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11.
Structural characterization of a new lipid/DNA complex showing a selective transfection efficiency in ovarian cancer cells 总被引:5,自引:0,他引:5
Caracciolo G Pozzi D Caminiti R Congiu Castellano A 《The European physical journal. E, Soft matter》2003,10(4):331-336
We investigated, for the first time, by using Energy Dispersive X-ray Diffraction, the structure of a new ternary cationic
liposome formulated with dioleoyl trimethylammonium propane (DOTAP), 1,2-dioleoyl-3-phosphatidylethanolamine (DOPE) and cholesterol
(Chol) (DDC) which has been recently found to have a selective high gene transfer ability in ovarian cancer cells. Our structural
results provide a further experimental support to the widely accepted statement that there is not a simple and direct correlation
between structure and transfection efficiency and that the factors controlling cationic lipid/DNA (CL-DNA) complexes-mediated
gene transfer depend not only on the formulations of the cationic liposomes and their thermodynamic phase, but also significantly
on the cell properties.
Received: 28 October 2002 / Accepted: 21 March 2003 / Published online: 15 April 2003
RID="a"
ID="a"e-mail: a.congiu@caspur.it 相似文献
12.
Matteo A.M. Tallone L. Boidi C. Cognolato L. Pozzi F. 《Optical and Quantum Electronics》2000,32(6-8):981-990
We present a semi-analytical modeling suitable for the investigation of the spectral characteristics of UV-waveguide Bragg gratings (UV-WBGs) having arbitrary apodization function and extending both in the film layer and in the overlayer. The modeling is based on a proper combination of coupled mode theory and transfer matrix formalism and provides a powerful tool for designing and simulation of complex UV-grating based structures. The results of a detailed investigation of UV-WBGs in doped silica based channel optical waveguides are presented and critical issues for upgrading the performances of related device are discussed. Validation of the modeling is provided by means of an extensive comparison between theoretical and experimental results relevant to UV-WBGs realized in phosphorous (P)- and boron (B)-doped silica based waveguides. 相似文献
13.
Fluorous quaternary ammonium and phosphonium salts, as well as fluorous macrocyclic ligands, such as crown and aza-crown ethers, have been gradually emerging as viable alternatives to classical phase transfer catalysts. The major results thus far obtained in this burgeoning field will be the focus of this review. 相似文献
14.
Capriotti AL Caracciolo G Cavaliere C Crescenzi C Pozzi D Laganà A 《Analytical and bioanalytical chemistry》2011,401(4):1195-1202
The knowledge about the interaction between plasma proteins and nanocarriers employed for in vivo delivery is fundamental
to understand their biodistribution. Protein adsorption onto nanoparticle surface (protein corona) is strongly affected by
vector surface characteristics. In general, the primary interaction is thought to be electrostatic, thus surface charge of
carrier is supposed to play a central role in protein adsorption. Because protein corona composition can be critical in modifying
the interactive surface that is recognized by cells, characterizing its formation onto lipid particles may serve as a fundamental
predictive model for the in vivo efficiency of a lipidic vector. In the present work, protein coronas adsorbed onto three
differently charged cationic liposome formulations were compared by a shotgun proteomic approach based on nano-liquid chromatography–high-resolution
mass spectrometry. About 130 proteins were identified in each corona, with only small differences between the different cationic
liposome formulations. However, this study could be useful for the future controlled design of colloidal drug carriers and
possibly in the controlled creation of biocompatible surfaces of other devices that come into contact with proteins into body
fluids. 相似文献
15.
D. Batani A. Conti A. Masini M. Milani M. Costato A. Pozzi E. Turcu R. Allot N. Lisi F. Musumeci A. Triglia 《Il Nuovo Cimento D》1996,18(5):657-662
Summary Soft-X-rays irradiation of yeast cells allows selective interference with different cellular structures. The monitoring of
different physical parameters leads to substantial variations in the response to X-rays showing that monotonicity should not
be taken for granted.
Also at INFM (Istituto Nazionale di Fisica della Materia). 相似文献
16.
