Expanded Bed Chromatography as a Tool for Nanoparticulate Separation: Kinetic Study and Adsorption of Protein Nanoparticles

Expanded bed adsorption was investigated together with its suitability for the practical recovery of nanoparticulate mimics of products such as plasmid DNA and viruses as putative gene therapy vectors. The study assessed the binding of protein nanoparticles fabricated from bovine serum albumin (BSA) with average size of 80 nm as a model system and viral size/charge mimic to the streamline DEAE adsorbent in the expanded bed column chromatography. The adsorption kinetics and adsorption mechanism for the BSA nanoparticles on the adsorbent were studied. In batch adsorption studies, the factors nanoparticle concentration, contact time and adsorbent amount, affecting adsorption isotherms were investigated. Subsequently the data were regressed against the Lagergren equation, which represents a first-order kinetics equation and also against a pseudo-second-order kinetics equation. The results demonstrated that the adsorption process followed a Langmuir isotherm equation. The kinetics of the adsorption process followed a pseudo-second-order kinetics model with a rate constant value of 0.025 g mg−1 min−1. The dynamic binding capacity of the BSA nanoparticles on an expanded bed was calculated. The recovery of the nanoparticles was more than 85%.