Effects of silver nanoparticles on the fluidity of bilayer in phospholipid liposome

This paper describes the formation and characterization of liposome entrapping the silver nanoparticles in bilayer. Silver nanoparticles were entrapped in the bilayer of dipalmitoylphosphatidylcholine (DPPC) liposome, named as silver-loaded liposome. Specifically, above the gel to liquid-crystalline phase transition temperature of this lipid (i.e., 41 degrees C), it was observed that membrane fluidities of silver-loaded liposomes were increased, and fluorescence anisotropy values were reduced from 0.114 to 0.097. This might be due to the structural modifications and interactions between DPPC molecules and. silver nanoparticles within the bilayer. It was also confirmed that silver nanoparticles were entrapped in hydrophobic region of lipid bilayer with transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) measurements. (c) 2005 Elsevier B.V. All rights reserved.