Lipid peptide nanocomplexes for gene delivery and magnetic resonance imaging in the brain.
Gadolinium-labelled nanocomplexes offer prospects for the development of real-time, non-invasive imaging strategies to visualise the location of gene delivery by MRI. In this study, targeted nanoparticle formulations were prepared comprising a cationic liposome (L) containing a Gd-chelated lipid at 10, 15 and 20% by weight of total lipid, a receptor-targeted, DNA-binding peptide (P) and plasmid DNA (D), which electrostatically self-assembled into LPD nanocomplexes. The LPD formulation containing the liposome with 15% Gd-chelated lipid displayed optimal peptide-targeted, transfection efficiency. MRI conspicuity peaked at 4h after incubation of the nanocomplexes with cells, suggesting enhancement by cellular uptake and trafficking. This was supported by time course confocal microscopy analysis of transfections with fluorescently-labelled LPD nanocomplexes. Gd-LPD nanocomplexes delivered to rat brains by convection-enhanced delivery were visible by MRI at 6 h, 24 h and 48 h after administration. Histological brain sections analysed by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) confirmed that the MRI signal was associated with the distribution of Gd(3+) moieties and differentiated MRI signals due to haemorrhage. The transfected brain cells near the injection site appeared to be mostly microglial. This study shows the potential of Gd-LPD nanocomplexes for simultaneous delivery of contrast agents and genes for real-time monitoring of gene therapy in the brain.
Molecular Immunology Unit, UCL Institute of Child Health, London WC1N 1EH, UK.
Michele J
MJ
Writer
Panagiotis G
PG
Kyrtatos
Alison S
AS
Bienemann
John A
JA
Pugh
Andrew S
AS
Lowe
Claudio
C
Villegas-Llerena
Gavin D
GD
Kenny
Edward A
EA
White
Steven S
SS
Gill
Cameron W
CW
McLeod
Mark F
MF
Lythgoe
Stephen L
SL
Hart
D000818:Animals; D001921:Brain / Q000378:metabolism; D045744:Cell Line, Tumor; D003287:Contrast Media / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D004247:DNA / Q000008:administration & dosage* / Q000737:chemistry; D005229:Fatty Acids, Monounsaturated / Q000737:chemistry; D005682:Gadolinium / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D016695:Glycosyltransferases / Q000008:administration & dosage* / Q000737:chemistry; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D010455:Peptides; D010714:Phosphatidylethanolamines / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D014162:Transfection / Q000379:methods
C410262:1,2-dioleoyl-glycero-3-phosphatidyl ethanolamine; D003287:Contrast Media; D005229:Fatty Acids, Monounsaturated; D010455:Peptides; D010714:Phosphatidylethanolamines; D000644:Quaternary Ammonium Compounds; D004247:DNA; D005682:Gadolinium; D016695:Glycosyltransferases; C441626:peptide P; C070046:1,2-dioleoyloxy-3-(trimethylammonium)propane