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.
FTIR for the study of the biochemical changes promoted by PDT mediated by 5-ALA and its methyl-ester in neoplastic skin lesions
2016 - ZEZELL, D.M.; LIMA, C.A.; GOULART, V.P.
Laser-induced fluorescence spectroscopy assess the Protoporphyrin IX generated by 5-aminolevulinic acid and its methyl ester in cutaneous malignant lesions
2016 - LIMA, CASSIO A.; GOULART, VIVIANE P.; ZEZELL, DENISE M.
Photodynamic therapy (PDT) of tumors is a therapeutic modality considered for the treatment of nonmelanoma skin cancers (NMSC) and other cutaneous diseases. PDT is a minimally invasive method, avoiding surgical intervention or the use of ionizing radiation. The cell death induced by PDT results from the local oxidative stress promoted by reactive oxygen species (ROS) induced by a photosensitizing drug activated by light of specific wavelength. The 5-aminolevulinic acid (ALA) and its methylated ester (MAL) as precursors of the endogenous photosensitizer protoporphyrin IX (PpIX) have been widely studied for the topical treatment of NMSC and other cutaneous diseases. However, the detailed role of PpIX generated by ALA/MAL in diseased and normal skin is incomplete. Understanding the PpIX fluorescence in neoplastic skin may be useful for optimization of PDT while minimizing side effects in the surrounding normal tissue. In this way, this study aimed to use laser-induced fluorescence (LIF) spectroscopy to evaluate the generation of PpIX in squamous cell carcinoma using photosensitizer creams based on ALA and MAL. Neoplastic lesions were induced in 20 Swiss mice using a well-established multi-stage chemical-carcinogenesis protocol and the PpIX generated in the mouse skin was monitored non-invasively by the fluorescence signal emitted after application of each photosensitizer. LIF measurements were collected every 30 minutes on the shaved backs of the mice using a bifurcated fiber-optic probe connected to a spectrometer. A diode laser emitting at 405 nm was used as excitation wavelength and fluorescence emission was measured at 635 nm. Measurements were recorded using the SpectraSuite software (Ocean Optics, USA) and the spectra were normalized by the power emitted by the diode laser as well as by the fluorescence intensity at 405nm. A pairwise comparison using T-Student statistical test was performed in each time interval and the data were considered statistically different for p-values  0.05. Our results showed no statistical significant difference between the groups for 0–90 minutes. On the other hand, the fluorescence intensity for neoplastic skin submitted to ALA was higher than that from tissue submitted to MAL at all times after 90 minutes and showed an increasing behavior with slight fluctuations over time. Considering the lipophilic and charge characteristics from MAL, we concluded that the lowest LIF measurements collected from tissue underwent this prodrug resulted from its higher penetration into the skin, whereas the highest PpIX emission obtained for ALA is an indicative of superficial generation of PpIX and its poor penetration into the tissue.
Chemometric methods applied to FTIR spectra to discriminate treated and non-treated cutaneous malignant lesions from healthy skin
2016 - LIMA, CASSIO A.; GOULART, VIVIANE; ZEZELL, DENISE
Chemometric methods were used to differentiate FTIR spectra of treated and nontreated malignant lesions from healthy skin. We conclude that the method can be used to evaluate the biological changes promoted by photodynamic treatment.
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.
Evaluation of squamous cell skin carcinoma using ATR-FTIR spectroscopy associated to cluster analysis
2014 - LIMA, C.A.; GOULART, V.; ZEZELL, D.M.
Efeito do laser de Nd:YAG na resistência a desmineralização do esmalte quando associado a aplicação de fluoreto
2008 - GOULART, VIVIANE P.; ZEZELL, DENISE M.
Aplicação de técnicas quimiométricas associadas a espectroscopia FT-IR para discriminar tecido sadio de lesões cutâneas potenciamente malignas
2015 - LIMA, CASSIO A.; GOULART, VIVIANE P.; ZEZELL, DENISE M.
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.
Biochemical changes in normal skin caused by squamous cell carcinoma using FTIR spectroscopy
2015 - LIMA, CASSIO; GOULART, VIVIANE; CORREA, LUCIANA; ZEZELL, DENISE