Development of temperature-responsive chromatography using functional polymers

We developed a novel chromatography system in which temperature controlled separation is achieved by only water as a mobile phase using packing materials modified with a temperature-responsive polymer, poly (N-isopropylacrylamide) (PNIPAAm). The ability of the proposed temperature-responsive chromatography system to separate solutes without using an organic solvent is advantageous from the point of view of maintaining the structure and activity of biologically active substance. Recently, we designed and synthesized copolymers that introduced ion-exchange groups, environmentally-responsive polymers, which respond to temperature and pH. Copolymer-grafted aminopropyl silica beads were used as HPLC packing materials. These separation systems are based on a new concept that the property of the stationary phase surface is altered by external stimuli, such as the pH and temperature. A temperature-responsive chromatography system utilizing PNIPAArn derivatives would be highly useful for peptide and protein separation, since chromatographic separation is performed under mild aqueous mobile phase conditions. Applications to bio-separation in various fields, such as medical and pharmaceutical sciences, is expected.