title: Ultrasound-responsive gene-activated matrices for osteogenic gene therapy using matrix-assisted sonoporation.
abstract: Gene-activated matrix (GAM)-based therapeutics for tissue regeneration are limited by efficacy, the lack of spatiotemporal control and availability of target cells, all of which impact negatively on their translation to the clinic. Here, an advanced ultrasound-responsive GAM is described containing target cells that facilitates matrix-assisted sonoporation (MAS) to induce osteogenic differentiation. Ultrasound-responsive GAMs consisting of fibrin/collagen hybrid-matrices containing microbubbles, bone morphogenetic protein BMP2/7 coexpression plasmids together with C2C12 cells were treated with ultrasound either in vitro or following parenteral intramuscular implantation in vivo. Using direct measurement for alkaline phosphatase activity, von Kossa staining and immunohistochemical analysis for osteocalcin expression, MAS-stimulated osteogenic differentiation was confirmed in the GAMs in vitro 7 days after treatment with ultrasound. At day 30 post-treatment with ultrasound, ectopic osteogenic differentiation was confirmed in vivo using X-ray microcomputed tomography and histological analysis. Osteogenic differentiation was indicated by the presence of ectopic bone structures in all animals treated with MAS. In addition, bone volumes in this group were statistically greater than those in the control groups. This novel approach of incorporating a MAS capability into GAMs could be exploited to facilitate ex vivo gene transfer with subsequent surgical implantation or alternatively provide a minimally invasive means of stimulating in situ transgene delivery for osteoinductive gene-based therapies. Copyright © 2017 John Wiley & Sons, Ltd.
authors.affiliation: Research Department of General Surgery, Division of Surgery and Interventional Science, Faculty of Medical Sciences, University College London, London, UK.
authors.forename: N
authors.initials: N
authors.lastname: Nomikou
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Centre, Austrian Cluster for Tissue Regeneration, European Institute of Excellence on Tissue Engineering and Regenerative Medicine Research (Expertissues EEIG) Vienna Branch, Vienna, Austria.|Department of Oral Biology, School of Dentistry, University of Leeds, Leeds, UK.
authors.forename: G A
authors.initials: GA
authors.lastname: Feichtinger
authors.affiliation: Department of Oral Biology, School of Dentistry, University of Leeds, Leeds, UK.
authors.forename: S
authors.initials: S
authors.lastname: Saha
authors.affiliation: Medical University of Vienna, Department of Traumatology, Vienna, Austria.|Bernhard Gottlieb University Clinic of Dentistry, Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Nuernberger
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Centre, Austrian Cluster for Tissue Regeneration, European Institute of Excellence on Tissue Engineering and Regenerative Medicine Research (Expertissues EEIG) Vienna Branch, Vienna, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Heimel
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Centre, Austrian Cluster for Tissue Regeneration, European Institute of Excellence on Tissue Engineering and Regenerative Medicine Research (Expertissues EEIG) Vienna Branch, Vienna, Austria.
authors.forename: H
authors.initials: H
authors.lastname: Redl
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, University of Ulster, Coleraine, UK.
authors.forename: A P
authors.identifier: 0000-0003-2397-648X
authors.initials: AP
authors.lastname: McHale
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D002470:Cell Survival; D018274:Electroporation / Q000379:methods*; D005109:Extracellular Matrix / Q000378:metabolism*; D005786:Gene Expression Regulation; D015316:Genetic Therapy; D051379:Mice; D010012:Osteogenesis / Q000235:genetics*; D013010:Sonication; D014465:Ultrasonics; D055114:X-Ray Microtomography
keywords: gene; matrix; osteogenesis; regeneration; sonoporation; ultrasound