Separation of CD34⁺ cells from human peripheral blood through polyurethane foaming membranes

Abstract Cell separation from peripheral blood was investigated using polyurethane (PU) foaming membranes and PU membranes (pore size, 5 or 12 μm) at different blood permeation speeds. Permeation ratio of hematopoietic stem cells (CD34⁺ cells) through the PU membranes was the lowest among the blood cells at any blood permeation speed. This is thought to be because CD34⁺ cells are more adhesive than red blood cells (RBCs), platelets, T cells, and B cells. Primitive hematopoietic stem and progenitor cells tend to adhere to the surface of mature blood cells, because of the high expression of cell‐adhesion molecules on the surface of the cells. Human serum albumin solution was exposed to PU‐COOH membranes to detach adhered cells from the surface of the membranes, allowing isolation of CD34⁺ cells and reduction of RBCs in the permeate solution. Most purified CD34⁺ cells (high recovery ratio of CD34⁺ cells divided by recovery ratio of RBCs) were obtained in the recovery process using PU‐COOH membranes (pore size, 5.2 μm) at a permeation speed of 0.3–1 mL/min. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006