Photo and Thermal Control of Liposome Solubilization

The solubilization Of liposomes induced by the addition of surfactants was photocontrolled under temperature control. The instability of the membrane was increased both by photoisomerization of photoresponsive molecules included in the membrane and by changing temperature. By addition of a spiropyran to the liposome membrane, charge-separated structure was formed by UV irradiation, causing local polarization and subsequent motion in the membrane. We found a difference in the solubilization processes in a specific temperature range under UV irradiated and nonirradiated conditions, and figured out that the solubilization of liposomes smaller than 2 mu m can be distinctly photocontrolled in a certain temperature range.