title: Tumor-specific gene transfer with receptor-mediated nanocomplexes modified by polyethylene glycol shielding and endosomally cleavable lipid and peptide linkers.
abstract: Synthetic nanoparticle formulations have the potential for tumor-targeted gene delivery. Receptor-targeted nanocomplex (RTN) formulations comprise mixtures of cationic liposomes and targeting peptides that self-assemble on mixing with nucleic acids. RTN formulations were prepared containing different polyethylene glycol (PEG)ylated lipids with esterase-cleavable linkers (e.g., ME42) to promote intracellular PEG detachment and nanoparticle disassembly. In addition, integrin-targeting peptides (peptide ME27) were tested with endosomal furin- and cathepsin B-cleavable peptide linkers located between the integrin-binding ligand and the K(16) nucleic acid-binding domain to promote intracellular disengagement from the receptor. ME42/ME27 RTNs formed stable particles of <200 nm in isotonic salt buffers, compared with 4-microm particles formed by un-PEGylated RTNs. Transfection efficiency by PEG-modified, cleavable RTNs improved approximately 2-fold in 4 different cell lines, with 80% efficiency in murine neuroblastoma cells. In an in vivo model of neuroblastoma, ME42/ME27 RTNs delivering luciferase genes were tumor specific, with little expression in other organs tested. PEGylation of the RTNs enhanced luciferase transfection 5-fold over non-PEG formulations, whereas the cleavability of the peptide ME27 enhanced transfection 4-fold over that of RTNs with noncleavable peptides. Cleavability of the lipid for in vivo transfections had no effect. PEGylated, cleavable RTN formulations offer prospects for tumor-specific therapeutic gene transfer.
authors.affiliation: Molecular Immunology Unit, Institute of Child Health, University College London, London, UK.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Grosse
authors.forename: Aristides D
authors.initials: AD
authors.lastname: Tagalakis
authors.forename: M Firouz Mohd
authors.initials: MF
authors.lastname: Mustapa
authors.forename: Martin
authors.initials: M
authors.lastname: Elbs
authors.forename: Qing-Hai
authors.initials: QH
authors.lastname: Meng
authors.forename: Atefeh
authors.initials: A
authors.lastname: Mohammadi
authors.forename: Alethea B
authors.initials: AB
authors.lastname: Tabor
authors.forename: Helen C
authors.initials: HC
authors.lastname: Hailes
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Hart
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D016503:Drug Delivery Systems / Q000379:methods; D011992:Endosomes / Q000378:metabolism; D018014:Gene Transfer Techniques; D006868:Hydrolysis; D008055:Lipids; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry* / Q000627:therapeutic use; D009447:Neuroblastoma / Q000473:pathology; D010455:Peptides; D011092:Polyethylene Glycols; D011355:Prodrugs; D013552:Swine
chemical_list: D000970:Antineoplastic Agents; D008055:Lipids; D010455:Peptides; D011355:Prodrugs; D011092:Polyethylene Glycols