Ultrasound-contrast agent mediated naked gene delivery in the peritoneal cavity of adult rat

Abstract

Gene transfer into the peritoneal cavity by nonviral methods may provide an effective therapeutic approach for peritoneal diseases. Herein, we investigated the feasibility and the effectiveness of ultrasound-microbubble-mediated delivery of naked plasmid DNA into the peritoneal cavity in rats. Following the intraperitoneal or the intravenous administration of a mixture of plasmid DNA (100 mg) and ultrasound contrast agent microbubbles, an ultrasound transducer was applied on the abdominal wall. The reporter pTRE plasmid encoding Smad7 was used to evaluate transfection efficiency. Smad7 expression was induced by doxycycline in drinking water. We detected less than 10% apoptotic cells and no inflammatory reaction in peritoneal tissues following the ultrasound-microbubble-mediated transfection. More importantly, the insonation significantly improved the transfection efficiency in peritoneal tissues. The transfection efficiency by intraperitoneal delivery route was higher than the intravenous route. The reporter gene, pTRE-Smad7, was readily detected in the parietal peritoneum, mesentery, greater omentum and adipose tissue. The peak of transgene expression occurred 2 days after transfection and the transgene expression diminished in a time-dependent manner thereafter. Overall, the effectiveness and simplicity of the ultrasound-microbubble-mediated system may provide a promising nonviral means for improving gene delivery for treating peritoneal diseases in vivo.

Ultrasound-assisted non-viral gene transfer to the salivary glands

“…It is important to note that previous reports of UAGT phenomena in vivo fall into two categories: (1) the gene delivery vector and microbubbles are sequestered within an anatomical space, after which ultrasound is applied; 25,26 and (2) Ultrasound-assisted gene transfer to the salivary glands MJ Passineau et al microbubbles are injected systemically to disseminate through the intravascular space, after which ultrasound is directed at the target tissue (usually an organ). 27,28 Our approach is in the former category as the intraductal volume of the salivary gland is encased within the capsule of connective tissue that encompasses the gland, sequestering our gene delivery and microbubbles.…”

Nano-sized carriers in gene therapy for peritoneal fibrosisin vivo

“…Ultrasound-mediated transgene delivery also resulted in effective delivery of transgenes to the peritoneum and therapeutic effects against peritoneal fibrosis in vivo [43]. …”

“…Ultrasound-microbubble-mediated gene transfer has been reported to deliver transgenes to the peritoneum and to have therapeutic effects against peritoneal fibrosis in vivo [43]. Plasmid DNA expressing mothers against decapentaplegic homolog 7 (Smad7) mixed with albumin-stabilized perfluorocarbon gas microbubbles was injected intraperitoneally, and the surface of the abdomen was then exposed to ultrasound from the costal margin to the pubic symphysis, resulting in overexpression of Smad7 in the peritoneum, adipose tissue, mesentery, greater omentum, and spleen, but not in the liver, kidney, pancreas, or intestine in a rat model [43].…”

“…Plasmid DNA expressing mothers against decapentaplegic homolog 7 (Smad7) mixed with albumin-stabilized perfluorocarbon gas microbubbles was injected intraperitoneally, and the surface of the abdomen was then exposed to ultrasound from the costal margin to the pubic symphysis, resulting in overexpression of Smad7 in the peritoneum, adipose tissue, mesentery, greater omentum, and spleen, but not in the liver, kidney, pancreas, or intestine in a rat model [43]. This delivery method was shown to maintain overexpression of Smad7 in the peritoneum for up to 2 weeks and inhibited peritoneal fibrosis in a rat peritoneal fibrosis model [43].…”

“…Plasmid DNA expressing mothers against decapentaplegic homolog 7 (Smad7) mixed with albumin-stabilized perfluorocarbon gas microbubbles was injected intraperitoneally, and the surface of the abdomen was then exposed to ultrasound from the costal margin to the pubic symphysis, resulting in overexpression of Smad7 in the peritoneum, adipose tissue, mesentery, greater omentum, and spleen, but not in the liver, kidney, pancreas, or intestine in a rat model [43]. This delivery method was shown to maintain overexpression of Smad7 in the peritoneum for up to 2 weeks and inhibited peritoneal fibrosis in a rat peritoneal fibrosis model [43]. Ultrasound-microbubble-mediated delivery of plasmid DNA expressing miRNA-29b and miRNA-30a to the peritoneum induced overexpression of the respective miRNAs in the peritoneum and inhibited mesothelial–mesenchymal transition of peritoneal mesothelial cells, resulting in inhibition of peritoneal fibrosis in a mouse peritoneal fibrosis model, by inhibiting TGF-β 1 and Snail signaling pathways, respectively [44,45].…”