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Abstract(s)
As nanopartículas de carbono Carbon dots (Cdots) são nanopartículas esféricas que consistem num núcleo de carbono sp2 /sp3 estabilizado por grupos como ácidos carboxílicos, álcoois e cetonas na sua superfície. As suas propriedades eletrónicas permitem-lhes atuar como doadores e recetores de electrões, tornando-os num material versátil, com aplicações em biomedicina, optoelectrónica, sensores e fotocatálise. Esta dissertação tem como principal objetivo avaliar a biocompatibilidade dos nanofluídos não-Newtonianos baseados em Cdots. Estes foram obtidos a partir de diferentes fontes de carbono (glucose, quitina e fibroína) e funcionalizados in situ com duas moléculas, cloreto de 1-butil-3-metillimidazolio [Bmim] e triflato de 1-tosilato-3-metil-imidazólio [Tmi] [Trif], também designado por IL1. De forma a atingir este objetivo testaram-se os nanofluídos em diferentes linhas celulares humanas e avaliou-se a sua potencial aplicabilidade na terapia fotodinâmica. Deste modo, avaliou-se a citotoxicidade in vitro em linhas celulares humanas que mimetizam a pele, como fibroblastos e células endoteliais, e numa linha celular que mimetiza o comportamento do cancro da mama. As células foram sujeitas a tratamentos com diferentes concentrações de nanofluídos baseados em Cdots na ausência e presença de irradiação com luz UV-A para estudar o seu efeito na viabilidade celular, na proliferação celular e na migração celular. No ensaio de viabilidade celular verificou-se uma estimulação da viabilidade celular quando o tratamento com os Cdots é aplicado, sendo o efeito muito marcado na linha celular de cancro da mama. Por outro lado, nos ensaios de proliferação celular observou-se uma diminuição da proliferação celular na presença dos Cdots, havendo um efeito mais marcado do tratamento na ausência de luz negra UV-A. Por último, no ensaio de migração observou-se uma diminuição da migração dos fibroblastos, das células endoteliais e das células de cancro da mama quando sujeitas a um tratamento com 0,2mg/mL com Cdots. Concluiu-se que os Cdots na ausência e presença de luz UV induziram um efeito diferente nas células. Também se concluiu que a concentração de 0,2 mg/mL era a mais favorável devido possivelmente uma melhor dispersibilidade das nanopartículas.
Carbon nanoparticles, Carbon dots (Cdots), are spherical nanoparticles that consist of a sp2 /sp3 carbon nucleus stabilized by surface groups, such as, carboxylic acids, alcohols and ketones. Their electronic properties allow them to act as electron donors and receivers, making them a versatile material, with applications in biomedicine, optoelectronics, sensors and photocatalysis. The main objective of this dissertation is to evaluate the biocompatibility of non-Newtonian nanofluids based on Cdots. The Cdots were obtained from different carbon sources (glucose, chitin and fibroin) and functionalized in situ with two molecules, 1-butyl-3-methyllimidazolium chloride [Bmim] and 1-tosylate-3-methyl-imidazolium triflate [Tmi] [Trif], also called IL1. In order to achieve this goal, nanofluids were tested in different human cell lines and their potential applicability in photodynamic therapy was evaluated. Thus, in vitro cytotoxicity was evaluated in human cell lines that mimic the skin, such as fibroblasts and endothelial cells, and in a cell line that mimics the behavior of breast cancer. The cells were subjected to treatments with different concentrations of nanofluids based on Cdots in the absence and presence of UV light irradiation to study its effect on cell viability, cell proliferation and cell migration. In the cell viability assay, there was a stimulation of cell viability when treatment with Cdots is applied, the effect being very marked in the breast cancer cell line. On the other hand, cell proliferation assays showed a decrease in cell proliferation in the presence of Cdots, with a more marked effect of the treatment in the absence of UV-A black light. Finally, in the migration assay a decrease in migration of fibroblasts, endothelial cells and breast cancer cells was observed when subjected to a treatment with 0.2mg/ml with Cdots. It was concluded that Cdots in the absence and presence of UV light induced a different effect on cells. It was also concluded that the concentration of 0.2 mg/ml was the most favorable, possibly due to a better dispersibility of the nanoparticles.
Carbon nanoparticles, Carbon dots (Cdots), are spherical nanoparticles that consist of a sp2 /sp3 carbon nucleus stabilized by surface groups, such as, carboxylic acids, alcohols and ketones. Their electronic properties allow them to act as electron donors and receivers, making them a versatile material, with applications in biomedicine, optoelectronics, sensors and photocatalysis. The main objective of this dissertation is to evaluate the biocompatibility of non-Newtonian nanofluids based on Cdots. The Cdots were obtained from different carbon sources (glucose, chitin and fibroin) and functionalized in situ with two molecules, 1-butyl-3-methyllimidazolium chloride [Bmim] and 1-tosylate-3-methyl-imidazolium triflate [Tmi] [Trif], also called IL1. In order to achieve this goal, nanofluids were tested in different human cell lines and their potential applicability in photodynamic therapy was evaluated. Thus, in vitro cytotoxicity was evaluated in human cell lines that mimic the skin, such as fibroblasts and endothelial cells, and in a cell line that mimics the behavior of breast cancer. The cells were subjected to treatments with different concentrations of nanofluids based on Cdots in the absence and presence of UV light irradiation to study its effect on cell viability, cell proliferation and cell migration. In the cell viability assay, there was a stimulation of cell viability when treatment with Cdots is applied, the effect being very marked in the breast cancer cell line. On the other hand, cell proliferation assays showed a decrease in cell proliferation in the presence of Cdots, with a more marked effect of the treatment in the absence of UV-A black light. Finally, in the migration assay a decrease in migration of fibroblasts, endothelial cells and breast cancer cells was observed when subjected to a treatment with 0.2mg/ml with Cdots. It was concluded that Cdots in the absence and presence of UV light induced a different effect on cells. It was also concluded that the concentration of 0.2 mg/ml was the most favorable, possibly due to a better dispersibility of the nanoparticles.
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Keywords
Nanopartículas Cdots Citotoxicidade Viabilidade Migração Proliferação Fibroblastos Angiogénese Cancro da mama Fotoluminescência ROS UV-A PDT Nanoparticles Cytotoxicity Viability Migration Proliferation fibroblasts Angiogenesis Breast cancer Photoluminescence