JPH0572831B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention particularly relates to a platelet storage container for storing concentrated platelets collected by component blood collection and a method for storing platelets. <Conventional technology> When performing a blood transfusion, currently, for reasons such as effective use of blood and reducing the burden on the recipient, the blood obtained from the donor is separated into its components by centrifugation, etc., and only the components necessary for the recipient are separated. A system is in place to transfuse blood. With the introduction of this component transfusion, blood can now be used more effectively than the conventional whole blood transfusion. However, in Japan, the maximum amount of blood that one donor can donate is limited to 400 ml, and the blood components that can be separated from it are smaller. Therefore, in order to secure the amount of blood components required by the transfusion recipient, blood components from a large number of donors are required, and the side effects of blood transfusions include alloimmunization, post-transfusion hepatitis, and other transfers caused by blood transfusion. There was a risk of contracting an infectious disease. Therefore, in recent years, in order to reduce this infectious disease,
A blood apheresis method has been introduced as a component blood collection method in which only necessary blood components are collected and other blood components are returned to the donor. This blood apheresis method mainly requires a sheet thickness of 0.35~0.45mm and an inner surface area of 600~650mm for the blood storage area.
^{cm2 ,} polyvinyl chloride blood bags containing DEHP as a plasticizer are used. If plasma (hereinafter referred to as "PC") is stored, the pH will drop significantly and functional deterioration will accelerate, so the shelf life is limited to within 24 hours after blood collection. Therefore, the current situation is that blood donors are forced to experience inconvenience both during the medical period in which they use blood donors. Therefore, at least similar to whole blood-derived PC, the validity period should be extended to around 72 hours, so that blood donors can participate in blood donation in plenty of time and the collected blood can be used effectively without expiring. It is hoped that Attempts have been made to extend the validity period by dividing 10 unit PCs into multiple bags and storing them, but in this case, two or more bags must be prepared and handled. It has the drawbacks of being complicated to operate and increasing the possibility of contamination, so it has not been put into practical use. <Problems to be Solved by the Invention> The present invention has been made in view of the above-mentioned drawbacks of the prior art, and its purpose is to provide a platelet storage container capable of storing more platelets for a long period of time, particularly 10 An object of the present invention is to provide a platelet storage container capable of storing unit PC for 72 hours or more. <Means to solve the problem> When storing 2 units of PC in the conventional blood bag mentioned above, it can be stored for about 72 hours, but 10 units of PC can be stored for about 72 hours.
In order to enable storage of PC for 72 hours or more, a container for storing PC must have a gas permeability comparable to or higher than that of the conventional blood bag, and must prevent a drop in pH. The present inventors measured the gas permeability in a flexible vinyl chloride (PVC) manufacturing device with the aim of making it possible to store 10 units of PC for more than 72 hours. We found a suitable value for the capacity and completed the present invention. That is, the present invention provides a platelet storage container made of soft polyvinyl chloride containing 30 to 70 parts by weight of di-(n-decyl) phthalate as a plasticizer based on 100 parts by weight of polyvinyl chloride, which comprises: The platelet storage container is characterized in that the sheet thickness is 0.27 to 0.45 mm, and the inner surface area of the portion that may be involved in gas permeability of the platelet storage portion is 400 to 700 cm ² . The amount of carbon dioxide permeation in the platelet storage area is 3.1ml.
