Investigation on effect of strain on oesophageal smooth muscle cells

Abstract

Oesophageal cancer is the sixth most common cause of cancer death worldwide. Treatment usually involves surgical resection and replacement. A tissue engineered bio-prosthesis promises better clinical outcomes than the current therapies. Understanding the response of the cells to mechanical stimulation is the key to determining the ideal conditions for the bioreactor pre-conditioning prior to implantation. The goal of this research is to investigate the characteristics of oesophageal smooth muscle cells for the use as a successful implant for the treatment of the oesophageal cancer and to study the mechanobiology of smooth muscle cells seeded onto a polyurethane (PU) membrane in a pressure actuated bioreactor. In the experiments, the cells are subject to varying magnitudes of strain at a frequency of 3.5 cycles/min after confluence. The results showed the dependence of the cellular alignment to the magnitude of the strain applied. Smooth muscle cells showed parallel alignment to the low strain percentage level (2.5%) and perpendicular alignment to higher percentage (5%). The smooth muscle cells are assumed to be elongated, and as the pressure increases, the cells change morphologically into an ellipse, with respect to the percentage of strain applied. It is this displacement which is calculated and is plotted for a graph to find the strain regime. MTS [3-(4, 5-dimethylthiazol-2-yl) 5-(3- carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay indicated the cellular metabolic rate which was found to be decreased after the stimulation. The expression of Vimentin was studied after the application of the strain to the cells in which the level of Vimentin was found to be increased as a result of the strain regime.