An experimental model of affinity cell separation

Abstract

Cell affinity separations are based on the selective attachment of cell phenotype using antibody or lectins specific for cell surface markers. The major physicochemical factors which influence ligandmediated cell adhesion dynamics and the efficiency of cell affinity separation have been examined. Uniform cell detachment forces were generated with a parallelplate flow cell (plate separation 100 pm, surface area 3 cm2). Hydrodynamic shear stress was used to measure cell adhesion strength and to separate cells on the basis of surface affinity. Human cell lines grown in tissue culture were separated on a flat derivatised glass immunoadsorbent which formed the floor of the flow chamber. Flow-cell residence time, detachment shear stress, temperature, and ligand density were shown to influence cell attachment probability. An understanding of the physical basis of ligandmediated cell adhesion provided a rationale for optimisation of affinity cell separation. At room temperature attachment of positive cells was rapid (<2 min) and adhesion strength was directly related to immunoadsorbent ligand density. Purity and recovery of enriched fractions were dependent on the separation shear stress and could be optimised using this parameter. Enrichment factors were greater than 100-fold, with at least 90% of positive cells recovered in enriched fractions. Enrichment purity and yields did not decline at higher loading densities (lo5 cells/cm2). Selective immunoadsorbent surface chemistry is a prerequisite for efficient affinity cell separation. Purity and recovery may be optimised by fractionating enriched and depleted cell populations with uniform fluid shear stress. o 1994 Wiley-Liss, Inc.

Hollow-fibre affinity cell separation system for CD34+ cell enrichment

“…The most significant physical attribute of a hollow-fibre system is the generation of uniform and controllable surface fluid shear stress at the lumenal attachment interface. Cell attachment is sensitive to the effects of local fluid shear stress, and control of this parameter can enhance enrichment purity and yield (16).…”

“…Fluid dynamic factors are an important consideration for the design and optimisation of affinity cell separation systems. An experimental model of affinity cell separation has been developed to determine the major physic-ochemical factors that influence the efficiency of cell separation (16). Human cell lines were separated on a flat, derivatised-glass immunoadsorbent that formed the floor of a parallel-plate flow chamber.…”

Amino Acid Ionic Liquid Modified Mesoporous Carbon: A Tailor‐made Nanostructure Biosensing Platform

“…A macroporous membrane will allow proteins to cross compartments, whereas a dialysis membrane will retain proteins within the cell growth compartment. The hollow‐fibre membrane may be modified with ligands for cell separation or attachment of anchorage‐dependent cell types 119, 120…”

Ex Vivo Manipulation of Cell Subsets for Cell Therapies

“…The immunoaffinity techniques that are scalable are based on plate (41,42), bead (43), and hollowfiber (44) immunoadsorption or magnetic labelling and sorting (4S,46). Although highly selective multiparameter sorting is possible using fluorescence activated cell sorting, the cell throughput is limited to less than 30,000 cells/s.…”

“…Bead immunoadsorption systems have a greater surface area to volume ratio, and recovery of antigen positive cells is possible by fluidizing the bead bed to generate surface fluid shear stress (43) or by the use of selective releasing agents such as chymopapain (44). Hollow-fiber immunoaffinity systems provide a platform for the control of detachment surface fluid shear stress, a major control parameter influencing enrichment purity and yield for cell adsorption techniques (42).…”