SERUM-LIPOSOME INTERACTION IS AN OXYGEN-DEPENDENT PROCESS

Measurements of heat dissipation, oxygen concentration and average ves icle size were correlated to study the effect of serum components on d ifferent types of liposome. The results indicate that the interaction between serum components and liposomes is exothermic and oxygen depend ent, and leads to disruption of vesicles. The dependence of this effec t on serum concentration, vesicle surface charge and type of liposome was also evaluated. Serum components did not produce any effect on con ventional liposomes in the absence of oxygen. Moreover, in hypoxic con ditions the serum-liposome interaction was delayed, Both results sugge st that this interaction is an oxygen-dependent event. Finally, we con firmed that sterically stabilised liposomes remain unalterated in the presence of serum.