(CO ₂ )/day・atm・ml (PC) (30° C.) or more is preferably the platelet storage container according to claim 1. Preferably, the platelet storage container is used to store 2×10 ¹¹ platelets (10 units) or more. Preferably, the platelet storage container is used to store 10 units or more of platelets with a platelet concentration of 0.92 to 2.4×10 ⁶ /μ. Preferably, the platelet storage container has a shelf life of 72 hours or more for stored platelets. Moreover, the present invention is preferably a method for preserving platelets, in which platelets are preserved using any of the above-mentioned containers for platelet preservation. Hereinafter, preferred embodiments of the platelet storage container and platelet storage method of the present invention will be described in detail. FIG. 1 shows an example of the configuration of a double bag in which a blood bag and a platelet storage container of the present invention (hereinafter referred to as "PC storage bag") are connected. The blood bag 1 on the right side of FIG. 1 is made of a sheet bag made of, for example, soft polyvinyl chloride, and is fused at a sealed portion 2 at its periphery by high-frequency heating or other heating methods. A blood component storage part 3 in which blood components are stored is formed in the inner part surrounded by this seal part 2. At the top of the blood bag 1, two outlets 4, 4 with peel tabs are formed, and between them is an outlet 5 for connecting to the PC storage bag.
is formed. Further, one end of a flexible tube 6 communicating with the blood component storage section 3 is connected to the upper part of the blood bag 1, and a plastic blood collection needle 8 is connected to the other end of the tube 6 via a hub 7. It is installed. Further, a cap 9 for enclosing a plastic type blood collection needle 8 is attached to the hub 7. On the other hand, the PC storage bag 10 of the present invention shown on the left side of FIG. It is fused by. A platelet storage portion 12 is formed in the inner portion surrounded by the seal portion 11, in which platelet plasma separated from the blood components in the blood bag 1 is stored. At the top of the PC storage bag 10, two outlet ports 13, 13 with peel tabs are formed. Furthermore, on the side of the outlet 13 at the top of the bag,
Plastic tube 1 communicating with platelet storage section 12
4 is connected, and the other end of the tube 14 is connected to
It is connected to the outlet 5 of the blood bag 1 via a connecting member 15. As a result, blood bag 1
The blood component storage section 3 and the platelet storage section 12 of the PC storage bag 10 communicate with each other via a tube 14. A branch pipe (not shown) is provided in the middle of the tube 14, one end of a tube similar to the tube 14 is connected to the branch pipe, and the other end is connected to another PC storage bag having the same configuration as the PC storage bag 10. It is also possible to connect a plurality of PC storage bags to the blood bag 1, such as connecting to a blood bag. A label 16 for displaying the contents, capacity, date, etc. of the bag is usually attached to the outer surface of the sheet of the PC storage bag 10. The part where this label 16 is attached is the PC storage bag 10.
gas permeation through the sheet is obstructed. Therefore, the portion of the platelet storage portion 12 that may be involved in gas permeability refers to the area excluding the area to which the label 16 is attached, that is, the area shaded in FIG. 1. Such a PC storage bag 10 is made of soft polyvinyl chloride containing di-(n-decyl) phthalate (DnDP) as a plasticizer. The reason why soft polyvinyl chloride is used as a constituent material for PC storage bags is that it has flexibility to withstand centrifugation operations and heat resistance to sterilization. Further, the present invention is characterized in that DnDP is used as a plasticizer. That is, conventional PC storage bags are mainly composed of soft polyvinyl chloride containing di(ethylhexyl) phthalate (DEHP) as a plasticizer, and the sheet thickness
0.35~0.45mm, inner surface area of platelet storage 600~650
It was about cm ² in size. 2 units PC in this bug
If stored, it can be stored for up to 72 hours, but if 10 units of PC are stored, the PH will decrease due to insufficient gas permeability of the sheet, and the shelf life will be less than 24 hours. Therefore, with this bug
In order to be able to store 10 units on a PC for more than 72 hours,
Increase the inner surface area of the platelet storage area (e.g.
