title: Microbubble ultrasound improves the efficiency of gene transduction in skeletal muscle in vivo with reduced tissue damage.
abstract: Intramuscular injection of naked plasmid DNA is a safe approach to the systemic delivery of therapeutic gene products, but with limited efficiency. We have investigated the use of microbubble ultrasound to augment naked plasmid DNA delivery by direct injection into mouse skeletal muscle in vivo, in both young (4 weeks) and older (6 months) mice. We observed that the albumin-coated microbubble, Optison (licensed for echocardiography in patients), significantly improves the transfection efficiency even in the absence of ultrasound. The increase in transgene expression is age related as Optison improves transgene expression less efficiently in older mice than in younger mice. More importantly, Optison markedly reduces muscle damage associated with naked plasmid DNA and the presence of cationic polymer PEI 25000. Ultrasound at moderate power (3 W/cm2 1 MHz, 60 s exposure, duty cycle 20%), combined with Optison, increases transfection efficiency in older, but not in young, mice. The safe clinical use of microbubbles and therapeutic ultrasound and, particularly, the protective effect of the microbubbles against tissue damage provide a highly promising approach for gene delivery in muscle in vivo.
authors.affiliation: Muscle Cell Biology, MRC Clinical Sciences Centre, Imperial College, Hammersmith Hospital, London, UK.
authors.forename: Q L
authors.initials: QL
authors.lastname: Lu
authors.forename: H-D
authors.initials: HD
authors.lastname: Liang
authors.forename: T
authors.initials: T
authors.lastname: Partridge
authors.forename: M J K
authors.initials: MJ
authors.lastname: Blomley
mesh_terms: D000375:Aging; D000418:Albumins; D000818:Animals; D003287:Contrast Media; D005466:Fluorocarbons; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods*; D049452:Green Fluorescent Proteins; D007273:Injections, Intramuscular; D008164:Luminescent Proteins / Q000032:analysis / Q000235:genetics; D051379:Mice; D008815:Mice, Inbred Strains; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D014162:Transfection / Q000379:methods*; D014465:Ultrasonics
chemical_list: D000418:Albumins; D003287:Contrast Media; C099458:FS 069; D005466:Fluorocarbons; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins