Drug Delivery by Ultrasound-Responsive Nanocarriers for Cancer Treatment

Abstract

Conventional cancer chemotherapies often exhibit insufficient therapeutic outcomes and dose-limiting toxicity. Therefore, there is a need for novel therapeutics and formulations with higher efficacy, improved safety, and more favorable toxicological profiles. This has promoted the development of nanomedicines, including systems for drug delivery, but also for imaging and diagnostics. Nanoparticles loaded with drugs can be designed to overcome several biological barriers to improving efficiency and reducing toxicity. In addition, stimuli-responsive nanocarriers are able to release their payload on demand at the tumor tissue site, preventing premature drug loss. This review focuses on ultrasound-triggered drug delivery by nanocarriers as a versatile, cost-efficient, non-invasive technique for improving tissue specificity and tissue penetration, and for achieving high drug concentrations at their intended site of action. It highlights aspects relevant for ultrasound-mediated drug delivery, including ultrasound parameters and resulting biological effects. Then, concepts in ultrasound-mediated drug delivery are introduced and a comprehensive overview of several types of nanoparticles used for this purpose is given. This includes an in-depth compilation of the literature on the various in vivo ultrasound-responsive drug delivery systems. Finally, toxicological and safety considerations regarding ultrasound-mediated drug delivery with nanocarriers are discussed.

Advances in Nanoliposomes for the Diagnosis and Treatment of Liver Cancer

“…Comparatively, miRNAs mediate the inhibition of translation and the termination of transcription of incompletely complementary mRNAs. 94 miRNAs may also mediate mRNA degradation in cytoplasmic compartments, known as processing bodies (P-bodies), thus preventing protein synthesis. 95 Primate synthesized siRNAs are unable to cross biological membranes by passive diffusion due to their high molecular weight and polyanionic nature; therefore, they require drug delivery strategies.…”

Stimuli-Responsive Drug Delivery Systems for the Diagnosis and Therapy of Lung Cancer

“…The fundamental mechanisms underlying ultrasound-mediated therapy mainly include thermal effect, mechanical effect, and chemical effect [ 50 ]. The thermal effects are attributed to acoustic energy produced by propagating ultrasound.…”

“…Sonoporation is the process of pore formation in a cell membrane upon exposure to ultrasound and belongs to one of the cavitation effects, which could facilitate the intracellular transport of drugs. Moreover, cavitation can also widen the interspace between endothelial cells and thus enhance the penetration into adjacent tissues [ 50 ]. However, unwanted cavitation effects may take place in the presence of residual air bubbles, and thus the implementation of ultrasound in the treatment of lung cancer would lead to undesired drug release in the process of drug transportation.…”

Exosomes and Other Extracellular Vesicles with High Therapeutic Potential: Their Applications in Oncology, Neurology, and Dermatology

“…EVs, and above all exosomes, are often classified by researchers as Smart Drug-Delivery Systems (SDDS), i.e., small molecules that can carry and release biologically active compounds in a controlled manner [3]. Similarly to other representatives of SDDSs, they use specific properties of pathological target cells, such as increased permeability of their cell membrane or overexpression of some receptors, to operate with high precision [4].…”