Fig. 2: Engineered muscle tissues (EMTs) exhibit improved contractile function in a time-dependent manner. | npj Microgravity

Fig. 2: Engineered muscle tissues (EMTs) exhibit improved contractile function in a time-dependent manner.

From: Simulated microgravity attenuates myogenesis and contractile function of 3D engineered skeletal muscle tissues

Fig. 2

a EMT culture procedure. Arrows indicate timepoints for force measurements and immunofluorescence staining. Created using Biorender®. b Twitch amplitude of EMTs under electrical stimuli (20 V, 1 Hz, 4 ms). c Tetanic amplitude of EMTs under electrical stimuli (20 V, 20 Hz, 4 ms). d Specific twitch force normalized by total cross-sectional areas of the myotubes. e Specific tetanic force normalized by total cross-sectional areas of the myotubes. Contraction of EMTs significantly increases from day 3 (D3) to D5. f Twitch contraction velocity of EMTs. g Twitch relaxation velocity of EMTs. Significant increase is exhibited in the twitch contraction and relaxation velocities from D3 to D5. h Twitch / tetanus ratio significantly increased from D3 to D5. i Representative contraction force traces of a 7-day-old EMT show synchronous twitch and tetanic forces as stimulation frequency increases. Data are mean ± SEM (N = 4, *P < 0.05, **P < 0.01, ***P < 0.001, ns = no significance by One-way ANOVA followed by multiple comparisons).

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