Liposomes incorporated with cholesterol for drug release triggered by magnetic field

Liposome formulated with cholesterol at different ratios was used to investigate the extent of drug release triggered by magnetic forces. Liposomes were prepared at various ratios of DPPC/cholesterol (4:0, 4:0.5, 4:1, 4:2, at 5 mM lipid concentration), and encapsulated 5(6)-Carboxylfluorescein [5(6)-CF] by the method of thin film hydration. They were then characterized by differential scanning calorimetry (DSC) and deformability experiments to investigate the relationship between physical stability and the addition of cholesterol. The influence of magnetic field on the release of encapsulated drug was also investigated. The results showed that deformability of liposomes decreased in terms of an increase in liposomal stability with increasing cholesterol incorporation. The zeta potential and particle sizes for liposomes under different strengths magnetic field changed dramatically, suggesting that the magnetic orientation of the lipid molecules caused changes in zeta potential and particle size. Liposome of DPPC/cholesterol=4:1 exhibited the highest physical stability and showed a 66% difference in drug release over the absence of a magnetic field. Liposome of DPPC/cholesterol=4:1 seems to be the optimal liposome formulation for drug release under a magnetic field.