Protein manipulation by stimuli-responsive polymers encapsulated in erythrocyte ghosts

Stimuli-responsive polymers exhibit dramatic, reversible alterations of their physical properties in response to minor environmental changes. Such alterations can be controlled systematically and are exploited in a variety of biologically relevant applications. We describe several properties of the temperature-responsive polymer, poly(N-isopropylacrylamide), encapsulated within erythrocyte ghosts. The manipulation of target proteins inside the cells was demonstrated with polymer biomolecule conjugates and fusion of differentially labeled erythrocyte ghosts. Harnessing the properties of such materials to actively alter the functionality of proteins provides unique modes of interference with cellular events.