Interactions of phosphorus-containing dendrimers with liposomes.

The influence of cationic phosphorus-containing dendrimers generation 3 and 4 on model DMPC or DPPC lipid membranes was studied. Measurements of fluorescence anisotropy and differential scanning calorimetry (DSC) were applied to assess changes in lipid bilayer parameters, including fluidity, anisotropy, and phase-transition temperature. Interaction with both hydrophobic and hydrophilic regions of the bilayer was followed by these methods. Dendrimers of both generations influence lipid bilayers by decreasing membrane fluidity. The results suggest that dendrimers can interact both with the hydrophobic part and the polar head-group region of the phospholipid bilayer. Higher generation dendrimers interact more strongly with model membranes, and the concentration, as well as the generation, is of similar importance.