Construction of a star-shaped copolymer as a vector for FGF receptor-mediated gene delivery in vitro and in vivo.
ABSTRACT The success of cancer gene therapy highly relies on the gene delivery vector with high transfection activity and low toxicity. In the present study, eight-armed polyethylene glycol (EAP) and low molecular weight (LMW) polyethylenimine (PEI) were used as basic units to construct the architecture of a new star-shaped EAP-PEI copolymer (EAPP). MC11, a peptide capable of selectively binding fibroblast growth factor receptor (FGFR) on tumor cell membranes, was further conjugated to EAPP to produce the vector EAPP-MC11 (EAPPM) to enhance tumor targetability. This tumor-targeting vector EAPPM was observed to retard the plasmids mobility at a nitrogen/phosphorus (N/P) ratio of 3. The vector could efficiently condense plasmids within 300 nm nanoparticles with a positive zeta potential at the N/P ratio of 20 or above. While the cytotoxicity of EAPPM polyplexes was similar to that of LMW PEI, it was significantly lower than that of PEI (25 kDa) in HepG2 and PC3 cell lines. In vitro gene transfection with pDNA mediated by EAPPM showed that the transfection efficiency increased 15 times in HepG2 cells but remained at a similar level in PC3 cells in comparison with that of EAPP. By systemic injection of EAPPM/pDNA complexes into a HepG2-bearing mice model, luciferase expression detected in lung, liver, and tumor tissues demonstrated EAPPM could deliver in a targeted manner a reporter gene into tumor tissues, where the luciferase expression of EAPPM was 4 times higher than that of EAPP and even 23 times higher than that of PEI (25 kDa). Furthermore, it was found that the systemic delivery of EAPPM/pCSK-α-interferon complexes in vivo were much more effective in inhibiting tumor growth than EAPP or PEI (25 kDa). These results clearly show that EAPPM is an efficient and safe vector for FGFR-mediated targeted gene delivery both in vitro and in vivo. With low cytotoxicity and high targetability, EAPPM may have great potential as a delivery vector for future cancer gene therapy applications.
- SourceAvailable from: Nikolay Berezhnoy[show abstract] [hide abstract]
ABSTRACT: The combination of cationic lipids with cationic peptides and DNA vectors can produce synergistic effects in gene delivery to eukaryotic cells. Binary complexes of cationic lipids with DNA are well-studied whereas little information is available about the structure of the ternary lipid/peptide/DNA (LPD) complexes and mechanisms defining DNA protection and delivery. Here we use synchrotron small angle X-ray scattering and dynamic light scattering zeta-potential measurements to determine structure and the net charge of supramolecular aggregates of complexes in mixtures of plasmid DNA, cationic liposomes formed from DOTAP, plus a linear cationic ε-oligolysine with the pendant α-amino acids Leu-Tyr-Arg (LYR), ε-(LYR)K10. These ternary complexes display multilamellar structures with relatively constant separation between DOTAP bilayers, accommodating a hydrated monolayer of parallel DNA rods. The DNA-DNA distance in the complexes varies as a function of the net positive to negative (lipid+peptide)/DNA charge ratio. An explanation for the observed dependence of DNA-DNA distance on charge ratio was proposed based on general polyelectrolyte properties of non-stoichiometric polycation-DNA mixtures.Biochimica et Biophysica Acta 04/2012; 1818(7):1794-1800. · 4.66 Impact Factor
- Journal of The American College of Cardiology - J AMER COLL CARDIOL. 01/2011; 57(14).
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ABSTRACT: To present our experience of the clinical management of spontaneous isolated dissection of superior mesenteric artery (SIDSMA) and analyse the clinical features, imaging findings, and treatment outcomes. In this retrospective study, eight consecutive patients with symptomatic SIDSMA were treated in Chang Gung Memorial Hospital between April 2007 and April 2010; among these patients, six underwent endovascular stent placement. The clinical manifestations, imaging findings, endovascular stent placement outcome, and follow-up results of the patients were retrospectively analysed. Eight patients were diagnosed with SIDSMA by contrast-enhanced computer tomography. One patient died due to comorbidity before angiography. Six patients underwent percutaneous endovascular stent placement in the superior mesenteric artery (SMA): four patients with bare stents and two with stent grafts. Because it was not appropriate to perform stent implantation in the remaining patient, he received only conservative treatment. All seven patients had an uneventful recovery and the follow-up period was 16 month, ranging from 1 to 35 months. For patients with symptomatic SIDSMA, endovascular repair is a feasible treatment choice with a high success rate and good clinical outcome.Clinical radiology 11/2011; 67(1):32-7. · 1.65 Impact Factor