Enhancement of nerve axonal extension by using the extracellular environmental stimulation were reported. In this study, we focused on the stretch stimulation, and developed a 3D cell culture system to mimic the in vivo extracellular matrices and investigated the fundamental mechanism of axonal extension enhancement.
Firstly, we fabricated the stretch stimulation device. The rat phenocromocytoma cells (PC12), the nerve-like cells, embedded in the collagen gel were poured into the stretch chamber. It was set in the stretch stimulation device, which could load the strain to the collagen gel. Secondly, we determined the structure of the stretch chamber to implement the uniform strain distribution in the culture region. Using the finite element (FE) analyses, we confirmed that the uniform strain is assigned in a region of 2.7 × 3.0 × 0.5 mm in the culture region, which is the candidate for the observation region. Thirdly, PC12 cells axonal extension under uniaxial cyclic stretch stimulation (4% strain, 1 Hz) of 24 hours was carried out. After 96 hours’ culture, we observed the 3D morphology of PC12 cells by the multiphoton excitation fluorescence microscope (MPM). Finally, we confirmed the availability of our stretch stimulation device and the enhancement effect of axonal extension.