact with the body fluid in the body fluid circulation area.

[0008] In the artificial organ of the present invention, the body fluid permeable membrane is preferably a hollow fiber membrane.

Further, in the artificial organ of the present invention, it is preferable that the body fluid permeable membrane is a synthetic polymer membrane containing a hydrophobic or hydrophobic portion.

[0010]

The biocompatible artificial organ of the present invention has a body fluid permeable membrane having a vitamin E coating amount of 1 to 1000 mg / m ^3.
It is preferred that

The artificial organ in the present invention is an artificial kidney,
An artificial liver, an artificial lung, a plasma separator, a blood circuit, an artificial blood vessel, and the like, which has a body fluid circulation area through which a body fluid such as blood flows in an artificial organ, and at least a part of the body fluid circulation area is a body fluid permeation. Preferably, it is a membrane. The artificial organ includes not only a tube and a connector for connecting the living body to the artificial organ, but also a blood circuit and the like.

Further, the solubility parameter δ in the present invention
Indicates the degree of affinity with vitamin E. When the solubility parameter δ is high, the hydrophilicity is strong, and when the solubility parameter δ is low, the hydrophobicity is strong. Further, when the solubility parameter δ is 13 (cal / cm ³ ) ^1/2 or less, the affinity with vitamin E is good and hydrophobic.
Further, regarding the method of calculating the solubility parameter δ, for example, see the Polymer Handbook (Basic Edition, pages 591 to 59).
3) and many other documents.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an example of an artificial kidney, ie, a hollow fiber membrane dialyzer. In this dialyzer 1, after inserting a hollow fiber bundle 5 composed of a large number of hollow fibers into a cylindrical main body 4 provided with an inlet pipe 2 and an outlet pipe 3 for dialysis fluid near both ends thereof, both ends thereof are made of polyurethane. The cylindrical body 4 is sealed together with the potting agents 6 and 7 at both ends. Headers 10 and 11 having an inflow port 8 and a discharge port 9 for bodily fluids are respectively in contact with both ends of the cylindrical main body 4, and caps 12 and 11 are provided.
13, the headers 10, 11 and the tubular main body 4 are fixed to each other. Further, tubes 14 and 15 connected to the human body are connected to the body fluid inlet 8 and the body fluid outlet 9 at both ends of the cylindrical main body 4.

The hollow fibers constituting the hollow fiber bundle 5 are made of polysulfone.
(Δ = 9.90) and the solubility parameter
δ is 13 (cal / cm ³ ) ^1/2 or less, and
It is sufficient that the amount of vitamin E eluted is 0%.

According to the present invention, the above-mentioned body fluid of the artificial kidney, for example, a contact portion of the artificial kidney with blood in the blood distribution area, for example, the inner surface of the hollow fiber membrane, the inner surface of the space formed by the header 10 and the potting agent 6, An inner surface of a space formed by the header 11 and the potting agent 7, an inner surface of the blood inlet 8, an inner surface of the blood outlet 9, inner surfaces of the tubes 14, 15,
Particularly, the hollow fiber membrane is coated with vitamin E on its inner surface. For example, in a hollow fiber type membrane, the inner surface of a hollow fiber membrane 16 is coated with a vitamin E film 17 as shown in FIG.

The vitamin E used in the present invention is fat-soluble. And tocotrienols such as tocotrienol and δ-tocotrienol. Also, vitamin E
Has a thickness of 0.001 to 1.0 μm, preferably 0.01 to 0.3 μm. When the film thickness is 0.001 μm or less, the effect of biocompatibility obtained by coating with vitamin E hardly appears, and the film thickness is 1.0 μm.
In the above case, the dialysis performance may be reduced.

Further, the coating amount of vitamin E is 1 to 10
00 mg / m ³ , preferably 10 to 300 mg / m ³ . When the coating amount of vitamin E is 1 mg / m ³ or less, the coating of vitamin E tends to be uneven, and the effect of biocompatibility is reduced. On the other hand, when the concentration is 1000 mg / m ³ or more, the film thickness of vitamin E becomes large, and the elution of vitamin E and the dialysis performance may decrease.

