Cauda V.,Instituto Italiano Of Tecnologia |
Chiodoni A.,Center for Sustainable Futures |
Tommasi T.,Center for Sustainable Futures
Journal of Biomedical Materials Research - Part B Applied Biomaterials | Year: 2016
Three different single-lumen double-J ureteral stents of different materials were studied and compared after the insertion into a dynamic in vitro model with sterile artificial urine up to 6 months. The aim was to evaluate, at selected time steps of 1, 3, and 6 months, the material performances of the stents in preventing the formation of inorganic encrustations. Morphological, compositional, and qualitative analyses were carried out both before stent insertion and after stent permanence for the different time steps, showing an increasing level of encrustation which remains particularly low in the case of two polyurethane stents. Mechanical tests show that both the polyurethane stents and the chitosan one do not decrease the tensile strength after 6 months of indwelling. Evaluation of the wetting behavior of the stent outer surfaces indicates a hydrophilic behavior in most of the cases, which is generally preserved after immersion in artificial urine for the different time steps. © 2016 Wiley Periodicals, Inc.
PubMed | Instituto Italiano Of Tecnologia, University of California at Irvine, Italian Institute of Technology and Sant'Anna School of Advanced Studies
Type: | Journal: Journal of visualized experiments : JoVE | Year: 2014
It has become increasingly evident that the spatial distribution and the motion of membrane components like lipids and proteins are key factors in the regulation of many cellular functions. However, due to the fast dynamics and the tiny structures involved, a very high spatio-temporal resolution is required to catch the real behavior of molecules. Here we present the experimental protocol for studying the dynamics of fluorescently-labeled plasma-membrane proteins and lipids in live cells with high spatiotemporal resolution. Notably, this approach doesnt need to track each molecule, but it calculates population behavior using all molecules in a given region of the membrane. The starting point is a fast imaging of a given region on the membrane. Afterwards, a complete spatio-temporal autocorrelation function is calculated correlating acquired images at increasing time delays, for example each 2, 3, n repetitions. It is possible to demonstrate that the width of the peak of the spatial autocorrelation function increases at increasing time delay as a function of particle movement due to diffusion. Therefore, fitting of the series of autocorrelation functions enables to extract the actual protein mean square displacement from imaging (iMSD), here presented in the form of apparent diffusivity vs average displacement. This yields a quantitative view of the average dynamics of single molecules with nanometer accuracy. By using a GFP-tagged variant of the Transferrin Receptor (TfR) and an ATTO488 labeled 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphoethanolamine (PPE) it is possible to observe the spatiotemporal regulation of protein and lipid diffusion on m-sized membrane regions in the micro-to-milli-second time range.
Gamucci O.,Italian Institute of Technology |
Bertero A.,Italian Institute of Technology |
Malvindi M.A.,Italian Institute of Technology |
Sabella S.,Italian Institute of Technology |
And 3 more authors.
Journal of visualized experiments : JoVE | Year: 2014
Engineered nanoparticles are endowed with very promising properties for therapeutic and diagnostic purposes. This work describes a fast and reliable method of analysis by flow cytometry to study nanoparticle interaction with immune cells. Primary immune cells can be easily purified from human or mouse tissues by antibody-mediated magnetic isolation. In the first instance, the different cell populations running in a flow cytometer can be distinguished by the forward-scattered light (FSC), which is proportional to cell size, and the side-scattered light (SSC), related to cell internal complexity. Furthermore, fluorescently labeled antibodies against specific cell surface receptors permit the identification of several subpopulations within the same sample. Often, all these features vary when cells are boosted by external stimuli that change their physiological and morphological state. Here, 50 nm FITC-SiO2 nanoparticles are used as a model to identify the internalization of nanostructured materials in human blood immune cells. The cell fluorescence and side-scattered light increase after incubation with nanoparticles allowed us to define time and concentration dependence of nanoparticle-cell interaction. Moreover, such protocol can be extended to investigate Rhodamine-SiO2 nanoparticle interaction with primary microglia, the central nervous system resident immune cells, isolated from mutant mice that specifically express the Green Fluorescent Protein (GFP) in the monocyte/macrophage lineage. Finally, flow cytometry data related to nanoparticle internalization into the cells have been confirmed by confocal microscopy.
PubMed | Instituto Italiano Of Tecnologia and Italian Institute of Technology
Type: | Journal: Journal of visualized experiments : JoVE | Year: 2016
Alterations in executive control and cognitive flexibility, such as attentional set-shifting abilities, are core features of several neuropsychiatric diseases. The most widely used neuropsychological tests for the evaluation of attentional set-shifting in human subjects are the Wisconsin Card Sorting Test (WCST) and the CANTAB Intra-/Extra-dimensional set shift task (ID/ED). These tasks have proven clinical relevance and have been modified and successfully adapted for research in animal models. However, currently available tasks for rodents present several limitations, mainly due to their manual-based testing procedures, which are hampering translational advances in psychiatric medicine. To overcome these limitations and to better mimic the original version in primates, we present the development of a novel operant-based two-chamber ID/ED Operon task for rodents. We demonstrated the effectiveness of this novel task to measure different facets of cognitive flexibility in mice including attentional set formation and shifting, and reversal learning. Moreover, we show the high flexibility of this task in which three different perceptual dimensions can be manipulated with a high number of stimuli cues for each dimension. This novel ID/ED Operon task can be an effective preclinical tool for drug testing and/or large genetic screening relevant to the study of executive dysfunction and cognitive symptoms found in psychiatric disorders.
PubMed | Instituto Italiano Of Tecnologia and Italian Institute of Technology
Type: | Journal: Journal of visualized experiments : JoVE | Year: 2015
Information coding in the Central Nervous System (CNS) remains unexplored. There is mounting evidence that, even at a very low level, the representation of a given stimulus might be dependent on context and history. If this is actually the case, bi-directional interactions between the brain (or if need be a reduced model of it) and sensory-motor system can shed a light on how encoding and decoding of information is performed. Here an experimental system is introduced and described in which the activity of a neuronal element (i.e., a network of neurons extracted from embryonic mammalian hippocampi) is given context and used to control the movement of an artificial agent, while environmental information is fed back to the culture as a sequence of electrical stimuli. This architecture allows a quick selection of diverse encoding, decoding, and learning algorithms to test different hypotheses on the computational properties of neuronal networks.
PubMed | Instituto Italiano Of Tecnologia
Type: Journal Article | Journal: Molecular & cellular oncology | Year: 2016
The discovery that inhibition of a circadian regulator enhances autophagy-dependent cancer cell death reveals potential avenues for the development of new multifunctional anticancer agents. Further studies may elucidate novel crosstalk between circadian rhythm, metabolism, and autophagy that determines cancer cell viability.