Influence of MWCNTs to Myocardial Contraction Rhythms on Differentiation of ES-D3 Cells in Three-dimensional Culture

The embryotoxicity of multi-walled carbon nanotubes (MWCNTs) has been investigated using the embryonic stem cell test (EST) protocol. Embryoid bodies (EBs) were generated with the hanging drop culture of ES-D3 cells, followed by one-week culture in three-dimensionally cultured collagen gel with MWCNTs. The contraction of myocardia that differentiated in teratomas could be microscopically observed. However, the myocardial contraction rhythms were examined by image analysis, because they markedly varied. Without MWCNTs, the contraction rhythms of the myocardia were constant. Some teratomas showed peristalsis, suggesting differentiation into the gastrointestinal tract. However, MWCNTs mixture had no effect on the peristaltic rhythms. Conductive MWCNTs that contaminate the scaffolds may have electrical effects. This phenomenon should be further investigated because biological problems are a concern regarding MWCNTs.