The current contrast agents used for urinary ultrasound imaging have issues such as short imaging duration and high costs. The aim of this study is to develop biosynthetic nanoscale ultrasound contrast agents and to verify their biosafety in mice. This study investigates the imaging efficacy of polyethylene glycol-modified biosynthetic nanobubbles (PEG-BNBs) in different animal models of vesicoureteral reflux (VUR).

The current contrast agents used for urinary ultrasound imaging have issues such as short imaging duration and high costs. The aim of this study is to develop biosynthetic nanoscale ultrasound contrast agents and to verify their biosafety in mice. This study investigates the imaging efficacy of polyethylene glycol-modified biosynthetic nanobubbles (PEG-BNBs) in different animal models of vesicoureteral reflux (VUR).

Nanoscale biosynthetic nanobubbles were successfully screened and PEG-modified, with the size of BNBs and PEG-BNBs ranging between 100nm and 400nm. There was no significant difference in weight change and biochemical indices between the experimental and control groups of mice(p>0.05). No mental or behavioral abnormalities were observed in the experimental group, and no pathological damage was found in tissue sections. PEG-BNBs demonstrated good imaging effects on mice with congenital VUR. Rat VUR models were successfully established, with PEG-BNBs showing good imaging effects on it. PEG-BNBs showed better imaging effects on renal reflux within the first 5 and 10 minutes after bladder perfusion of the contrast agent.

In this study, nanoscale biosynthetic nanobubbles were successfully screened and PEG - modified. PEG - BNBs exhibited biosafety in mice as there were no significant differences in weight, biochemical indices, behavior, or tissue damage. They demonstrated good imaging efficacy in different animal models of vesicoureteral reflux, with better imaging stability and longer imaging duration compared to SonoVue. PEG - BNBs are potentially effective and cost - efficient contrast agents for urinary ultrasound imaging.

This is the first study on the application of nanoscale contrast agents in urinary tract ultrasonography, indicating that PEG-BNBs are simple to extract, cost-effective, and biologically safe. PEG-BNBs demonstrated good imaging effects in rat bladders and across different animal VUR models. Compared with SonoVue, PEG-BNBs showed better imaging stability and a longer duration of imaging for VUR, facilitating the identification of subtle VUR. PEG-BNBs are potentially viable contrast agents for CeVUS, contributing to the widespread application of these techniques, improving patient comfort during examinations, and reducing the risk of radiation exposure.