Selective injection of fluorescence sensor encapsulated in the functional lipid capsule for intracellular measurement

We developed selective transfection of single fluorescence sensor into a specific cell by optically controlled cell immobilization and membrane fusion of lipid capsule for intracellular measurement. The single fluorescent sensor was encapsulated in the lipid capsule using novel packaging based on a multi-layering method. The liposomes with number-controlled lipid bulyer contain 1,3,3-Trimethylindolino-6´-nitrobenzopyrylospiran (SP), a photochromic chemical that controls the surface potential of the liposome was used as lipid capsule. The lipid capsule is manipulated by optical tweezers to the target cell inside the microfluidic chip. While the surface potential of the liposome was negative under VIS illumination, it becomes positive by UV-induced photoisolation of SP. The positively-charged liposome immobilized to the negatively-charged cell membrane by Coulomb attraction. We demonstrated the selective immobilization of the lipid capsule to Madin-Darby canine kidney (MDCK) cells and observed the transfected sensor in the cell nucleus.