Author(s): Memari E; Singh D; Alkins R; Helfield B;

Cellular immunotherapy remains hindered in the context of solid tumors due to the immunosuppressive microenvironment, in which key endothelial cell adhesion molecules (CAM) are suppressed. Microbubble-mediated focused ultrasound is being explored for targeted immunotherapy and can exert local shear stress upon neighboring endothelial cells. However, fluid ...

Article GUID: 40657183

Author(s): Gharamaleki SK; Helfield B; Rivaz H;

Super-resolution imaging has emerged as a rapidly advancing field in diagnostic ultrasound. Ultrasound Localization Microscopy (ULM) achieves sub-wavelength precision in microvasculature imaging by tracking gas microbubbles (MBs) flowing through blood vessels. However, MB localization faces challenges due to dynamic point spread functions (PSFs) caused by ...

Article GUID: 40640235

Author(s): Zajac Z; Helfield B; Williams R; Sheeran P; Tremblay-Darveau C; Yoo K; Burns PN;

Objectives: The development of low boiling point liquid droplets as phase-change contrast agents allows for the local creation of microbubbles at a point of interest in vivo. Although there are many possible applications, few investigations have used selectively created microbubble boluses to measure volumetric flowrate. In this study, the flow ratio betw ...

Article GUID: 40387284

Author(s): He S; Singh D; Helfield B;

Gene therapy targeting ischemic heart disease is a promising therapeutic avenue, but it is mostly restricted to viral-based delivery approaches which are limited due to off-target immunological responses. Focused ultrasound presents a non-viral, image-guided technique in which circulating intravascular microbubble contrast agents can reversibly enhance va ...

Article GUID: 39850318

Author(s): Hazel K; Singh D; He S; Guertin Z; Husser MC; Helfield B;

CRISPR-Cas9 ribonucleoproteins (RNPs) have been heavily considered for gene therapy due to their high on-target efficiency, rapid activity and lack of insertional mutagenesis relative to other CRISPR-Cas9 delivery formats. Genetic diseases such as hypertrophic cardiomyopathy currently lack effective treatment strategies and are prime targets for CRISPR-Ca ...

Article GUID: 39797397

Author(s): Yusefi H; Helfield B;

Clinical ultrasound contrast agent microbubbles remain intravascular and are between 1-8 µm in diameter, with a volume-weighted mean size of 2-3 µm. Despite their worldwide clinical utility as a diagnostic contrast agent, and their continued and ongoing success as a local therapeutic vector, the fundamental interplay between microbubbles - including bubbl ...

Article GUID: 39705920

Author(s): Baez A; Singh D; He S; Hajiaghayi M; Gholizadeh F; Darlington PJ; Helfield B;

While met with initial and ground-breaking success targeting blood borne cancers, cellular immunotherapy remains significantly hindered in the context of solid tumors by the tumor microenvironment. Focused ultrasound, in conjunction with microbubbles, has found tremendous potential as a targeted and local drug/gene delivery technique for cancer therapy. T ...

Article GUID: 39502696

Author(s): Memari E; Helfield B;

The recent and exciting success of anti-inflammatory therapies for ischemic heart disease (e.g. atherosclerosis) is hindered by the lack of site-specific and targeted therapeutic deposition. Microbubble-mediated focused ultrasound, which uses circulating, lipid-encapsulated intravascular microbubbles to locally enhance endothelial permeability, offers an ...

Article GUID: 38988819

Author(s): Singh D; Memari E; He S; Yusefi H; Helfield B;

Over the past two decades, there has been tremendous and exciting progress toward extending the use of medical ultrasound beyond a traditional imaging tool. Ultrasound contrast agents, typically used for improved visualization of blood flow, have been explored as novel non-viral gene delivery vectors for cardiovascular therapy. Given this adaptation to ul ...

Article GUID: 38983873

Author(s): Memari E; Khan D; Alkins R; Helfield B;

Focused ultrasound (FUS) combined with intravascularly circulating microbubbles can transiently increase the permeability of the blood-brain barrier (BBB) to enable targeted therapeutic delivery to the brain, the clinical testing of which is currently underway in both adult and pediatric patients. Aside from traditional cancer drugs, this technique is bei ...

Article GUID: 38266715

Author(s): Yusefi H; Helfield B;

Phospholipid encapsulated ultrasound contrast agents have proven to be a powerful addition in diagnostic imaging and show emerging applications in targeted therapy due to their resonant and nonlinear scattering. Microbubble response is affected by their intrinsic (e.g. bubble size, encapsulation physics) and extrinsic (e.g. boundaries) factors. One of the ...

Article GUID: 38217906