VIVIANE PEREIRA GOULART

VIVIANE PEREIRA GOULART

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Optimization and therapeutic effects of PDT mediated by ALA and MAL in the treatment of cutaneous malignant lesions: a comparative study
2016 - LIMA, CASSIO A.; GOULART, VIVIANE P.; BECHARA, ETELVINO J.H.; CORREA, LUCIANA; ZEZELL, DENISE M.
5-aminolevulinic acid (ALA) and its methylated ester (MAL) are the most common topical agents used in photodynamic therapy (PDT) as precursors of the photosensitizer protoporphyrin IX (PpIX). The induction of newly PpIX depends on incubation time of each photosensitizer in the tissue and the presence of high intralesional porphyrin levels is an important parameter for the PDT effectiveness. This study used laser-induced fluorescence (LIF) spectroscopy to evaluate the optimum time to light exposure of PDT mediated by ALA (20% w/w) and MAL (10% w/w) to treat malignant lesions precursors of cutaneous squamous cell carcinoma induced in mice. The therapeutic effects obtained by optimized ALA- and MAL-PDT were assessed 10 and 20 days after treatments. Higher PpIX levels were evidenced in the lesions photosensitized by ALA than MAL and according to LIF measurements the PDT irradiation was performed, respectively, at 300 and 330 minutes after ALA and MAL incubation. Histopathological analysis evidenced necrosis and epithelial atrophy after 10 days of PDT using both prodrugs, as well as reepitelization and collagen deposition at 20 days. Thus, despite the distinct concentration of ALA and MAL used in the formulation of each photosensitizing cream, PDT mediated by both photosensitizing agents obtained similar therapeutic outcomes.
Using fourier transform infrared spectroscopy to evaluate biological effects induced by photodynamic therapy
2016 - LIMA, CASSIO A.; GOULART, VIVIANE P.; CORREA, LUCIANA; ZEZELL, DENISE M.
Background and Objective: Vibrational spectroscopic methods associated with multivariate statistical techniques have been succeeded in discriminating skin lesions from normal tissues. However, there is no study exploring the potential of these techniques to assess the alterations promoted by photodynamic effect in tissue. The present study aims to demonstrate the ability of Fourier Transform Infrared (FTIR) spectroscopy on Attenuated total reflection (ATR) sampling mode associated with principal component-linear discriminant analysis (PC-LDA) to evaluate the biochemical changes caused by photodynamic therapy (PDT) in skin neoplastic tissue. Materials and Methods: Cutaneous neoplastic lesions, precursors of squamous cell carcinoma (SCC), were chemically induced in Swiss mice and submitted to a single session of 5-aminolevulinic acid (ALA)-mediated PDT. Tissue sections with 5mm thickness were obtained from formalin-fixed paraffin-embedded (FFPE) and processed prior to the histopathological analysis and spectroscopic measurements. Spectra were collected in mid-infrared region using a FTIR spectrometer on ATR sampling mode. Principal Component-Linear Discriminant Analysis (PC-LDA) was applied on preprocessed second derivatives spectra. Biochemical changes were assessed using PCA-loadings and accuracy of classification was obtained from PC-LDA . Results: Sub-bands of Amide I (1,624 and 1,650 cm1 ) and Amide II (1,517 cm1 ) indicated a protein overexpression in non-treated and post-PDT neoplastic tissue compared with healthy skin, as well as a decrease in collagen fibers (1,204, 1,236, 1,282, and 1,338 cm1 ) and glycogen (1,028, 1,082, and 1,151 cm1 ) content. Photosensitized neoplastic tissue revealed shifted peak position and decreased b-sheet secondary structure of proteins (1,624 cm1 ) amount in comparison to non-treated neoplastic lesions. PC-LDA score plots discriminated non-treated neoplastic skin spectra from post-PDT cutaneous lesions with accuracy of 92.8%, whereas non-treated neoplastic skin was discriminated from healthy tissue with 93.5% accuracy and post-PDT cutaneous lesions was discriminated from healthy tissue with 89.7% accuracy. Conclusion: PC-LDA was able to discriminate ATR-FTIR spectra of non-treated and post-PDT neoplastic lesions, as well as from healthy skin. Thus, the method can be used for early diagnosis of premalignant skin lesions, as well as to evaluate the response to photodynamic treatment.
Noninvasive monitoring of photodynamic therapy on skin neoplastic lesions using the optical attenuation coefficient measured by optical coherence tomography
2015 - GOULART, VIVIANE P.; SANTOS, MOISES O. dos; LATRIVE, ANNE; FREITAS, ANDERSON Z.; CORREA, LUCIANA; ZEZELL, DENISE M.
Photodynamic therapy (PDT) has become a promising alternative for treatment of skin lesions such as squamous cell carcinoma. We propose a method to monitor the effects of PDT in a noninvasive way by using the optical attenuation coefficient (OAC) calculated from optical coherence tomography (OCT) images. We conducted a study on mice with chemically induced neoplastic lesions and performed PDT on these lesions using homemade photosensitizers. The response of neoplastic lesions to therapy was monitored using, at the same time, macroscopic clinical visualization, histopathological analysis, OCT imaging, and OCT-based attenuation coefficient measurement. Results with all four modalities demonstrated a positive response to treatment. The attenuation coefficient was found to be 1.4 higher in skin lesions than in healthy tissue and it decreased after therapy. This study shows that the OAC is a potential tool to noninvasively assess the evolution of skin neoplastic lesions with time after treatment.
ATR-FTIR spectroscopy for the assessment of biochemical changes in skin due to cutaneous squamous cell carcinoma
2015 - LIMA, CASSIO A.; GOULART, VIVIANE P.; CORREA, LUCIANA; PEREIRA, THIAGO M.; ZEZELL, DENISE M.
Nonmelanoma skin cancers represent 95% of cutaneous neoplasms. Among them, squamous cell carcinoma (SCC) is the more aggressive form and shows a pattern of possible metastatic profile. In this work, we used Fourier transform infrared spectroscopy (FTIR) spectroscopy to assess the biochemical changes in normal skin caused by squamous cell carcinoma induced by multi-stage chemical carcinogenesis in mice. Changes in the absorption intensities and shifts were observed in the vibrational modes associated to proteins, indicating changes in secondary conformation in the neoplastic tissue. Hierarchical cluster analysis was performed to evaluate the potential of the technique to differentiate the spectra of neoplastic and normal skin tissue, so that the accuracy obtained for this classification was 86.4%. In this sense, attenuated total reflection (ATR)-FTIR spectroscopy provides a useful tool to complement histopathological analysis in the clinical routine for the diagnosis of cutaneous squamous cell carcinoma.
Skin ablation using high intensity femtosecond laser
2010 - SANTOS, MOISES O. dos; GOULART, VIVIANE P.; ROSSI, WAGNER de; FREITAS, ANDERSON Z. de; CORREA, PAULO R.; SAMAD, RICARDO E.; VIEIRA JUNIOR, NILSON D.; ZEZELL, DENISE M.
Chemical effects of Nd:YAG laser on enamel microstructure detected by FTIR and its influence of calcium fluoride formation and retention
2010 - GOULART, VIVIANE P.; ANA, PATRICIA A. da; ZEZELL, DENISE M.