Two types of magnetite-containing liposomes for magnetocontrolled drug release

The paper is dedicated to a comparative study of pharmaceutical properties of magnetite containing liposomes. We have investigated two types of liposomes: 1) magnetic shell liposomes containing magnetic nanoparticles in the coating lipid bilayer and 2) magnetic core liposomes containing the nanoparticles in the internal volume (water phase). Both types of liposomes were obtained by the thin film hydration method from phosphatidylcholine and cholesterol. Fluorescent dye 5,6-carboxyfluorescein was used as a marker substance to indicate release. The dimensional characteristics, the degree of dye release under the influence of an alternating magnetic field, the speed of spontaneous release and the stability of liposomes during storage were investigated. It has been shown that liposomes with nanoparticles in the internal space are more stable, have low rate of spontaneous release of the incorporated substance, but the rate of release under the influence of an alternating field is also low. Liposomes with magnetic nanoparticles inside the lipid bilayer have high release degree influenced by alternating magnetic field, but they are less stable during storage and more prone to spontaneous loss of the active substance. (paper)