Estudo in vitro da interação de titânio irradiado por feixe de laser Yb:YAG com e sem recobrimento de apatitas, empregando-se cultura de células estaminais humanas
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Data
2009-07-21
Autores
Tavares, Hewerson Santos [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Superfícies de titânio apresentam importantes propriedades físico-químicas e morfológicas com aplicações em muitos dispositivos que requerem interação com o tecido ósseo. O objetivo do presente estudo foi avaliar in vitro utilizando-se cultura de células estaminais a interação da superfície de titânio irradiado com laser em menor fluência (L1); laser com maior fluência (L2) e superfície L2 com recobrimento de apatitas, (HA). A irradiação laser Yb:YAG em diferentes parâmetros ocasionou a formação de óxidos de titânio nas superfícies irradiadas, que podem influenciar diretamente a integração biológica. As superfícies obtidas foram caracterizadas por Microscopia Eletrônica de Varredura (MEV) e Difração de raios X (DRX) e a camada de hidroxiapatita foi avaliada por espectroscopia no infra vermelho transformada de Fourier (FTIR) e medidas de ângulo de contato. As avaliações in vitro foram realizadas utilizando as superfícies L1, L2 e HA diretamente em contato com células humanas indiferenciadas. Os parâmetros biológicos avaliados foram: adesão, proliferação, e metabolismo celular. Foi determinada a concentração de fosfatase alcalina (ALP) e conteúdo total de proteína, produção de osteocalcina e diferenciação osteogênica pela associação das análises. A morfologia celular foi avaliada por MEV, e a micro análise por espectroscopia por energia dispersiva de raios X (EDS) e microscopia de fluorescência. Os resultados indicaram que todos os grupos experimentais apresentaram menor adesão e proliferação celulares nos estágios iniciais em relação ao grupo controle, com aumento da proliferação após 14 dias. Também aos 14 dias houve aumento na taxa de metabolismo celular em todos os grupos experimentais. Os níveis de ALP/Proteína associados aos dados sobre metabolismo celular indicaram sinais bioatividade do grupo HA aos 21 dias. Conclusão:..
Titanium surfaces have important physical-chemistry and morphological properties with many applications on biomedical devices whose have bone tissue interaction. The laser beam irradiation on titanium surfaces presented in this study was evaluated by the osseointegration of human mesenchymal stem cells. In this study was performed laser irradiation (Low fluency L1; high fluency L2; high fluency associated apatite treatment HA; and the control group machined surface). The laser irradiated structures were initially characterized by Scanning Electronic Microscopy (SEM) and x ray diffraction (DRX) the HA group was subjected apatites treatment following the characterization by DRX, contact angle measurements and Infra red spectroscopy. The biological evaluations were performed by primary culture and differentiation of human stem cell. The parameters of in vitro evaluations were: Cell adhesion and proliferation by DNA quantification, cell metabolism, and cell morphology by SEM and fluorescence microscopy. The osteogenic differentiation was determined by ALP/Osteocalcin levels associated with SEM-EDS comparison. Results: All the experimental groups show less cell adhesion and proliferation at the initial stage of experiments than control group between 1 - 7 days. After 7 days the proliferation and cell metabolism increase on all experimental groups. The SEM micrographies associated with ALP/osteocalcin levels showed significant osteogenic differentiation on L1 group with significance differences of ALP/protein levels at day 7 (P<0.05), in addition, the HA group shows high levels ALP/Protein at 21 days. Conclusion: The laser beam irradiation process presented is clean, rapid and easy way to obtain a layer of oxides with micro and nanostructures. The best performance was found for L1 group with significant levels of osteocalcin and associated with morphological comparison, all experimental groups... (Complete abstract click electronic access below)
Titanium surfaces have important physical-chemistry and morphological properties with many applications on biomedical devices whose have bone tissue interaction. The laser beam irradiation on titanium surfaces presented in this study was evaluated by the osseointegration of human mesenchymal stem cells. In this study was performed laser irradiation (Low fluency L1; high fluency L2; high fluency associated apatite treatment HA; and the control group machined surface). The laser irradiated structures were initially characterized by Scanning Electronic Microscopy (SEM) and x ray diffraction (DRX) the HA group was subjected apatites treatment following the characterization by DRX, contact angle measurements and Infra red spectroscopy. The biological evaluations were performed by primary culture and differentiation of human stem cell. The parameters of in vitro evaluations were: Cell adhesion and proliferation by DNA quantification, cell metabolism, and cell morphology by SEM and fluorescence microscopy. The osteogenic differentiation was determined by ALP/Osteocalcin levels associated with SEM-EDS comparison. Results: All the experimental groups show less cell adhesion and proliferation at the initial stage of experiments than control group between 1 - 7 days. After 7 days the proliferation and cell metabolism increase on all experimental groups. The SEM micrographies associated with ALP/osteocalcin levels showed significant osteogenic differentiation on L1 group with significance differences of ALP/protein levels at day 7 (P<0.05), in addition, the HA group shows high levels ALP/Protein at 21 days. Conclusion: The laser beam irradiation process presented is clean, rapid and easy way to obtain a layer of oxides with micro and nanostructures. The best performance was found for L1 group with significant levels of osteocalcin and associated with morphological comparison, all experimental groups... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Materiais biomédicos, Titanio, Celulas - Cultura, Laser, Biomaterials
Como citar
TAVARES, Hewerson Santos. Estudo in vitro da interação de titânio irradiado por feixe de laser Yb:YAG com e sem recobrimento de apatitas, empregando-se cultura de células estaminais humanas. 2009. 57 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Química, 2009.