CAMILA RAMOS SILVA
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Resumo IPEN-doc 30132 Photodynamic inactivation against the critical priority pathogen Candida auris2023 - SILVA, ABDENEGO R.; CABRAL, FERNANDA V.; SILVA, CAMILA R.; SILVA, DANIELA F.T.; FREITAS, ANDERSON Z.; FONTES, ADRIANA; RIBEIRO, MARTHA S.Fungal pathogens and their associated infections present a growing challenge to global public health. Among these pathogens, Candida auris has emerged as a highly hazardous hospital-acquired microorganism, included in the critical priority group by the World Health Organization. Methylene Blue (MB) is a widely acknowledged photosensitizer utilized in antifungal photodynamic inactivation (PDI) and holds significant clinical applications. The MB methylation results in the formation of a more lipophilic compound, the 1,9-dimethyl MB (DMMB), which can have an enhanced interaction with cell membranes. Nevertheless, PDI mediated by DMMB to combat fungi remains little explored. In this study, we assessed the impact and underlying mechanisms of PDI using MB (MB-PDI) or DMMB (DMMB-PDI) combined with a red LED against C. auris. PDI was conducted on the CBS 10913 strain of C. auris, utilizing different concentrations of MB (0 – 100 μM) or DMMB (0 – 3 μM) at light doses of 10 or 30 J/cm². To evaluate the PDI efficacy, we measured colony-forming units and monitored reactive oxygen species (ROS) production. Additionally, we assessed lipid peroxidation (LPO) and mitochondrial membrane potential (ΔΨm) to gain insights into the differences between MB and DMMB. Our findings revealed that DMMB-PDI successfully eradicated C. auris yeasts at 3 μM concentration, irrespective of the light dose, whereas MB (100 μM) only exhibited cell eradication at the highest light dose. ROS formation was more pronounced for DMMB than MB at 10 J/cm2. At 30 J/cm2, MB and DMMB produced similar ROS levels. In sublethal conditions, DMMB-PDI induced significantly higher LPO, and ΔΨm levels compared to MB-PDI. Furthermore, DMMB-PDI effectively inhibited biofilm formation and disrupted mature biofilms, with no observed toxicity in fibroblast cells. In conclusion, our study demonstrates the potential of DMMB-PDI as a promising weapon to combat the global priority pathogen C. auris. The enhanced PDI efficacy and biofilm eradication capacity of DMMB make it a valuable candidate for further exploration in the fight against this hazardous pathogen. As the incidence of drug-resistant fungal infections continues to rise, the development of innovative and effective therapeutic strategies like DMMB-PDI is crucial in safeguarding public health worldwide.Resumo IPEN-doc 29999 Terapia fotodinâmica associada à quimioterapia em células de câncer de mama triplo-negativo2022 - SILVA, CAMILA R.; RIBEIRO, MARTHA S.INTRODUÇÃO: O câncer de mama triplo-negativo (TNBC) representa 20% das incidências de câncer de mama com uma mortalidade estimada em 40%. As principais características desse tipo de câncer seriam o seu alto poder de metástase e resistência aos tratamentos convencionais como a quimioterapia. Diante disso, há uma crescente busca por terapias adjuvantes para auxiliar o tratamento do TNBC. Nesse contexto, a terapia fotodinâmica (TFD) têm se mostrado promissora no tratamento de diversos tipos de câncer e recentemente a literatura descreve o seu uso em associação com os tratamentos convencionais para auxiliar no combate ao câncer. OBJETIVO: Associar a TFD com quimioterapia no tratamento de células TNBC. METODOLOGIA: Células TNBC, células de câncer de mama responsivas à quimioterapia (MCF-7) e células não tumorais de mama (MCF-10A) foram cultivadas, semeadas (2 x 104 células) e após a TFD usando a porfirina TMPyP (30 μM) e luz vermelha (λ= 660 ± 11 nm) com as fluências de 20 J/cm² e 50 J/cm² receberam doxorrubicina (DOX) na concentração de 5 μg/mL. Após 24-h da quimioterapia, a atividade mitocondrial foi avaliada para todos os grupos experimentais (n=6). RESULTADOS: As células MCF-7 e MCF-10A usadas como controle apresentaram redução significativa na atividade mitocondrial quando expostas à DOX. Por outro lado, as células TNBC não apresentaram redução estatisticamente significativa quando submetidas ao mesmo protocolo. No entanto, na associação da TFD+DOX, as células TNBC apresentaram redução significativa na atividade mitocondrial, independente da fluência usada. CONCLUSÃO: A associação da TFD com doxorrubicina apresentou menor atividade mitocondrial para as células TNBC.Artigo IPEN-doc 29934 Noninvasive red Laser intervention before radiotherapy of triple-negative breast cancer in a murine model2023 - SILVA, CAMILA R.; PEREIRA, SAULO T.; SILVA, DANIELA F.T.; PRETTO, LUCAS R. de; FREITAS, ANDERSON Z.; ZEITUNI, CARLOS A.; ROSTELATO, MARIA E.C.M.; RIBEIRO, MARTHA S.In proton beam treatments, the superposition of several weighted Bragg curves with different incident energies is required to homogeneously irradiate a large tumor volume, creating a spread-out Bragg peak (SOBP). This