Molecular interactions between dipalmitoyl phosphatidylcholine (DFFC) and lipophilic substances in a lipid bilayer were investigated by measurements of the encapusulation efficieny of glucose, micropolarity and microfluidity.
The encapusulation efficiency of glucose in liposomes decreased rapidly with an increase in concentrations of polar aliphatic substances such as 1-octanol and octanoic acid, but was almost independent of the non-polar hydrocarbon octane. The micropolarity of the lipid bilayer decreased with increasing concentration of octane (and/or 1-octanol), but was independent of octanoic acid. The microfluidity of the lipid bilayer and rates of glucose leakage for several lipophilic substances varied in the order, 1-octanol>octanoic acid> octane.
The permeability of liposomes was found to depend on the position of lipophilic substance in membranes and hydrophobic interactions between lipid and lipophilic substances in the lipid bilayer.
