TIRM MEASUREMENTS WITH CELLS AND LIPOSOMES

Quantification of nonspecific, biological interactions can provide ins ight on the mechanisms of cellular adhesion and lead to more effective use of liposomes for drug delivery. The nonspecific interactions betw een both cells and liposomes and a glass plate were measured using tot al internal reflection microscopy (TIRM), The sphere-plate geometry an d high resolution make TIRM well suited for measuring weak, biological forces, The measured potential energies of interaction agree well wit h theory. Debye lengths calculated independently from solution conduct ivity measurements agree with the values obtained experimentally with TIRM. These results are the first reported TIRM measurements with cell s and liposomes. (C) 1998 Academic Press.