An electrostatic conjugate composed of liposomes, polylysine and a polylactide micelle: a biodegradability–cytotoxicity relationship

A low-toxic ternary complex composed of anionic liposomes, cationic polylysine and slightly negative micelles from a polylactide–polyethylene glycol diblock copolymer is described. Liposomes with the encapsulated antitumor antibiotic Doxorubicin (Dox) retain their integrity after incorporation into the ternary complex. The incubation of cells with the Dox-loaded ternary complex leads to its penetration into the cells, the release of Dox from liposomes and predominant drug accumulation in cell nuclei. The ternary complex degrades to nanoparticles in the presence of proteolytic enzymes to produce low-toxic digestion products.