AVALIAÇÃO DOS EFEITOS DE NANOTUBOS DE CARBONO DE PAREDE MÚLTIPLA CARBOXILADOS EM CÉLULAS DO SISTEMA IMUNOLÓGICO

Made available in DSpace on 2018-06-27T18:56:33Z (GMT). No. of bitstreams: 2 Gabriela de Moraes Barbosa.pdf: 1970444 bytes, checksum: cc094467f0ae630c8ca1d2412d92b154 (MD5) Gabriela de Moraes Barbosa.pdf.jpg: 3366 bytes, checksum: 682fcf8d3a97c6bde3382a41872a5ae8 (MD5) Previous issue date: 2010-11-09Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe carbon nanotubes (CNTs) display exclusive properties which are of great interest to biotechnology area. The idea of utilizing CTNs as drug carriers, adjuvant for vaccines and biosensors is attracting much interest from scientific community. However, biocompatibility and toxicity in vitro and in vivo of these structures need to be investigated. The aim of this study was to determine the effects of functionalized multiwalled carbon nanotubes (MWCNTs) on cells of the immune system. For in vitro test, splenocytes and bone marrow cells were isolated from BALB/c female mice. The group of treated cells was cultured with carboxylic MWCNTs suspensions at different concentrations (1, 5 or 10 ng/mL), while the control group was only cultured with medium RMPI 1640 and 10% fetal calf serum (FCS). After 24, 48 and 72 hours of cultivation, the viability proliferation and interaction were analyzed by transmission electron microscopy (TEM) analysis of carboxylic MWCNTs with cells. In vivo study, carboxylic MWCNTs were administered intravenously with a concentration of 50 and 100 &#956;g. After 24 hours, splenocytes were isolated, labeled with anti-CD3+ and anti- B220+ antibodies and analyzed by Fluorescence Activated Cell Sorting (FACS). Total IgG production was determined in mice serum after 20 days of administration. The results showed no significant difference (p < 0.05) in the cell viability test of splenocytes, although it has been observed an increase in the frequency of cells directly proportional to the concentrations of carboxylic MWCNTs suspensions in the period of 48 hours. For marrow cells it was observed an inversion in the frequency of cells in the periods of 24 and 48 hours. Regarding the proliferation of splenocytes, groups of cells treated with carboxylic MWCNTs showed significant difference (p<0.05) when compared to control positive group (CpG oligonucleotide). In the analyses performed by TEM, it was not found any type of interaction of carboxylic MWCNTs with splenocytes treated with carboxylic MWCNTs in the concentration of 10 ng/mL. According to the analyses carried out by flow cytometry, the percentage of CD3+ cells and B220+ cells showed no significant difference in relation to the control group. In Enzyme Immunoassay (ELISA), the total IgG antibody production did not increase in the serum of mice treated with carboxylic MWCNTs when compared to control. Thus, the results in vitro and in vivo indicate that carboxylic MWCNTs did not present stimulatory effects on cells of the immune system and, at the same conditions, no cellular toxicity.Os nanotubos de carbono (NTCs) apresentam propriedades exclusivas que são de grande interesse para a área de biotecnologia. A idéia de se utilizar NTCs como carreadores de fármacos, adjuvantes para vacinas e biosensores, vem despertando muito interesse da comunidade científica. No entanto, a biocompatibilidade e toxicidade in vitro and in vivo dessas estruturas precisam ser investigadas. O objetivo desse estudo foi determinar os efeitos dos nanotubos de carbono de paredes múltiplas (NTCPMs) carboxilados sobre células do sistema imunológico. Para os testes in vitro, esplenócitos e células da medula óssea foram isolados de camundongos BALB/c fêmeas. O grupo de células tratadas foi cultivado com suspensões de NTCPMs carboxilados em diferentes concentrações (1, 5 ou 10 ng/mL), enquanto o grupo controle foi cultivado apenas com meio RMPI 1640 e 10% soro fetal bovino (SFB). Após 24, 48 e 72 horas de cultivo, foram analisadas viabilidade, proliferação e interação por análise de microscopia eletrônica de transmissão (MET) dos NTCPMs carboxilados com as células. No estudo in vivo, NTCPMs carboxilados foram administrados pela via intravenosa com concentração de 50 e 100 &#956;g. Após 24 horas, os esplenócitos foram isolados, marcados com anticorpos anti-CD3+ e anti-B220+ e analisados por citometria de fluxo. A produção de IgG total foi determinada no soro de camundongos após 20 dias da administração. Os resultados encontrados indicaram que não houve diferença significativa (p<0,05) no teste de viabilidade celular de esplenócitos, embora tenha sido observado um aumento na freqüência de células diretamente proporcional às concentrações das suspensões de NTCPMs carboxilados no tempo de 48 horas. Para as células da medula, foi observada uma inversão na frequência de células nos tempos de 24 e 48 horas. Em relação à proliferação de esplenócitos, os grupos de células tratadas com NTCPMs carboxilados apresentaram diferença significativa (p