A sterically stabilized immunolipoplex for systemic administration of a therapeutic gene

Abstract

A sterically stabilized immunolipoplex (TsPLP), containing an antitransferrin receptor single-chain antibody fragment (TfRscFv)-PEG molecule, has been developed to specifically and efficiently deliver a therapeutic gene to tumor cells. A postcoating preparation strategy was employed in which a DNA/lipid complex (lipoplex) was formed first and then sequentially conjugated with PEG and TfRscFv. The complex prepared by this method was shown to be superior in ability to deliver genes to tumor cells than when prepared by a common precoating strategy, in which DNA is mixed with TfRscFv-PEG conjugated liposome. Using prostate cancer cell line DU145, a comparison was made between the in vitro and in vivo gene delivery efficiencies of four complexes, Lipoplex (LP), PEG-Lipoplex (PLP), TfRscFv-PEG-Lipoplex (TsPLP) and our standard TfRscFv-Lipoplex (TsLP). In vitro, the order of transfection efficiency was TsLP4LPETsPLP4PLP. However, in vivo the order of transfection efficiency, after systemic administration via the tail vein, was TsPLP4TsLP4LP or PLP with TsPLPmediated exogenous gene expression in tumor being twofold higher than when mediated by TsLP. This suggests that the in vitro transfection efficiency of TsPLP was not indicative of its in vivo efficiency. In addition, it was found that the level of exogenous gene expression in the tumor mediated by TsPLP was higher than that mediated by TsLP and did not decrease over the time. More importantly, high exogenous gene expression in tumor, but low expression in liver, was observed after an i.v. delivery of TsPLP carrying either the GFP reporter gene or the p53 gene, indicating that tumor preferential targeting was maintained by this complex in the presence of PEG. These findings show that incorporation of PEG into our targeted lipoplex results in a more efficient delivery of the complex to the tumor cells, possibly by inhibiting the first pass clearance observed with non-PEG containing liposomes. Therefore, these data demonstrate that TsPLP is a improvement over our previously established tumor targeted gene delivery complex for systemic gene therapy of cancer.

Self‐assembled Cationic Peptide Nanoparticles Capable of Inducing Efficient Gene Expression In Vitro

“…The introduction of histidine residues into oligopeptides was reported to promote gene transfection through the enhancement of this ''proton-sponge'' mechanism. [12][13][14] However, for most oligopeptides reported in the literature, the number of cationic charges per molecule is limited. Therefore, the DNA-binding ability of oligopeptides is relatively weak, resulting in larger oligopeptide-DNA complexes and lower-gene-transfection efficiency compared to their cationic polymer counterparts.…”

Transferrin Receptor Targeting Nanomedicine Delivering Wild Type P53 Gene Sensitizes Pancreatic Cancer to Gemcitabine Therapy

“…The observed effect was dose-dependent, suggesting that the demonstrated transfection efficiency is mediated through targeting the Tf receptor. 14,15,27 Tumor localizing ability of the TfRscFv-LipA nanoparticle to hepatic metastatic pancreatic cancer tumors…”

A Class of Cationic Triblock Amphiphilic Oligopeptides as Efficient Gene‐Delivery Vectors

“…[1][2][3][4] Existing oligopeptide designs consist mainly of i) cationic arginine, either as a homopolymer [5] or conjugated to a hydrophobic compound, [1] or ii) cationic lysine, [6] which is either functionalized with endosomolytic agents, for example pHsensitive histidine moieties, [2] melittin peptide, [7] adenovirus, [8,9] and the influenza virus hemagglutinin subunit HA-2, [10] or incorporated with several cysteine residues and one tryptophan residue, [11,12] to improve transfection ability. Here, we design novel short triblock amphiphilic oligopeptides based on pure amino acids, which combine all the above features and can also form micellar particles in an aqueous medium.…”