T. Di Matteo F. Pozzi T. Aste 《The European Physical Journal B - Condensed Matter and Complex Systems》2010,73(1):3-11
Two kinds of filtered networks: minimum spanning trees (MSTs) and planar maximally filtered graphs (PMFGs) are constructed from dynamical correlations computed over a moving window. We study the evolution over time of both hierarchical and topological properties of these graphs in relation to market fluctuations. We verify that the dynamical PMFG preserves the same hierarchical structure as the dynamical MST, providing in addition a more significant and richer structure, a stronger robustness and dynamical stability. Central and peripheral stocks are differentiated by using a combination of different topological measures. We find stocks well connected and central; stocks well connected but peripheral; stocks poorly connected but central; stocks poorly connected and peripheral. It results that the Financial sector plays a central role in the entire system. The robustness, stability and persistence of these findings are verified by changing the time window and by performing the computations on different time periods. We discuss these results and the economic meaning of this hierarchical positioning. 相似文献
17.
Caracciolo G Pozzi D Caminiti R Amenitsch H 《The journal of physical chemistry. B》2006,110(42):20829-20835
The mechanism of formation of multicomponent lipoplexes was investigated by means of synchrotron Small-Angle X-ray Diffraction (SAXD). Mixed lipid dispersions were prepared by mixing different populations of binary cationic liposomes. When adding DNA to mixed lipid dispersions, multicomponent lipoplexes spontaneously formed exhibiting structural properties, i.e., membrane thickness, surface charge density, and one-dimensional DNA packing density, intermediate between those of binary lipoplexes. These results suggested that DNA lets liposomes come into contact and fuse and that a complete lipid mixing at the molecular level occurs. The equilibrium structure of multicomponent lipoplexes was found to be unique and did not depend on the number and kind of populations composing lipid dispersion but only on the lipid species involved and on their relative molar ratio. According to recent theoretical models we identified two-dimensional lipid mixing entropy as the key factor regulating the existence of only multicomponent lipoplexes with ideally mixed lipid species. 相似文献
18.
Paolo Manganotti Michele Acler Emanuela Formaggio Mirko Avesani Franco Milanese Andrea Baraldo Silvia Francesca Storti Anna Gasparini Roberto Cerini Roberto Pozzi Mucelli Antonio Fiaschi 《Magnetic resonance imaging》2010
Objective
Whereas several studies have used functional magnetic resonance imaging (fMRI) to investigate motor recovery, whether therapy to decrease post-stroke hypertonus alters central motor patterns remains unclear. In this study, we used continuous electromyography (EMG)-fMRI to investigate possible changes in movement-related brain activation in patients receiving Botulinum toxin (BoNT-A) for hand-muscle hypertonus after chronic stroke.Methods
We studied eight stroke patients all of whom had hemiparesis and associated upper-limb hypertonus. All patients underwent an fMRI-EMG recording and clinical-neurological assessment before BoNT-A and 5 weeks thereafter. The handgrip motor task during imaging was fixed across both patients and controls. The movements were metronome paced, movement amplitude and force were controlled with a plastic orthosis, dynamometer and EMG recording. An age-matched control group was recruited from among healthy volunteers underwent the same fMRI-EMG recording.Results
Before BoNT-A, while patients moved the paretic hand, fMRI detected wide bilateral activation in the sensorymotor areas (SM1), in the supplementary motor area (SMA) and cerebellum. After BoNT-A blood oxygenation level-dependent (BOLD) activation decreased in ipsilateral and contralateral motor areas and became more lateralized. BOLD activation decreased also in ipsilateral cerebellar regions and in the SMA.Conclusion
Changes in peripheral upper-limb hypertonus after BoNT-A were associated to an improvement in active movements and more lateralized and focalized activation of motor areas. The clinical and EMG-fMRI coregistration technique we used to study hand-muscle hypertonus in patients receiving BoNT-A after chronic stroke should be useful in future studies seeking improved strategies for post-stroke neurorehabilitation. 相似文献19.
Ferroxidase Activity in Eukaryotic Ferritin is Controlled by Accessory‐Iron‐Binding Sites in the Catalytic Cavity
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Dr. Caterina Bernacchioni Dr. Cecilia Pozzi Flavio Di Pisa Prof. Stefano Mangani Prof. Paola Turano 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(45):16213-16219
Ferritins are iron‐storage nanocage proteins that catalyze the oxidation of Fe2+ to Fe3+ at ferroxidase sites. By a combination of structural and spectroscopic techniques, Asp140, together with previously identified Glu57 and Glu136, is demonstrated to be an essential residue to promote the iron oxidation at the ferroxidase site. However, the presence of these three carboxylate moieties in close proximity to the catalytic centers is not essential to achieve binding of the Fe2+ substrate to the diferric ferroxidase sites with the same coordination geometries as in the wild‐type cages. 相似文献
20.