Evaluation of biological responses to polymeric biomaterials by RT-PCR analysis. I. Study of IL-1 beta mRNA expression.

In this study, we introduce a novel research methodology, the evaluation of mRNA expression of cells contacting with polymeric materials using reverse transcription-polymerase chain reaction (RT-PCR) analysis HL-60 was used as a model of the macrophages. The expression of interleukin-1 beta (IL-1 beta) mRNA, a cytokine secreted by macrophages, was selected to estimate the extent of inflammation. The expression of IL-1 beta mRNA in the HL60 cells cultured on various substrates and in various conditions was studied. Expression of IL-1 beta could be successfully determined by RT-PCR analysis. A 48 h incubation period was necessary to clarify the expression of IL-1 beta mRNA. It became clear that lipopolysaccharide stimulation was not necessary in this analysis because of the high sensitivity of RT-PCR analysis. It is concluded that RT-PCR analysis is a powerful tool for studying cell-polymer interaction, and is a complementary method for ELISA.