Polymer Nanoparticles Covered with Phosphorylcholine Groups and Immobilized with Antibody for High-Affinity Separation of Proteins

Abstract

Novel polymer nanoparticles were prepared for the selective capture of a specific protein from a mixture with high effectiveness. The nanoparticle surface was covered with hydrophilic phosphorylcholine groups and active ester groups for easy immobilization of antibodies. Phospholipid polymers (PMBN) composed of 2-methacryloyloxyethyl phosphorylcholine, n-butyl methacrylate, and p-nitrophenyloxycarbonyl polyethyleneglycol methacrylate, were synthesized for the surface modification of poly( l-lactic acid) nanoparticles. Surface analysis of the nanoparticles using laser-Doppler electrophoresis and X-ray photoelectron spectroscopy revealed that the surface of nanoparticles was covered with PMBN. Protein adsorption was evaluated with regard to the nonspecific adsorption on the nanoparticles that was effectively suppressed by the phosphorylcholine groups. The immobilization of antibodies on nanoparticles was carried out under physiological conditions to ensure specific binding of antigens. The antibody immobilized on the nanoparticles exhibited high activity and strong affinity for the antigen similar to that exhibited by an antibody in a solution. The selective binding of a specific protein as an antigen from a protein mixture was relatively high compared to that observed with conventional antibody-immobilized polymer nanoparticles. In conclusion, nanoparticles having both phosphorylcholine and active ester groups for antibody immobilization have strong potential for use in highly selective separation based on the biological affinities between biomolecules.

Enzymatic Biofuel Cells—Fabrication of Enzyme Electrodes

“…Biomaterials based on novel phospholipid polymers with unit imitating biomembrane have been developed. They have excellent biocompatibility and the ability of maintaining enzyme activity [20,108]. These new methods and materials provide new means in developing enzyme electrode with required stability.…”

Bioinspired interface for nanobiodevices based on phospholipid polymer chemistry

“…To recognize the activity of biomolecules after immobilization, the dissociation constant of the antigen/antibody complex substantially defines the performance of affinity-based separation, diagnosis and detection systems (Watanabe & Ishihara 2007;Goto et al 2008a). To evaluate the performance of PMBN/PLA nanoparticles as affinity nanoparticles, the dissociation constant of the antigen/antibody complex on the PMBN/PLA nanoparticles was measured.…”

Molecular simulation of protein-surface interactions: Benefits, problems, solutions, and future directions (Review)

“…13,15,23 Because of its importance, protein adsorption behavior has been intensively studied over the past several decades. While much has been learned from these efforts, a detailed understanding of the molecular mechanisms underlying protein adsorption behavior and how to control it is still lacking, which means that the design of surfaces for biomedical and biotechnology applications can, at best, only be approached by educated trial-and-error methods.…”