FR2856004A1 - Sterile connecting procedure for two plastic tubes used e.g. with blood products consists of crushing zones near tube ends, cutting and joining with membrane and piercing membrane from inside - Google Patents

Abstract

The procedure for joining two plastic tubes (1, 2) together end to end, using a moving piercing element (3) inside one of them, consists of crushing a zone (4, 5) close to the end of each tube, making a hot cut across the crushed zones to eliminate their ends in a sterile manner, bringing the crushed zones together after cooling to join the two tubes together coaxially with a membrane (6) between them, and piercing the membrane by moving the piercing element inside the tubes, which restores the shape of the tubes at the same time. The cutting is carried out at a temperature close to the melting point of the tube material, and the movement of the piercing element, which is in the form of a hollow needle, is made by manipulating the tube that contains it.

Description

I

  The invention relates to a sterile connection method of two tubings made of thermoplastic material, as well as a bag system for the cryopreservation of biological material and a bag system for cell culture, said systems being arranged for placing work of said process.

  It typically applies to the case where the biological material is a blood product.

  For the collection and / or preparation of blood products, it is known to use so-called closed bag systems in which the bags and the tubes are pre-connected and then sterilized at the time of manufacture. This type of system makes it possible to handle blood products under conditions of sterility sufficient to allow their subsequent use in the therapeutic field.

  In certain applications, it is however not possible or desirable to use a closed bag system in which all the elements necessary for the preparation of the blood product are connected during manufacture.

  To solve this problem, it has been proposed, in particular in documents EP044 204, EP-0 134 630 and EP-0 208 004, methods for sterile connection of two tubes of thermoplastic material which allow for example to connect an additional bag to a bag system existing without breaking the sterility thereof.

  The problem which arises with such methods is that a membrane forms in the junction between the two connected tubes, said membrane preventing the flow of the fluid. For certain thermoplastic materials, such as PVC, the membrane can be easily ruptured by manipulation of the junction. But for other materials, such as EVA, the presence of this membrane makes it impossible to use the sterile connection methods of the prior art.

  However, in the field of cryopreservation or cell culture, it is not possible to use PVC bag systems because this material does not withstand the temperature of liquid nitrogen and does not have a satisfactory culture. However, in such applications, additional bags such as rinsing, transfer or separation bags must be sterile connected to the bag system, which requires working in an aseptic environment to avoid introducing contaminants into the system. This results in particular in a processing complexity and therefore an increased cost.

  The invention particularly aims to solve this problem by providing bag systems comprising a membrane piercing member which can be actuated during a sterile connection process.

  To this end, and according to a first aspect, the invention relates to a method of sterile connection of two tubes of thermoplastic material, a piercing member being movably arranged inside at least one of the tubes, said method comprising the steps providing for: - crushing an area of each of the pipes; - make a hot cut through the crushed areas, so as to sterile eliminate part of the tubing before connection; - Bringing said zones together so that, after cooling, the two zones are joined together with the two tubes arranged substantially coaxially, a membrane being formed in the junction between the two tubes; move the piercing member to perforate the membrane so as to ensure fluid communication between the pipes.

  According to a second aspect, the invention relates to a bag system for the cryopreservation of biological material, in particular blood products, comprising a bag intended to receive the biological material and a tube in communication with an orifice of said bag, the bag and the tubing being made of thermoplastic material resistant to the temperature of liquid nitrogen, a piercing member being movably disposed inside the tubing so, by implementing the method according to the invention to be able to connect sterile tubing from another bag system on said tubing.

  According to a third aspect, the invention relates to a bag system for cell culture, comprising a bag intended to receive the cells and a tube in communication with an orifice of said bag, the bag and the tube being made of thermoplastic material , a piercing member being movably arranged inside the tubing so that, by implementing the method according to the invention, it is possible to sterile connect a tubing of another bag system to said tubing.

