Gas-Assisted Superparamagnetic Extraction for Potential Large-Scale Separation of Proteins

In this study, gas-assisted superparamagnetic extraction (GASE), a novel technology that combined superparamagnetic extraction technology with flotation technology, was proposed for potential large-scale separation of proteins. GASE includes adsorption for trapping proteins, and flotation and high gradient magnetic separator (HGMS) for recovering proteins-loaded magnetic particles from the dilute biosuspension. Citrate-modified superparamagnetic nanoparticles (CMNs) and bovine serum albumin (BSA) were used as a model. The feasibility of flotation for these particles enrichment was demonstrated. The results indicated that the BSA-loaded CMNs could be well concentrated in either foaming flotation or nonfoaming flotation by simple adjustment of the initial solution pH, without extra detergents and operations. The flotation conditions were consistent with the adsorption ones, and no proteins were desorbed from CMNs in the GASE process. Under the optimal conditions, the enrichment ratio and recovery percentage reached 31 and 99% in 1.5 min, respectively.