paper confirms on the suitability of two different methods to create SOBPs – Bortfeld/Jette's and MCMC (Monte Carlo calculations and Matrix Computations), using Monte Carlo simulations performed with TOPAS and MCNP6.1. To generate the SOBPs, algorithms were developed for implementation of the two methods, which enabled to find the weights for thirty variations of SOBPs, categorized according to their width and maximum depths. The MCMC method used weight optimization in designing SOBPs to avoid negative values. In contrast, the Bortfeld/Jette's method yielded the SOBPs according to the variation of a power-law parameter ( ) introduced by the range-energy relationship. Optimal values of , from MCNP and TOPAS, were selected in order to retrieve SOBPs with the best smoothness and then related to those obtained from the literature. In comparing both methods and codes, dose homogeneity parameters ( ) were used to examine the SOBP flatness and gamma analyses were employed to assess the dose deposition along its full extension. The results showed that the SOBPs designed using the MCMC method had better values and computational performance for both codes when compared to the Bortfeld/Jette's method. The gamma analyses highlighted significant differences between the entrance doses comparing the two different methods, for SOBPs with intermediate and high depths and small width. This evaluation was not possible with the values alone, which stresses the relevance of a broad analysis to avoid unintended doses in healthy tissues.Artigo IPEN-doc 29884 New insights in phenothiazinium-mediated photodynamic inactivation of candida auris2023 - SILVA, ABDENEGO R.; CABRAL, FERNANDA V.; SILVA, CAMILA R.; SILVA, DANIELA F.T.; FREITAS, ANDERSON Z.; FONTES, ADRIANA; RIBEIRO, MARTHA S.n recent years, Candida auris has emerged as a hazardous hospital-acquired pathogen. Its resistance to antifungal treatments makes it challenging, requiring new approaches to manage it effectively. Herein, we aimed to assess the impact of photodynamic inactivation mediated by methylene blue (MB-PDI) or 1,9-dimethyl MB (DMMB-PDI) combined with a red LED against C. auris. To evaluate the photoinactivation of yeasts, we quantified colony-forming units and monitored ROS production. To gain some insights into the differences between MB and DMMB, we assessed lipid peroxidation (LPO) and mitochondrial membrane potential (ΔΨm). After, we verified the effectiveness of DMMB against biofilms by measuring metabolic activity and biomass, and the structures were analyzed through scanning electron microscopy and optical coherence tomography. We also evaluated the cytotoxicity in mammalian cells. DMMB-PDI successfully eradicated C. auris yeasts at 3 μM regardless of the light dose. In contrast, MB (100 μM) killed cells only when exposed to the highest dose of light. DMMB-PDI promoted higher ROS, LPO and ΔΨm levels than those of MB. Furthermore, DMMB-PDI was able to inhibit biofilm formation and destroy mature biofilms, with no observed toxicity in fibroblasts. We conclude that DMMB-PDI holds great potential to combat the global threat posed by C. auris. © 2023 by the authors.Resumo IPEN-doc 29546 Photobiomodulation therapy as a radiosensitizer for triple-negative breast cancer2022 - SILVA, CAMILA R.; PEREIRA, SAULO de T.; PRETTO, LUCAS R. de; FREITAS, ANDERSON Z. de; RIBEIRO, MARTHA S.INTRODUCTION: Radiotherapy (RT) is an essential cancer treatment and is estimated that approximately 52% of oncological patients will be submitted to this technique once. However, some tumors, such as triple-negative breast cancer (TNBC), present radioresistance, demanding high doses of ionizing radiation (IR) and a prolonged period of treatment, which contributes to secondary malignancies due to deposition of dose in organs at risk and several side effects. Moreover, this subtype of cancer shows a high incidence of metastasis and decreases the survival expectancy of the patient. Thus, the search for new agents that can act as a radiosensitizer to improve the RT effects has been growing. Conversely, photobiomodulation therapy (PBM), which is a promising therapy with increasing adhesion in clinical practice, has been used to mitigate the adverse effects of RT. Indeed, recent studies have associated PBM with RT to combat cancer. OBJECTIVES: In this study, we used TNBC-bearing mice as a radioresistant cancer model to verify if PBM could act as a radiosensitizer MATERIALS AND METHODS: PBM was applied in two different protocols before the RT with a high dose (60 Gy fractioned in 4 sessions). We evaluated the tumor volume progression, animal clinical evolution, lung metastases by optical coherence tomography, and animal survival DISCUSSION AND RESULTS: Our data indicate that PBM before each RT session arrested the tumor volume, improved the clinical signals of the animals, reduced the nodules in the lung, and extended animal survival. CONCLUSION: In the light of the knowledge gained, our data indicate that PBM