  Other objects and advantages of the invention will become apparent during the description which follows, given with reference to the appended drawings in which: 1s - FIG. 1 schematically represents the steps of the sterile connection method according to the invention; - Figures 2, 4 and 5 schematically show a front view of a bag system according to the invention; - Figure 3 shows schematically a front view of a 20 pocket system connectable to a pocket system according to the invention; - Figure 6 shows schematically a front view of two bag systems connectable to a closed tube according to the method of the invention; - Figures 7 and 8 show schematically two different embodiments of the piercing member; - Figure 9 shows schematically a front view of a bag system according to the invention comprising several means limiting the movement of the piercing member in the tubing.

  In FIG. 1 are shown schematically the different stages of the method according to a first aspect of the invention allowing sterile connection of a first tube 1 and a second tube 2.

  The two pipes 1, 2 are formed from a thermoplastic material of identical or different nature. When the pipes are not made of the same material, the materials of each of the pipes must be compatible, that is to say have a melting point close to each other.

  In particular, the first tube 1 and the second tube 2 comprise a material based on EVA (ethylene-vinyl acetate), for example a layer of EVA and a layer of polyvinyl chloride (PVC) which are associated one on the other.

  A piercing member 3 is movably arranged inside at least one of the pipes 1.

  The method according to the invention provides for the following steps: (a) crushing a zone 4, 5 of each of the pipes 1, 2; (b) performing a hot cut through the crushed zones 4, 5, so as to sterile eliminate part of the tubes before connection; (c) bringing said zones together so that, after cooling, the two zones are joined together with the two tubes arranged substantially coaxially, a membrane 6 being formed in the junction between the two tubes; (d) move the piercing member 3 to perforate the membrane 6 so as to ensure fluid communication between the pipes 1, 2.

  The crushing of the tubes 1, 2 in step (a) and the heating of the crushed zones 4, 5 in step (b) cause the formation of the membrane in step (c).

  The hot cutting of step (b) is carried out using a sharp blade 7 and heated to the melting point of the thermoplastic material so as to melt it.

  In a particular embodiment, steps (a) to (c) of the method are carried out using a commercially available sterile connection device, such as the SCD 312 manufactured by Terumo.

  Finally, step (d) of displacement of the piercing member 3 is ensured by manipulation of the tubing 1 containing it.

  The piercing member 3 is first brought, for example by the effect of gravity, to the membrane 6 which has formed at the junction of the two pipes 1, 2.

  Then, the displacement of the piercing member 3 is carried out with the fingers of the hand by successive pressures of the tubing I at the rear end of the piercing member, so as to push this piercing member 3 to the 10 across the membrane 6.

  Once the piercing member 3 through the membrane 6, it is left in place or is moved into another portion of the tubing 1.

  Prior to the displacement of the piercing member 3, the junction is manipulated so as to reshape the crushed areas 4, 5. This step can be done automatically if the material of the pipes is sufficiently elastic.

  The connection is said to be sterile because, when the tubes are closed or in a closed system, the crushing provided for in step (a) has the consequence of avoiding an exchange of fluids and gases between the inside and the outside. tubing.

  In particular, during the cutting of the crushing zones, the fluids which may be contained in the pipes cannot exit the pipes and, conversely, the outside air cannot penetrate inside the pipes.

  In a particular embodiment, the pipes 1, 2 to be connected are in fluid communication with at least one pocket in a closed system 8, 9.

  Examples of such closed systems 8, 9 are shown in FIGS. 2 to 5 and 9 and include a pocket 10, 11 and a tube 1, 2 in communication with an orifice 12, 13 of said pocket 10, 1 1.

  In these examples, the end of the tubing which is used for the sterile connection method according to the invention and which is not in communication with the orifice 12, 13 of the bag 10, 11 is closed by a weld 14, a rod 15 or a filling means such as a perforator 16, a male 17 or female 18 Luer type connector or an injection site 19.

