JP2906409B2 - Blood filter - Google Patents

Description

The present invention relates to a blood filter, particularly a body fluid containing leukocytes,
A filter for removing leukocytes from lymph fluids and their processing, and in particular, by specifying the size, shape characteristics and structure of constituent fibers, a leukocyte removal filter with excellent leukocyte removal rate and red blood cell recovery rate with less blood cell damage About.

2. Description of the Related Art The recent thinking on blood transfusion has shifted from conventional whole blood transfusion to components according to the needs of patients. That is, in the conventional whole blood transfusion and red blood cell concentration blood transfusion, side effects such as fever, headache, and nausea due to the incompatibility of histocompatible antigens often occur in patients transfused with the whole blood transfusion or red blood cell concentration liquid transfusion. Therefore, it has been considered that it is better to perform transfusion of blood containing only red blood cells without containing extra components as much as possible in general blood transfusion requiring only red blood cells.

Methods for removing leukocytes from whole blood are roughly classified into a centrifugation method, a dextran sedimentation method, and a filter method. From the viewpoint of simplicity of operation and low cost, a filter method has been mainly studied. In the filter method, efforts have been made to increase the leukocyte removal property and separation efficiency by examining the fiber material and the filling method, particularly by the fiber diameter and the filling rate.For example, reducing the fiber diameter and increasing the filling rate in Japanese Patent Publication No. 58-54125. It is known that this increases the surface of the fiber in contact with leukocytes and improves the leukocyte removal rate.

However, it is difficult to reduce the fiber diameter only to a certain extent, and when the filling rate is increased, the leukocyte removal rate decreases in a short time.

(Problems to be Solved by the Invention) The present invention has been made by focusing on the above problems. That is, it is an object of the present invention to provide a leukocyte filter having an excellent leukocyte removal rate and an excellent erythrocyte recovery rate by increasing the surface area of fibers in contact with leukocytes without reducing the fiber diameter so much and without increasing the filling rate. .

(Means for Solving the Problems) The present invention provides a bulk density of 0.05 to 0.5 g using a synthetic fiber having an irregular cross section having a single fiber fineness of 0.25 denier or less and a surface area increase ratio F represented by the following formula of 1.15 or more. / cm ³ , basis weight 10-10
A blood filter comprising a non-woven fabric of 0 g / cm ² laminated in a plurality of layers.

The filter referred to in the present invention refers to a filter in which a plurality of non-woven fabric seeds composed of fibers having an irregular cross section are laminated.

The fineness of the monofilament of the synthetic fiber constituting the blood filter according to the present invention must be 0.25 denier or less, preferably 0.1 denier or less, and the cross section of the single fiber has an irregular shape and the surface area increase ratio is 1.15 or more. Such a synthetic fiber is characterized in that it is in an opened state, whereby the surface area of the fiber is increased, and a leukocyte removing effect excellent in a leukocyte removing rate and a red blood cell recovery rate is exhibited.

If the fineness of the synthetic fibers constituting the blood filter according to the present invention is 0.25 denier or more, the area of contact with leukocytes decreases, the leukocyte removal property is poor, and the drape property and softness are poor due to the irregular cross-sectional effect, which is not preferable. If the fineness is excessively small, the single fibers constituting the structure are easily deformed easily by a weak force. Therefore, the preferable fineness is from 0.05 denier to 0.005 denier. The cross-section of the synthetic fiber constituting the blood filter according to the present invention has a modified cross-section, so that the increase in surface area is 1.15 or more, preferably 1.30 or more, and the surface area increase is less than 1.15, as compared with the round cross-section fiber. The ratio is not preferable because the leukocyte removal rate is less improved than that of the fiber having a round cross section. Here, the surface area increase ratio is preferably as large as possible, but it is estimated that the limit is about 10 from the viewpoint of production. The cross-sectional shape of the synthetic fiber is not particularly limited.

