Calculated Dynamic Parameters for Different Acoustical Power.

<p>Notes. Values for velocity and τ represent mean ± SE. The radius of the focal region is 0.2 mm. Efficiency of power conversion is 68.8%. Fluid shear stress and radiation force were calculated according to both formulas (see text for details).</p

Changes in fluorescence intensities of MC3T3-E1 cells loaded with Calcium GreenTM-1.

<p>Time-lapse sequence images showing calcium influx in the cells before pulsed ultrasound radiation (A), at the start (B) of radiation and during the radiation (C and D). Compared to cells without ultrasound radiation, the pulsed ultrasound evoked a significant increase in intracellular calcium levels (E). Dotted lines represent duration of radiation on- and off-switch, respectively. Scale bar, 10 µm.</p

Primary cilium projections from the surface of an MC3T3-E1 osteoblast and its bending during radiation of pulsed ultrasound.

<p>The upper panel shows primary cilium stained with an antibody against acetylated α-tubulin (red) (arrowheads, A and D), cell body stained with CMFDA (green) (B and D) and nucleus stained with DAPI (blue) (C and D) in a MC3T3-E1 osteoblast. The lower panel shows the top views of bending movement of a primary cilium (arrowheads) extending from the surface of an MC3T3-E1 osteoblast before (E) and during (F and G) application of pulsed ultrasound from top to bottom. Scale bar, 10 µm.</p

Schematic diagram of the transducer assembly. A

<p>: Spherical transducer with coupling cone and a centrally attached laser guideline light. The ellipsoidal acoustic focal zone covers approximately 4 mm axially and 0.4 mm transversely at the half-pressure points. <b>B</b>: Normalized pressure distribution through the culture dish for the single element on the radial plane at the distance of 62.75 mm of the transducer’s surface. <b>C</b>: The focal point of focused ultrasound guided by red laser light in the middle field of view of the microscope objective. Scale bar, 50 µm.</p

Schematic diagram of experimental setup for spatiotemporal measurements of the effects of acoustic radiation force on MC3T3-E1 cells.

<p>The setup includes an inverted microscope and a high intensity focused ultrasound system. Movement of the spherical transducer is controlled by the three-dimensional support framework.</p

Measured average ultrasound-induced temperature rise vs. duration of different acoustical power and stimulation modes.

<p>Error bars (30-s intervals) show the standard deviation between the different measurements. Temperature was measured with a thermocouple probe immersed in the culture medium.</p

Confocal scanning images from the live/dead assay, of the MC3T3-E1 osteoblast region with pulsed ultrasound applied in Petri dishes.

<p>Compared to controls (A), viability of cell cultures assessed 24 hours post-ultrasound treatment (B) showed no significant change. Scale bar, 20 µm.</p

Pulsed ultrasound radiation affects the arrangement of actin cytoskeleton in MC3T3-E1 osteoblasts.

<p>Pulsed ultrasound was applied for 1 min, cells were then rinsed three times with fresh DPBS (total time,10 min), then fixed and stained with rhodamine-phalloidin. Actin stress fibers were imaged in control cells (A) and 10 min (B) after ultrasound radiation. Actin stress fibers increased following pulsed ultrasound radiation. Scale bar, 10 µm.</p