Collagen Content and Quantification.

<div><p>a) Sirius Red stain showing collagen clusters forming in extracellular matrix. Control samples show little or no collagen and Gravity (G) samples showed evenly distributed collagen clusters over the ECM. Simulated microgravity (M) samples showed little or no collagen clusters and much more comparable to control cultures. Application of LIPUS to simulated microgravity + LIPUS (MU) samples apparently increased collagen content, making them more comparable to G samples. Gravity + LIPUS (GU) samples showed denser collagen clusters and formation of thick collagen fibers (scale bar 500um).</p> <p>b) Sirius red quantification showed a significant decrease in collagen content in M cultures to the levels of control. Application of LIPUS restores collagen content in MU cultures, making them more comparable to G samples. LIPUS exposure significantly increases collagen in MU and GU samples (*p < 0.001).</p>