(approximately 1000 cm ² ), or the sheet thickness needs to be made even thinner, which is disadvantageous in terms of downsizing PC storage bags. On the other hand, with the PC storage bag of the present invention,
By using DnDP as a plasticizer, the sheet wall thickness and the effective inner surface area of the platelet storage area are kept at the same level as conventional bags, that is, the values described below, while the gas permeability of the sheet is improved and the 10 unit PC is reduced to 72 It can be stored for more than an hour. The content of such plasticizer DnDP is preferably 30 to 70 parts by weight based on 100 parts by weight of polyvinyl chloride. This is because if the amount is less than 30 parts by weight, the bag will not have flexibility, and if it exceeds 70 parts by weight, the amount of plasticizer eluted into the bag will increase. Further, a stabilizer or the like can be added to the sheet material. Examples of the stabilizer include epoxy compounds and Ca-Zn stabilizers. The sheet thickness of the platelet storage section 12 is 0.27 to 0.45.
mm, preferably 0.35 to 0.45 mm. If the sheet wall thickness is less than 0.27 mm, sufficient strength cannot be obtained, and the PH
If the sheet wall thickness exceeds 0.45 mm, the inner surface area of the portion that may be involved in the gas permeability of the platelet storage section, which will be described later, will increase to 400 mm.
This is because the desired gas permeability cannot be obtained at ~700 cm ² . Inner surface area of the portion of the platelet storage portion 12 that may be involved in gas permeability (hereinafter referred to as "effective inner surface area")
is 400 to 700 cm ² , preferably 600 to 650 cm ² . If the effective internal surface area is less than 400 cm ² , the desired gas permeability cannot be obtained, and if it exceeds 700 cm ² , the bag becomes large in size and becomes difficult to operate. In addition, the amount of carbon dioxide permeation in the platelet storage section 12 is 3.1 ml (CO ₂ )/day・atm・ml (PC) (30
℃) or more, preferably 3.6ml (CO ₂ )/day・
atm・ml (PC) (30℃) or more, preferably 4.0
ml (CO ₂ )/day・atm・ml (PC) (30°C) or higher is recommended. Carbon dioxide permeation amount is 3.1ml (CO ₂ )/day・atm・
If the temperature is less than ml (PC) (30°C), it will be difficult to store platelets for a long period of time, especially to store 10 units of PC for more than 72 hours. With the configuration described above, the concentration of platelets of 2×10 ¹¹ (10 units) or more, especially platelets, can be increased.
A PC storage bag capable of storing 10 units or more of platelets of 0.92 to 2.4×10 ⁶ μ for a shelf life of 72 hours or more is provided. The PC storage bag of the present invention is preferably one for storing 10 units or more of PC, but it is preferable to store 10 units or more of PC, but for storing less than 10 units, for example, about 7 to 9 units.
This does not exclude cases where the PC is saved. Next, a method for preserving platelets using a PC storage bag will be explained. For example, platelet-rich plasma separated using a pheresis system, model V50 (not shown) manufactured by Haemoneteix, is collected into the blood component storage section 3 of the blood bag 1. Next, this blood bag is centrifuged to separate platelet-rich and platelet-poor plasma. After that, tube 14 of PC storage bag 10
The connecting member 15 at the tip is connected to the outlet 5 of the blood bag 1, and the platelet concentrate is passed through the tube 14 to the PC.
Move to the platelet storage section 12 of the storage bag 10. This operation is repeated several times to store, for example, 10 units (approximately 200 ml) of platelets in the platelet storage portion 12, and the tube 14 is closed with a creme or the like. In this state, the PC storage bag 10 is stored in the atmosphere. At this time, the shelf life of the stored platelets is 72 hours or more. Note that the storage temperature of platelets is preferably 20 to 24°C in consideration of the recovery rate and lifespan of platelets, but in special cases, storage at temperatures other than this is also possible. <Example> Next, the present invention will be described in more detail based on specific experimental examples. The experimental method was as follows. (1) PC storage bags PC storage bags of the present invention having the structure shown in FIG. 1 (invention examples, comparative examples 1 and 2) were manufactured. These bags are all made of soft polyvinyl chloride, and the type of plasticizer, its content, and sheet thickness are as shown in Table 1 below. (2) Gas permeability of bag Fully automatic gas permeability measuring device (manufactured by Ritsushi Co., Ltd.)