  In the pocket systems 8 of FIGS. 2, 4, 5 and 9, a piercing member 3 is movably arranged inside a tube 1 so that, by implementing the method according to the invention, being able to sterile connect a tubing 2 of another bag system 9 to said tubing 1. An example of such another closed bag system 9 is shown in FIG. 3.

  In FIG. 3, the other bag system 9 comprises a tube 2 in fluid communication with the orifice 13 of a first bag 11. At least 15 an additional bag 20 is possibly placed in fluid communication with said tube 2. The first pocket 11 and the additional pocket 20 are empty or contain a solution such as a culture medium or a NaCl-type rinsing solution.

  In another embodiment shown in FIG. 6, the tubing 1 containing the piercing member 3 is closed at its two ends and the other tubing 2 to be connected is in fluid communication with at least one pocket 11 in a closed system 9.

  The tubing is closed at its two ends, for example by a weld 21 or a rod (not shown) or a combination of the two (not shown).

  Advantageously, the closed tubing 1 contains two piercing members or, as shown, a single piercing member 3, the two ends of which are capable of piercing a membrane.

  This closed tube is used to sterile connect two tubes 2 not containing a piercing member. The connection method is implemented twice and makes it possible to sterile connect two bag systems 9 of which no tubing is provided with a piercing member.

  According to a second aspect, the invention provides a bag system 8 for the cryopreservation of biological material, in particular blood products. Such a system is already described in relation to FIGS. 4 and 5 and comprises a pocket 10 intended to receive the biological material and a tube 1 in communication with an orifice 12 of said pocket, the bag 10 and the tube 1 being made of material. thermoplastic resistant to the temperature of liquid nitrogen. A piercing member 3 is movably disposed inside the tubing 1 so that, by implementing the method according to the invention, it is possible to sterile connect a tubing 2 of another bag system 3 to said tubing 1.

  For example, the material forming the bag 10 and the tubing 1 comprises ethylene vinyl acetate (EVA). In particular, the bag material is EVA and the tubing material comprises a layer of EVA and a layer of polyvinyl chloride (PVC) which are associated with each other.

  According to a third aspect described in relation to FIGS. 4, 5, the bag system 8 is suitable for cell culture and comprises a bag 10 intended to receive the cells and a tube 1 in communication with an orifice 12 of said bag, the bag and the tubing being made of thermoplastic material. A piercing member 3 is movably arranged inside the tubing so that, by implementing the method according to the invention, it is possible to sterile connect tubing 2 of another bag system 9 to said tubing 1.

  For example, the material forming the bag 10 and the tubing 1 comprises EVA or a polyolefin such as polyethylene or polypropylene or a fluoropolymer or polystyrene.

  The variants described below relate to the pocket systems 8 according to the two aspects of the invention.

  According to a first variant shown in Figure 4, the bag system 8 further comprises at least one means for filling the bag 10, said means being in fluid communication with the bag 10 via the tubing 1 containing l drilling member 3.

  According to a second variant shown in FIG. 5, the communication means allowing the bag to be filled are in fluid communication with the bag 10 by means of another tube 22 not containing a piercing member 3.

  Examples of means for filling the bag include a perforator 16, a male 17 or female 18 Luer type connector, or even an injection site 19.

  The piercing member 3 is made of plastic or metal. The piercing member has at least two functions. First, it pierces the membrane which forms at the junction of the two tubes 1, 2 during the implementation of the method. To do this, the piercing member 3 is provided with at least one acute or pointed part. It also ensures the passage of the fluid.

  In a first embodiment shown in FIG. 7, the piercing member 3 is a hollow needle. The fluid mainly flows through the body of the needle.

  According to another embodiment shown in FIG. 8, the piercing member 3 is a grooved rod, one of the ends of which is in the shape of a point. The fluid then flows on either side of the grooved rod.

