An Ultrasonically Actuated Needle Promotes the Transport of Nanoparticles and Fluids

TL;DR

This paper introduces an ultrasonically actuated needle that enhances nanoparticle and fluid transport in tissue models, potentially improving targeted drug delivery beyond traditional ultrasound methods.

Contribution

It demonstrates the feasibility of using a 33 kHz ultrasonic needle to increase delivery volume of nanoparticles in tissue-mimicking media through simulation and experimental validation.

Findings

Ultrasonically actuated needle effectively transports nanoparticles in agarose gel.

Simulation shows a threefold increase in delivery volume in liver tissue.

Experimental results closely match simulation predictions.

Abstract

Non-invasive therapeutic ultrasound methods, such as high-intensity focused ultrasound (HIFU), have limited access to tissue targets shadowed by bones or presence of gas. This study demonstrates that an ultrasonically actuated medical needle can be used to translate nanoparticles and fluids under the action of nonlinear phenomena, potentially overcoming some limitations of HIFU. A simulation study was first conducted to study the delivery of a tracer with an ultrasonically actuated needle (33 kHz) inside a porous medium acting as a model for soft tissue. The model was then validated experimentally in different concentrations of agarose gel showing a close match with the experimental results, when diluted soot nanoparticles (diameter < 150 nm) were employed as delivered entity. An additional simulation study demonstrated a threefold increase of the volume covered by the delivered agent in liver under a constant injection rate, when compared to without ultrasound. This method, if developed to its full potential, could serve as a cost effective way to improve safety and efficacy of drug therapies by maximizing the concentration of delivered entities within e.g. a small lesion, while minimizing exposure outside the lesion.