Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Int J Nanomedicine ; 16: 1601-1616, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33688181

RESUMO

INTRODUCTION: Cancer is the second leading cause of death globally and is responsible, where about 1 in 6 deaths in the world. Therefore, there is a need to develop effective antitumor agents that are targeted only to the specific site of the tumor to improve the efficiency of cancer diagnosis and treatment and, consequently, limit the unwanted systemic side effects currently obtained by the use of chemotherapeutic agents. In this context, due to its unique physical and chemical properties of graphene oxide (GO), it has attracted interest in biomedicine for cancer therapy. METHODS: In this study, we report the in vivo application of nanocomposites based on Graphene Oxide (nc-GO) with surface modified with PEG-folic acid, Rhodamine B and Indocyanine Green. In addition to displaying red fluorescence spectra Rhodamine B as the fluorescent label), in vivo experiments were performed using nc-GO to apply Photodynamic Therapy (PDT) and Photothermal Therapy (PTT) in the treatment of Ehrlich tumors in mice using NIR light (808 nm 1.8 W/cm2). RESULTS: This study based on fluorescence images was performed in the tumor in order to obtain the highest concentration of nc-GO in the tumor as a function of time (time after intraperitoneal injection). The time obtained was used for the efficient treatment of the tumor by PDT/PTT. DISCUSSION: The current study shows an example of successful using nc-GO nanocomposites as a theranostic nanomedicine to perform simultaneously in vivo fluorescence diagnostic as well as combined PDT-PTT effects for cancer treatments.


Assuntos
Grafite/química , Fotoquimioterapia , Terapia Fototérmica , Nanomedicina Teranóstica , Adsorção , Animais , Benzofuranos/química , Carcinoma de Ehrlich/patologia , Carcinoma de Ehrlich/terapia , Humanos , Verde de Indocianina/farmacologia , Masculino , Camundongos , Nanocompostos/química , Tamanho da Partícula , Rodaminas/farmacologia , Espectrometria de Fluorescência , Análise Espectral Raman , Eletricidade Estática , Carga Tumoral
2.
Int J Mol Sci ; 23(1)2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-35008458

RESUMO

Within phototherapy, a grand challenge in clinical cancer treatments is to develop a simple, cost-effective, and biocompatible approach to treat this disease using ultra-low doses of light. Carbon-based materials (CBM), such as graphene oxide (GO), reduced GO (r-GO), graphene quantum dots (GQDs), and carbon dots (C-DOTs), are rapidly emerging as a new class of therapeutic materials against cancer. This review summarizes the progress made in recent years regarding the applications of CBM in photodynamic (PDT) and photothermal (PTT) therapies for tumor destruction. The current understanding of the performance of modified CBM, hybrids and composites, is also addressed. This approach seeks to achieve an enhanced antitumor action by improving and modulating the properties of CBM to treat various types of cancer. Metal oxides, organic molecules, biopolymers, therapeutic drugs, among others, have been combined with CBM to treat cancer by PDT, PTT, or synergistic therapies.


Assuntos
Carbono/química , Neoplasias/terapia , Fotoquimioterapia/métodos , Terapia Fototérmica/métodos , Animais , Humanos , Fototerapia/métodos
3.
J Biophotonics ; 12(8): e201800461, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30972966

RESUMO

Photobiomodulation was explored to find evidence of stimulation during the development of newborn rats. A light chamber device was used, and rat pups were divided into groups after birth. Investigation of the process' security was performed before the full experiment. Following a protocol of alternating illumination and mother's presence during the first 13 days, we observed that, in the group that received photobiomodulation, the pups opened their eyes faster, indicating earlier achievement of maturity. The rate of weight gain also indicates faster metabolic activity in the group that was photostimulated. This study is the first step toward the use of photobiomodulation for premature newborn human babies.


Assuntos
Aceleração , Crescimento e Desenvolvimento/efeitos da radiação , Terapia com Luz de Baixa Intensidade , Nascimento Prematuro/radioterapia , Animais , Animais Recém-Nascidos , Peso Corporal/efeitos da radiação , Humanos , Ratos
4.
J Biophotonics ; 11(2)2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28700130

RESUMO

It is well known that, under exposure to bright light, eggs tend to hatch earlier than control, without any damage to the birds. This report aims to systematically show the effect and establishes a proposal for a possible application to accelerate chicken egg formation, which could be extrapolated or adapted as a great advance in premature human newborns. Comparing several protocols, the experiments show that lower doses of light slowly delivered for 24 h promote higher efficiency in embryo development, increasing on average 25% of its size and more than 70% in weight when compared to the control. This weight difference shows promising results compared to rates of up to 17% found in the literature. These results can be a first step to reduce the stay of premature human infants in hospitals because light, when applied in very low doses, can accelerate the natural biological processes without risks.


