EP2834008B1

EP2834008B1 - Container with separable chambers for the treatment of biological tissues by centrifugal separation.

Info

Publication number: EP2834008B1
Application number: EP13724385.3A
Authority: EP
Inventors: Ilaria MERCURIALI; Laura REHAK
Original assignee: Leader Medica Srl
Current assignee: Leader Medica Srl
Priority date: 2012-04-02
Filing date: 2013-03-29
Publication date: 2016-06-01
Anticipated expiration: 2033-03-29
Also published as: ITPD20120102A1; ES2589129T3; WO2013150432A1; EP2834008A1

Description

Technical field

The present invention relates to a container with separable chambers for the treatment of biological tissues by centrifugal separation, having the characteristics stated in the preamble of the main claim.

Prior art

In the medical field there is a known requirement to treat biological tissues for the purpose of separating one or more of their cell components. A known and widely used method of achieving this separation consists in subjecting a specimen of the tissue of interest to a centrifugation treatment, at a suitable rotation speed, so that the heavier cell components of the tissue are separated from the lighter cell components.
By using this method, therefore, it is possible to obtain fractions with high concentrations of certain cell components which may be of particular interest.
An application of particular relevance is the centrifugal separation of blood for the purpose of obtaining plasma which has a high platelet concentration and is substantially free of red blood cells (commonly known in the field under the acronym PRP, for platelet-rich plasma), which is very useful for tissue repair and regeneration treatment.
The centrifugation of blood causes the red blood cells, which are heavier, to be separated towards the bottom of a container in which the blood is collected, while the supernatant is formed by plasma and platelets which are lighter and can therefore be taken off subsequently.
Test tubes are normally used to contain the blood during centrifugation treatment. With this type of container, however, the two blood fractions, which were initially well separated, unavoidably become partially remixed on completion of the centrifugal separation. It is therefore necessary to handle the test tubes with skill and care after they are extracted from the centrifuge, and to collect the desired blood fraction immediately.
WO 2010/131880 describes a container in which blood is collected for centrifugation treatment, and which has a first and a second chamber which are adjacent to each other and are connected by a passage, with means provided for closing this passage. Thus, on completion of the blood centrifugation operation, the two chambers can be separated by closing the passage between them, so that the blood fractions present in the chambers cannot become remixed in any way.
Clearly, care must be taken to ensure that the passage between the first and second chamber is located at the separation interface between the blood fractions before the passage is closed, and the container is therefore designed to be formed from two cylindrical bodies in which the first and second chamber are respectively defined, these chambers being separately engaged by screwing on to a third body, which is interposed between the two cylindrical bodies and has an element for closing the passage between the two chambers.
The position of the passage between the two chambers is adjusted by suitably screwing or unscrewing one of the two cylindrical bodies towards or away from the central body, and the passage is subsequently closed by tightening the other of the two bodies on to the central body.
In this type of known container, however, the positioning of the passage between the two chambers exactly at the interface between the two blood fractions may not be simple or straightforward, because the passage is located in a position where screw threads between the central body and the cylindrical bodies are present.
A second drawback of the container described in WO 2010/131880 is the fact that the blood is introduced into a first axial end of the container, and is taken from the opposite end on completion of the centrifugal separation, thus increasing the possibility of operator error.
Furthermore, the blood is introduced into the container through a plug of elastomeric material, which is positioned so as to close the aforesaid first end, and which, during centrifugation, is inevitably subjected to high pressure exerted by the blood, possibly causing leakage through the hole formed in the elastomeric plug, if the hole is large. Because of this characteristic it is inadvisable to use needles with a size exceeding 21 gauge, for example.
EP 1346773 and WO 2009/139632 disclose a container with separable chambers for blood treatment, comprising a first tubular body and a second tubular body which is telescopically slidable inside the first tubular body. The second tubular body is fixed to a plug which is engaged by screwing on to an end of the first tubular body, and has an end inside the first tubular body which is closed by a filter membrane through which blood serum or plasma can pass, whereas the heavier components, particularly the red blood cells, cannot pass through the filter. Additionally, a rod is fixed to the plug and extends coaxially inside the second tubular body, bearing a head at its opposite end.
The operation of this container is such that, when the blood to be treated has been introduced into the first tubular body, the plug is screwed on to the first tubular body so that the end of the second tubular body with the filter membrane is pushed into the volume of blood, thus separating, by filtration, the component without red blood cells, which passes through the filter membrane and is collected in the second tubular body. The second tubular body is screwed on to the first tubular body up to a predetermined point determined by an end stop, after which the rotation and screwing of the plug on the first tubular body is continued so as to break the connection with the second tubular body, and the head is moved so as to close the end of the second tubular body, thus separating the chamber inside the second tubular body from the chamber formed in the first tubular body.
However, this container is not suitable for separation treatment by means of centrifugation. Furthermore, with this type of container it is impossible to select the point at which the chambers are separated, since the end of the second tubular body can be closed only when the screwing of the second tubular body on to the first tubular body has been completed.

