177 research outputs found
Lapatinib/Paclitaxel polyelectrolyte nanocapsules for overcoming multidrug resistance in ovarian cancer.
The sonication-assisted layer-by-layer (SLBL) technology was developed to combine necessary factors for an efficient drug-delivery system: (i) control of nanocolloid size within 100 - 300 nm, (ii) high drug content (70% wt), (iii) shell biocompatibility and biodegradability, (iv) sustained controlled release, and (v) multidrug-loaded system. Stable nanocolloids of Paclitaxel (PTX) and lapatinib were prepared by the SLBL method. In a multidrug-resistant (MDR) ovarian cancer cell line, OVCAR-3, lapatinib/PTX nanocolloids mediated an enhanced cell growth inhibition in comparison with the PTX-only treatment. A series of in vitro cell assays were used to test the efficacy of these formulations. The small size and functional versatility of these nanoparticles, combined with their ability to incorporate various drugs, indicates that lapatinib/PTX nanocolloids may have in vivo therapeutic applications
Alpha-enolase (ENO1) controls alpha v/beta 3 integrin expression and regulates pancreatic cancer adhesion, invasion, and metastasis
Background: We have previously shown that in pancreatic ductal adenocarcinoma (PDA) cells, the glycolytic enzyme alpha-enolase (ENO1) also acts as a plasminogen receptor and promotes invasion and metastasis formation. Moreover, ENO1 silencing in PDA cells induces oxidative stress, senescence and profoundly modifies PDA cell metabolism. Although anti-ENO1 antibody inhibits PDA cell migration and invasion, little is known about the role of ENO1 in regulating cell-cell and cell-matrix contacts. We therefore investigated the effect of ENO1 silencing on the modulation of cell morphology, adhesion to matrix substrates, cell invasiveness, and metastatic ability. Methods: The membrane and cytoskeleton modifications that occurred in ENO1-silenced (shENO1) PDA cells were investigated by a combination of confocal microscopy and atomic force microscopy (AFM). The effect of ENO1 silencing was then evaluated by phenotypic and functional experiments to identify the role of ENO1 in adhesion, migration, and invasion, as well as in senescence and apoptosis. The experimental results were then validated in a mouse model. Results: We observed a significant increase in the roughness of the cell membrane due to ENO1 silencing, a feature associated with an impaired ability to migrate and invade, along with a significant downregulation of proteins involved in cell-cell and cell-matrix adhesion, including alpha v/beta 3 integrin in shENO1 PDA cells. These changes impaired the ability of shENO1 cells to adhere to Collagen I and IV and Fibronectin and caused an increase in RGD-independent adhesion to vitronectin (VN) via urokinase plasminogen activator receptor (uPAR). Binding of uPAR to VN triggers integrin-mediated signals, which result in ERK1-2 and RAC activation, accumulation of ROS, and senescence. In shENO1 cancer cells, the use of an anti-uPAR antibody caused significant reduction of ROS production and senescence. Overall, a decrease of in vitro and in vivo cell migration and invasion of shENO1 PDA cells was observed. Conclusion: These data demonstrate that ENO1 promotes PDA survival, migration, and metastasis through cooperation with integrins and uPAR
Stress relaxation and creep experiments with the atomic force microscope: a unified method to calculate elastic moduli and viscosities of biomaterials (and cells)
We show that the atomic force microscope can perform stress relaxation and
creep compliance measurements on living cells. We propose a method to obtain
the mechanical properties of the studied biomaterial: the relaxation time, the
elastic moduli and the viscosity.Comment: 17 pages, three figure
Comparative analysis of medicinal plants used in traditional medicine in Italy and Tunisia
<p>Abstract</p> <p>Background</p> <p>Italy and Tunisia (Africa for the Romans), facing each other on the opposite sides of the Mediterranean Sea, have been historically linked since the ancient times. Over the centuries both countries were mutually dominated so the vestiges and traces of a mutual influence are still present. The aim of the present study is to conduct a comparative analysis of the medicinal species present in the respective Floras in order to explore potential analogies and differences in popular phytotherapy that have come out from those reciprocal exchanges having taken place over the centuries</p> <p>Methods</p> <p>The comparative analysis based on the respective floras of both countries takes into consideration the bulk of medicinal species mutually present in Italy and Tunisia, but it focuses on the species growing in areas which are similar in climate. The medicinal uses of these species are considered in accordance with the ethnobotanical literature.</p> <p>Results</p> <p>A list of 153 medicinal species belonging to 60 families, present in both floras and used in traditional medicine, was drawn. A considerable convergence in therapeutic uses of many species emerged from these data.</p> <p>Conclusion</p> <p>This comparative analysis strengthens the firm belief that ethno-botanical findings represent not only an important shared heritage, developed over the centuries, but also a considerable mass of data that should be exploited in order to provide new and useful knowledge.</p
Anisotropic colloids through non-trivial buckling
We present a study on buckling of colloidal particles, including
experimental, theoretical and numerical developments. Oil-filled thin shells
prepared by emulsion templating show buckling in mixtures of water and ethanol,
due to dissolution of the core in the external medium. This leads to
conformations with a single depression, either axisymmetric or polygonal
depending on the geometrical features of the shells. These conformations could
be theoretically and/or numerically reproduced in a model of homogeneous
