Ultrasound cavitation modulates intracellular ROS and gene expression in antibacterial sonodynamic therapy

Area of Science:

• Biomedical Engineering
• Antimicrobial Therapies
• Nanotechnology

Background:

• Antibacterial sonodynamic therapy (aSDT) is a non-invasive method using ultrasound activation for antimicrobial treatment.
• Curcumin (CUR) is explored as a sonosensitizer to enhance aSDT efficacy.
• Understanding the mechanisms of aSDT is crucial for optimizing its application.

Purpose of the Study:

• To investigate the mechanisms of curcumin-enhanced antibacterial sonodynamic therapy (aSDT).
• To evaluate the roles of reactive oxygen species (ROS), microbubble cavitation, and apoptosis in aSDT.
• To analyze the effects of aSDT on Pseudomonas aeruginosa at the genetic and morphological levels.

Main Methods:

• Bacterial viability assays and biomass quantification.
• Flow cytometry for apoptosis detection and intracellular ROS measurement.
• RNA sequencing (RNA-seq), qRT-PCR, and scanning electron microscopy (SEM) for gene expression and morphological analysis.

Main Results:

• aSDT efficacy showed a dose-dependent relationship with cavitation intensity.
• Primary mechanisms include ultrasound-induced mechanical membrane disruption and apoptosis via extracellular ROS.
• aSDT modulated gene expression in P. aeruginosa, disrupted biofilms, and impaired redox homeostasis.

Conclusions:

• Curcumin-enhanced aSDT effectively targets bacteria through mechanical disruption and ROS-induced apoptosis.
• The synergistic effects of ultrasonic cavitation and sonosensitizer are key to aSDT's bactericidal action.
• aSDT offers a promising strategy for combating bacterial infections by disrupting cellular integrity and homeostasis.