Abstract
It is useful if the bioactive macromolecules, such as cytokines, could be delivered to the desired site. Liposomes have been used successfully as carriers for various agents. Targeting of liposomes to the desirable site has been also achieved to some extent, and the release of the contents at the target site has been attempted by means of thermosensitive liposomes utilizing phase transition of lipid bilayer. Thermosensitiye Iiposomes with internal solution of 2-fold higher osmotic pressure and sized through 200 nm-pore, released encapsulated macromolecules effectively when they were incubated at 40∼42°C, since transient swelling during phase transition of liposomes with hyper-osmotic internal aqueous phase causes permeation of large molecules through lipid bilayer. Long-circulating, serum stable, type of thermosensitive liposomes were also attemped to be prepared for practical usage of liposomes as a tool for macromolecule delivery.