could act as a radiosensitizer.Artigo IPEN-doc 29354 Bimodal treatment for triple-negative breast cancer by combining optical and gamma radiation2022 - SILVA, CAMILA R.; RIBEIRO, MARTHA S.Triple-negative breast cancer is resistant to chemo and radiation therapy. Light-based technologies have been reported as promising allies to cancer treatment. Herein, we combined photodynamic and gamma therapies to verify their potential to treat TNBC.Artigo IPEN-doc 29066 Responses of melanoma cells to photobiomodulation depend on cell pigmentation and light parameters2022 - CONTATORI, CAROLINA G. de S.; SILVA, CAMILA R.; PEREIRA, SAULO de T.; RODRIGUES, MARIA F.S.D.; LUNA, ARTHUR C. de L.; MARQUES, MARCIA M.; RIBEIRO, MARTHA S.Melanoma is a highly aggressive skin cancer that requires new approaches for its management. Low-level laser therapy, currently named photobiomodulation therapy (PBM), has been used to improve different conditions but its effects and safe use on melanoma remain unexplored. Herein, we investigated the PBM impact on melanoma cells differing by pigmentation using near-infrared (NIR) and red lasers in vitro. In vivo, we evaluated the effects of the red laser on melanoma-bearing mice. Amelanotic (SK-MEL-37) and melanotic (B16F10) cells were exposed in vitro to a NIR (780 nm, 40 mW) or a red laser (660 nm, 40 mW) in 3 different light doses: 30, 90, and 150 J/cm2 and responses were assessed regarding mitochondrial activity, invasiveness, migration, and VEGF production. In vivo, melanoma-bearing mice received the red laser delivering 150 J/cm2 directly to the tumor on 3 consecutive days. Mice were monitored for 15 days regarding tumor progression and mouse survival. We noticed that amelanotic cells were unresponsive to NIR light. In contrast, NIR irradiation at 30 J/cm2 promoted an increase in the invasiveness of pigmented cells, even though all light doses have inhibited cell migration. Regarding the red laser on pigmented cells, the highest light dose (150 J/cm2) decreased the VEGF production and migration. In vivo, melanoma-bearing mice treated with red laser showed smaller tumor volume and longer survival than controls. We conclude that PBM appears to be safe for amelanotic non-pigmented melanoma but triggers different responses in melanotic pigmented cells depending on light parameters. Additionally, a high dose of red laser impairs the invasive behavior of melanoma cells, probably due to the decrease in VEGF synthesis, which may have contributed to tumor arrest and increased mouse survival. These findings suggest that red laser therapy could be a new ally in the supportive care of melanoma patients.Capítulo IPEN-doc 28956 Dosimetria e modo de aplicação dos lasers de baixa potência2021 - RIBEIRO, MARTHA S.; SILVA, CAMILA R.; YOSHIMURA, TANIA M.Resumo IPEN-doc 28901 Efeitos da fotobiomodulação pré-exposição à radiação ionizante em células de câncer de mama2021 - SILVA, CAMILA R.; PEREIRA, SAULO T.; CONTATORI, CAROLINA G.S.; PINTO, MAYARA S.; SALVEGO, CAMILA A.; RIBEIRO, MARTHA S.Resumo IPEN-doc 28611 Photodynamic therapy associated with ionizing radiation in the treatment of triple-negative breast cancer cells2021 - SILVA, CAMILA R.; PINTO, MAYARA S.; RIBEIRO, MARTHA S.INTRODUCTION Breast cancer is the most common cancer for women worldwide. According to the World Health Organization, it is considered the 5 th leading cause of death from cancer. Triple-negative breast cancer (TNBC) is a subtype of this disease that represents around 20% of all invasive breast cancer, whose main characteristics are resistance to conventional treatments, such as exposure to ionizing radiation (IR). On the order hand, the photodynamic therapy (PDT) using porphyrins and their derivatives has been described in the literature as a potential therapy against cancer. OBJECTIVES Thus, our goal in this work was to associate PDT and IR in the treatment of TNBC. MATERIALS AND METHODS MDA-MB-231 cells at a concentration of 2x104 cells were submitted to PDT using TMPyP porphyrin (30 μM) and a red light (660 ±11 nm) with fluences of the 23 and 57.5 J/cm 2 (57.3 mW/cm 2). Immediately post-PDT, cells were divided into groups: non-treated (control), only IR and PDT associated with IR (PDT57+IR and PDT23+IR) and then, exposed to IR with a dose of 2.5 Gy. Past 24-h of the PDT-session, the cell viability, clonogenicity and total glutathione were verified. DISCUSSION AND RESULTS Cells exposed to IR not presented statistically significance difference compared to the control group. However, treated groups showed around 38% lower cell viability in relation to the control and IR groups. For the clonogenic assay a reduction of the approximately 65% was observed between IR and treated groups. Regarding to the total glutathione, all groups showed an increase when compared to control group. Nonetheless, no were identified differences between IR and treated groups. CONCLUSION Taken together, our results indicate that PDTassociate with IR may be an ally in TNBC treatment.