State-of-the-art of ultrasound-triggered drug delivery from ultrasound-responsive drug carriers

ABSTRACT

Introduction

Delivering sufficient therapeutics at the target site without off-target effects is a major goal of drug delivery technology innovation. Among the established methods, ultrasound (US) with US-responsible carriers holds great promise and demonstrates on-demand delivery of a variety of functional substances with spatial precision of several millimeters in deep-seated tissues in animal models and humans. These properties have motivated several explorations of US with US responsible-responsible carriers as a modality for neuromodulation and the treatment of various diseases, such as stroke and cancer.

Areas covered

We briefly discuss three specific mechanisms that enhance in vivo drug delivery via US with US-responsible carriers: 1) permeabilizing cellular membrane, 2) increasing the permeability of vessels, and 3) promoting cellular endocytotic uptake. We then reviewed the state-of-the-art materials for US-triggered drug delivery, including conventional US contrast agents, and nanocarrier formulations, such as inorganic nanoparticles and gas vesicles.

Expert opinion

In this article, we summarized recent progress for each of US-responsible drug carrier, focusing on the routes of enhancing delivery and applications. The mechanisms of interaction between US-responsible carriers and US waves, such as cavitation, streaming, hyperthermia, and ROS, as well as how those interactions can improve drug release and cell/tissue uptake.

KEYWORDS:

• Ultrasound
• ultrasound-responsive carrier
• microbubble
• nanoparticle
• droplet
• drug delivery

Article highlights

• The overall treatment efficacy of chemotherapy can be improved by designing a remotely and locally drug delivery strategy.

• Ultrasound is one of non-ionizing energy that can be non-invasively focused in deep living tissues.

• Ultrasound can be utilized as triggers for US-mediated drug release from US-responsive drug carriers.

• US and US-responsive drug carriers lead to a series of physicochemical effects that can promote drug delivery.

• The various advantages of US systems have been proofed their potential for tumor therapy, thrombolysis, tissue engineering, wound healing, and vaccination.

This box summarizes key points contained in the article.

Acknowledgments

This paper was funded by the Ministry of Science and Technology (MOST) of Taiwan, under grants nos. 108-2221-E-007-040-MY3, 108-2221-E-007-041-MY3, 110-2221-E-007-019-MY3, 110-2628-E-A49-015-, 111-2628-E-A49-020-, 111-2321-B-002-014, 110-2636-E-006-014, 111-2636-E-006-025, by National Tsing Hua University (Hsinchu, Taiwan) under grants nos. 111Q2713E1.

Declaration of interest

The authors have declared that no competing interests exist.