title: Intracellular trafficking of cationic liposome-DNA complexes in living cells.
abstract: Three-dimensional single-particle tracking (SPT) was used to calculate the mean square displacement (MSD) and the diffusion coefficients of multicomponent cationic liposome-DNA complexes (lipoplexes) in CHO-K1 living cells. In untreated (NT) control cells, we found that the intracellular lipoplex motion was either directed or Brownian with active transportation being definitely more frequent (more than 70%) than Brownian diffusion. The MSD analysis was supported by the calculation of the three-dimensional asphericity,A3, which was close to unity, denoting the preponderant occurrence of movement along a direction. To elucidate the role of the cytoskeleton structure in the lipoplex trafficking, cells were treated with cytoskeleton (actin microfilaments and microtubules) polymerization inhibitors (latrunculin B and nocodazole, respectively). When cells were treated with inhibitors, the lipoplex movement tended towards a random walk at the expense of directed motion. The disassembly of microtubules had a stronger effect on the reduction of directional movement than that of actin microfilaments. Relevance of the results for enhanced gene delivery is discussed.
authors.affiliation: Department of Molecular Medicine, "Sapienza" University of Rome, Viale Regina Elena 324, 00161 Rome, Italy. giulio.caracciolo@uniroma1.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Coppola
authors.affiliation: Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, 3120 Natural Sciences 2, Irvine, California 92697-2715, USA.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Estrada
authors.affiliation: Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, 3120 Natural Sciences 2, Irvine, California 92697-2715, USA.
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Digman
authors.affiliation: Department of Molecular Medicine, "Sapienza" University of Rome, Viale Regina Elena 324, 00161 Rome, Italy. giulio.caracciolo@uniroma1.it.
authors.forename: Daniela
authors.initials: D
authors.lastname: Pozzi
authors.affiliation: Center for Nanotechnology Innovation, @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Cardarelli
authors.affiliation: Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, 3120 Natural Sciences 2, Irvine, California 92697-2715, USA.
authors.forename: Enrico
authors.initials: E
authors.lastname: Gratton
authors.affiliation: Department of Molecular Medicine, "Sapienza" University of Rome, Viale Regina Elena 324, 00161 Rome, Italy. giulio.caracciolo@uniroma1.it.
authors.forename: Giulio
authors.initials: G
authors.lastname: Caracciolo