Acoustic radiation force for vascular cell therapy: in vitro validation

Area of Science:

• Biomedical Engineering
• Regenerative Medicine
• Cardiovascular Research

Background:

• Cell-based therapies offer promise for restoring arterial endothelial layers damaged by atherosclerosis or interventions.
• Mesenchymal stem cells (MSCs) are a viable option for this purpose.
• A novel technique utilizes MSCs coated with cationic lipid microbubbles (MBs) and acoustic radiation force (ARF) for targeted delivery.

Purpose of the Study:

• To characterize ultrasound parameters for optimizing acoustic-based delivery of cell therapy.
• To determine the relationship between ultrasound intensity and MSC-MB complex adhesion and velocity.
• To assess potential thermal effects associated with different ultrasound intensities.

Main Methods:

• In vitro experiments were conducted using a vascular flow phantom.
• MB-tagged MSCs were delivered to the phantom wall using ARF generated by an intravascular ultrasound catheter.
• The translational motion velocity and adhesion of MB-cell complexes were analyzed at varying ultrasound intensities.

Main Results:

• MSC radial velocity and adhesion increased with time-averaged ultrasound intensity up to 1.65 W/cm².
• Higher intensities beyond 1.65 W/cm² did not yield significant improvements in adhesion.
• A temperature increase of 5.5 ± 0.8°C was observed at the optimal intensity, while higher intensities caused greater heating (11.6 ± 1.3°C at 6.60 W/cm²).

Conclusions:

• Acoustic radiation force provides an effective method for delivering MB-tagged MSCs to arterial injury sites.
• Optimizing ultrasound intensity is crucial to maximize cell adhesion while minimizing thermal damage to cells and surrounding tissues.
• The findings support the development of ultrasound-guided cell delivery systems for cardiovascular regenerative medicine.