Design and construction of a uniaxial cell stretcher

In vitro mechanical cell stimulators are used for the study of the effect o f mechanical stimulation on anchorage-dependent cells. We developed a new m echanical cell stimulator, which uses stepper motor technology and computer control to achieve a high degree of accuracy and repeatability. This devic e also uses high-performance plastic components that have been shown to be noncytotoxic, dimensionally stable, and resistant to chemical degradation f rom common culture laboratory chemicals. We show that treatment with glow d ischarge for 25 s at 20 mA is sufficient to modify the surface of the rubbe r to allow proper adhesion for polymerization of aligned collagen. We show through finite element analysis that the middle area of the membrane, away from the clamped ends, is predictable, homogeneous, and has negligible shea r strain. To test the efficacy of the mechanical stretch, we examined the e ffect of mechanical stimulation on the production of beta (1)-integrin by n eonatal rat cardiac fibroblasts. Mechanical stimulation was tested in the r ange of 0-12% stretch and 0-10-cycles/min stretch frequency. The fibroblast s respond with an increase in beta (1)-integrin at 3% stretch and a decreas e at 6 and 12% stretch. Stretch frequency was found to not significantly ef fect the concentration of beta (1)-integrin. These studies yield a new and improved mechanical cell stimulator and demonstrate that mechanical stimula tion has an effect on the expression of beta (1)-integrin.