title: Role of liposome and peptide in the synergistic enhancement of transfection with a lipopolyplex vector.
abstract: Lipopolyplexes are of widespread interest for gene therapy due to their multifunctionality and high transfection efficiencies. Here we compared the biological and biophysical properties of a lipopolyplex formulation with its lipoplex and polyplex equivalents to assess the role of the lipid and peptide components in the formation and function of the lipopolyplex formulation. We show that peptide efficiently packaged plasmid DNA forming spherical, highly cationic nanocomplexes that are taken up efficiently by cells. However, transgene expression was poor, most likely due to endosomal degradation since the polyplex lacks membrane trafficking properties. In addition the strong peptide-DNA interaction may prevent plasmid release from the complex and so limit plasmid DNA availability. Lipid/DNA lipoplexes, on the other hand, produced aggregated masses that showed poorer cellular uptake than the polyplex but contrastingly greater levels of transgene expression. This may be due to the greater ability of lipoplexes relative to polyplexes to promote endosomal escape. Lipopolyplex formulations formed spherical, cationic nanocomplexes with efficient cellular uptake and significantly enhanced transfection efficiency. The lipopolyplexes combined the optimal features of lipoplexes and polyplexes showing optimal cell uptake, endosomal escape and availability of plasmid for transcription, thus explaining the synergistic increase in transfection efficiency.
authors: UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, United Kingdom.
authors: Mustafa M
authors: MM
authors: Munye
authors: National Physical Laboratory, Teddington, Middlesex, TW11 0LW, United Kingdom.
authors: Jascindra
authors: J
authors: Ravi
authors: UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, United Kingdom.
authors: Aristides D
authors: AD
authors: Tagalakis
authors: UCL School of Pharmacy, 29-39 Brunswick Square, London, WC1N 1AX, United Kingdom.
authors: David
authors: D
authors: McCarthy
authors: National Physical Laboratory, Teddington, Middlesex, TW11 0LW, United Kingdom.
authors: Maxim G
authors: MG
authors: Ryadnov
authors: UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, United Kingdom.
authors: Stephen L
authors: SL
authors: Hart
mesh_terms: D002460:Cell Line; D004247:DNA / Q000737:chemistry; D015870:Gene Expression; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D006801:Humans; D008081:Liposomes / Q000737:chemistry; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry / Q000648:ultrastructure; D010455:Peptides / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D014162:Transfection / Q000379:methods*
chemical_list: D008081:Liposomes; D010455:Peptides; D011108:Polymers; D004247:DNA