Multipurpose platform based on LiNbO3 crystals for novel scenarios in soft matter manipulation

La possibilità di manipolare e dosare la cosiddetta “materia soffice” con tecniche che siano versatili ma anche dotate di elevata risoluzione spaziale, è di grande interesse per una vasta gamma di applicazioni. Questo lavoro di tesi si inserisce in questo contesto proponendo una piattaforma di tipo ferroelettrico in cui la polarizzazione spontanea di cristalli quali il niobato di litio (LiNbO3) è sfruttata ad arte per generare forze di tipo elettro-dinamico su scala micrometrica. Tali forze sono in grado di dosare e indirizzare opportunamente piccoli volumi di materiale fluido di tipo polimerico ma anche di tipo biologico. In particolare, i campi elettrici generati tramite effetto piroelettrico integrato su cristallo sono utilizzati qui per diversi tipi di applicazioni. I risultati mostrano come fluidi polimerici possono essere elettro-filati in modo controllato, evitando le instabilità tipiche dell’electrospinning tradizionale. Polimeri con proprietà ottiche opportune possono essere usati per stampare matrici di microlenti plastiche e versatili. L’energia solare può essere accumulata e sfruttata per sorgenti alternative di campi elettrici. Infine, la morfologia e le proprietà di adesione di cellule di fibroblasti viventi possono essere pilotate tramite le cariche di superficie espresse da tali supporti

Alfaxalone and Dexmedetomidine as an alternative to gas anesthesia for micro-CT lung imaging in a bleomycin-induced pulmonary fibrosis murine model

Micro-CT imaging could be considered a powerful non-invasive tool for accessing pulmonary fibrosis in mice. However, the choice of the anesthesia protocol plays a fundamental role to obtain robust and reproducible data, avoiding misinterpretations of the results. Inhaled anesthesia is commonly used for micro-CT lung imaging, but sometimes the standardization of the protocol may be challenging for routine activities in drug discovery. In this study we used micro-CT to evaluate the effects of two anesthetic protocols, consisting in Alfaxalone and Dexmedetomidine mixture, as injectable agents, and gaseous isoflurane, on vehicle and bleomycin-treated mice. No significant differences were highlighted between the protocols either for lung aeration degrees by micro-CT or histologic analyses in both the controls and bleomycin-treated groups. Our results support Alfaxalone and Dexmedetomidine mixture as a suitable and safe alternative compared to isoflurane for lung imaging. We also concluded that this injectable mixture may be applied for several imaging technologies and on different mice models

Quantification of Lung Fibrosis in IPF-Like Mouse Model and Pharmacological Response to Treatment by Micro-Computed Tomography

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive degenerative lung disease leading to respiratory failure and death. Although anti-fibrotic drugs are now available for treating IPF, their clinical efficacy is limited and lung transplantation remains the only modality to prolong survival of IPF patients. Despite its limitations, the bleomycin (BLM) animal model remains the best characterized experimental tool for studying disease pathogenesis and assessing efficacy of novel potential drugs. In the present study, the effects of oropharyngeal (OA) and intratracheal (IT) administration of BLM were compared in C57BL/6 mice. The development of lung fibrosis was followed in vivo for 28 days after BLM administration by micro-computed tomography and ex vivo by histological analyses (bronchoalveolar lavage, histology in the left lung to stage fibrosis severity and hydroxyproline determination in the right lung). In a separate study, the antifibrotic effect of Nintedanib was investigated after oral administration (60 mg/kg for two weeks) in the OA BLM model. Lung fibrosis severity and duration after BLM OA and IT administration was comparable. However, a more homogeneous distribution of fibrotic lesions among lung lobes was apparent after OA administration. Quantification of fibrosis by micro-CT based on % of poorly aerated tissue revealed that this readout correlated significantly with the standard histological methods in the OA model. These findings were further confirmed in a second study in the OA model, evaluating Nintedanib anti-fibrotic effects. Indeed, compared to the BLM group, Nintedanib inhibited significantly the increase in % of poorly aerated areas (26%) and reduced ex vivo histological lesions and hydroxyproline levels by 49 and 41%, respectively. This study indicated that micro-computed tomography is a valuable in vivo technology for lung fibrosis quantification, which will be very helpful in the future to better evaluate new anti-fibrotic drug candidates

Indocyanine-enhanced mouse model of bleomycin-induced lung fibrosis with hallmarks of progressive emphysema

