Permeability of small hydrophilic solutes in small unilamellar vesicle (SUV)

Permeabilities of hydrophilic solutes with and without net charge in small unilamellar vesicles (SUV) were determined. Their permeabilities showed str ong dependence on molecular weight. The permeabilities of net zero charged molecule (glucose and alanine) in SUV consisting of dioreoylphosphatidylcho line (DOPC) or soybean phosphatidylcholine (SoyPC) were larger than those i n SUV consisting of dimyristoylphosphatidylcholine (DMPC). The permeabiliti es of net charged molecules (lysine and glutamate), on the other hand, in S UV consisting of DOPC or SoyPC were lower than those in SUV consisting of D MPC. These results suggest that the electrostatic potential barrier of lipi d bilayer has significant effects on the permeabilities of hydrophilic solu tes in the liposomes. (C) 1999 Elsevier Science S.A. All rights reserved.