Super-Resolution Ultrasound Based Cell Tracking With Polymeric Nanobubbles

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Nanotechnology

Background:

• Tracking transplanted cells in vivo is crucial for cell-based therapy development and monitoring.
• Current methods face challenges in achieving single-cell resolution and precise localization.

Purpose of the Study:

• To develop a novel nanobubble (NB)-based acoustic labeling strategy for ultrasound localization microscopy (ULM).
• To enable real-time, super-resolution tracking of transplanted cells within tumors.
• To identify the specific vasculature responsible for cell delivery.

Main Methods:

• Development of stable, biocompatible poly(butyl cyanoacrylate) nanobubbles (NBs) for intracellular uptake.
• Utilizing ultrasound localization microscopy (ULM) for real-time visualization and trajectory reconstruction of NB-labeled cells.
• Integration of cell trajectory data with super-resolution vascular maps.

Main Results:

• Nanobubbles (NBs) were efficiently internalized by cells, generating strong intracellular ultrasound signals.
• ULM successfully visualized and tracked individual NB-labeled bone marrow-derived mononuclear cells in murine breast cancer models.
• NB labeling allowed for the identification of specific blood vessels responsible for cell delivery, while unlabeled cells were undetectable.

Conclusions:

• The NB-based acoustic labeling strategy enables precise, single-cell scale tracking of transplanted cells in vivo.
• This clinically compatible imaging approach expands ULM applications beyond vascular mapping.
• Provides a platform for dynamic, high-resolution monitoring of cell-based therapies.