Modification of Multiliposomal Nanocontainers with Albumin as a Method for Increasing Their Resistance to Enzymatic Hydrolysis

The influence of a pancreatic enzyme, lipase, on doxorubicin-loaded anionic liposomes, their complexes with spherical polycationic brushes, and ternary complexes with brushes and bovine serum albumin has been studied. The two-stage kinetics of the enzyme-induced disturbance of liposomal membrane integrity has been investigated using fluorescence spectroscopy. A 120-min induction period free of any serious damage to liposome membranes has been found for all enzyme-treated samples. This period is followed by rapid release of encapsulated doxorubicin. Enzymatic hydrolysis of the liposomes and their binary complexes with brushes has been found to proceed at the same rate, while a rather long resistance to the disturbance of liposome integrity has been observed for the ternary complexes. It has been assumed that albumin plays the role of a sterically screening agent, which hinders the enzymatic hydrolysis in multiliposomal complexes.