Interaction of Fullerenes C60 with Large Unilamellar Vesicles

In order to explore the fullerene-lipid interaction, we have studied the effects caused by C-60 on Large Unilamellar Vesicles (LUV). For this purpose liposomes composed of L-a Phosphatidylcholine (PC) and 1,2-dimyristoyl-sn-glycero-3-phospocholine (DMPC) and Cholesterol (Chol) in 2:1 molar ratio were used. The dispersions were characterized by means of Dynamic Light Scattering (DLS), zeta-potential measurements and Differential Scanning Calorimetry studies (DSC). The incorporation of C-60 into liposomes altered their physicochemical properties. A reduction to the mean diameter of the liposomes was observed when C-60 were incorporated, which might imply deformations on the lipid membrane induced by fullerenes. An increase to the surface charge of the liposomes was noticed when C-60 molecules were present in the membrane providing evidence of their successful incorporation into the liposomal bilayers. Finally the miscibility of liposomes with C-60 was investigated by DSC. Alterations occurred to the main transition of the liposomes when C-60 molecules were present in the membrane might be attributed to the penetration of the carbonaceous material into the lipid bilayers.