[0020] Such vitamin E is used in an amount of 0.01 to 20 w.
/ V%, preferably 0.1 to 10 w / v%, as an organic solvent solution, flows into the body fluid circulation area of the artificial organ (the blood circulation area in the case of the artificial kidney shown in FIGS. 1 and 2) for a predetermined time. For example, by contacting for 30 seconds to 60 minutes, preferably 1 to 10 minutes, the inner surface of the body fluid flow area, for example,
Inner surface of hollow fiber membrane, inner surface of space formed by header 10 and potting agent 6, inner surface of space formed by header 11 and potting agent 7, inner surface of blood inlet 8, inner surface of blood outlet 9, tube 14, 15 inside,
In particular, the inside of the hollow fiber membrane is sufficiently blended with vitamin E. Then, after discharging the solution, a gas inert to the vitamin E, for example, air, nitrogen, carbon dioxide gas or the like is introduced at a temperature of 10 to 80 ° C., preferably 15 to 30 ° C., and the organic solvent is introduced. Is evaporated to form a film of vitamin E on the contact surface, and if necessary, further washed with water. In this case, the coating operation may be performed without connecting the tubes 14 and 15 to form a vitamin E coating on the main part, particularly on the permeable membrane part.

The organic solvent used in the present invention is insoluble in the synthetic polymer membrane. For example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, Alcohols such as 2-ethylhexanol, diethyl ether and the like, or, for example, 1,2,2-trichloro-1,2,2-trifluoroethane, trichlorofluoromethane, 1,1,2,2-tetrachloro-1, 2-
Chlorofluorocarbons such as difluoroethane or the like, for example, methyl fluoride, carbon tetrafluoride, tetrafluoroethane,
Perfluorocycloalkanes such as tetrafluoroethylene, perfluoromethylpropylcyclohexane and perfluorobutylcyclohexane; and fluorinated hydrocarbons such as perfluorodecane, perfluoromethyldecalin and perfluoroalkyltetrahydropyran.

In the above, the artificial kidney, which is a dialyzer, has been mainly described.
It can also be used for plasma separators, blood circuits, artificial blood vessels and the like. A remarkable effect can be obtained by forming a vitamin E coating on a site having a permeable membrane for body fluids, especially blood.

Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

(Example 1) Inner diameter: about 200 μm, outer diameter: about 2
80 μm, length about 14 cm, solubility parameter δ 9.9
As shown in FIG. 1, 341 0 (cal / cm ³ ) ^1/2 polysulfone hollow fibers were inserted into the cylindrical main body 1 and both ends were fixed with polyurethane potting agents 6, 7, and both ends were further fixed. Attach headers 10 and 11 to
A dialyzer (artificial kidney) 1 was prepared by being fixed by 2 and 13. The surface area of the dialyzer 1 is 3 mm.
00 cm ³ .

On the other hand, 1.0 g of vitamin E (DL-α-tocopherol) was dissolved in 100 ml of ethanol to adjust the concentration of an ethanol solution of vitamin E to 1 w / v%. Then, a 50 ml syringe was connected to one end of the dialyzer 1 and the other end was immersed in a vitamin E solution, and the plunger of the syringe was operated to fill the dialyzer with the vitamin E solution. In this state, it was left at room temperature for 2 minutes. Next, after raising the dialyzer to discharge the vitamin E solution, an aspirator was connected, nitrogen gas was blown at a temperature of 25 ° C. to dry, and ethanol was removed.
Further, in order to complete the drying, it was left in an oven at 60 ° C. overnight. The amount of vitamin E in the dialyzer thus obtained was 0.63 mg.

Example 2 Using the same polysulfone hollow fiber as in Example 1, the concentration of vitamin E in an ethanol solution of vitamin E was set at 5 w / v%, and a dialyzer was produced in the same manner as in Example 1. . The vitamin E coating amount in this dialyzer was 3.13 mg.

( Reference Example 1 ) Inner diameter of about 250 μm, outer diameter of about 3
Using 273 polyacrylonitrile (hereinafter simply referred to as PAN) hollow fibers having a length of 20 μm and a length of about 14 cm,
Vitamin E concentration in ethanol solution of vitamin E was 5
A dialyzer was manufactured in the same manner as in Example 1 except that the ratio was w / v%. The membrane surface area of this dialyzer is 300c
At m ³ , the vitamin E coverage in the dialyzer is 4.1
9 mg.

Example 3 10 g of polysulfone was dissolved in 20 ml of dichloromethane and precipitated in 200 ml of methanol for purification. The obtained precipitate was filtered and dried at 60 ° C. 4.5 g of purified polysulfone and 0.25 g of polyvinylpyrrolidone were added to 25 ml of dimethylacetamide.
After dissolving into a 10 × 10 cm glass plate,
m, and solidified in a water bath. The obtained polysulfone flat membrane was sufficiently washed with water and then dried at 60 ° C. Next, the flat membrane of polysulfone was immersed in a 5 w / v% ethanol solution of vitamin E for 5 minutes, and then the flat membrane was lifted up and blown dry at a temperature of 25 ° C. further,
To ensure complete drying, it was left overnight in an oven at 60 ° C. The amount of vitamin E in the dialyzer thus obtained was 0.72 mg at 50 cm ³ .

(Comparative Example 1) For comparison, an inner diameter of about 2
Using 341 regenerated cellulose hollow fibers of 00 μm, outer diameter of about 240 μm, and length of about 14 cm, the concentration of vitamin E in an ethanol solution of vitamin E was 5 w / v%, and a dialyzer was produced in the same manner as in Example 1. did. The membrane surface area of this dialyzer was 300 cm ³ , and the amount of vitamin E in the dialyzer was 3.25 mg.

Comparative Example 2 For comparison, Example 1 was used.
Using the same polysulfone hollow fiber as in Example 1, a dialyzer was produced in the same manner as in Example 1 without treatment with an ethanol solution of vitamin E.

(Comparative Example 3) For comparison, Example 3 was used.
A flat membrane of polysulfone was produced in the same manner as in Example 3 by using the same polysulfone as in Example 1 and not treating with an ethanol solution of vitamin E.

(Experimental Example 1) Using the dialyzers of Examples 1 and 2, Reference Example 1 and Comparative Example 1, the amount of vitamin E eluted in plasma was examined.

First, 500 ml of bovine blood was dispensed into a 50 ml polypropylene test tube, and centrifuged at 3000 rpm for 15 minutes to obtain 200 ml of bovine plasma. In addition, 50
50 ml of bovine plasma was dispensed into a test tube made of polypropylene, and the test tube containing bovine plasma was connected to the blood inlet 8 of the dialyzer 1 via a pump via a vinyl chloride tube 14, and the blood outlet of the dialyzer 1 was further connected. 9 and the bovine plasma-containing test tube were connected by a vinyl chloride tube 15,
An experimental circuit was prepared. And 37 tubes containing bovine plasma
And maintained in a constant temperature bath at 10 ° C, and pumped bovine plasma at 10 ml / m
After circulating through the dialyzer for 4 hours at a flow rate of in, the amount of vitamin E eluted into bovine plasma after 4 hours was measured.

The amount of vitamin E eluted in plasma was measured as follows.

First, 1 ml of bovine plasma after the end of circulation was collected, and 1 ml of ethanol was added thereto and mixed for 30 seconds to remove proteins in bovine plasma. Next, 5 ml of hexane was added and mixed for 1 minute to transfer vitamin E in bovine plasma to the hexane layer. This was centrifuged at 1500 rpm for 10 minutes, and the amount of vitamin E in the upper hexane layer was quantified by liquid chromatography. The measurement conditions for liquid chromatography are as follows:
Column: Amide-80, 4.6 × 25 cm (Toso T
SK gel), n-hexane: i-propanol = 98: 2 as moving layer, flow rate: 1.5 ml / min, injection volume: 10 μl, detection: UV monitor at 292 nm
I went in.

Table 1 shows the measurement results of the amount of vitamin E eluted in plasma in Experimental Example 1.

[0037]

[Table 1]

(Experimental Example 2) Examples 1-2 and Comparative Example 2
In order to evaluate the biocompatibility of vitamin E using a dialyzer, extracorporeal circulation experiments were performed on rabbits, and the number of hollow fibers in which blood remained in the hollow fibers after completion of extracorporeal circulation was examined.

