Percorrer por autor "Moura, Nuno M. M."
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- Graphene oxide and graphene quantum dots as delivery systems of cationic porphyrins: photo-antiproliferative activity evaluation towards T24 human bladder cancer cellsPublication . Menilli, Luca; Monteiro, Ana R.; Lazzarotto, Silvia; Morais, Filipe M. P.; Gomes, Ana T. P. C.; Moura, Nuno M. M.; Fateixa, Sara; Faustino, Maria A. F.; Neves, Maria G. P. M. S.; Trindade, Tito; Miolo, GiorgiaThe development of new photodynamic therapy (PDT) agents designed for bladder cancer (BC) treatments is of utmost importance to prevent its recurrence and progression towards more invasive forms. Here, three different porphyrinic photosensitizers (PS) (TMPyP, Zn-TMPyP, and P1-C5 ) were non-covalently loaded onto graphene oxide (GO) or graphene quantum dots (GQDs) in a one-step process. The cytotoxic effects of the free PS and of the corresponding hybrids were compared upon blue (BL) and red-light (RL) exposure on T24 human BC cells. In addition, intracellular reactive oxygen species (ROS) and singlet oxygen generation were measured. TMPyP and Zn-TMPyP showed higher efficiency under BL (IC50: 0.42 and 0.22 µm, respectively), while P1-C5 was more active under RL (IC50: 0.14 µm). In general, these PS could induce apoptotic cell death through lysosomes damage. The in vitro photosensitizing activity of the PS was not compromised after their immobilization onto graphene-based nanomaterials, with Zn-TMPyP@GQDs being the most promising hybrid system under RL (IC50: 0.37 µg/mL). Overall, our data confirm that GO and GQDs may represent valid platforms for PS delivery, without altering their performance for PDT on BC cells.
- The impact of metal ions on the photo-antibacterial efficiency of metalloporphyrins with triphenylphosphonium unitsPublication . Chaves, Inês; Morais, Filipe F. M.; Vieira, Cátia; Bartolomeu, Maria; Gomes, Ana T. P. C.; Faustino, M. Amparo F.; Neves, M. Graça P. M. S.; Almeida, Adelaide; Moura, Nuno M. M.The influence of metal ions on the photochemical, photophysical, and antibacterial properties of three cationic porphyrin-triphenylphosphonium conjugates was investigated for the first time. Coordination with Zn(II), Pd(II) and Co(II) enabled fine-tuning of these conjugates properties, with Zn(II) complexes demonstrating particular promise. While Pd(II) and Co(II) complexes failed to generate singlet oxygen (1O2), thereby reducing their efficacy in bacteria photoinactivation, Zn(II) complexes exhibited efficient 1O2 generation and strong bacterial adhesion. Among these, the Zn(II) metalloporphyrin 2-Zn, featuring a well-optimized structure with three triphenylphosphonium units and six positive charges, showed exceptional effectiveness against Gram-negative Escherichia coli at lower concentrations. It significantly outperformed its free-base counterpart, reducing the required irradiation time by more than 65 %. Furthermore, 2-Zn demonstrates to be safe, exhibiting no cytotoxicity towards Vero cells. These findings highlight the potential of Zn(II) porphyrin-triphenylphosphonium complexes as efficient photosensitizers for antimicrobial photodynamic therapy (aPDT), offering a promising approach to address the growing challenge of antibiotic bacterial resistance in both clinical and environmental contexts.
- PVP formulations of bis-cyclometalated iridium(III) complexes bearing β-modified porphyrin ligands: characterization and photodynamic action on bladder cancer cellsPublication . Moura, Nuno M. M.; Reis, Melani J. A.; Lodeiro, Carlos; Neves, M. Graça P. M. S.; Cavaleiro, José A. S.; Ribeiro, Carlos F.; Fernandes, Rosa; Gomes, Ana T. P. C.Cancer stands as the second leading global cause of death, following heart disease. Considering the severe side effects revealed by some chemotherapeutics for tumor treatment and anticancer therapies, the scientific community is actively exploring more effective alternatives. Photodynamic Therapy (PDT) mediated by porphyrin-based photosensitizers (PS) has emerged as an attractive alternative to more conventional therapies. In this study, we incorporated bis-cyclometalated iridium(III) complexes featuring porphyrin-arylbipyridine ligands into poly(vinylpyrrolidone) (PVP) micelle. This integration resulted in photostable PVP-PS formulations with a remarkable capability to generate singlet oxygen. These formulations were also efficiently internalized by HT-1379 cells and due to these features, their photodynamic action against human bladder cancer cells (HT-1376 cell line) was assessed. All the formulations demonstrated high photodynamic activity, with PVP-2 and PVP-3 proving to be the most promising PS, as evidenced by their lower IC50PDT values. It was also demonstrated that all PVP-based formulations provide a safe and effective approach for photodynamic therapy (PDT) in bladder cancer, as no cytotoxic effects were observed in Vero cells.
- Unraveling the photodynamic activity of cationic benzoporphyrin-based photosensitizers against bladder cancer cellsPublication . Gomes, Ana T. P. C.; Neves, M. Graça P. M. S.; Fernandes, Rosa; Ribeiro, Carlos F.; Cavaleiro, José A. S.; Moura, Nuno M. M.In this study, we report the preparation of new mono-charged benzoporphyrin complexes by reaction of the appropriate neutral benzoporphyrin with (2,2′-bipyridine)dichloroplatinum(II) and of the analogs’ derivatives synthesized through alkylation of the neutral scaffold with iodomethane. All derivatives were incorporated into polyvinylpyrrolidone (PVP) micelles. The ability of the resultant formulations to generate reactive oxygen species was evaluated, mainly the singlet oxygen formation. Then, the capability of the PVP formulations to act as photosensitizers against bladder cancer cells was assessed. Some of the studied formulations were the most active photosensitizers causing a decrease in HT-1376 cells’ viability. This creates an avenue to further studies related to bladder cancer cells.