title: Enhanced lung gene expression after aerosol delivery of concentrated pDNA/PEI complexes.
abstract: A major limitation of many self-assembling nonviral gene transfer formulations is that they are commonly prepared at relatively low component concentrations. While this typically has little impact on their use in cell culture, it can severely limit the progress of in vivo studies. In order to overcome this, we have developed a simple, scalable, pharmaceutically acceptable concentration method that has allowed us to increase the concentration of a commonly used pDNA/PEI formulation from 0.2 to >8 mg/ml plasmid DNA (pDNA). Crucially, the concentration method was found to have only minimal impact on the electrostatic properties or size of the pDNA/PEI particles. When delivered as an aerosol to the mouse lung, the concentrated pDNA/PEI formulations resulted in a 15-fold increase in lung reporter gene expression, with minimal impact in terms of inflammation or toxicity. Importantly, this performance advantage was replicated after aerosol administration to sheep lungs, with reporter gene expression being similarly approximately 15-fold higher than with the conventional pDNA/PEI formulation, and lung inflammation falling to background levels. These findings demonstrate that concentrated pDNA/PEI formulations offer increased aerosol gene transfer with decreased inflammatory sequelae, and represent a promising advance in the field of nonviral lung gene transfer. It seems likely that similar benefits might be achievable with alternative delivery routes and with other nonviral formulations.
authors.affiliation: Nuffield Department of Clinical Laboratory Sciences, University of Oxford, John Radcliffe Hospital, Oxford, UK.
authors.forename: Lee A
authors.initials: LA
authors.lastname: Davies
authors.forename: Gerry
authors.initials: G
authors.lastname: McLachlan
authors.forename: Stephanie G
authors.initials: SG
authors.lastname: Sumner-Jones
authors.forename: David
authors.initials: D
authors.lastname: Ferguson
authors.forename: Alison
authors.initials: A
authors.lastname: Baker
authors.forename: Peter
authors.initials: P
authors.lastname: Tennant
authors.forename: Catherine
authors.initials: C
authors.lastname: Gordon
authors.forename: Christina
authors.initials: C
authors.lastname: Vrettou
authors.forename: Eilidh
authors.initials: E
authors.lastname: Baker
authors.forename: Jie
authors.initials: J
authors.lastname: Zhu
authors.forename: Eric W F W
authors.initials: EW
authors.lastname: Alton
authors.forename: David D S
authors.initials: DD
authors.lastname: Collie
authors.forename: David J
authors.initials: DJ
authors.lastname: Porteous
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Hyde
authors.forename: Deborah R
authors.initials: DR
authors.lastname: Gill
mesh_terms: D000336:Aerosols; D000818:Animals; D004247:DNA / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D008168:Lung / Q000378:metabolism*; D051379:Mice; D010957:Plasmids / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D011094:Polyethyleneimine / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D012756:Sheep
chemical_list: D000336:Aerosols; D011094:Polyethyleneimine; D004247:DNA