title: Cationic liposomes formulated with DMPC and a gemini surfactant traverse the cell membrane without causing a significant bio-damage.
abstract: Cationic liposomes have been intensively studied both in basic and applied research because of their promising potential as non-viral molecular vehicles. This work was aimed to gain more information on the interactions between the plasmamembrane and liposomes formed by a natural phospholipid and a cationic surfactant of the gemini family. The present work was conducted with the synergistic use of diverse experimental approaches: electro-rotation measurements, atomic force microscopy, ζ-potential measurements, laser scanning confocal microscopy and biomolecular/cellular techniques. Electro-rotation measurements pointed out that the interaction of cationic liposomes with the cell membrane alters significantly its dielectric and geometric parameters. This alteration, being accompanied by significant changes of the membrane surface roughness as measured by atomic force microscopy, suggests that the interaction with the liposomes causes locally substantial modifications to the structure and morphology of the cell membrane. However, the results of electrophoretic mobility (ζ-potential) experiments show that upon the interaction the electric charge exposed on the cell surface does not vary significantly, pointing out that the simple adhesion on the cell surface of the cationic liposomes or their fusion with the membrane is to be ruled out. As a matter of fact, confocal microscopy images directly demonstrated the penetration of the liposomes inside the cell and their diffusion within the cytoplasm. Electro-rotation experiments performed in the presence of endocytosis inhibitors suggest that the internalization is mediated by, at least, one specific pathway. Noteworthy, the liposome uptake by the cell does not cause a significant biological damage.
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 2, 00185 Roma, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Stefanutti
authors.affiliation: Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Roma, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Papacci
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 2, 00185 Roma, Italy; dCNR-IPCF, Sapienza Università di Roma, P.le Aldo Moro 2, 00185 Roma, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Sennato
authors.affiliation: CNR, Istituto di Metodologie Chimiche and Dipartimento di Chimica Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Roma, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Bombelli
authors.affiliation: National Nanotechnology Laboratory, Institute Nanoscience-CNR (NNL, CNR-NANO), I-73100 Lecce, Italy and c/o Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 2, 00185 Roma, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Viola
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 2, 00185 Roma, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Bonincontro
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 2, 00185 Roma, Italy; dCNR-IPCF, Sapienza Università di Roma, P.le Aldo Moro 2, 00185 Roma, Italy; Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Viale Regina Elena, 291-00161 Roma, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Bordi
authors.affiliation: CNR, Istituto di Metodologie Chimiche and Dipartimento di Chimica Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Roma, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Mancini
authors.affiliation: National Nanotechnology Laboratory, Institute Nanoscience-CNR (NNL, CNR-NANO), I-73100 Lecce, Italy and c/o Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 2, 00185 Roma, Italy; Università del Salento, Dip. di Matematica e Fisica Ennio de Giorgi and Istituto Italiano di Tecnologia, Center for Biomolecular Nanotechnologies, Lecce, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Gigli
authors.affiliation: Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Roma, Italy. Electronic address: gianfranco.risuleo@uniroma1.it.
authors.forename: G
authors.initials: G
authors.lastname: Risuleo
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D003593:Cytoplasm / Q000737:chemistry / Q000378:metabolism; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D008561:Membrane Fusion; D051379:Mice; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D008081:Liposomes; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; D004134:Dimyristoylphosphatidylcholine
keywords: Biological effect; Cationic gemini surfactant; Cell surface roughness; Liposome penetration; Phospholipid liposome