Browsing by Author "Gomes, Ana T. P. C."
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- Antimicrobial activity of a 3D-printed polymethylmethacrylate dental resin enhanced with graphenePublication . Salgado, Helena; Gomes, Ana T. P. C.; Duarte, Ana S.; Ferreira, José M. F.; Fernandes, Carlos; Figueiral, Maria Helena; Mesquita, PedroThe present study aimed to test, in vitro, the antimicrobial activity against Candida albicans and Streptococcus mutans and the surface roughness of a 3D-printed polymethylmethacrylate dental resin enhanced with graphene. A 3D-printed polymethylmethacrylate dental resin was reinforced with four different concentrations of graphene: 0.01, 0.1, 0.25 and 0.5 wt%. Neat resin was used as a control. The specimens were printed in a liquid crystal display printer. Disc specimens were used in antimicrobial evaluation, and bar-shaped specimens were used to measure surface roughness. The study of antimicrobial activity included the inhibition of the growth of C. albicans and S. mutans and their adhesion to the resin’s surface. Surface roughness increased with the increase in the graphene concentration. The growth inhibition of C. albicans was observed in the different concentrations of graphene after 24 h, with no recovery after 48 h. The specimens doped with graphene were capable of inactivating S. mutans after 48 h. The surface-adhesion studies showed that the density of microbial biofilms decreases in the case of specimens doped with graphene. Graphene, despite increasing the resin’s surface roughness, was effective in inhibiting the growth and the adhesion to the resin’s surface of the main inducers of prosthetic stomatitis.
- Antimicrobial properties and bioactivity potential of smart nanoparticles for dental applicationsPublication . Correia, Bruna L.; Malekshiri, Moslem; Bartolomeu, Maria; Silva, Virgília; Oliveira, Ana; Noites, Rita; Cardoso, Miguel; Mendes, Karina; Gomes, Ana T. P. C.; Duarte, Ana Sofia
- Can corrole dimers be good photosensitizers to kill bacteria?Publication . Lacerda, Paula S. S.; Bartolomeu, Maria; Gomes, Ana T. P. C.; Duarte, Ana S.; Almeida, Adelaide; Faustino, Maria A. F.; Neves, Maria G. P. M. S.; Barata, Joana F. B.Corroles possess key photophysical and photochemical properties to be exploited as thera-peutic agents in antimicrobial photodynamic therapy (aPDT). Herein, we present for the first time the antimicrobial efficiency of three corrole dimers and of the corresponding precursor against the Gram(+) bacterium Staphylococcus aureus. Additionally, to explore future clinical applications, the cytotoxicity of the most promising derivatives towards Vero cells was evaluated. The aPDT assays performed under white light irradiation (50 mW/cm2; light dose 450 J/cm2) and at a corrole concen-tration of 15 µM showed that some dimers were able to reduce 99.9999% of S. aureus strain (decrease of 5 log10 CFU/mL) and their photodynamic efficiency was dependent on position, type of linkage, and aggregation behavior. Under the same light conditions, the corrole precursor 1 demonstrated notable photodynamic efficiency, achieving total photoinactivation (>8.0 log10 CFU/mL reduction) after the same period of irradiation (light dose 450 J/cm2). No cytotoxicity was observed when Vero cells were exposed to corrole 1 and dimer 3 for 24 h according to ISO guidelines (ISO 10993-5) for in vitro cytotoxicity of medical devices. The results show that corrole dimers, dependent on their structures, can be considered good photosensitizers to kill Staphylococcus aureus.
- Deep Eutectic Solvents as alternative solvents in Antimicrobial Photodynamic TherapyPublication . Vieira, Cátia; Bartolomeu, Maria; Pedro, Sónia N.; Gomes, Ana T. P. C.; Dias, Cristina J.; Gamelas, Sara R. D.; Lourenço, Leandro M. O.; Freire, Carmen S. R.; Neves, M. Graça P. M. S.; Faustino, M. Amparo F.; Almeida, Adelaide
- Dentistry under a new light: antimicrobial photodynamic therapy as sustainable solution for periodontitis and periimplantitis treatmentPublication . Mello-Moura, Anna Carolina Volpi; Esteves, Diogo; Andreolli, Daniel; Gomes, Ana T. P. C.Oral health conditions can significantly impact on the quality of life. Despite the scientific progress in the understanding of the pathogenesis and oral diseases causes, these are a global public health. Poor oral health results in pain, substandard nutrition, work absence and lowered self-esteem. Chronic oral infection is a proven risk factor for diabetes, heart, and lung disease. Periodontitis and periimplantitis are oral conditions that have an infection etiology. Despite of the current available techniques used for these diseases’ treatment, none guaranties the total eradication neither prevent (re)infection. It is urgent to find alternative treatments to mitigate these difficulties and improve the diseases’ prognosis. Antimicrobial Photodynamic Therapy (aPDT) arises as an alternative with unique features and presents advantages when compared the use of conventional antimicrobials, showing to be efficient and preventing the development of resistance. aPDT has been extensively studied to treat periimplantitis and periodontitis, but the developed protocols are restricted to phenothiazinium photosensitizers, such as methylene blue, and to the use of red lasers as light source. It is intended to develop an effective therapeutic approach to treat periimplantitis and periodontitis based on aPDT using porphyrins already approved for clinical and the dental curing light (DCL-available in all dental clinics) as light source. The in vitro photoinactivation assays of periodontopathogens (E. faecalis and C. albicans) were carried out in PBS, with the disodium salt of Protoporphyrin IX (Proto IX) as photosensitizer and DCL as a light source. The ex vivo antimicrobial inactivation of such periodontopathogens were also evaluated under the same aPDT protocol in teeth and dental implants. In vitro assays showed an effective photoinactivation of the periodontopathogens when exposed to different concentrations of Proto IX and with DCL. Ex vivo assays in dental implants showed promising results, with high photoinactivations rates of E. faecalis. However, probably due to the complex tooth matrix, the aPDT efficiency in teeth was modest. The aPDT protocol achieved by the combination of Proto IX and DCL showed to be efficient in the inactivation of periodontopathogens. These results open new perspectives for an efficient aPDT protocol development to treat periodontitis and periimplantitis that can be easily implemented in all dental clinics and available to entire population, contributing to the democratization of medical services.