L100-3001 model) was used to measure the gas permeability of the bag sheet, and based on this, from the sheet thickness, effective internal surface area, and PC capacity, the
The amount of CO ₂ gas permeated was calculated. (3) Preparation and storage of PC Blood bag containing 56ml of CPD solution (manufactured by Terumo Corporation)
400ml of whole blood was collected and used as the raw material.
Centrifuge (DAMON/INC DPR-
Platelet-rich plasma (PRP) was obtained by centrifugation at 1100×g, 6 min, and 22° C. Furthermore, centrifuge at 2500 x g for 6 min at 22°C.
Platelets were obtained by separating the upper platelet-poor plasma (PPP). Add 40% homogeneous plasma from donated blood to this.
ml was added, the mixture was allowed to stand still at 22°C for 60 minutes, and then shaken for 60 minutes using a tumbler agitator (HELMR PA18 6 rpm) to prepare PC. After pooling 30 units of this same type of PC, 10 units (approximately 200 ml) each were stored in three bags: the present invention example and comparative examples 1 and 2, and stored with shaking at 22°C. The shaker used was Eight Shaker manufactured by Yayoi Co., Ltd., and the samples were stored at 30 rpm for up to 96 hours. (4) Platelet function test The time immediately after pooling was defined as 0 hours, and 2 ml was taken from the stored PC every 24, 48, 72, and 96 hours, and the following items were measured. Platelet count (concentration) Automatic blood cell counter (Sysmex MODEL CC)
-180, manufactured by Toa Medical Electronics Co., Ltd.) PH PH meter (HORIBA/F8DP type) used Aggregation capacity (ADP, collagen, ADP + collagen) and low osmotic shock recovery rate (%
HSR) Plasma LDH activity (platelet leakage rate) Plasma glucose concentration and plasma lactate concentration Mean platelet volume (MVP) Morphology (morphology score) The shelf life of platelets is determined by comprehensively evaluating the above items, and in particular: We decided to place a high importance on the item PH (time until PH decrease occurs). The results of the above experiment are shown in Table 1 below.

[Table] As shown in Table 1 above, in the PC storage bag of the present invention example in which the plasticizer was DnDP, 10 units of PC could be stored for 72 hours due to its excellent CO ₂ gas permeability. In particular, platelet concentration 0.92-2.4×10 ⁶ μ
It was significant that 10 units of PC could be stored for more than 72 hours in the pH range of 7.0 to 7.5. On the other hand, the bag of Comparative Example 1, which uses DEHP as the plasticizer, has poor _CO2 gas permeability, so 10 units
I was only able to save my PC for up to 24 hours. In addition, even if the plasticizer is DEHP, the effective internal surface area
In the bag of Comparative Example 2, which is 1000 cm ² , it is possible to store 10 units of PC for 72 hours as in the example of the present invention, but in this case, the size of the bag is large. <Effects of the Invention> According to the platelet storage container of the present invention, the shelf life of platelets can be extended, and in particular, platelets of 2×10 ¹¹ (10 units) or more can be retained for 72 hours or more. can. By using di-(n-decyl) phthalate as a plasticizer for the soft polyvinyl chloride constituting the container, the above effects can be achieved with the same container size as conventional containers.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an example of the structure of the platelet storage container of the present invention. Explanation of symbols 1...Blood bag, 2...Seal part,
3... Blood component storage unit, 4, 5... Outlet, 6... Tube, 7... Hub, 8... Plastic blood collection needle, 9
...Cap, 10...PC storage bag, 11...Seal part, 12...Platelet storage part, 13...Outlet, 1
4...Tube, 15...Connecting member, 16...Label.

Claims (1)

[Scope of Claims] 1. A platelet storage container made of soft polyvinyl chloride containing 30 to 70 parts by weight of di-(n-decyl) phthalate as a plasticizer based on 100 parts by weight of polyvinyl chloride, comprising: A container for platelet storage, characterized in that the sheet thickness of the platelet storage portion is 0.27 to 0.45 mm, and the inner surface area of the portion that may be involved in gas permeability of the platelet storage portion is 400 to 700 cm ² .