Óxidos de nióbio e titânio como agentes de separação de carga para a indução da terapia fototérmica do câncer

Abstract

This project aims to study the photothermal capacity of polyaniline doped with the semiconductors titanium oxide and niobium oxide (1-60% w / w), in order to increase the separation of charges in the polymeric network, which leads to the formation of the polyaniline emerald salt, responsible for the formation of heat through a non-radioactive decay of the excited electron. The samples were synthesized and characterized using absorption spectroscopies in the UV-vis and infrared regions, observing the bands related to polyaniline and their chemical bonding respectively. In addition, the samples were characterized by Scanning Electron Microscopy with EDS, observing the presence of dopants on the polyaniline surface. In the UV-Vis spectra at pH 7.4 and 6.5 a shift towards the red region was observed with increasing acidity, which is characteristic of the formation of the polyaniline emerald salt, responsible for the formation of heat by decay nonradioactive. In the analysis of the photothermal effect, it was possible to observe a difference in the amount of heat released between the pH values for samples doped with niobium pentoxide while, in the samples with titanium oxide, there was not a big difference. A temperature greater than 45 ° C was reached at pH 6.5 temperatures necessary to cause cell death of cancer cells, and that at pH 7.4, the temperature was less than 40 ° C. The analyzes performed were satisfactory to make polyaniline doped with niobium pentoxide as a candidate for cancer photothermal agent for its use in cancer photothermal therapy.