The synthetic fiber constituting the blood filter according to the present invention is not particularly limited as long as it is a synthetic polymer capable of being melt-spun, such as polyester, polyamide, polyolefin, polyacrylonitrile, and polyvinyl chloride. Examples thereof include those having a relatively high modulus, such as an aromatic polymer, or those capable of imparting properties such as heat resistance, chemical resistance, and weather resistance.

The bulk density of the nonwoven fabric constituting the filter of the present invention is 0.05
~0.5g / cm ^3, preferably 0.1~0.3g / cm ^3, the mass per unit area 10~100g / cm
² , wherein the nonwoven fabric is a single layer or a plurality of layers laminated.

Example 1 Using a melt blow nozzle shown in FIG. 1 (1 in the figure, an orifice hole, 4 indicates an excessive detection end), an intrinsic viscosity of 0.65
Polyethylene terephthalate of orifice hole equivalent diameter 0.
4mmφ, a nozzle of the type shown in Fig. 2 (e), formed by 0.023 denier having an irregular cross-section by a conventional melt-blowing method, with a basis weight of 40g / cm ² made of ultrafine fibers having a surface area increase ratio of 1.42, and a thickness of 10mm
Was obtained.

Fifteen such filters were stacked, and the leukocyte removal performance of fresh bovine blood to which ACD was added was evaluated in a filter holder having an effective diameter of 8 cm. The evaluation was performed by measuring the number of blood cells of blood sampled from the inlet and outlet channels of the test filter using a microsyringe with a Coulter counter (manufactured by Coulter Electronics Co., Ltd.). Table 1 shows the leukocyte removal rate and erythrocyte recovery rate at a flow rate of 40 ml / mn and a treated blood volume of 500 ml.

Example 2 A nonwoven fabric was prepared from polyethylene terephthalate having an intrinsic viscosity of 0.65 under the same conditions as in Example 1 by using a nozzle having an orifice hole shape (equivalent to a circle having a diameter of 0.4 mn) shown in FIG. The characteristics of the obtained non-woven fabric are fineness of 0.023 denier and 40g.
/ cm ² and the surface area increase ratio was 1.32.

The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Example 3 Polyethylene terephthalate having an intrinsic viscosity of 0.65 was added to the second
In FIG. (C), a fiber having a density of 0.015 denier and a surface area increase ratio of 1.3 under the same conditions as in Example 1 using a nozzle having an orifice hole shape,
A nonwoven fabric having a basis weight of 40 g / cm ² was obtained. Table 1 shows the leukocyte removing effect.

Comparative Example 1 The orifice shape is as shown in FIG.
A nonwoven fabric was prepared under the same conditions as in Example 1 except that 0.3 mm was used. The characteristics of the obtained nonwoven fabric were a fineness of 0.046 g / d, a basis weight of 40 g / cm ² , and a surface area increase ratio of 1.00. The same evaluation as in Example 1 was performed, and the results are shown in Table 1.

Comparative Example 2 A nonwoven fabric was prepared under the same conditions as in Example 1 except that the nozzle (circle equivalent diameter φ0.4 mm) shown in FIG. 2 (c) was used as the orifice shape.

The characteristics of the obtained nonwoven fabric are fineness 0.012 g / d, basis weight 40 g / c.
m ² and the surface area increase ratio was 1.10. Evaluation was performed in the same manner as in Example 1, and the results are shown in Table 1.

(Effects of the Invention) The present invention is configured as described above, and provides a leukocyte removal filter which increases the fiber surface area by specifying the diameter cross-sectional shape of the fibers constituting the nonwoven fabric and has excellent leukocyte removal properties. It was possible to do.

[Brief description of the drawings]

FIG. 1 shows a spinning nozzle by a melt blow method, and FIG.
The figure shows the hole shape of the spinning nozzle and the cross section of a single yarn.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) A61M 1/34

Claims (1)

(57) [Claims] 1. A bulk density of 0.05 to 0.5 g / cm ³ , a basis weight of 10 to 100 g using a synthetic fiber having an irregular cross section having a single fiber fineness of 0.25 denier or less and a surface area increase ratio F represented by the following formula of 1.15 or more:
A blood filter, comprising a plurality of nonwoven fabrics of / cm ² laminated on each other.