The development of new drugs for idiopathic pulmonary fibrosis strongly relies on preclinical experimentation, which requires the continuous improvement of animal models and integration with in vivo imaging data. Here, we investigated the lung distribution of bleomycin (BLM) associated with the indocyanine green (ICG) dye by fluorescence imaging. A long-lasting lung retention (up to 21 days) was observed upon oropharyngeal aspiration (OA) of either ICG or BLM þ ICG, with significantly more severe pulmonary fibrosis, accompanied by the progressive appearance of emphysema-like features, uniquely associated with the latter combination. More severe and persistent lung fibrosis, together with a progressive air space enlargement uniquely associated with the BLM þ ICG group, was confirmed by longitudinal micro-computed tomography (CT) and histological analyses. Multiple inflammation and fibrosis biomarkers were found to be increased in the bronchoalveolar lavage fluid of BLM- and BLM þ ICG-treated animals, but with a clear trend toward a much stronger increase in the latter group. Similarly, in vitro assays performed on macrophage and epithelial cell lines revealed a significantly more marked cytotoxicity in the case of BLM þ ICG-treated mice. Also unique to this group was the synergistic upregulation of apoptotic markers both in lung sections and cell lines. Although the exact mechanism underlying the more intense lung fibrosis phenotype with emphysema-like features induced by BLM þ ICG remains to be elucidated, we believe that this combination treatment, whose overall effects more closely resemble the human disease, represents a valuable alternative model for studying fibrosis development and for the identification of new antifibrotic compounds.</p

Abordar la complejidad de lo social. Reflexiones didácticas acerca del problema de enseñar a conceptualizar en la Formación Docente

El trabajo que a continuación presentamos surge de una dificultad en nuestra labor como profesoras del área de Ciencias Sociales del Instituto de Formación Docente Continua de El Bolsón, Provincia de Río Negro: cómo enseñar a conceptualizar lo social, escapando del sentido común que de manera reiterada se venía “colando”, sin solución de ontinuidad, en las producciones de nuestros estudiantes. A partir de dicha situación, decidimos, no sólo plantear un programa integrado en área, sino abordar desde la misma, y teóricamente, el problema que estábamos detectando: la situación ambigua de las Ciencias Sociales y la necesidad de detenerse a analizar y reflexionar sobre el sentido común. De esta manera,convertimos al análisis del sentido común en el eje teórico y metodológico a partir del cual comenzar a pensar los distintos temas que veníamos desarrollando en el programa de estudios.Fil: Tozzini, María Alma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Investigaciones Socio-Históricas Regionales. Centro de Estudios de Historia Regional - Nodo Cehir - Ishir; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Diversidad Cultural y Procesos de Cambio. Universidad Nacional de Río Negro. Instituto de Investigaciones en Diversidad Cultural y Procesos de Cambio; ArgentinaFil: Mecozzi, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Investigaciones Socio-Históricas Regionales. Centro de Estudios de Historia Regional - Nodo Cehir - Ishir; ArgentinaFil: Lorenzi, Laura. Instituto de Formación Docente Continua de El Bolsón; Argentin

Mechanisms of browning development in aggregates of marine organic matter formed under anoxic conditions: A study by mid-infrared and near-infrared spectroscopy

In this paper we analyze some chemical aspects concerning the browning development associated to the aggregation of marine organic matter (MOM) occurring in anoxic conditions. Organic matter samples obtained by the degradation of different algal samples were daily taken to follow the evolution of the aggregation process and the associated browning process. These samples were examined by Fourier transform mid infrared (FTIR) and Fourier transform near infrared (FTNIR) spectroscopy and the colour changes occurring during the above mentioned aggregation process were measured by means of Colour Indices (Cis). Spectral Cross Correlation Analysis (SCCA) was applied to correlate changes in CI values to the structural changes of MOM observed by FTIR and FTNIR spectra which were also submitted to Two-Dimensional Hetero Correlation Analysis (2HDCORR). SCCA results showed that all biomolecules present in MOM aggregates such as carbohydrates, proteins and lipids are involved in the browning development. In particular, SCCA results of algal mixtures suggest that the observed yellow-brown colour can be linked to the development of non enzymatic (i.e. Maillard) browning reactions. SCCA results for MOM furthermore suggest that aggregates coming from brown algae also showed evidence of browning related to enzymatic reactions. In the end 2HDCORR results indicate that hydrogen bond interactions among different molecules of MOM can play a significant role in the browning development. In this study the combination of spectroscopic techniques such as FTIR and FTNIR with Colour Indices measurements shows a peculiar ability to improve the knowledge of the complex mechanisms related to the aggregation of marine organic matter and its colour development under anoxic conditions such like those present in the marine environments at high depth. (C) 2013 Elsevier B.V. All rights reserved

Quick liquid packaging: Encasing water silhouettes by three-dimensional polymer membranes

One of the most important substances on Earth is water. It is an essential medium for living microorganisms and for many technological and industrial processes. Confining water in an enclosed compartment without manipulating it or by using rigid containers can be very attractive, even more if the container is biocompatible and biodegradable. Here, we propose a water-based bottom-up approach for facile encasing of short-lived water silhouettes by a custom-made adaptive suit. A biocompatible polymer self-assembling with unprecedented degree of freedom over the water surface directly produces a thin membrane. The polymer film could be the external container of a liquid core or a free-standing layer with personalized design. The membranes produced have been characterized in terms of physical properties, morphology and proposed for various applications from nano- to macroscale. The process appears not to harm cells and microorganisms, opening the way to a breakthrough approach for organ-on-chip and lab-in-a-drop experiments