Effect of Photo-Mediated Ultrasound Therapy on Nitric Oxide and Prostacyclin from Endothelial Cells

• Published in: Applied Sciences
• Main Authors: Madhumithra Subramanian Karthikesh, Sa Wu, Rohit Singh, Yannis Paulus, Xueding Wang, Xinmai Yang
• Format: Article
• Language: English
• Published: MDPI AG 2022-03-01
• Subjects: ultrasound; photo-mediated ultrasound therapy; cavitation; endothelial cells; nitric oxide; blood vessel model
• Online Access: https://www.mdpi.com/2076-3417/12/5/2617

Several studies have investigated the effect of photo-mediated ultrasound therapy (PUT) on the treatment of neovascularization. This study explores the impact of PUT on the release of the vasoactive agents nitric oxide (NO) and prostacyclin (PGI₂) from the endothelial cells in an in vitro blood vessel model. In this study, an in vitro vessel model containing RF/6A chorioretinal endothelial cells was used. The vessels were treated with ultrasound-only (0.5, 1.0, 1.5 and 2.0 MPa peak negative pressure at 0.5 MHz with 10% duty cycle), laser-only (5, 10, 15 and 20 mJ/cm² at 532 nm with a pulse width of 5 ns), and synchronized laser and ultrasound (PUT) treatments. Passive cavitation detection was used to determine the cavitation activities during treatment. The levels of NO and PGI₂ generally increased when the applied ultrasound pressure and laser fluence were low. The increases in NO and PGI₂ levels were significantly reduced by 37.2% and 42.7%, respectively, from 0.5 to 1.5 MPa when only ultrasound was applied. The increase in NO was significantly reduced by 89.5% from 5 to 20 mJ/cm², when only the laser was used. In the PUT group, for 10 mJ/cm² laser fluence, the release of NO decreased by 76.8% from 0.1 to 1 MPa ultrasound pressure. For 0.5 MPa ultrasound pressure in the PUT group, the release of PGI₂ started to decrease by 144% from 15 to 20 mJ/cm² laser fluence. The decreases in NO and PGI₂ levels coincided with the increased cavitation activities in each group. In conclusion, PUT can induce a significant reduction in the release of NO and PGI₂ in comparison with ultrasound-only and laser-only treatments.