spherical thin shells with bending and stretching elasticity, submitted to an
isotropic external pressure.Comment: submitted to EPJ
Ethnobotanical remarks on Central and Southern Italy
<p>Abstract</p> <p>Background</p> <p>The present paper is a brief survey on the ethnobotanical works published by the Authors since 1981, concerning the research carried out in some southern and central Italian regions. Before Roman domination these territories were first inhabited by local people, while the southern areas were colonized by the Greeks. These different cultural contributions left certain traces, both in the toponyms and in the vernacular names of the plants and, more generally, in the culture as a whole.</p> <p>Methods</p> <p>Field data were collected through open interviews, mainly of farmers, shepherds and elderly people, born or living in these areas for a long time. Voucher specimens of collected plants are preserved in the respective herbaria of the Authors and in the herbarium of "Roma Tre" University. Important contributions have been made by several students native to the areas under consideration. A comparative analysis with local specific ethnobotanical literature was carried out.</p> <p>Results</p> <p>The paper reports several examples concerning human and veterinary popular medicine and in addition some anti-parasitic, nutraceutic, dye and miscellaneous uses are also described. Moreover vernacular names and toponyms are cited. Eight regions of central and southern Italy (particularly Latium, Abruzzo, Marche and Basilicata) were investigated and the data obtained are presented in 32 papers. Most of the species of ethnobotanical interest have been listed in Latium (368 species), Marche (274) and Abruzzo (203). The paper also highlights particularly interesting aspects or uses not previously described in the specific ethnobotanical literature.</p> <p>Conclusion</p> <p>Phyto-therapy in central and southern Italy is nowadays practised by a few elderly people who resort to medicinal plants only for mild complaints (on the contrary food uses are still commonly practised). Nowadays therapeutic uses, unlike in the past, are less closely or not at all linked to ritual aspects. Several plants deserve to be taken into consideration not only from the anthropological or cultural point of view, but also for further phyto-chemical investigation. Our studies, as well as those of other authors, try to provide an original picture of the local ethno-biodiversity.</p
The future of layer-by-layer assembly: A tribute to ACS Nano associate editor Helmuth Möhwald
Layer-by-layer (LbL) assembly is a widely used tool for engineering materials and coatings. In this Perspective, dedicated to the memory of ACS Nano associate editor Prof. Dr. Helmuth Möhwald, we discuss the developments and applications that are to come in LbL assembly, focusing on coatings, bulk materials, membranes, nanocomposites, and delivery vehicles
Measurement of the adhesion between single melamine-formaldehyde resin microparticles and a flat fabric surface using AFM
An understanding of the adhesion of microparticles, particularly microcapsules, containing a functional component to a fabric surface is crucial to an effective application of this component to the fibre. Fabric surface is very rough; hence, direct measurement of the adhesion of single microparticles to surfaces with a roughness greater than the particle diameter is difficult. In the study reported here, cotton films were generated by dissolving cotton powder in an organic solvent and their properties including surface roughness, thickness, contact angle and purity were characterised. The adhesive forces between single melamineformaldehyde (MF) resin microparticles and a cotton film under ambient conditions with a relative humidity of above 40% were measured using atomic force microscopy; they are considered to be dominated by capillary forces. It was found that there was little adhesion between a MF microparticle and a cotton film in an aqueous solution of sodium dodecylbenzene sulphonate as surfactant. Repulsion between them was observed, but it reduced with increase in the surfactant concentration and decrease in the pH of the solution. The repulsion contributions are thought to originate mainly from electrostatic repulsion. It is believed that the studies on the adhesion between single MF microparticles and a cotton film under ambient conditions or dispersed in surfactant solutions, are beneficial to the attempts to enhance the adhesion of microcapsules to fabric surfaces via a modification of their surface composition and morphology
Notulae to the Italian alien vascular flora: 2
In this contribution, new data concerning the Italian distribution of alien vascular flora are presented. It includes new records, exclusions and confirmations for Italy or for Italian administrative regions for taxa in the genera Ageratum, Aster, Buddleja, Cedrus, Centranthus, Cephalotaxus, Clerodendrum, Cotoneaster, Cyperus, Honorius, Lantana, Ligustrum, Morus, Muscari, Oenothera, Opuntia, Platycladus, Plumbago, Pseudotsuga, Sedum, Sporobolus, Stachys, Ulmus and Yucca. A nomen novum, Stachys talbotii, is proposed as a replacement name for Sideritis purpurea
Notulae to the Italian alien vascular flora: 2
In this contribution, new data concerning the Italian distribution of alien vascular flora are presented. It includes new records, exclusions and confirmations for Italy or for Italian administrative regions for taxa in the genera Ageratum, Aster, Buddleja, Cedrus, Centranthus, Cephalotaxus, Clerodendrum, Cotoneaster, Cyperus, Honorius, Lantana, Ligustrum, Morus, Muscari, Oenothera, Opuntia, Platycladus, Plumbago, Pseudotsuga, Sedum, Sporobolus, Stachys, Ulmus and Yucca. A nomen novum, Stachys talbotii, is proposed as a replacement name for Sideritis purpurea
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