[Toxicity of cationic liposome Lipofectamine 2000 in human pancreatic cancer Capan-2 cells].
ABSTRACT To investigate the toxicity of cationic liposome Lipofectamine 2000 (Lipo) in human pancreatic cancer Capan-2 cells.
Capan-2 cells were cultured in the presence of Lipo at toxic concentrations, and the cell growth, apoptosis and cell cycle changes were evaluated by cell counting and flow cytometry.
The concentrations of both Lipo and siRNA affected the transfection efficiency. In a transfection volume of 2 ml, the presence of 5 microl Lipo resulted in slowed growth of Capan-2 cells, which was especially obvious after 3 days (P<0.001). Prolonged culture of the transfected cells caused significant increases in early apoptotic cells (P<0.05) and in the damaged or necrotic cells (P<0.001), and resulted in reduced viable cells (P<0.01); these changes became obvious after a 48-hour culture, which also increased the ratio of G(0)/G(1) phase cells (P<0.05) and decreased those of G(2)/M phase cells (P<0.01), S phase cells (P<0.01), and the late apoptotic cells (P<0.05).
Toxic concentrations of Lipo can affect the growth, apoptosis and cell cycles of Capan-2 cells in vitro, and this urges careful concentration selection when using Lipo for gene transfer into different cells.
SourceAvailable from: David L Selwood[Show abstract] [Hide abstract]
ABSTRACT: In order to deliver siRNA for therapeutic use several hurdles must be addressed. Metabolic degradation must be blocked, the RNAi cellular machinery is located in the cytoplasm, while double stranded siRNA is large, highly charged and impermeable to cell membranes. To date the solutions to the delivery issues have mostly involved different forms of lipid particle encapsulation. Cell penetrating peptides (CPPs) and their mimics or analogues offer a different approach and this is an emerging field with the first in vivo examples now reported. Recent reports point to lipid receptors being involved in the cellular uptake of both types of transporter. This review examines the delivery of siRNA with a focus on CPPs and their small molecule and oligomeric mimics. The current status of siRNA delivery methods in clinical trials is examined. It now seems that the goal of delivering siRNA therapeutically is achievable but will they form part of a sustainable healthcare portfolio for the future. © 2012 John Wiley & Sons A/S.Chemical Biology & Drug Design 09/2012; DOI:10.1111/cbdd.12052 · 2.51 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Structural modifications of the siRNA backbone improved its physiochemical properties for incorporating in gene carriers without loss of gene-silencing efficacy. These modifications provide a wider variety of choice of vector systems for siRNA delivery. We developed a tumor-targeted siRNA delivery system using polymerized siRNA (poly-siRNA) and natural polymer gelatin. The polymerized siRNA (poly-siRNA) was prepared through self-polymerization of thiol groups at the 5'-end of sense and anti-sense strands of siRNA and was encapsulated in the self-assembled thiolated gelatin (tGel) nanoparticles (NPs) with chemical cross-linking. The resulting poly-siRNA-tGel (psi-tGel) nanoparticles (average of 145nm in diameter) protect siRNA molecules from enzymatic degradation, and can be reversibly reduced to release functional siRNA molecules in reductive conditions. The psi-tGel NPs presented efficient siRNA delivery in red fluorescence protein expressing melanoma cells (RFP/B16F10) to down-regulate target gene expression. In addition, the NPs showed low toxicity at a high transfection dose of 125μg/mLpsi-tGel NPs, which included 1μM of siRNA molecules. In tumor-bearing mice, the psi-tGel NPs showed 2.8 times higher tumor accumulation than the naked poly-siRNA, suggesting tumor-targeted siRNA delivery of psi-tGel NPs. Importantly, the psi-tGel NPs induced effective tumor RFP gene silencing in vivo without remarkable toxicity. The psi-tGel NPs have great potential for a systemic siRNA delivery system for cancer therapy, based on their characteristics of low toxicity, tumor accumulation, and effective siRNA delivery.Journal of Controlled Release 09/2013; DOI:10.1016/j.jconrel.2013.09.002 · 7.63 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Gold nanoparticles (AuNP) were conjugated with cysteine terminated KDEL (Lys-Asp-Glu-Leu) peptide and siRNA directed against NADPH Oxidase 4 (Nox4). Fluorescence microscopy analysis provided evidence of cytocellular retrograde transport pathways and sub-cellular colocalization of AuNP nanoconstructs in both undifferentiated C2C12 myoblasts and differentiated C2C12 myotubes. The cellular trafficking of AuNP nanoconstructs in undifferentiated myoblasts suggests stable and efficient transfection of siRNA as demonstrated by colocalization of AuNP-delivered KDEL and siRNA. The cellular uptake of AuNP nanoconstructs was more efficient than Lipofectamine mediated transfection in differentiated myotubes (P<0.05) compared to undifferentiated myoblasts, suggesting that AuNP nanoconstructs provide an efficient platform for siRNA delivery to differentiated myotubes. The localization of these nanoconstructs in undifferentiated myoblasts suggests that most of the siRNA was localized in the endoplasmic reticulum (ER) with a minimal distribution in the Golgi bodies suggesting that the ER is a primary localization site for AuNP-KDEL mediated delivery of nanoconstructs.Nanomedicine: nanotechnology, biology, and medicine 08/2013; DOI:10.1016/j.nano.2013.07.015 · 6.93 Impact Factor