Objective        To design a uniaxial cyclic stretching model of tendon stem cells (TSCs)

in vitro

.        Methods        After our silicone-made micro-grooved dishes were analyzed for strain distributions by the finite element software ABAQUS. Freshly isolated and identified TSCs were cultured on the dishes

and then observed for their adherent growth. A programmable logic controller (PLC) was used to make the mechanic

al running parts of the model do cyclically stretching for the dishes. Dishes were divided into 16 groups

with the cyclic stretching for 24 h under different stretch frequencies (0.5

1.0

2.0 and 3.0 Hz) and strains (4%

8%

16% and 20%). The actual running frequency and displacement distance of these silicone dishes were measured. Inverted microscopy was employed to observe the falling off or floating of the TSCs. F-actin in the cytoskeleton were observed by laser confocal scanning microscopy when the cells were stretched for 8 or 12 h under the frequency of 1 Hz and strain of 8%.        Results        The strain distribution was uniform on the self-made silicone dishes. Effective strain range of the bottom membrane accounted for about 91% of its total area in the dishes. When cultured on the dishes for 10 h

all TSCs attached on the dishes and grew along with microgroove direction. Stretching model ran stably under different stretching conditions. There was no significant difference in the actual running frequency and strain displacement distance of the silicone dishes with the set frequency and theoretical strain displacement distance (

P

>0.05). No obvious falling off or floating was observed in the TSCs cultured on the dishes. F-actin filaments seemed much thinner

and some of them were broken

and the red fluorescence dyeing (F-actin) was weakened and unevenly distributed in the streched cells than the cells without stretching.       Conclusion        Our established uniaxial cyclic stretching model is easy to operate

with wild range of parameters

and is used to simulate conditions for adherent cells under different biomechanical loading

in vitro

.