Free gas micro-/nano-bubble water: a novel dispersion system to prepare ultrasound imaging vehicles.

Objectives: Free gas micro-/nano-bubbles (MNBs) in water have demonstrated significant potential in various industrial applications, including water treatment, enhanced transport processes, and disinfection. However, the feasibility of utilizing MNBs water as a dispersed system for preparing ultrasound imaging vehicles is seldom explored. This study aims to investigate the potential of MNBs water for this purpose.

Methods: Initially, MNBs water containing sulfur hexafluoride (SF₆) was prepared and characterized. Subsequently, the potential of SF₆ MNBs water to form lipid-shelled bubbles for ultrasound imaging was evaluated. This involved the incubation of lyophilized phospholipids with SF₆ MNBs water.

Results: The study confirmed the presence of SF₆ MNBs in water. Through the incubation process, it was possible to obtain lipid-shelled bubbles with a nano-sized and narrow size distribution. These bubbles exhibited comparable echogenicity to those produced by conventional mechanical agitation methods during the initial 5 min of in vitro observation.

Conclusions: SF₆ MNBs water represents a novel dispersion medium for generating nano-sized lipid-shelled bubbles. This approach offers a promising new method for extravascular ultrasound imaging and drug delivery, potentially expanding the applications of MNBs in medical imaging and therapeutic delivery systems.