Navegando por Assunto "Nitric oxide"

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    N-Doped Carbon Dot-Based Nanoconjugates with Simultaneous Generation of Nitric Oxide and Singlet Oxygen for Phototherapeutic Applications
    (ACS Publications) Laneri, Francesca; Parisi, Cristina; Andrigo, Vittoria; Pinto, Juliana Guerra; Marcolino, Luciana Maria Cortez; Ferreira-Strixino, Juliana; Natile, Marta Maria; Sortino, Salvatore
    Nitric oxide (NO) and singlet oxygen (O2) represent two of the most intriguing agents for unconventional phototherapeutic applications in cancer. In this contribution, N-doped carbon dots (NCDs) with strong absorption in the biocompatible green region have been synthesized and covalently decorated with an otherwise blue-light-activatable NO photodonor (NOPD), leading to a nanoconjugate ca. 3.5 nm in diameter. The NCD core of the nanoconstruct acts as a green light antenna, permitting the release of NO from the NOPD by an intramolecular photoinduced electron transfer, with an improvement of more than 100 nm in the excitation wavelength. Simultaneously, green light excitation generates O2 by collisional energy transfer with molecular oxygen. Due to its emissive properties, the nanoconjugate can be visualized in 9L/LacZ brain cancer cells, where it localizes mainly in the cytoplasm. Amplified mortality of cancer cells is observed upon green light irradiation due to the mutual photodynamic action of NO and O2.
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    Stepwise Nitric Oxide Release and Antibacterial Activity of a Nitric Oxide Photodonor Hosted within Cyclodextrin Branched Polymer Nanocarriers
    (ACS Publications) Martins, Tassia Joi; Parisi, Cristina; Pinto, Juliana Guerra; Brambilla, Isabelle de Paula Ribeiro; Malanga, Milo; Ferreira-Strixino, Juliana; Sortino, Salvatore
    A hydrophobic nitric oxide (NO) photodonor integrating both nitroso and nitro functionalities within its chromophoric skeleton has been synthesized. Excitation of this compound with blue light triggers the release of two NO molecules from the nitroso and the nitro functionalities via a stepwise mechanism. Encapsulation of the NO photodonor within biocompatible neutral, cationic, and anionic β-cyclodextrin branched polymers as suitable carriers leads to supramolecular nanoassemblies, which exhibit the same nature of the photochemical processes but NO photorelease performances enhanced by about 1 order of magnitude when compared with the free guest. Antibacterial tests carried out with methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii demonstrate an effective antibacterial activity exclusively under light activation and point out a differentiated role of the polymeric nanocarriers in determining the outcome of the antibacterial photodynamic action.