Description of the invention

The problem tackled by the present invention is that of providing a container with separable chambers for the treatment of blood by centrifugal separation which overcomes the limitations described above with reference to the cited prior art.
Within the scope of this problem, one object of the invention is to provide a container which is reliable, easily produced, and inexpensive.
This problem is resolved and this object is achieved by the present invention by providing a container having separable chambers made in accordance with the claims below.

Brief description of the drawings

The characteristics and advantages of the present invention will be made clearer by the detailed description of some preferred examples of embodiment thereof, illustrated, for the purposes of guidance and in a nonlimiting way, with reference to the attached drawings, in which:

Figure 1 is a schematic view, in longitudinal section, of a first example of a container with separable chambers realised in accordance with the present invention,
Figure 2 is a view in longitudinal section of a variant embodiment of the container with separable chambers of Figure 1, and
Figures 3 and 4 are views in longitudinal section of a second example of a container with separable chambers realised in accordance with the present invention, in different operating positions.

Preferred embodiments of the invention

With initial reference to Figure 1, the number 1 indicates the whole of a first example of a container with separable chambers made according to the present invention.
The container 1 is designed to be used as a vessel for collecting a fluid biological tissue to be subjected to a centrifugal separation treatment. In particular, it can be used for the centrifugal separation of whole blood, bone marrow, cord blood or adipose tissue. It is preferably used for the centrifugal separation of whole blood.
The container 1 comprises a first, tubular, body 2, of substantially cylindrical shape, extending along a longitudinal axis X between a first and a second longitudinal end 3 and 4.
A separator element 5 is engaged in an axially slidable manner inside the first body 2, this element defining a first chamber 6 and a second chamber 7 which are located inside the first body 2 on axially opposite sides of the separator element 5.
The separator element 5 has a through opening 8 which can put the first and second chamber 6 and 7 into fluid communication.
A closing element 9 is also associated with the separator element 5, and can be selectively moved by an operator between a first operating position, in which the opening 8 is closed, and a second operating position, in which the opening 8 is open. Thus, by moving the closing element 9 between the first and second operating position it is possible to prevent or allow the passage of fluid between the first and second chamber 6 and 7.
The container 1 also enables the position of the separator element 5 to be varied as desired inside the first body 2 by using suitable adjustment means. These means preferably comprise a second body 10 connected to the separator element 5 and coupled externally to the first body 2 so as to be movable relative thereto in the axial direction X.
In this first embodiment, the separator element 5 comprises a substantially disc-shaped piston 11, which is joined to the second body 10 by means of a first rod 12 which is internally hollow and tubular in shape.
The cross section of the first rod 12 is substantially smaller, by at least 20%, than the internal cross section of the first body 2, so that the second chamber 7 is formed in the first body 2 between the first rod 12 and the first body 2.
A first sealing gasket 13 is provided between the piston 11 and the first body 2, so that when the fluid is required to pass from the first chamber 6 to the second chamber 7 it can do so only through the opening 8. This opening comprises an axial through hole 8a formed in the piston 11, which puts the first chamber 6 into fluid communication with the inside of the first rod 12, and a plurality of through slots 8b formed in the first rod and opening into the second chamber 7.
The second body 10 is engaged by a screw coupling on the first end 3, using an external thread 3a of the first body 2, so that, by rotating it in one or other direction about the axis X, the piston 11 can be moved in a corresponding way in the axial direction.
The first rod 12 therefore extends through the first end 3, at which end a second sealing gasket 14 is suitably provided, this gasket being interposed between the first body 2 and the first rod 12 to prevent the outflow of fluid from the second chamber 7.
The container 1 further comprises a third body 15, connected to the closing element 9 and coupled to the first body 2 or the second body 10 while being movable relative to the second body 10, so as to allow the closing element 9 to move between the first and the second operating position independently of the position of the separator element 5 inside the first body 2.
Preferably, the third body 15 is coupled by a screw coupling to the second body 10 at the opposite end from the first body 2.
The closing element 9 comprises a second rod 16, extending from the third body 15 through the second body 10 and through the first rod 12.
The second rod 16 is housed inside the first rod 12 in an axially slidable manner and has a head 17, axially opposed to the third body 15, which can close the opening 8 as a result of the axial movement of the second rod 16 inside the first rod 12.
In order to prevent any leakage of fluid through the first rod 12, a third sealing gasket 18 is provided between the latter and the second rod 16, and, in order to ensure the closure of the opening 8 when the head 17 is moved into the first operating position, a fourth sealing gasket 19 is preferably provided on the head.
The first chamber 6 is closed at the end opposite the separator element 5 by a plug 20 of elastomeric material fitted into the second end 4 of the first body 2.
In the embodiment shown in Figure 1, the head 17, when moved into the second operating position away from the piston 11, is housed slidably inside the first rod 12, while in the first operating position it is brought to bear against the piston 11 to close the opening 8.
On the other hand, in the variant embodiment shown in Figure 2, indicated as a whole by the number 100, the head 17, when moved into the second operating position away from the piston 11, projects into the first chamber 6, outside the first rod 12 and beyond the piston 11.
The operating modes of the container 1 will now be described.
The fluid biological tissue, for example a whole blood sample of about 25 ml, is introduced into the first body 2 through the plug 20, by means of a syringe with a needle.
In this step, the separator element 5 is positioned inside the first body 2 in an intermediate position between the ends 3 and 4, with the head 17 moved into the second operating position, so that the fluid can pass from the first chamber 6 to the second chamber 7 through the opening 8, while the second and third sealing gaskets prevent the outflow of fluid from the first body 2. The volume of fluid introduced into the first body 2 is normally sufficient to fill the second chamber 7 and partially fill the first chamber 6. The container 1 is then placed in a centrifuge with its first end 3 in a position farther from the axis of rotation of the centrifuge than the second end 4.
The centrifuge is operated for a period and at a rotation speed such that the biological tissue is separated into at least two fractions with different concentrations of cell components. In particular, in the case of whole blood, the centrifugation operation yields a heavier fraction, mainly composed of red blood cells, and located in the second chamber 7 towards the first end 3; a lighter fraction, essentially composed of plasma and located in the part of the first chamber 6 nearer the second end 4; and an intermediate fraction, composed of plasma with a high concentration of platelets, located between the other two fractions.
At this point, while the container 1 is kept in a vertical position with its second end 4 uppermost, the separator element 5 is moved axially inside the first body 2 by screwing the second body 10 inwards or outwards, until the piston 11 is brought exactly to the interface between the two fluid fractions which are to be finally separated.
It should be noted that this operation can be performed in a rapid and precise way because the first body 2 has no screw threads or other types of coupling in its central area which might obstruct the view of the fluid inside this body.
When the piston 11 has been correctly positioned, the third body 15 is suitably rotated relative to the second body 10, thereby bringing the head 17 to bear against the piston 11 so as to close the opening 8 and prevent the subsequent passage of fluid between the first chamber 6 and the second chamber 7 by hydraulically separating the two chambers.
The light fraction can then be taken from the first chamber 6, for example by means of a syringe with a needle inserted through the plug 20.
If the required fraction to be separated is the heavy fraction, it is simply necessary to place the container 1 in the centrifuge with its first end 3 in a position nearer to the axis of rotation of the centrifuge than the second end 4. Thus, on removal from the centrifuge, the heavier fraction will be in the first chamber 6, and, after the two chambers have been suitably separated by the method stated above, the heavier fraction can be taken from the first chamber, again through the plug 20.
In the case of whole blood, it is preferable to place the container in the centrifuge with its second end 4 in a position nearer to the axis of rotation of the centrifuge, and then to separate the two chambers 6 and 7 by positioning the piston 11 at the interface between the heavier fraction, composed of red blood cells, and the intermediate fraction, composed of platelet-rich plasma.
At this point, if the blood fraction of interest is composed of both the light plasma fraction and the intermediate platelet-rich plasma fraction, the container can be gently agitated to promote mixing between the light and intermediate fractions, which can then be taken from the first chamber 6 using a syringe with a needle.
On the other hand, if the blood fraction of interest is composed solely of the intermediate fraction of platelet-rich plasma, the light plasma fraction is first taken from the upper part of the first chamber 6, without previous agitation, after which the intermediate fraction of platelet-rich plasma is taken. On the other hand, if the blood fraction of interest is composed solely of the intermediate fraction of platelet-rich plasma, the light plasma fraction is first taken from the upper part of the first chamber 6, without previous agitation, after which the intermediate fraction of platelet-rich plasma is taken.
In Figures 3 and 4, the number 200 indicates the whole of a second example of a container with separable chambers made according to the present invention, in which parts similar to those of the first exemplary embodiment are identified by the same reference numerals.
The container 200 differs from the container 1 in the different shape of the separator element 5, which is such that the second chamber 7 is formed in the separator element 5, rather than in the first body 2.
In particular, the separator element 5 of the container 200 comprises a first rod 112, which is also internally hollow, and which is connected to the second body 10 so as to slide inside the first body 2.
The first rod 112 has a cross section substantially identical to the internal cross section of the first body 2, such that the wall of the first rod 112 lies next to the wall of the first body 2, with minimal clearance to allow mutual sliding.
The first rod 112 is open at one end 113, facing the first chamber 6 and at the opposite end to the second body 10, thus forming the opening 8 of the separator element 5.
The first sealing gasket 13, between the separator element 5 and the first body 2, is positioned at the end 113 of the first rod 112, while there is no need to provide a second sealing gasket 14.
In a similar arrangement to that of the container 1, the second rod 16 of the closing element 9 extends coaxially inside the first rod 112, through the second body 10, and is connected to the third body 15 which is screwed on to the second body 10 at the opposite end to the first body 2. A sealing gasket 114 is provided between the second rod 16 and the second body 10. The cross section of the second rod 16 is substantially smaller than that of the first rod 112, so that the second chamber 7 is formed between the first rod 112 and the second rod 16.
Preferably, as in the variant of Figure 2, the head 17 of the second rod 16, when moved into the second operating position, projects into the first chamber 6, outside the first rod 112.
The mode of operation of the container 200 is preferably such that the biological fluid to be treated by centrifugation, for example whole blood, is introduced into the first body 2 through the plug 20, by means of a syringe with a needle.
In this step, the separator element 5 is preferably positioned inside the first body 2 in a position where it has been moved towards the first end 3, with the head 17 moved into the first operating position, so that the fluid is confined solely in the first chamber 6 (see Figure 3).
The centrifugation operation takes place as described above with reference to the preceding example, and at the end of the operation the head 17 is moved into the second operating position to allow the fluid to enter the second chamber 7 through the opening 8. At this point, while the container 200 is kept in a vertical position with its second end 4 uppermost, the second body 10 is screwed on to the first body 2 so as to move the end 113 of the first rod 112 to the desired position, at the interface between the two fluid fractions that are to be separated.
When the desired position has been reached, the third body 15 is actuated to move the closing element 9 into the first operating position.
Thus the present invention resolves the problem outlined above, while also providing numerous other benefits, including the fact that the fractions can be separated in a correct and precise way inside the container and that the passage between the chambers can be closed independently of the position of the separator element which defines the volumetric ratio between the chambers.
Furthermore, the possibility of operator error is reduced, since access to the inside of the container is possible at one end only.
Another advantage lies in the fact that, in most cases, the container has to be placed in the centrifuge with the end closed by the plug of elastomeric material facing towards the axis of rotation of the centrifuge, so that the plug is not subject to fluid pressure during the treatment. This advantageously allows needles of any size, including large sizes, to be used if necessary, without giving rise to problems of leakage during centrifugation.

Claims

A container for the treatment of a biological tissue by centrifugal separation, comprising:
- a first, tubular, body (2) in which the biological tissue is collected,

- a separator element (5), which is slidably engaged inside the first body (2) so as to form a first chamber (6) and a second chamber (7) of the container, the separator element having at least one opening (8) for putting the first and second chambers into fluid communication,

- a second body (10) connected to the separator element (5) and coupled to the first body (2) so as to be movable relative thereto in order to adjust the position of the separator element (5) inside the first body (2),

- a closing element (9) which is associated with the separator element (5) and is selectively movable by an operator between a first operating position, in which the opening (8) is closed to prevent the passage of fluid between the first and second chambers, and a second operating position, in which the opening (8) is open to allow the passage of fluid between the first and second chambers,
characterized in that it comprises a third body (15) connected to the closing element and coupled to the first body (2) or the second body (10) while being movable relative to the second body (10) so as to move the closing element (9) between the first operating position and the second operating position, independently of the position of the separator element (5) inside the first body (2).
A container according to Claim 1, wherein the second body (10) is engaged by screwing with a first end (3) of the first body (2).
A container according to Claim 1 or 2, wherein the separator element (5) comprises a piston (11) which is slidable inside the first body (2) and is connected to the second body (10) by means of a first rod (12).
A container according to Claim 3, wherein a first sealing gasket (13) is placed between the separator element (5) and the first body (2).
A container according to Claim 3 or 4, wherein the cross section of the first rod (12) is substantially smaller than the internal cross section of the first body (2), so that the second chamber (7) is formed in the first body (2) between the first rod (12) and the first body (2).
A container according to any one of Claims 3 to 5, wherein the first rod (12) extends through the first end (3), at which end a second sealing gasket (14) is interposed between the first body (2) and the first rod (12).
A container according to Claim 1 or 2, wherein the separator element (5) comprises a first rod (112) which is slidable inside the first body (2) and is connected to the second body (10), the first rod (112) being internally hollow, so that the second chamber is formed inside the second rod.
A container according to Claim 7, wherein the first rod (112) has a cross section which is substantially identical to the internal cross section of the first body (2).
A container according to Claim 7 or 8, wherein the first rod (112) is open at one of its ends opposite the second body (10) so as to form the opening (8) of the separator element (5).
A container according to any one of Claims 3 to 9, wherein the first rod (12, 112) is internally hollow and the closing means (9) comprise a second rod (16) which extends through the first rod (12, 112) and which is axially slidable inside the latter, the second rod being provided with a head (17) which can close the opening (8) as a result of the movement of the second rod (16) inside the first rod (12, 112).
A container according to Claim 10 when dependent on Claim 5, wherein a third sealing gasket (18) is placed between the first rod (12) and the second rod (16).
A container according to Claim 10 or 11, wherein the second rod (16) extends through the second body (10) and is connected to the third body (15).
A container according to Claim 12, wherein the third body (15) is coupled to the second body (10) at the opposite end from the first body (2).
A container according to Claim 13, wherein the third body (15) is engaged by screwing on to the second body (10).
A container according to any one of Claims 10 to 14, wherein the head (17), when moved into the second operating position, is received slidably inside the first rod (12).
A container according to any one of Claims 10 to 14, wherein the head (17), when moved into the second operating position, projects into the first chamber (6), beyond the first rod (12, 112).