High PEGylation efficiency of pentaethylenehexamine-end poly(ethylene glycol) (mPEG-N6) for active-ester surface.

The chemical surface-modification of carboxylated polystyrene submicroparticles (sMPs) with α-methoxy-poly(ethylene glycol)-pentaethylenehexamine (mPEG-N6), which possesses multiple amino end-groups at one end, was explored with respect to modification efficiency. As a control, a PEG mono-aminated at one end (mPEG-N1) was employed in parallel experiments. Dynamic light scattering (DLS), electrophoretic mobility (μ(e)), Fourier transform infra-red (FT-IR) absorption, and 3-(p-carboxybenzoyl)quinoline-2-caboxaldehyde (CBQCA) assays were carried out.

Development of a high-performance immunolatex based on "soft landing" antibody immobilization mechanism.

Rabbit anti-human ferritin (anti-hFT) polyclonal immunoglobulin G (IgG) and poly(ethylene glycol) (PEG) were sequentially co-immobilized onto polystyrene submicroparticles (sMPs) to construct sMP/anti-hFT/PEG (SAP) immunolatex. Chemical immobilization of anti-hFT was performed at different pH levels to evaluate variations in antigen recognition. Basic pH disfavored conjugation of anti-hFT to sMPs, but remarkably increased its antigen recognition in comparison to that at neutral pH.

Efficient inhibition of interfacial nonspecific interaction to create practically utilizable high ferritin-response immunolatex.

Immunolatex particles (LAmP-s), which were prepared by covalently co-immobilizing antiferritin and a mixture of pentaethylenehexamine-ended poly(ethylene glycol) (N6-PEG) of two different chain lengths onto the surface of polystyrene submicroparticles, were formulated with various antiferritin loads. Following the quantification of the bound antiferritin, as well as the differentiation of the physically adsorbed antiferritin from chemically bound antiferritin, using the copper reduction/bicinchoninic acid reaction (the Micro BCA method), dynamic light scattering (DLS) and electrophoretic mobility (mu(e)) measurements were performed to characterize the size, homogeneity, and surface charge of the complex. Compared to the control immunolatex particles, which were prepared similarly but traditionally using bovine serum albumin (BSA) as a blocking agent (LAB-s), the LAmP-s complex showed a difference only in the surface charge property, because of the altered surface treatment in the case of the LAmP-s (PEGylation) and LAB-s complexes (BSA covering).