A thermosensitive amphoteric microsphere and its potential application as a biological carrier

Thermosensitive poly(N-isopropylacrylamide) moieties were introduced onto amphoteric styrene/glycidyl methacrylate copolymer seed microspheres prepared by use of amphoteric initiators. The resulting microspheres exhibited thermosensitive and amphoteric behavior, so dual sensitivity to both pH and temperature was observed. The colloidal properties of the microspheres before and after seeded polymerization were characterized by varying the temperature and the pH. The results indicated that the specific surface structure emerged when the environmental conditions were changed. In addition, the reactive epoxy groups on the microsphere surface could be utilized to immobilize the protein molecules. The behavior of protein adsorption and immobilization onto the microspheres was examined in order to understand their potential applications in biological areas.