title: Minimally invasive closed-chest ultrasound-guided substance delivery into the pericardial space in mice.
abstract: Organ-directed gene transfer remains an attractive method for both gaining a better understanding of heart disease and for cardiac therapy. However, virally mediated transfer of gene products into cardiac cells requires prolonged exposure of the myocardium to the viral substrate. Pericardial injection of viral vectors has been proposed and used with some success to achieve myocardial transfection and may be a suitable approach for transfection of atrial myocardium. Indeed, such an organ-specific method would be particularly useful to reverse phenotypes in young and adult genetically altered murine models of cardiac disease. We therefore sought to develop a minimally invasive technique for pericardial injection of substances in mice. Pericardial access in anaesthetised, spontaneously breathing mice was achieved using continuous high-resolution ultrasound guidance. We could demonstrate adequate delivery of injected substances into the murine pericardium. Atrial epicardial and myocardial cells were transfected in approximately one third of mice injected with enhanced green fluorescent protein-expressing adenovirus. Cellular expression rates within individual murine atria were limited to a maximum of 20 %; therefore, expression efficiency needs to be further improved. Minimally invasive, ultrasound-guided injection of viral material appears a technically challenging yet feasible method for selective transfection of atrial epi- and myocardium. This pericardial injection method may be useful in the evaluation of potential genetic interventions aimed at rescuing atrial phenotypes in transgenic mouse models.
authors.affiliation: Department of Cardiology and Angiology, University Hospital Münster, Münster, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Laakmann
authors.forename: L
authors.initials: L
authors.lastname: Fortmüller
authors.forename: I
authors.initials: I
authors.lastname: Piccini
authors.forename: S
authors.initials: S
authors.lastname: Grote-Wessels
authors.forename: W
authors.initials: W
authors.lastname: Schmitz
authors.forename: G
authors.initials: G
authors.lastname: Breves
authors.forename: P
authors.initials: P
authors.lastname: Kirchhof
authors.forename: L
authors.initials: L
authors.lastname: Fabritz
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D004452:Echocardiography / Q000295:instrumentation / Q000379:methods*; D018014:Gene Transfer Techniques / Q000295:instrumentation; D005822:Genetic Vectors / Q000008:administration & dosage*; D049452:Green Fluorescent Proteins / Q000235:genetics; D057809:HEK293 Cells; D006334:Heart Function Tests; D006801:Humans; D007267:Injections; D051379:Mice; D008822:Mice, Transgenic; D010496:Pericardium / Q000000981:diagnostic imaging* / Q000378:metabolism; D010957:Plasmids; D014162:Transfection / Q000379:methods
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins