Imperforate bowl: centrifugal separators – Process
Reexamination Certificate
2001-07-30
2004-05-11
Kim, John (Department: 1723)
Imperforate bowl: centrifugal separators
Process
C494S001000, C494S002000, C494S010000, C494S037000, C494S043000, C494S056000, C435S002000
Reexamination Certificate
active
06733433
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the automated processing and separation of biological cells as found in whole blood, and relates more specifically to a functionally closed system allowing to extract certain cell populations like hematopoietic stem cells, for immediate use or their mixing with an additive solution or a storage solution for later separate storage operations and to the methods for carrying out such an extraction.
BACKGROUND OF THE INVENTION
Blood separation systems and methods have emerged over the past 20 years in response to the growing need for efficient blood component therapies. Among them are the transplantation of hematopoietic progenitor stem cells, which in many cases is the only remaining cure to oncological disorders. Patients in need of a stem cell transplant have mainly three options:
1) Adult bone marrow stem cells;
2) Peripheral blood stem cells found in the circulatory system;
3) Stem cells found in umbilical cord and placental blood retrieved at birth of a new born infant.
For most stem cell transplants, the main limitation has been the risk of graft-versus-host-disease (GVHD), requiring an excellent HLA-match tissue (HLA=Human Leucyte Associated).
Umbilical cord blood is a rich source of the primitive hematopoietic stem and progenitor cells, with extensive proliferation capacity and capacity to self-renew. This field has advanced rapidly from clinical implants utilizing only HLA-matched grafts to unrelated donor cell transplants which open a much larger indication for stem cell transplantation. This increase in clinical experience with cord blood is due mainly to the establishment of banks for storage of hematopoietic stem cells from unrelated umbilical blood cord.
Blood volumes recovered from umbilical cord are usually very low (40 to 150 ml) and there is some concern that any attempt at product manipulation and concentration might result in stem cell loss, which might impair engraftments. Therefore umbilical cord blood is sometimes stored as is, with preservative solution added. A much preferred way would be to eliminate most unwanted cells like red cells and white cells, resulting in a considerable volume reduction. Less preservative solution would be required, smaller bags, smaller storage spaces would be used and considerable energy savings achieved, all of this translating in substantial cost savings. The quality of the stem cell product when retransfused would be improved as well, as lysed cells resulting from storage would be drastically reduced.
No device or automated system exists for processing and concentrating on line umbilical cord stem cells. There is nevertheless a considerable interest for concentrating umbilical cord blood stem cells without loss or altering their functionality.
EP-B-0 912 250 (C. FELL), the contents whereof are herein incorporated by way of reference, describes a system for the processing and separation of biological fluids into components, comprising a set of containers for receiving the biological fluid to be separated and the separated components, and optionally one or more additional containers for additive solutions. A hollow centrifuge processing chamber is rotatable about an axis of rotation by engagement of the processing chamber with a rotary drive unit. The processing chamber has an axial inlet/outlet for biological fluid to be processed and for processed components of the biological fluid. This inlet/outlet leads into a separation space of variable volume wherein the entire centrifugal processing of biological fluid takes place. The processing chamber comprises a generally cylindrical wall extending from an end wall of the processing chamber, this generally cylindrical wall defining therein the hollow processing chamber which occupies a hollow open cylindrical space coaxial with the axis of rotation, the axial inlet/outlet being provided in said end wall coaxial with the generally cylindrical wall to open into the hollow processing chamber. The processing chamber contains within the generally cylindrical wall an axially movable member such as a piston. The separation space of variable volume is defined in an upper part of the processing chamber by the generally cylindrical wall and by the axially movable member contained in the generally cylindrical wall of the processing chamber, wherein axial movement of the movable member varies the volume of the separation space, the movable member being axially movable within the processing chamber to intake a selected quantity of biological fluid to be processed into the separation space via the inlet before or during centrifugal processing and to express processed biological fluid components from the separation space via the outlet during or after centrifugal processing. Means are provided for monitoring the position of the movable member to thereby control the amount of intaken biological fluid and the expression of separated components. The system further comprises a distribution valve arrangement for establishing selective communication between the processing chamber and selected containers or for placing the processing chamber and containers out of communication.
The system according to EP-B-0 912 250 is designed to operate for the separation of biological fluids, and has proven to be very polyvalent for many separation applications, especially for on-line separation of components from a donor or a patient.
DISCLOSURE OF THE INVENTION
According to the invention, such system is arranged to operate in a separation mode and in a non-separation transfer mode, which provides greater possibilities for use of the system including new applications which were heretofore not contemplated, such as separation of hematopoietic stem cells and in general laboratory processing. According to the invention, the system is arranged to operate such that:
in the separation mode fluids can be intaken into the processing chamber while the chamber is rotating or stationary, fluid intaken into the chamber is centrifuged and separated into components, and the separated components expressed while the chamber is rotating or, optionally, for the last separated component, while the chamber is stationary; and
in the transfer mode the processing chamber intakes fluid and expresses fluid with the chamber stationary, The valve actuation arrangement is actuable to transfer amounts of fluid from one container to another via the processing chamber, by moving he member, without centrifugation or separation of the fluid into components, and the means for monitoring the position of the movable member controls the amounts of non-separated fluids transferred.
Further features of the invention are set out in the claims. This invention thus proposes a functionally closed processing kit associated with a portable apparatus, whose function is to monitor and automate the procedure. The kit, usually disposable for avoiding the likelihood of disease transmission, is based on a centrifugal processing chamber whose volume can be varied during operation, allowing to adjust to the exact quantity of blood to process. Such variable volume chamber is described in the aforementioned EP-B-0 912 250 (C. FELL). The chamber is connected to a set of bags and tubing lines for the collection of the separated components. The blood bag containing the blood to process is generally connected to the disposable set through the use of a sterile connecting device, or an aseptic connection under laminar flow. It is however possible to have this bag prefilled with anticoagulant and preconnected to the disposable kit.
A bag containing an additive solution can be connected to the disposable kit via a bacterial filter. The other bags are provided for the collection of the separated components. The stem cell collection bag material is optimally chosen for the storage conditions.
The tubing line selection for conveying the separated products into the proper bags is accomplished by a set of rotational valves called stopcocks that can be arranged in a manifold array, or by a single multiport rotational valve, f
Biosafe S.A.
Kim John
Sturm & Fix LLP
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