23 research outputs found

    The Ontology of Vision. The Invisible, Consciousness of Living Matter

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    If I close my eyes, the absence of light activates the peripheral cells devoted to the perception of darkness. The awareness of ‘seeing oneself seeing’ is in its essence a thought, one that is internal to the vision and previous to any object of sight. To this amphibious faculty, the diaphanous color of darkness, Aristotle assigns the principle of knowledge. Vision is a whole perceptual system, not a channel of sense. Functions of vision are interweaved to the texture of human interaction within a terrestrial environment that is in turn contained into the cosmic order. Within the internal resonance of a double reflection, the living being is the transitive host between two orders of scale, both bigger and smaller than the individual and unity. In the perceptual integrative system of human vision, the convergence-divergence of the corporeal presence and the diffraction of its own appearance is the margin. The sensation of being no longer coincides with the breath of life, it does not seems ‘real’ without the trace of some visible evidence and its simultaneous ‘sharing.’ Without a shadow, without an imprint, and destined for multiple invisible witnesses, the numeric copia of the physical presence inhabits the transient memory of our electronic prostheses. A rudimentary ‘visuality’ replaces tangible experience dissipating its meaning and the awareness of being alive. Transversal to the civilizations of the ancient world, through different orders of function and status, the anthropomorphic figuration of archaic sculpture questions the idea of Being. Ancient statues do not appear in order to be visible as artworks, but rather to exist. The awareness of human finiteness seals the compulsion to ‘give body’ to an invisible apparition that shapes the figuration of Being as the corporeal expression of an ontogenetic waking of human consciousness.Subject and object, the term humanum fathoms the relationship between matter and its living dimension, this de facto vision and the ‘there is’ which it contains. The project reconsiders the rift between the terms vision–presence in the contemporary perception of anthropomorphic figuration according to the immaterial heritage of archaic human statuary and the esoteric legacy of its origins

    Purinergic Calcium Signals in Tumor-Derived Endothelium

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    Tumor microenvironment is particularly enriched with extracellular ATP (eATP), but conflicting evidence has been provided on its functional effects on tumor growth and vascular remodeling. We have previously shown that high eATP concentrations exert a strong anti-migratory, antiangiogenic and normalizing activity on human tumor-derived endothelial cells (TECs). Since both metabotropic and ionotropic purinergic receptors trigger cytosolic calcium increase ([Ca2+]c), the present work investigated the properties of [Ca2+]c events elicited by high eATP in TECs and their role in anti-migratory activity. In particular, the quantitative and kinetic properties of purinergic-induced Ca2+ release from intracellular stores and Ca2+ entry from extracellular medium were investigated. The main conclusions are: (1) stimulation of TECs with high eATP triggers [Ca2+]c signals which include Ca2+ mobilization from intracellular stores (mainly ER) and Ca2+ entry through the plasma membrane; (2) the long-lasting Ca2+ influx phase requires both store-operated Ca2+ entry (SOCE) and non-SOCE components; (3) SOCE is not significantly involved in the antimigratory effect of high ATP stimulation; (4) ER is the main source for intracellular Ca2+ release by eATP: it is required for the constitutive migratory potential of TECs but is not the only determinant for the inhibitory effect of high eATP; (5) a complex interplay occurs among ER, mitochondria and lysosomes upon purinergic stimulation; (6) high eUTP is unable to inhibit TEC migration and evokes [Ca2+]c signals very similar to those described for eATP. The potential role played by store-independent Ca2+ entry and Ca2+-independent events in the regulation of TEC migration by high purinergic stimula deserves future investigation

    Quatsomes Loaded with Squaraine Dye as an Effective Photosensitizer for Photodynamic Therapy

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    Photodynamic therapy is a non-invasive therapeutic strategy that combines external light with a photosensitizer (PS) to destroy abnormal cells. Despite the great progress in the development of new photosensitizers with improved efficacy, the PS’s photosensitivity, high hydrophobicity, and tumor target avidity still represent the main challenges. Herein, newly synthesized brominated squaraine, exhibiting intense absorption in the red/near-infrared region, has been successfully incorporated into Quatsome (QS) nanovesicles at different loadings. The formulations under study have been characterized and interrogated in vitro for cytotoxicity, cellular uptake, and PDT efficiency in a breast cancer cell line. The nanoencapsulation of brominated squaraine into QS overcomes the non-water solubility limitation of the brominated squaraine without compromising its ability to generate ROS rapidly. In addition, PDT effectiveness is maximized due to the highly localized PS loadings in the QS. This strategy allows using a therapeutic squaraine concentration that is 100 times lower than the concentration of free squaraine usually employed in PDT. Taken together, our results reveal the benefits of the incorporation of brominated squaraine into QS to optimize their photoactive properties and support their applicability as photosensitizer agents for PDT
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