Construction of stable anionic liposome-plasmid particles using the heating method: a preliminary investigation.

Recent advances in liposome technology have resulted in the production of effective drug delivery formulations, although toxicity concerns remain. In order to overcome this problem we prepared anionic liposomes without using any volatile organic solvent or detergent. Liposomes prepared by this heating method (HM-liposomes) were characterised in terms of morphology, stability and DNA incorporation efficiency. Scanning tunnelling microscopy (STM) and optical microscopy were used to study the morphological characteristics and size distribution of HM-liposomes. Microscopic studies revealed formation of spherical bilayered structures with stabilities of at least eight months and also enabled measuring the diameter and the bilayer thickness of the vesicles. Plasmid DNA encapsulation efficiencies of up to 70.3% were determined for HM-liposomes.