AIM To investigate factors affecting the properties of antisense oligodeoxy nucleoti des (ASON) liposomes complex and their
cellular uptake. METHODS Three types of blank liposomes were prepared by reverse phase evaporation vesic les, and the complex were obtained through physical absorption. The light micros cope was used to observe morphology characteristics of the complex. Drug loading capacity was analyzed by agarose gel electrophoresis. The transfected cell perc entage and means fluorescence intensity were determined by flow cytometric analy sis using M 3 myeloma cell as a model. RESULTS The neutral liposome showed no aggregation while the cationic liposomes appeared some different extent aggregation in different medium when associated antisense oligodeoxynucleotides. The drug
loading capacity depended on the ratio of +/- and the cationic charge density on the lipid membrane. The two kinds of catio nic liposomes appeared different principles of loading ASON. As far as cellular uptake, The neutral liposomes showed no improvement of cellular uptake of ASON. However, the cationic liposomes were shown to enhance the cellular uptake of ASO N if the appropriate +/- charge ratio was used. The optimal cellular uptake was achieved when +/- charge ratio was at 0 5∶1 and 1∶1 for SA I liposome and SA II liposomes,respectively. CONCLUSION The cationic liposomes improved the loading capacity and
cell uptake of antisens e oligodeoxynucleotides, which was determined by +/- charge ratio and charge density.