Development of therapeutic microbubbles for enhancing ultrasound-mediated gene delivery

Abstract

Ultrasound (US)-mediated gene delivery has emerged as a promising non-viral method for safe and selective gene delivery. When enhanced by the cavitation of microbubbles (MBs), US exposure can induce sonoporation that transiently increases cell membrane permeability for localized delivery of DNA. The present study explores the effect of generalizable MB customizations on MB facilitation of gene transfer compared to Definity®, a clinically available contrast agent. These modifications are 1) increased MB shell acyl chain length (RN18) for elevated stability and 2) addition of positive charge on MB (RC5K) for greater DNA associability. The MB types were compared in their ability to facilitate transfection of luciferase and GFP reporter plasmid DNA in vitro and in vivo under various conditions of US intensity, MB dosage, and pretreatment MB-DNA incubation. The results indicated that both RN18 and RC5K were more efficient than Definity®, and that the cationic RC5K can induce even greater transgene expression by increasing payload capacity with prior DNA incubation without compromising cell viability. These findings could be applied to enhance MB functions in a wide range of therapeutic US/MB gene and drug delivery approach. With further designs, MB customizations have the potential to advance this technology closer to clinical application.

Prolonging pulse duration in ultrasound-mediated gene delivery lowers acoustic pressure threshold for efficient gene transfer to cells and small animals

“…We have previously shown the potential for UMGD as means for a targeted and safer method of gene delivery [1–4,18]. Other methods incorporating delivery systems such as viral vectors or adenoviral vectors are hampered by immunotoxicity or poor genetic payload, respectively [20–23].…”

“…RN18 microbubbles were prepared according to the previously described protocol [18]. The MB shells were comprised of lipids at a 82:10:8 M ratio of 1,2-distearoyl- sn -glycero-3-phosphocholine (DSPC), 1,2-distearoyl- sn -glycero-3-phosphate (DSPA), and N-(Carbonylmethoxypolyethyleneglycol 5000)-1,2-distearoyl- sn -glycero-e-phosphoethanolamine (MPEG-5000-DSPE) purchased from Avanti ® Polar Lipids, Inc. (Alabaster, AL).…”

A novel technology: microfluidic devices for microbubble ultrasound contrast agent generation

“…Microbubbles coated with various materials achieved multiple functions including drug or gene delivery, diseasetargeting, multiple mode imaging, and therapies [4,6,7,15,50,51,56,92,104]. For instance, gold nanoparticles or indocyanine green-encapsulated microbubbles have been used for simultaneous photoacoustic and US imaging [103], and microbubbles coated with doxorubicin-loaded superparamagnetic PLGA-iron oxide have been used in dual-mode US/magnetic resonance (MR) imaging and lymph node metastasis therapy [67].…”

Fluidic Generator Of Microbubbles – Oscillator With Gas Flow Reversal For A Part Of Period

“…They are used in gene manipulation (Sun et al, 2014), biosensors (Kuznetsova and Coakley, 2007), mixing of reactants for chemical reaction or sorting (Wang, 2012). Important progress is also being done in optofluidics, where ordered arrays of microbubbles can create tuneable optical components (Hashimoto et al, 2006;Allouch et al, 2014).…”