Autor(es):
Cardoso, Ana Sofia 
Data: 2008
Identificador Persistente: http://hdl.handle.net/10362/5794
Origem: Repositório Institucional da UNL
Detalhes do Documento
In vitro studies of gum arabic-coated magnetic nanoparticles with mammalian cel...
Descrição
Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Biotecnologia The aims of this work were the functionalization of magnetic nanoparticles (MNPs)with Gum Arabic (GA) and the study of the effect of these modified particles on the growth and survival of mammalian cell cultures. MNPs consisting of Fe3O4 were synthesized by the Massart Method and further functionalized with GA by adsorption and covalent coupling via GA amino or carboxylic acid groups. The GA adsorption and binding isotherms displayed a Langmuir type. The maximum of GA coated on MNPs followed the order MNP_GAAPTS < MNP_GA_GAADS < MNP_GAADS < MNP_GAEDC,where MNPs coated with GA via EDC activation gave the best result for coupling (2,80g GA bound/g MNP for 2,62 mg/ml GA (eq.)). The particles were characterized by FTIR, BET, TEM and DLS, showing the greater dispersion and colloidal stability of particles in aqueous solution when GA is present. Cultures of mammalian cell lines(HEK293, CHO and TE671) were grown in the presence of uncoated and GA coated MNPs. Cellular viability was assessed for different incubation periods by means of the Trypan Blue exclusion test and by comparing cellular density with that of cells grown in the absence of particles. Different MNPs need different incubation periods to deposit at cellular surface, and the results vary with the cell type tested. With HEK293 cells, MNP_GAAPTS attach to the cell surface after only 30 minutes, while bare magnetite and MNP_GAEDC have a greater effect on compromising cellular viability. On the other hand, MNP_GAADS needed longer incubation periods to attach to the cell surface and caused less cellular damage for identical incubation times with the other particles tested.
Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Biotecnologia The aims of this work were the functionalization of magnetic nanoparticles (MNPs)with Gum Arabic (GA) and the study of the effect of these modified particles on the growth and survival of mammalian cell cultures. MNPs consisting of Fe3O4 were synthesized by the Massart Method and further functionalized with GA by adsorption and covalent coupling via GA amino or carboxylic acid groups. The GA adsorption and binding isotherms displayed a Langmuir type. The maximum of GA coated on MNPs followed the order MNP_GAAPTS < MNP_GA_GAADS < MNP_GAADS < MNP_GAEDC,where MNPs coated with GA via EDC activation gave the best result for coupling (2,80g GA bound/g MNP for 2,62 mg/ml GA (eq.)). The particles were characterized by FTIR, BET, TEM and DLS, showing the greater dispersion and colloidal stability of particles in aqueous solution when GA is present. Cultures of mammalian cell lines(HEK293, CHO and TE671) were grown in the presence of uncoated and GA coated MNPs. Cellular viability was assessed for different incubation periods by means of the Trypan Blue exclusion test and by comparing cellular density with that of cells grown in the absence of particles. Different MNPs need different incubation periods to deposit at cellular surface, and the results vary with the cell type tested. With HEK293 cells, MNP_GAAPTS attach to the cell surface after only 30 minutes, while bare magnetite and MNP_GAEDC have a greater effect on compromising cellular viability. On the other hand, MNP_GAADS needed longer incubation periods to attach to the cell surface and caused less cellular damage for identical incubation times with the other particles tested.
Tipo de Documento
Dissertação de Mestrado
Idioma Inglês
Orientador(es) Roque, Ana; Santos, Isabel
Idioma Inglês
Orientador(es) Roque, Ana; Santos, Isabel
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