Assuntos
Luz , Óvulo/crescimento & desenvolvimento , Óvulo/efeitos da radiação , Animais , Embrião de Galinha , Membrana Corioalantoide/efeitos da radiação , Humanos , Recém-Nascido , Óvulo/imunologia , Fototerapia
5.
Photodiagnosis Photodyn Ther ; 17: 205-207, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27613999

RESUMO

Aktinic Keratosis is common and if left untreated may develop into life threatening squamous cell carcinoma. Therefore early intervention is the standard of care. While many treatments are available PDT continues to move to the for - front for this indication (Brito et al., 2016 [31]). Topical PS is commercially available that are able to reliably ablate these lesions. Innovative protocols including sunlight, large volume LED arrays and maneuvers to improve treatment parameters and cosmesis continue to make this a worldwide treatment of choice for AK.


Assuntos
Ceratose Actínica/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Humanos , Ceratose Actínica/terapia , Fotoquimioterapia/efeitos adversos , Fármacos Fotossensibilizantes/efeitos adversos
6.
Photodiagnosis Photodyn Ther ; 11(1): 22-6, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24412582

RESUMO

Non-melanoma skin cancer is the most prevalent cancer type in Brazil and worldwide. Photodynamic therapy (PDT) is a noninvasive technique with excellent cosmetic outcome and good curative results, when used for the initial stages of skin cancer. A Brazilian program was established to determine the efficacy of methyl aminolevulinate (MAL)-PDT, using Brazilian device and drug. The equipment is a dual device that combines the photodiagnosis, based on widefield fluorescence, and the treatment at 630nm. A protocol was defined for the treatment of basal cell carcinoma with 20% MAL cream application. The program also involves the training of the medical teams at different Brazilian regions, and with distinct facilities and previous PDT education. In this report we present the partial results of 27 centers with 366 treated BCC lesions in 294 patients. A complete response (CR) was observed in 76.5% (280/366). The better response was observed for superficial BCC, with CR 160 lesions (80.4%), when compared with nodular or pigmented BCC. Experienced centers presented CR of 85.8% and 90.6% for superficial and nodular BCC respectively. A high influence of the previous doctor experience on the CR values was observed, especially due to a better tumor selection.


Assuntos
Ácido Aminolevulínico/análogos & derivados , Carcinoma Basocelular/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Ácido Aminolevulínico/uso terapêutico , Brasil , Carcinoma Basocelular/patologia , Feminino , Humanos , Masculino , Estudos Prospectivos , Neoplasias Cutâneas/patologia
7.
Biophys Chem ; 137(2-3): 81-7, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18676081

RESUMO

Human nerve growth factor-induced B (NGFI-B) is a member of the NR4A subfamily of orphan nuclear receptors (NRs). Lacking identified ligands, orphan NRs show particular co-regulator proteins binding properties, different from other NRs, and they might have a non-classical quaternary organization. A body of evidence suggests that NRs recognition of and binding to ligands, DNA, homo- and heterodimerization partners and co-regulator proteins involve significant conformational changes of the NR ligand-binding domains (LBDs). To shed light on largely unknown biophysical properties of NGFI-B, here we studied structural organization and unfolding properties of NGFI-B ligand (like)-binding domain induced by chemical perturbation. Our results show that NGFI-B LBD undergoes a two-state guanidine hydrochloride (GndHCl) induced denaturation, as judged by changes in the alpha-helical content of the protein monitored by circular dichroism spectroscopy (CD). In contrast, changes in the tertiary structure of NGFI-B LBD, reported by intrinsic fluorescence, reveal a clear intermediate state. Additionally, SAXS results demonstrate that the intermediate observed by intrinsic fluorescence is a partially folded homodimeric structure, which further unfolds without dissociation at higher GndHCl concentrations. This partially unfolded dimeric assembly of NGFI-B LBD might resemble an intermediate that this domain access momentarily in the native state upon interactions with functional partners.


Assuntos
Proteínas de Ligação a DNA/química , Conformação Proteica , Receptores de Esteroides/química , Dicroísmo Circular , Proteínas de Ligação a DNA/genética , Guanidina/química , Humanos , Modelos Moleculares , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares , Desnaturação Proteica , Dobramento de Proteína , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Receptores de Esteroides/genética , Proteínas Recombinantes/química , Espalhamento de Radiação , Espectrometria de Fluorescência , Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA