Evaluation of 2-Methacryloyloxyethyl Phosphorylcholine Polymeric Nanoparticle for Immunoassay of C-Reactive Protein Detection

Publisher Website
Google Scholar
Abstract
To prepare novel 2-methacryloyloxyethyl phosphorylcholine (MPC)−polymeric nanoparticle (MPC−PNP), water-soluble amphiphilic phospholipid polymer, poly [MPC-co-n-butyl methacrylate (BMA)-co-p-nitrophenyloxycarbonyl poly(ethylene glycol) methacrylate (MEONP) (PMBN)], which has active ester groups for bioconjugation on the side chains, was synthesized. MPC−PNP was prepared by a solvent evaporation technique where the poly(l-lactic acid) was used as core and PMBN was applied as an emulsifier and a surface modifier under systematical design of well-arranged phospholipids polar groups in its surface. Characteristics for MPC−PNP were thoroughly investigated with dynamic light scattering, electrophoresis light scattering, X-ray photoelectron spectroscopy, and field emission scanning electron microscopy measurements. Through a protein adsorption test, the phosphorylcholine group on the surface of MPC−PNPs, which had their active ester groups substituted by glycine, were shown to suppress the nonspecific adsorption of bovine serum albumin. These particles were used for C-reactive protein (CRP) detection, where anti-CRP monoclonal antibodies were immobilized on the MPC−PNP using the active ester group, while the remaining active ester groups were thoroughly reacted with glycine. The detection limit about serum-free CRP in the calibration curve was shown to extend from 0.01 to 10 mg/dL when anti-CRP antibody immobilized MPC−PNP was used for serum-free CRP detection. This compares favorably with measurement using polystyrene nanoparticles that were shown to detect from 0.1 to 10 mg/dL by an immunoagglutination technique. Also, for the detection of CRP in serum, MPC−PNP was shown to give the same calibration curve explained by the efficient suppression of nonspecific binding. Furthermore, denaturation of immobilizing anti-CRP antibody on the MPC−PNP hardly occurred despite increasing the temperature. It is concluded that MPC−PNP is unique due to the design of its interfacial properties, also it will perform well in a diagnostic immunoassay because of its optimized material properties.