Page 83 - Cellular Imaging in Regenerative Medicine, Cancer and Osteoarthritis

MHz focused transducer was configured at a 45° angle below the sample and the acoustic focus was aligned with the center of each subsection.
During the experiment, the position of the OptiCell chamber was manipulated so that the center of each subsection was insonified in sequence at a predefined pressure (10 to 160 kPa peak negative pressure (PNP), Fig 1C). A prolonged burst of 10,000 cycles with a repetition rate of 20 Hz was applied generated by an arbitrary waveform generator (33220A, Agilent, Palo Alto, CA, USA) and amplified using a broadband amplifier (ENI A-500, Electronics & Innovation, Rochester, NY, USA). The first subsection, without the application of ultrasound, was used as the control. The effect of the different total insonification time was determined (1 s, 10 s, and 30 s) at 40, 80, and 160 kPa PNP when SPIO were added 5 min prior to insonfication. To investigate the effect of the incubation time with SPIO, the OptiCells were incubated at 37°C for 5 min, 1 h, and 3 h after insonification when SPIO were added 5 min prior to insonification. The effect of SPIO addition time (-5, 0, 5, and 15 min with
Figure 1 Experimental setup. A Schematic representation of the tMB adhering to HUVECs during treatment. B Timing diagram of the experiment. The time of insonification (0 min) was used as the reference time. Targeted microbubbles (tMB) were added 5 min before the ultrasound was applied; SPIO was added 5 min before (i.e. -5 min), just before (i.e. 0 min), 5 min after, and 15 min after insonification. Cells were fixated 60 min after SPIO addition. C Scheme of insonification of subsections of the OptiCellTM chamber (to scale). The acoustic pressure is given in PNP. D The treatment setup.
SPIO cell labeling using ultrasound
81
4