  Means for limiting the movement of the piercing member 3 inside the tube 1 are optionally provided. In particular, when the tubing 1 is connected to an orifice 12 of a pocket 10, it is desirable that the piercing member is not found inside the pocket 10.

  In a first variant, the external diameter of the piercing member 3 is slightly less than the internal diameter of the tube 1 in which it is arranged. Thus, the piercing member 3 moves in the pipe 1 only under the effect of a slight external stress.

  According to another variant, the piercing member 3 moves freely in the tubing. One or more means for limiting the movement of the piercing member are arranged between the orifice of the pocket 12 and the piercing member 3, as shown in FIG. 9.

  A perforated disc 23 is disposed above the orifice of the pocket 12. The diameter of the perforation (s) is less than the diameter of the piercing member 3 so that the passage of the fluid is ensured while preventing the passage of the piercing member 3 in the pocket 10.

  A circuit opener 24 at the orifice 12 of the pocket 10 also makes it possible to retain the piercing member 3 outside the pocket 10.

  In another variant, the means for limiting the movement of the piercing member 3 is arranged outside the system 8. For example, a clamp 25 is placed between the orifice 12 of the pocket 10 and the member drilling 3.

  In another example, the portion of the tubing comprising the piercing member is shaped in a loop using a part 26 comprising two housings that can receive a tubing 1. The loop is released after the formation of the membrane 6 according to the method of the invention so as to allow the movement of the piercing member towards said membrane 6.

  One or a combination of two or more of these displacement limiting means is used.

  A particular application of the method according to the invention is described below in relation to the cryopreservation and thawing of a suspension of red blood cells.

  According to the invention, the bag system 8 used for the cryopreservation of a suspension of red blood cells is of the type shown in FIG. 4. This cryopreservation system is closed and comprises a bag 10 of 5 EVA cryopreservation. The pocket is provided with an orifice 12 to which is connected a first EVA tubing 1 containing a piercing member 3 in the form of a hollow metal needle.

  The EVA bag is provided with a second orifice to which a second tube 22 is connected. The tube consists of an external layer of EVA and an internal layer of PVC.

  The second tube 22 is connected to other tubes, the ends of which include a perforator 16, a male Luer connector 17, a female Luer connector 18. On one of these tubes is an injection site 19. This system with pockets 8 provides the user with a choice of connectors. He is thus free to choose the connector that suits him.

  During cryopreservation, a suspension of red blood cells, for example from a donation of whole blood, is transferred into the EVA pocket of the system.

  Then, the cryopreservative, for example glycerol, is added to the suspension of red blood cells contained in the EVA bag via, for example, the injection site 19.

  We then perform a thermal weld at the second tube 22 to separate the set of connectors from the rest of the cryopreservation system. The remaining system is that shown in FIG. 2 in which the EVA bag 10 contains the suspension of red blood cells added with the cryopreservative. The system is frozen for storage in liquid (-196 C) or gaseous nitrogen.

  When thawing with a view to using the bag 10 containing the suspension of red blood cells added with cryopreservative, it is necessary to remove the cryopreservative by means of successive washing with a NaCl type solution.

  Another closed pocket system 9 is used. This washing system as described in FIG. 3 comprises a bag 11 containing a NaCI type washing solution and an empty bag 20 connected to a closed tube 2 by a rod 15. The closed tube 2 is made of the same material as the first tube 1 of the cryopreservation system 8.

  According to the method of the invention, a sterile connection is made, for example using the sterile connection device SCD 312 manufactured by Terumo, between the first tube 1 of the cryopreservation system 8 containing the hollow needle and the tubing closed 2 by a ring of the washing system 9.

  The hollow needle moved through the membrane which has formed between the two tubes, makes it possible to establish a fluid communication between the two systems 8 and 9.

