DANIELA DE FATIMA TEIXEIRA DA SILVA

DANIELA DE FATIMA TEIXEIRA DA SILVA

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Photodynamic inactivation against the critical priority pathogen Candida auris
2023 - 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.
Light-tissue interaction of laser with neonatal rat brains
2023 - FABRETTI, L.T.; SILVA, D.F.T.; RAELE, M.P.; KATO, I.T.
Optical properties of the antibiotic Levofloxacin
2022 - SALANI, R.; DEANA, A.M.; SILVA, D.F.T.; PAVANI, C.
In an infectious clinical condition, the gold standard treatment is antibiotic therapy. However, some medications could suffer photodegradation when exposed to light (artificial, environmental, or a therapy as photobiomodulation). Light absorption by these molecules could initiate chemical reactions. Thus, an understanding of how light interacts with antibiotic (ATB) is necessary and this is possible through the study of its optical properties. To measure diffuse transmittance (Td) and diffuse reflectance (Rd) of levofloxacin (LVX) and indirectly to determine the absorption (μa), reduced scattering (μ’s) and reduced attenuation (μ’t) coefficients of this ATB. The ATB used was the LVX (500mg, tablet, Tavok®). The tablet was macerated and the powder was solubilized in MilliQ® water at a final concentration of 10x10-3mol/L. A spectrophotometer was used to register the Td and Rd spectra of the solution. Quartz cuvettes with an optical path of 1.0cm were used and the data were registered in the range of 400 to 1000nm. From the Td and Rd spectra, the values of the μa, μ’s and μ’t of the ATB were calculated using the Kubelka-Munk function. Statistical analysis to compare ATB coefficients at 450, 530, 590, 660, 780 and 810nm was performed using the Origin software. Two way-ANOVA with Tukey post hoc test and significance level α<0.05 was used. The Td value was 10% at 450nm and increased to 32% at 810nm. The Rd was 45% at 450nm and decreased to 19% at 810nm. There was no significant difference in μa (0.44 ±0.18cm-1 at 450nm, 0,56±0.27cm-1 at 530nm, 0.64±0.33cm-1 at 590nm, 0.59±0.32cm-1 at 660nm, 0.47± 0.31cm-1 at 780nm and 0.44±0.31cm-1 at 810nm). The μ's decreased with increasing wavelength being 3.08 ± 1.84cm-1 at 450nm, 0.92±0.51cm-1 at 660nm, 0.71±0.42cm-1 at 780nm and 0.65±0.39cm-1 at 810nm. The μ't also decreased with the increasing wavelength being 3.52±1.94cm-1 at 450nm, 1.52±0.82cm-1 at 660nm, 1.18±0.73cm-1 at 780 nm and 1.09±0.70 cm-1 at 810nm. The presence of red and yellow ferric oxide can be related to the high μa values. The low values of Td and high values of the μ’s can be related to the magnesium stearate present in the tablet. The high values of μ’t suggest that ATB absorbed light. The values of the coefficients studied may have been influenced by the excipients present in the tablet formulation. Therefore, future studies with the pure active ingredient of ATB may provide more concrete information about the optical properties of LVX.
Noninvasive red Laser intervention before radiotherapy of triple-negative breast cancer in a murine model
2023 - 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.
New insights in phenothiazinium-mediated photodynamic inactivation of candida auris
2023 - 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.
Photodynamic therapy mediated by a red LED and methylene blue inactivates resistant leishmania amazonensis
2023 - CABRAL, FERNANDA V.; YOSHIMURA, TANIA M.; SILVA, DANIELA de F.T. da; CORTEZ, MAURO; RIBEIRO, MARTHA S.
Cutaneous leishmaniasis is a neglected parasitic disease that leads to destructive lesions. The emergence of drug resistance has been a global concern over the past years. Photodynamic therapy (PDT) mediated by a red LED and methylene blue (MB) involves the overproduction of oxidative stress, which oxidizes several cellular biomolecules and prevents the selection of resistant strains. Herein, we investigated the potential of PDT mediated by MB against wild-type and miltefosine-resistant strains of Leishmania amazonensis. As a result, both strains were susceptible to PDT, thus encouraging us to seek the best conditions to overcome the drug resistance problem in cutaneous leishmaniasis.
Comparison of linear polarization degree in health and wounded rat skin
2001 - RIBEIRO, MARTHA S.; FREITAS, ANDERSON Z.; SILVA, DANIELA F.T.; ZEZELL, DENISE M.; PELLEGRINI, CLEUSA M.R.; COSTA, FABIANO G.; ZORN, TELMA M.T.
Optical properties of mice skin for optical therapy relevant wavelengths: influence of gender and pigmentation
2015 - SABINO, C.P.; DEANA, A.M.; SILVA, D.F.T.; FRANCA, C.M.; YOSHIMURA, T.M.; RIBEIRO, M.S.
Propriedades ópticas da pele de camundongos (630-905 nm): influência da idade e massa corpórea
2014 - SABINO, C.P.; DEANA, A.M.; SILVA, D.F.T.; FRANÇA, C.M.; YOSHIMURA, T.M.; RIBEIRO, M.S.
Conceitos físicos básicos aplicados à terapia laser de baixa potência
2012 - SILVA, DANIELA de F.T. da; LOPES, LUCIANA A.; RIBEIRO, MARTHA S.