First, the rabbit was fixed in a dorsal position on a Kitajima-type fixing stand, the hair on the operative field was cut with an electric clipper, and wiped with alcohol wool. Then make an incision along the median line with scissors from the submandibular to the clavicle, open the fascia, taking care not to damage the nerves, branch vessels and surrounding tissues, right (left)
The common carotid artery was dissected. The left (right) facial vein was then similarly carefully peeled. Then, with the blood vessel clamped, a Surflow (registered trademark of Terumo Corporation) indwelling needle equipped with a rubber cap for co-infusion filled with physiological saline was inserted into the vein, and ligated and fixed. further,
One side (venous side) of the circuit was connected to the venous side of a dialyzer filled with saline with a polyvinyl chloride tube filled with saline. Similarly, an indwelling needle was inserted into the artery, ligated and fixed, and then connected to the arterial side of the dialyzer via a pump using a polyvinyl chloride tube filled with physiological saline.

Using the rabbit extracorporeal circuit thus produced, an extracorporeal circulation experiment was performed as follows.

First, the blood vessel was unclamped and extracorporeal circulation was performed for 2 hours while maintaining the flow rate at 10 ml / min with a pump. After the end of the circulation, clamp the arterial and venous blood vessels again,
The arterial circuit and the venous circuit were cut at a portion near the indwelling needle. Then, 50 ml of physiological saline is pumped for 10 m.
The circuit and the inside of the dialyzer were washed by a single pass at a flow rate of 1 / min. Cut the hollow fibers at the center of the dialyzer after washing, count the number of hollow fibers with residual blood with a microscope, and determine the residual blood rate by the total number of hollow fibers in the dialyzer and the number of hollow fibers with residual blood. Calculated.

Table 2 shows the calculation results of the residual blood rate after the end of extracorporeal circulation in Experimental Example 2.

[0043]

[Table 2]

(Experimental Example 3) Using the flat membranes of Example 3 and Comparative Example 3 as polysulfone membranes, the integrated emission intensity was measured to evaluate the amount of active oxygen production.

First, a 6% dextran T-70 physiological saline solution was added to 20 U / ml heparinized human blood at a ratio of 9: 1.
And gently mixed at a rate of, and allowed to stand for about 2 hours. Then, the supernatant was gently collected, and the leukocyte phagocytes in the supernatant were dissolved in Hank's ballance salt solution for 1 × 10 ⁶ ce.
It was adjusted to 11 / ml and used as a test solution. Then, a 40 cm ² flat membrane and 1.2 ml of the test solution were added to the cuvette so that the entire membrane was immersed in the test solution. The cuvette used was made of glass and previously coated with NCT-911 (Toshiba Silicone) using silicone.
Furthermore, 0.1 mM 2-methyl-6 (-
10 μl of (p-methoxyphenol) -3,7-dihydroimidazo (-1,2-a) -pyrazin-3-one was added, and the luminescence intensity integrated value at 37 ° C. for 15 minutes was immediately measured with a luminescence reader. For comparison, the integrated luminescence intensity of the cuvette alone was also measured.

Table 3 shows the measurement results of the integrated luminescence intensity for evaluating the amount of active oxygen produced in Experimental Example 3.

[0047]

[Table 3]

Table 1 showing the experimental results of Experimental Examples 1 to 3 described above.
3 show that in Table 1, the cellulose membrane of Comparative Example 1 had a solubility parameter δ of 15.70 (cal /
cm ³ ) ^1/2 and 88% of the vitamin E coverage eluted in the plasma circulation due to its high hydrophilicity. On the other hand, the polysulfone membranes of Example 1 and Example 2 had a solubility parameter δ of 9.90 (cal / cm ³ ) ^1/2 and had a hydrophobic part, so that vitamin E was completely eluted into plasma. However, it is strongly immobilized by a hydrophobic-hydrophobic bond with vitamin E. The solubility parameter δ of the PAN membrane of Reference Example 1 was 12.35 (cal / cm 3) 1/2, but the elution rate of vitamin E was about 1%, which was slightly lower than that of the cellulose membrane. Was.

In Table 2, the residual blood rate of the polysulfone membrane of Comparative Example 2 not treated with vitamin E was 37.9%, whereas the polysulfone treated with 1 w / v% vitamin E of Example 1 was used. In the membrane, the residual blood rate was 27.0%, and in the polysulfone membrane treated with 5 w / v% of vitamin E in Example 2, the residual blood rate was 18.6%, clearly inhibiting the platelet aggregation of vitamin E. The effect reduces the residual blood rate after extracorporeal circulation in rabbits, indicating excellent biocompatibility.