  The NaCl solution is then introduced into the bag 10 in EVA. This bag 20 containing the suspension of red blood cells, the cryopreservative and the NaCl solution is centrifuged so as to obtain the NaCl solution and the cryopreservative in the supernatant and the suspension of red blood cells in the bottom. The supernatant is sent to the empty bag 20 of the washing system and the washing system 9 is separated from the cryopreservation system 8 by thermal welding.

  The washing operation is repeated with another washing system 9 until substantial elimination of the cryopreservative.

  The connection between the cryopreservation system 8 and the washing system 9 is made sterile, which makes it possible to avoid bacterial contamination of the suspension of red blood cells.

Claims (15)

  1. Method for sterile connection of two tubes (1, 2) made of thermoplastic material, a piercing member (3) being movably disposed inside 5 at least one of the tubes (1), said method comprising steps providing for: (a) crushing a zone (4, 5) of each of the tubes (b) performing a hot cut through the crushed zones (4, 5), so as to sterilely eliminate part of the tubes beforehand at connection; (c) bringing said zones together so that, after cooling, the two zones are joined together with the two pipes (1, 2) arranged substantially coaxially, a membrane (6) being formed in the junction between the two pipes; (d) moving the piercing member (3) to perforate the membrane (6) so as to ensure fluid communication between the pipes (1, 2).   2. Method according to claim 1, characterized in that prior to the displacement of the piercing member (3), the junction is manipulated so as to reshape the crushed areas (4, 5).   3. Method according to claim 1 or 2, characterized in that the cutting is carried out in the vicinity of the melting temperature of the thermoplastic material making up the pipes (1, 2).   4. Method according to any one of claims 1 to 3, characterized in that the movement of the piercing member (3) is ensured by manipulation of the tubing (1) containing it.   5. Method according to any one of claims 1 to 4, characterized in that the two pipes (1, 2) are formed from a material of different nature.   6. Method according to any one of claims 1 to 5, characterized in that at least one tube (1, 2) comprises a material based on vinyl ethylene acetate (EVA).   7. Method according to any one of claims 1 to 6, characterized in that at least one tube (1, 2) is in fluid communication with at least one pocket in a closed system (8, 9).   8. Pouch system (8) for the cryopreservation of biological material, in particular blood products, comprising a pocket (10) intended to receive the biological material and a tube (1) in communication with an orifice (12) of said pocket (10), the bag (10) and the tubing (1) being made of thermoplastic material resistant to the temperature of liquid nitrogen, said system (8) being characterized in that a piercing member (3) is disposed movably inside the tubing (1) so, by implementing the method according to any one of claims 1 to 7, to be able to sterile connect a tubing (2) of another system with pockets (9) on said tubing (1).   9. A bag system (8) for cell culture, comprising a bag (10) intended to receive the cells and a tube (1) in communication with an orifice (12) of said pocket (10), the bag (10 ) and the tubing (1) being made of thermoplastic material, said system (8) being characterized in that a piercing member (3) is movably arranged inside the tubing (1) so that by implementing the method according to any one of claims 1 to 7, to be able to sterile connect a tubing (2) of another bag system (9) on said tubing.   10. System according to claim 8 or 9, characterized in that the material forming the pocket (10) and the tubing (1) comprises ethylene vinyl acetate (EVA).   11. System according to claim 10, characterized in that the material forming the tubing (1) comprises a layer of EVA and a layer of polyvinyl chloride (PVC) which are associated with each other.   12. System according to any one of claims 8 to 11, characterized in that the piercing member (3) is formed of a hollow needle.   13. System according to any one of claims 8 to 12, characterized in that it comprises at least one means (16,17 18,19) allowing the filling of the bag (10), said means being in fluid communication with the pocket (10) via the tubing (1).   14. System according to any one of claims 8 to 13, characterized in that the piercing member (3) is freely movable inside the tube (1).   15. System according to any one of claims 8 to 13, characterized in that it comprises means (23,24,25,26) for limiting the movement of the piercing member (3) inside the tubing (1).