Utilização de células de linhagem odontoblástica (MDPC-23) em estudos de citotoxicidade e na avaliação do efeito de fatores de crescimento sobre a expressão de genes específicos
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Data
2005-02-24
Autores
Souza, Pedro Paulo Chaves de [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Este estudo teve como objetivo geral utilizar células da linhagem MDPC-23 em testes de citotoxicidade de materiais e na investigação dos efeitos de proteínas bioativas no estímulo da síntese de componentes da matriz dentinária. Os objetivos específicos foram avaliar o efeito citotóxico de soluções utilizadas na lavagem de paredes cavitárias e de materiais dentários recomendados para aplicação em dentina sobre células de linhagem odontoblástica MDPC-23. Também foi intuito avaliar o efeito do concentrado de proteínas extraídas da dentina de coelho sobre a expressão de genes específicos. Este trabalho, apresentado na forma de três artigos científicos, utilizou a técnica de MTT para avaliar o efeito citotóxico de soluções de CLX em variadas concentrações sobre as células MDPC-23. Esta técnica foi utilizada também para a investigação do efeito citotóxico de três diferentes cimentos de ionômero de vidro modificados por resina: Vitrebond (VB); Vitremer (VM); e RelyX Luting Cement (RX), associada ao teste de implantação destes materiais resinosos no tecido conjuntivo subcutâneo de ratos. A expressão dos genes que codificam para colágeno tipo-1 e fibronectina nas células expostas ao concentrado de proteínas extraídas da dentina de coelhos foi avaliada por RT-PCR. Os resultados demonstraram que a CLX é citotóxica às células da linhagem MDPC-23 de maneira dose-dependente. Também foi demonstrado que os cimentos de ionômero de vidro são biocompatíveis ao tecido conjuntivo subcutâneo de ratos, apesar de apresentarem diferentes graus de citotoxicidade sobre as células odontoblastóides. As proteínas bioativas extraídas da dentina de coelhos apresentaram efeito estimulatório na expressão de genes que codificam para colágeno tipo-1 e fibronectina. Pode-se concluir que as células MDPC-23 são um modelo que pode ser utilizado nos testes de... .
The general aim of this in vitro and in vivo study was to evaluate the cytotoxicity of rinsing solutions and dental materials as well as to determine the expression of genes related with the dentinogenesis. The specific objectives were to evaluate the cytotoxicity effects of rinsing solutions used to clean cavity walls and dental materials used to restore dental cavities. The effects of EDTA soluble dentin proteins (members of TGF-â superfamily) on specific gene espression was also evaluated. For this porpose three scientific papers were prepared: 1) MTT assay was employed to investigate the cytotoxic effects of different concentrations of chlorhexidine to MDPC-23 cells as well as to; 2) to determine the cytotoxicity of three different resin-modified glass-ionomer cements (RMGIC): Vitrebond (VB); Vitremer (VM); and RelyX Luting Cement (VM). The results of this in vitro study was compared to the in vivo study in which RMGICs were implanted into the connective tissue of rats; 3) Type-1 collagen and fibronectin gene expression on cells exposed to EDTAsoluble dentin proteins was assessed by means of semi-quantitative RT-PCR. The results demonstrated that chlorhexidine is cytotoxic to MDPC-23 cells in a dose-dependent way. It was also demonstrated that RMGICs are biocompatible following implantation into surgical pockets prepared in the dorsal connective tissue of rats in spite of the different degrees of in vitro cytotoxicity presented by these materials to MDPC-23 cells. The stimulatory effects of the bioactive molecules on the expression of the genes that encodes to type-1 collagen and fibronectin was clearly demonstrated. Based on the experimental conditions, it was concluded that MDPC-23 cells are suitable model to be used on cytotoxicity tests of dental materials and rinsing solutions as well as to evaluate the dentinogenesis mechanisms.
The general aim of this in vitro and in vivo study was to evaluate the cytotoxicity of rinsing solutions and dental materials as well as to determine the expression of genes related with the dentinogenesis. The specific objectives were to evaluate the cytotoxicity effects of rinsing solutions used to clean cavity walls and dental materials used to restore dental cavities. The effects of EDTA soluble dentin proteins (members of TGF-â superfamily) on specific gene espression was also evaluated. For this porpose three scientific papers were prepared: 1) MTT assay was employed to investigate the cytotoxic effects of different concentrations of chlorhexidine to MDPC-23 cells as well as to; 2) to determine the cytotoxicity of three different resin-modified glass-ionomer cements (RMGIC): Vitrebond (VB); Vitremer (VM); and RelyX Luting Cement (VM). The results of this in vitro study was compared to the in vivo study in which RMGICs were implanted into the connective tissue of rats; 3) Type-1 collagen and fibronectin gene expression on cells exposed to EDTAsoluble dentin proteins was assessed by means of semi-quantitative RT-PCR. The results demonstrated that chlorhexidine is cytotoxic to MDPC-23 cells in a dose-dependent way. It was also demonstrated that RMGICs are biocompatible following implantation into surgical pockets prepared in the dorsal connective tissue of rats in spite of the different degrees of in vitro cytotoxicity presented by these materials to MDPC-23 cells. The stimulatory effects of the bioactive molecules on the expression of the genes that encodes to type-1 collagen and fibronectin was clearly demonstrated. Based on the experimental conditions, it was concluded that MDPC-23 cells are suitable model to be used on cytotoxicity tests of dental materials and rinsing solutions as well as to evaluate the dentinogenesis mechanisms.
Descrição
Palavras-chave
Odontoblastos, Cultura de células, Materiais biomédicos, Dentinogênese, Odontoblasts, Cell culture, Biocompatible materials, Dentinogenesis
Como citar
SOUZA, Pedro Paulo Chaves de. Utilização de células de linhagem odontoblástica (MDPC-23) em estudos de citotoxicidade e na avaliação do efeito de fatores de crescimento sobre a expressão de genes específicos. 2005. 119 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Odontologia, 2005.