Formation of multi-compartmental particles by controlled aggregation of liposomes

Abstract

The formation of multi-compartmental colloidal particles by controlled aggregation of 100nm cationic liposomes was investigated. The aggregation was performed under quiescent (perikinetic) conditions and was controlled by the ionic strength of the solution. The time required for obtaining 500nm particles by liposome aggregation ranged from several hours to a few minutes when increasing the NaCl concentration from 50mM to 100mM. It was shown that the aggregation process can be effectively terminated by capping the liposome clusters by a biocompatible non-ionic polymeric surfactant (Poloxamer 188). The clusters were stable in time and resistant to further increase in ionic strength as well as to mechanical agitation. These results demonstrate that multi-compartmental liposome-based carriers with a controlled size can be prepared in a relatively simple and robust way, and used for further studies in environments with variable salinity and hydrodynamic conditions.