System for using ligands in particle separation

Details System for using ligands in particle separation System for using ligands in particle separation

2000-05-16

2001-08-28

Kim, John (Department: 1723)

Liquid purification or separation

Serially connected distinct treating with or without storage...

C210S257100, C210S259000, C210S417000, C210S502100, C210S504000, C210S435000, C210S088000, C210S436000, C210S518000, C210S494300, C210S088000

Reexamination Certificate

active

06280622

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system and method for separating particles. The invention has particular advantages in connection with separating blood components, such as antigen-specific blood cells.
This application is related to U.S. Pat. No. 5,674,173, issued on Oct. 7, 1997; U.S. patent application Ser. No. 08/423,583, filed on Apr. 18, 1995 (abandoned); U.S. patent application Ser. No. 08/634,167, filed on Apr. 18, 1996 (pending); and U.S. patent application Ser. No. 09/009,378, filed on Jan. 20, 1998 (pending). The entire disclosure of this U.S. patent and the entire disclosures of these U.S. patent applications are incorporated herein by reference.
2. Description of the Related Art
In many different fields, liquids carrying particle substances must be filtered or processed to obtain either a purified liquid or purified particle end product. In its broadest sense, a filter is any device capable of removing or separating particles from a substance. Thus, the term “filter” as used herein is not limited to a porous media material but includes many different types of processes where particles are either separated from one another or from liquid.
In the medical field, it is often necessary to filter blood. Whole blood consists of various liquid components and particle components. Sometimes, the particle components are referred to as “formed elements.” The liquid portion of blood is largely made up of plasma, and the particle components primarily include red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes). While these constituents have similar densities, their average density relationship, in order of decreasing density, is as follows: red blood cells, white blood cells, platelets, and plasma. In addition, the particle constituents are related according to size, in order of decreasing size, as follows: white blood cells, red blood cells, and platelets.
Although blood is primarily made up of white blood cells, red blood cells, and platelets, there are a number of other particle components of blood. For example, blood includes T-cells (a type of white blood cell), B-cells, monocytes (another type of white blood cell), stem cells, and NK cells. Most of these particles have similar sizes and/or densities. However, some of these particles have different surface chemistry characteristics designated with a specific “CD+” marker or symbol. For example, T-cells include CD2+ cells, CD3+ cells, CD4+ cells, and CD8+ cells; B-cells include CD9+ cells, CD10+ cells, and CD19+ cells; monocytes include CD14+ cells; stem cells include CD34+ cells; leukocytes include CD45+ cells; and NK cells include CD56+ cells. Corresponding antibodies, identified with an “anti-CD” marker or symbol, are capable of binding to these cells having particular surface chemistry characteristics. For example, anti-CD2 is capable of binding with CD+2 cells; anti-CD3 is capable of binding with CD3+ cells; and anti-CD4 is capable of binding with CD+4 cells. In a similar manner, anti-CD8, anti-CD9, anti-CD10, anti-CD14, anti-CD15, anti-CD19, anti-CD20, anti-CD34, anti-CD38, anti-CMRF44, anti-CD45, anti-CD56, anti-CD83, anti-glyocophorin, anti-cytokeratin, and anti-EPCAM are capable of binding with CD8+ cells, CD9+ cells, CD10+ cells, CD14+ cells, CD15+ cells, CD19+ cells, CD20+ cells, CD34+ cells, CD38+ cells, CMRF44+ cells, CD45+ cells, CD56+ cells, CD83+ cells, glyocophorin+ cells, cytoketatin+ cells, and EPCAM+ cells, respectively, for example.
Most current separation devices rely on density and size differences or surface chemistry characteristics to separate and/or filter blood components for transfusion or reinfusion purposes. Typically, blood components are separated or harvested from other blood components using a centrifuge. The centrifuge rotates a blood reservoir to separate components within the reservoir using centrifugal force. In use, blood enters the reservoir while it is rotating at a very rapid speed and centrifugal force stratifies the blood components, so that particular components may be separately removed. Although some centrifugal separation techniques are effective at separating some blood components from one another, many centrifugal separation processes are not capable of producing a highly purified end product.
In one type of separation procedure, a peripheral blood collection (withdrawn from an artery or vein) or a bone marrow blood collection is purified in a centrifugal separation process to isolate what is known as a peripheral blood cell collection or bone marrow blood cell collection, respectively. The peripheral blood cell collection or bone marrow blood cell collection primarily includes plasma, red blood cells, white blood cells (leukocytes, such as T-cells and monocytes), and stem cells. These cell collections also may include amounts of B-cells and NK cells.
After undergoing a therapeutic treatment, such as chemotherapy or radiation therapy, to eliminate cancerous tumor cells, cancer patients often receive a transfusion of a peripheral blood cell collection or a bone marrow blood cell collection to replace stem cells destroyed as a side effect of the treatment. To reduce risks associated with infusing blood components from a foreign donor, some of these transfusions are autologous, where blood components collected from the patient are later reinfused back to the patient. Another type of transfusion, known as allogenic transfusion, involves collecting blood components from a donor and then infusing the collected blood components into a recipient who is different from the donor. Sometimes, however, the recipient of an allogenic transfusion experiences a disease commonly known as graft versus host disease. In graft versus host disease, particular T-cells, which may accompany the blood components, are infused into the recipient and “recognize” that the recipient's body is “foreign” from that of the donors. These T-cells “attack” healthy cells in the recipient's body, rather than performing a normal immunological protective function. Recent studies have shown that a particular type of T-cells, namely CD8+ cells, could cause graft versus host disease.
Several prior attempts to separate stem cells from T-cells prior to reinfusion have been made. In one separation method, a selective antibody, anti-CD34, is introduced into a collected blood component sample after separating a substantial number of platelets and red blood cells from the sample. This selective antibody chemically attaches to stem cells (CD34+ cells) to “mark” them. To separate the marked stem cells from the remaining blood components, the collected blood components are passed between stationary beads coated with a material which chemically bonds with the selective antibody. These chemical bonds retain the marked stem cells on the beads to filter them from the remaining blood components.
To remove the marked stem cells from the beads, an operator agitates the beads or flushes a chemical solution through the beads to break the chemical bonds between the material and selective antibody. This separation process, however, is extremely expensive, tedious, and time consuming and often requires an initial centrifugation procedure to remove platelets and red blood cells. In addition, sometimes the beads do not remove a significant number of stem cells, and a substantial number of T-cells often remain in the separated end product.
In another type of separation procedure, magnetic particles or fluid having an attached antibody, anti-CD34, are added to a blood component collection. The antibody binds with stem cells (CD34+ cells) in the sample to link the magnetic particles and stem cells together. To separate the stem cells, a magnetic separator is used to attract the magnetic substance and stem cells, and linked a substance is then added to break the chemical bo

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