Sonodynamic therapy: Ultrasound parameters and in vitro experimental configurations

Author(s)

Martins, Yugo Araujo ^[1] ; Pavan, Theo Zeferino ^[2] ; Lopez, Renata Fonseca Vianna ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Pharmaceut Sci Ribeirao Preto, Pharmaceut Sci Dept, FCFRP USP, Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Fac Philosophy Sci & Letters Ribeirao Preto FFCLR, Dept Phys, Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: International Journal of Pharmaceutics; v. 610, DEC 15 2021.
• Web of Science Citations: 0

Abstract

Sonodynamic therapy (SDT) is a new therapeutic modality for noninvasive cancer treatment based on the association of ultrasound and sonosensitizer drugs. Up to date, there is not a consensus on the standardization of the experimental conditions for the in vitro studies to correctly assess cell viability during SDT. Therefore, this review article mainly describes how the main ultrasound parameters and experimental setups of ultrasound application in vitro studies can influence the SDT bioeffects/response. The sonodynamic action is impacted by the combination of frequency, intensity, duty cycle, and ultrasound application time. The variation of experimental setups in cell culture, such as the transducer position, cell-transducer distance, coupling medium thickness, or type of culture, also influences the sonodynamic response. The intensity, duty cycle, and sonication duration increase cytotoxicity and reactive oxygen species production. For similar ultrasound parameters, differences in the experimental configuration impact cell death in vitro. Four main experimental setups are used to assess for SDT in cell culture (i) a planar transducer placed directly in contact with the bottom of the culture microplate; (ii) microplate positioned in the transducer's far-field using a water tank; (iii) sealed cell culture tubes immersed in water away from the transducer; and (iv) transducer dipped directly into the well with cell culture. Because of the significant variations in the experimental setups, sonodynamic response can significantly vary, and the translation of these results for in vivo experimentation is difficult. Therefore, a well-designed and detailed in vitro experimental setup is vital for understanding the interactions among the biological medium, the sonosensitizer, and the ultrasound for the in vitro to in vivo translation in SDT. (AU)

• FAPESP's process: 17/17442-7 - Evaluation of the low-frequency ultrasound potential for the sonodynamic therapy of skin cancer
• Grantee: Yugo Araújo Martins
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 14/22451-7 - Sustained drug delivery systems targeting the epithelial tissue
• Grantee: Renata Fonseca Vianna Lopez
• Support Opportunities: Research Projects - Thematic Grants