- Disinfection of wastewater in the mitigation of SARS-CoV-2 by photodynamic treatmentPublication . Almeida, Adelaide; Gomes, Marta; Bartolomeu, Maria; Vieira, Cátia; Gomes, Ana T. P. C.; Faustino, M. Amparo F.; Neves, M. Graça P. M. S.
- Exploring the inflammatory profile of homelessness population: a comprehensive analysis of individuals in two temporary shelters in LisbonPublication . Gomes, Ana T. P. C.; Mendes, Karina; Ferrito, Cândida; Andrade, Filipa; Neves-Amado, João; Resende, Ana; Santos, Paulo; Manso, Dina; Almeida, António; Vollrath, Antónia; Lopes, Rafaela; Barros, Marlene; Rosa, Nuno; Figueiredo, Amélia SimõesBackground: Homeless people are continuously facing adverse living conditions as poor access to basic nutrition, hygiene conditions and healthcare services, being at increased risk of severe infectious diseases as HIV and hepatitis as well as cardiovascular diseases and mental disorders. The characterization of homeless people’s health is fundamental to identify their health care needs. Considering that the aforementioned diseases are associated with chronic inflammatory processes, the main goal of this study was to characterize the inflammatory profile of a homeless population through quantification in saliva of a panel of inflammatory cytokines. Methods: The inflammatory profile was assessed in 114 individuals residing in two temporary shelters located in Lisbon and that accepted to participated in the study. Inflammatory proteins were quantified using a Multiplex Immunoassay approach. Data analysis was performed using the GraphPad Prism software and statistical significance among the groups was assessed using the nonparametric Mann–Whitney test. Results: Even though some protein levels might be masked by drug treatment, data analysis showed high levels of INF-ϒ, IL-10 and TNF-α in the infectious disease group, critical cytokines for the immune response against viruses and bacteria. Also, cytokines like IL-1β and IL-6 were detected at statistically significant levels in the cardiovascular disease group and all cytokines included in this study were quantified in the mental disorders group. Conclusion: These findings may help the healthcare services in the evaluation of treatment efficacy and disease monitoring, and in the development of effective public healthcare strategies and policy interventions to improve quality of life of the homeless population.
- 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.
- Investigation of the potential of deep eutectic solvents (DES) as alternative solvents in antimicrobial photodynamic therapyPublication . Vieira, Cátia; Bartolomeu, Maria; Pedro, Sónia N.; Gomes, Ana T. P. C.; Dias, Cristina J.; Gamelas, Sara R. D.; Lourenço, Leandro M. O.; Freire, Carmen S. R.; Neves, M. Graça P. M. S.; Faustino, M. Amparo F.; Almeida, AdelaideAntimicrobial Photodynamic Therapy (aPDT) is gaining recognition as an effective approach for the photoinactivation of a broad spectrum of microorganisms [1,2]. Due to their apolar behavior, photosensitizers (PS) often have low solubility in aqueous media requiring the use of toxic organic solvents that are incompatible with their application in the field [4]. In this study, the potential of Deep Eutectic Solvents (DES) to prepare formulations of one chlorin (bearing five cationic charges) and two porphyrins (neutral THPP, and tetra cationic Tetra-Py(+)-Me) poorly water-soluble was investigated. To this purpose, formulations of each PS were prepared in DMSO and three DES (betaine:glycerol, proline:xylitol and betaine:citric acid) and their physio-chemical properties, cytotoxicity for mammalian cells, and photodynamic action towards Escherichia coli, as a gramnegative bacterium model, were evaluated. The physico-chemical experiments revealed that all PS were soluble in the selected DES. However, PS stability varied highly depending on the solvent used. In dark conditions, chlorin remained stable in DES formulations while strong aggregation was observed in DMSO. In contrast, THPP showed better stability in the former solvent. Tetra-cationic porphyrin was stable in the dark regardless of the solvent used, but upon irradiation, DES formulations increased this PS photostability. Regarding the biological experiments, betaine:glycerol and proline:xylitol formulations lacked toxicity towards mammalian cells and improved Tetra-Py(+)Me photodynamic activity against E. coli. On the other hand, betaine:citric acid formulation, although highly toxic to Vero cells, enhanced the photodynamic action of both THPP and Tetra-Py(+)-Me. Overall, these findings indicate that DES have a high potential to prepare formulations of PS with low solubility in aqueous solutions and, in some cases, can improve their antimicrobial photodynamic activity.
- Microbial DNA extraction methods for microbial screening - saliva vs biofilm comparisonPublication . Gomes, Ana T. P. C.; Pinto, Marla; Abrantes, Patrícia; Almeida, Rita; Mendes, Karina; Duarte, Ana S.; Silva, Raquel M.; Rosa, Nuno; Correia, Maria; Barros, Marlene
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