144 research outputs found

    Huisgen-based conjugation of water-soluble porphyrins to deprotected sugars: Towards mild strategies for the labelling of glycans

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    Fully deprotected alkynyl-functionalised mono- and oligosaccharides undergo CuAAC-based conjugation with water-soluble porphyrin azides in aqueous environments. The mild reaction conditions are fully compatible with the presence of labile glycosidic bonds. This approach provides an ideal strategy to conjugate tetrapyrroles to complex carbohydrates

    Mechanisms of growth inhibition of primary prostate epithelial cells following gamma irradiation or photodynamic therapy including senscence, necrosis, and autophagy, but not apoptosis

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    In comparison to more differentiated cells, prostate cancer stem-like cells are radioresistant, which could explain radio-recurrent prostate cancer. Improvement of radiotherapeutic efficacy may therefore require combination therapy. We have investigated the consequences of treating primary prostate epithelial cells with gamma irradiation and photodynamic therapy (PDT), both of which act through production of reactive oxygen species (ROS). Primary prostate epithelial cells were cultured from patient samples of benign prostatic hyperplasia and prostate cancer prior to treatment with PDT or gamma irradiation. Cell viability was measured using MTT and alamar blue assay, and cell recovery by colony-forming assays. Immunofluorescence of gamma-H2AX foci was used to quantify DNA damage, and autophagy and apoptosis were assessed using Western blots. Necrosis and senescence were measured by propidium iodide staining and beta-galactosidase staining, respectively. Both PDT and gamma irradiation reduced the colony-forming ability of primary prostate epithelial cells. PDT reduced the viability of all types of cells in the cultures, including stem-like cells and more differentiated cells. PDT induced necrosis and autophagy, whereas gamma irradiation induced senescence, but neither treatment induced apoptosis. PDT and gamma irradiation therefore inhibit cell growth by different mechanisms. We suggest these treatments would be suitable for use in combination as sequential treatments against prostate cancer

    NanoSOSG: A Nanostructured Fluorescent Probe for the Detection of Intracellular Singlet Oxygen

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    A biocompatible fluorescent nanoprobe for singlet oxygen (1O2) detection in biological systems was designed, synthesized, and characterized, that circumvents many of the limitations of the molecular probe Singlet Oxygen Sensor Green® (SOSG). This widely used commercial singlet oxygen probe was covalently linked to a polyacrylamide nanoparticle core using different architectures to optimize the response to 1O2. In contrast to its molecular counterpart, the optimum SOSG-based nanoprobe, which we call NanoSOSG, is readily internalized by E. coli cells and does not interact with bovine serum albumin. Furthermore, the spectral characteristics do not change inside cells, and the probe responds to intracellularly generated 1O2 with an increase in fluorescence

    Aetiologic diagnosis of hearing loss in children identified through newborn hearing screening testing

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    With the implementation of universal newborn hearing screening (UNHS) programmes and early diagnosis and treatment of hearing problems, the need has clearly emerged to implement and carry out a systematic and coordinated protocol for the aetiological diagnosis of permanent hearing impairment (PHI). Within the framework of the Italian Ministry of Health project CCM 2013 “Preventing Communication Disorders: a Regional Program for early Identification, Intervention and Care of Hearing Impaired Children”, it has been decided to consider the problems relative to aetiological diagnosis of child PHI within UNHS programmes. The specific objective was to apply a shared diagnostic protocol that can identify the cause in at least 70% of cases of PHI. For this part of the project, four main recommendations were identified that can be useful for an efficient aetiological diagnosis in children affected by PHI and that can offer valid suggestions to optimise resources and produce positive changes for third-level audiologic centres

    Early care in children with permanent hearing impairment

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    The implementation of regional protocols for newborn hearing screening and early audiologic diagnosis represent the first step of the entire diagnostic, rehabilitative and prosthetic programme for children with permanent hearing impairment. The maximum benefit of early diagnosis can indeed be obtained only by prompt rehabilitation aimed at fostering the child’s communicative, linguistic and cognitive development. Within the framework of the CMM 2013 project of the Ministry of Health entitled “Preventing Communication Disorders: a Regional Program for Early Identification, Intervention and Care of Hearing Impaired Children”, the problems concerning the promotion of the global development of children with PHI throughan early rehabilitation project based on shared knowledge and scientific evidence. In this project, our specific aim was to define the features and modes of access to a precise and specialised rehabilitation project for the small hearing-impaired child within three months from audiologic diagnosis. Three main recommendations relative to assessment and rehabilitation aspects of early care emerged from the study

    Synthesis and bactericidal properties of porphyrins immobilized in a polyacrylamide support: influence of metal complexation on photoactivity

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    Spectroscopic and photodynamic properties of three novel polymeric hydrogels bearing porphyrins have been studied in vitro on the recombinant bioluminescent Gram-negative Escherichia coli DH5α to assess their ability to inactivate bacterial strains in solution. The three different hydrogels were formed by polymerization of 5-[4-2-(2-(2-acrylamidoethoxy)ethoxy)ethyl]carboxyphenyl-10,15,20-tris(4-N-methylpyridyl)porphyrin trichloride (5) and its complexes with Pd(II) (6) and Cu(II) (7) respectively, to form three optically transparent polyacrylamide hydrogels. All of the porphyrins are tricationic and they bear at the meso positions three N-methylpyridyl rings and one terminal acryloyl group connected through a flexible hydrophilic linker, particularly suitable for the later polymerization and incorporation into a hydrogel. The hydrogels were characterized by IR and scanning electron microscopy and incorporation of the dye was confirmed by UV-visible spectroscopy. All the hydrogels are characterized by a non-ordered microporous structure. The E. coli exhibited a decrease of 1.87 log after 25 min irradiation when the porphyrin hydrogel 9 was evaluated. When the Pd(II) and Cu(II)porphyrin hydrogels were tested (10, 11), they showed a 2.93 log decrease and 1.26 log decrease in the survival of the E. coli after 25 min irradiation, respectively. Similar results were obtained when the porphyrins were tested in solution. Of the three hydrogels, the Pd(II)porphyrin hydrogel (10) proved to be the one with the highest photokilling ability under illumination, and also exhibited the lowest toxicity in the absence of light. Hydrogels 9 and 10 were found to be active for five cycles, suggesting the possibility of reuse
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