Comportamento eletroquímico da liga Ti-10mo-20nb

Ligas de Ti, do tipo b compostas de elementos não tóxicos estão sendo desenvolvidas para implantes biomédicos. As vantagens destas ligas incluem seu baixo módulo de elasticidade, boa compatibilidade mecânica assim como boa resistência à corrosão e, além disso, as variáveis de processamento podem ser controladas para obter propriedades desejadas. Estudos preliminares mostraram que a liga Ti-10Mo-20Nb envelhecida a 500ºC/4 h apresentou alta razão dureza/módulo de elasticidade. Diante do contexto, o objetivo deste trabalho é apresentar o comportamento eletroquímico da liga Ti-10Mo- 20Nb envelhecida a 500ºC/4 h. O testes de corrosão foram realizados na temperatura de 25oC. Os resultados mostraram que esta exibiu uma camada passivadora

Asparaginase induces selective dose- and time- dependent cytotoxicity, apoptosis, and reduction of NFκB expression in oral cancer cells

Asparaginase is fundamental to the treatment of haematological malignancies. However, little has been studied on the effects that asparaginase could exert on solid tumours. Thus, this study aimed to evaluate the effects of asparaginase on an oral carcinoma cell line. The cytotoxicity of asparaginase in SCC- 9 (tongue squamous cell carcinoma) and HaCaT (human keratinocyte) cell lines was evaluated with MTT cell viability assay. The cells were treated with asparaginase at 0.04, 0.16, 0.63, 1.0, 1.5, 2.5, and 5.0 IU/mL. Dose- response curves and IC50 values were obtained and the Tumour Selectivity Index (TSI) was calculated. The effect of asparaginase on procaspase- 3 and nuclear factor κB (NFκB) expression was evaluated with western blot because it was reported that the overexpression of NFκB has been shown to contribute to tumour cell survival, proliferation, and migration. Caspase 3/7 staining was performed to identify cell death using flow cytometry. Effective asparaginase concentrations were lower for SCC- 9 cells when compared to HaCaT cells. The cytotoxicity results at 48 and 72 hours were significantly different for SCC- 9 cells. The TSI indicated that asparaginase was selective for the tumour cells. A decrease in procaspase- 3 and NFκB protein levels was observed in SCC- 9 cells. Furthermore, asparaginase resulted in significant apoptosis after 48 and 72 hours. Based on these results, asparaginase was cytotoxic in a dose- and time- dependent manner, induces apoptosis, and reduces NFκB expression in oral cancer cells. These results encourage further studies on the effectiveness of this enzyme as a treatment for solid tumours, especially head and neck cancer.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154950/1/cep13256.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154950/2/cep13256_am.pd