Cell partitioning in aqueous two-phase polymer systems.

This review addresses whole cell separation and isolation using aqueous two-phase systems based on biocompatible polymers. The physicochemical factors that influence phase separation and systems properties are analysed. Especially, emphasis is given to the polyethylene glycol (PEG) and dextran two-phase systems and to stimuli-responsive soluble-insoluble polymers. The major factors that affect cell partitioning, such as polymer molecular weight and concentration, temperature, ionic species and pH, and affinity extraction, are also evaluated taking into account the cell types and cell surface properties. The applications of aqueous two-phase separation in cell processing are described, namely the new developments in continuous cell partitioning in microdevices and extractive bioconversions with relevance to the biomedical sector.