In Experimental Example 3, since the measurement including the outer surface (inner surface) of the hollow fiber which does not come into contact with blood is performed in the hollow fiber shape, the measurement in the flat membrane shape is performed on the assumption that all surfaces of the material come into contact with blood. This was done on the inner surface (outer surface) of the hollow fiber membrane.
There is no substitute for measuring only. In Table 3,
The luminescence intensity integrated value of the polysulfone membrane of Comparative Example 3 not treated with vitamin E was 378 kcpm, whereas Experimental Example 4
The emission intensity integrated value of the polysulfone membrane treated with Vitamin E was 203 kcpm, and it is clear that the amount of active oxygen produced by membrane stimulation was suppressed by coating with Vitamin E. Further, the integrated value of the luminescence intensity of only the cuvette was 192 kcpm,
It can be seen that the difference from the luminescence intensity integrated value of the polysulfone film treated with the above was slight. Thus, it is considered that production of active oxygen is suppressed by coating with vitamin E, and various diseases caused by active oxygen can be reduced.

The embodiment has been described above using the polysulfone hollow fiber membrane . In the present invention, the solubility parameter δ is 1
³ (cal / cm 3) ^1/2 or less der Ri vitamin E in plasma
Any membrane may be used as long as it has a 0% elution amount, and is not limited to a hollow fiber membrane, and may be a flat membrane or the like.

[0052]

As described above, according to the artificial organ of the present invention, the artificial organ has a body fluid permeable membrane, and the body fluid permeable membrane has a solubility parameter δ of 13 (cal / cm).
^{3) 1/2} Ri der Ru polysulfone Tona less, further, by characterized by comprising coated vitamin E to the surface sites capable of contacting the body fluid of at least the body fluid permeable membrane,
By improving affinity with vitamin E which is a fat-soluble vitamin and suppressing elution into blood, an artificial organ with less side effects on the living body and improved biocompatibility can be provided. In addition, the residual blood rate can be reduced. Further, the production of active oxygen is suppressed, and various diseases caused by active oxygen can be reduced.

Further, the artificial organ of the present invention is further characterized in that at least the surface of a part of the artificial organ which comes into contact with the body fluid in the body fluid circulation area is coated with vitamin E, thereby further improving biocompatibility. Can improve and reduce the residual blood rate. Furthermore, production of active oxygen is suppressed.

Further, the artificial organ of the present invention is characterized in that the body fluid permeable membrane is a hollow fiber type membrane, so that the effective membrane area is increased and the dialysis property is improved.

Further, the artificial organ of the present invention is characterized in that the body fluid permeable membrane is a hydrophobic or synthetic polymer membrane containing a hydrophobic portion, thereby further improving the affinity with vitamin E, Elution to the skin can be suppressed, and biocompatibility can be improved.

Further, the biocompatible artificial organ of the present invention has a body fluid permeable membrane having a vitamin E coating amount of 1 to 1000 mg / m ^3.
Thus, the coating of vitamin E is not uneven, and the biocompatibility can be improved without lowering the dialysis performance.

[Brief description of the drawings]

FIG. 1 is a perspective view of a dialyzer according to an embodiment of the present invention, which has a partially cut-out portion.

FIG. 2 is a longitudinal sectional view of a hollow fiber membrane showing an example of the present invention.

[Explanation of symbols]

 Reference Signs List 1 dialyzer 2 dialysate inlet pipe 3 dialysate outlet pipe 4 cylindrical main body 5 hollow fiber membrane 6,7 potting agent 8 body fluid inlet 9 body fluid outlet 10,11 header 12,13 cap 14,15 tube 16 hollow fiber membrane 17 Coating

Continuation of the front page (56) References JP 2-17208 (JP, B2) JP 62-41738 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61M 1 / 14-1/18 A61L 33/00

Claims (2)

(57) [Claims] 1. An artificial organ having a body fluid permeable membrane,
The body fluid permeable membrane has a solubility parameter δ of 13 (cal /
cm ^{3) 1/2} Ri Der Ru polysulfone Tona or less, and more,
An artificial organ, wherein at least the surface of a part of the body fluid permeable membrane which can come into contact with body fluid is coated with vitamin E. 2. The surface of a site which can be in contact with at least a body fluid.
With a body fluid permeable membrane coated with vitamin E
A humor permeable membrane having a solubility parameter δ of 1
3 (cal / cm ³ ) ^1/2 or less,
An artificial organ, wherein the elution amount of E is 0%.