Concanavalin A Binding on PHEMA Beads and Their Interactions with Myeloma Cells

Abstract

The aim of this study is to prepare concanavalin A (Con A) bound poly(2-hydroxy ethyl methacrylate) (PHEMA) beads for cell affinity chromatography. In the first step, PHEMA beads were produced by suspension polymerization, and activated by cyanogen bromide (CNBr) in an alkaline medium (pH 11.5), and then, the bio-ligand "Con A" was attached by covalent binding onto the CNBr activated beads. PHEMA beads were characterized by scanning electron microscopy (SEM), surface area and pore size measurements. The PHEMA beads have a spherical shape and porous structure. The specific surface area of the PHEMA beads was found to be 39.7 m 2 /g with a size range of 150-200 µm in diameter and the swelling ratio was 55%. The amount of bound Con A was controlled by changing pH and the initial concentrations of CNBr and Con A. The non-specific adsorption of Con A on the plain PHEMA beads was 0.1 mg/g. The maximum Con A binding was 4.8 mg/g at pH 7.25. Both plain and Con A bound PHEMA beads were interacted first with the myeloma cell suspension in phosphate buffer. Myeloma cell attachment was very low for the plain PHEMA beads, while the number of myeloma cells attached increased almost 20 fold when the Con A bound beads were used. In order to look at whether or not the interaction of the Con A bound PHEMA beads and myeloma cells are affected from the biological molecules and other cells in the medium. We selected sheep blood itself as the medium, and mixed with the myeloma cell suspension and changed the environment. Cell adhesion decreased but not very significantly by changing the medium from simple buffer to sheep blood.

A glucose sensor via stable immobilization of the GOx enzyme on an organic transistor using a polymer brush

“…We focused on a mixed brush comprising of poly(glycidyl methacrylate) (PGMA) and poly(2‐hydroxyethyl methacrylate) (PHEMA) which is a soft, flexible system that provides attachment points for the enzyme and is compatible with biological media. Additionally, PHEMA has been shown to prevent non‐specific adsorption thus confirming that this substrate selection is optimal for GOx attachment to our device …”

Concanavalin A immobilized magnetic poly(glycidyl methacrylate) beads for prostate specific antigen binding

“…They have been used to determine the cancer biomarkers in recent years [5]. Lectins are carbohydrate-binding proteins and play a key role in diverse biological applications [6,7]. Their binding affinity has been widely used for the separation of glycoproteins from complex media and their specificities allow the discovery of new biomarkers of various diseases including cancer.…”

Performance of Protein-A-Based Affinity Membranes for Antibody Purification

“…The suspension was gently agitated at 25 • C and the activation procedure was continued for 60 min at a constant pH of 11.5. After the activation reaction, unreacted sites were quenched by washing with 0.1 M NaHCO 3 and any remaining active groups (e.g., isourea) on the surfaces were blocked by treatment with ethanol amine (pH 9.1) and FeCl 3 solution for 1 h [29]. Then, the activated membranes were washed four times with distilled water containing 0.5 M NaCl.…”