Influence of lipid composition on the thermotropic behavior and size distribution of mixed cationic liposomes.
Cationic liposomes are studied mainly as nonviral nucleic acid delivery systems and to a lesser extent as carriers/adjuvants of vaccines and as low-molecular-weight drug carriers. It is well established that the performance and the biological activity of liposomes in general are strongly related to their physicochemical properties. We investigated the thermotropic behavior and the size distribution of mixed cationic liposomes formulated with different percentages of 1,2 dimyristoyl-sn-glycero-3-phosphatidylcholine and one of four cationic amphiphiles characterized by a pyrrolidinium headgroup with the aim of achieving a better understanding of how the molecular structure of the cationic amphiphile and its mole percentage affect the physicochemical properties of the liposomes. Multilamellar vesicles and large unilamellar vesicles were studied by differential scanning calorimetry and turbidity, respectively, to characterize the thermotropic behavior and lipid phase, whereas dynamic light scattering was used to determine size distribution. This study shows that subtle modifications in the cationic amphiphile's molecular structure and in liposome composition may have dramatic effects on the organization of the liposome bilayer and hence on the morphological and physicochemical features of the liposomes, thus being highly relevant to the biological features investigated previously.
Laboratory of Membrane and Liposome Research, Hebrew University, Hadassah Medical School, Jerusalem, Israel.
Yechezkel
Y
Barenholz
Cecilia
C
Bombelli
Maria Grazia
MG
Bonicelli
Pietro
P
di Profio
Luisa
L
Giansanti
Giovanna
G
Mancini
Fabrizio
F
Pascale
D002152:Calorimetry, Differential Scanning; D002412:Cations / Q000737:chemistry; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D004337:Drug Carriers / Q000138:chemical synthesis* / Q000378:metabolism; D015394:Molecular Structure; D009391:Nephelometry and Turbidimetry; D010316:Particle Size; D011759:Pyrrolidines / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D013816:Thermodynamics; D053835:Unilamellar Liposomes / Q000138:chemical synthesis* / Q000378:metabolism
D002412:Cations; D004337:Drug Carriers; D011759:Pyrrolidines; D013501:Surface-Active Agents; D053835:Unilamellar Liposomes; D004134:Dimyristoylphosphatidylcholine