ABSTRACT
Introduction: Drug delivery pertaining to acoustic cavitation generated from ultrasonic (US) irradiation is advantageous for devising smarter and more advanced therapeutics. The aim is to showcase microbubbles as drug carriers and robust theranostic for non-invasive therapies across diverse biomedical disciplines, highlighting recent technologies in this field for overcoming the blood-brain barrier (BBB) to treat cancers and neurological disorders.
Areas covered: This article reviews work on the optimized tuning of ultrasonic parameters, sonoporation, transdermal and responsive drug delivery, acoustic cavitation in vasculature and oncology, contrast imaging for real-time magnification of cell-microbubble dynamics and biomolecular targeting. Scholarly literature was sought through database search on key terminology, latest topics, reputable experts and established journals over the last five years.
Expert opinion: Cavitation offers immense promise in overcoming current diffusion and convection limitations for treating skull/brain/vascular/tissue injuries and ablating tumors to minimize chronic/acute effects. Since stable cavitation facilitates the restoration of US-opened BBB and the modulation of drug concentration, US equipment with programmable imaging modality and sensitivity are envisaged to create safer miniaturized devices for personalized care. Due to differing biomedical protocols with regard to specific medical conditions, quantitative and qualitative controls are mandatory before translation to real-life clinical applications can be accomplished.
Article highlights
Acoustic cavitation is vital in diagnostic ultrasound (US) for controlling cell membrane permeability to render transient pore formation, in which linear oscillation safely creates localized bubble motion and reversible cell deformation.
Sonoporation is minimally invasive and less systemically toxic than conventional therapies for enhanced cellular uptake, in situ drug, gene and bioactive agents delivery.
With the aid of drug carriers (micelles, liposomes) or polymer/silica-based nanoparticles, cavitations can stabilize against dissolution in the blood and permeate the leaky tumor vasculature for passive accumulation.
Convection-enhanced drug delivery (CED) employing tunable frequencies, intensities, pulse sequences and time-reversal acoustics (TRA) in vivo can selectively ablate brain tumors, permitting adjustable drug distribution and dosage at diseased sites.
Transcranial vibro-acoustography (VA) is effective in assaying mechanical characteristics of breast lesions, brain injuries and tissue calcifications in vivo under US irradiation.
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Declaration of interest
The authors are grateful for the financial support by the Australian Research Council (ARC) for this research (project grants numbers: DP120101680, FT110100711 and DE14010054). The authors gratefully acknowledge the School of Chemical Engineering at the University of Adelaide (UoA) and the Faculty of Health & Life Sciences at Coventry University for their support in this work. The authors hereby declare no conflicts of interest and are solely responsible for the content of this article. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.