dioleoyl-phosphatidylethanolamine and Neuroblastoma

Application of superparamagnetic iron oxide nanoparticles (SPIOs) as the contrast agent has improved the quality of magnetic resonance (MR) imaging. Low efficiency of loading the commercially available iron oxide nanoparticles into cells and the cytotoxicity of previously formulated complexes limit their usage as the image probe. Here, we formulated new cationic lipid nanoparticles containing SPIOs feasible for in vivo imaging.. Hydrophobic SPIOs were incorporated into cationic lipid 1,2-dioleoyl-3-(trimethylammonium) propane (DOTAP) and polyethylene-glycol-2000-1,2-distearyl-3-sn-phosphatidylethanolamine (PEG-DSPE) based micelles by self-assembly procedure to form lipid-coated SPIOs (L-SPIOs). Trace amount of Rhodamine-dioleoyl-phosphatidylethanolamine (Rhodamine-DOPE) was added as a fluorescent indicator. Particle size and zeta potential of L-SPIOs were determined by Dynamic Light Scattering (DLS) and Laser Doppler Velocimetry (LDV), respectively. HeLa, PC-3 and Neuro-2a cells were tested for loading efficiency and cytotoxicity of L-SPIOs using fluorescent microscopy, Prussian blue staining and flow cytometry. L-SPIO-loaded CT-26 cells were tested for in vivo MR imaging.. The novel formulation generates L-SPIOs particle with the average size of 46 nm. We showed efficient cellular uptake of these L-SPIOs with cationic surface charge into HeLa, PC-3 and Neuro-2a cells. The L-SPIO-loaded cells exhibited similar growth potential as compared to unloaded cells, and could be sorted by a magnet stand over ten-day duration. Furthermore, when SPIO-loaded CT-26 tumor cells were injected into Balb/c mice, the growth status of these tumor cells could be monitored using optical and MR images.. We have developed a novel cationic lipid-based nanoparticle of SPIOs with high loading efficiency, low cytotoxicity and long-term imaging signals. The results suggested these newly formulated non-toxic lipid-coated magnetic nanoparticles as a versatile image probe for cell tracking.

Topics: Adenocarcinoma; Animals; Cations; Cell Differentiation; Cell Line, Tumor; Colorectal Neoplasms; Contrast Media; Fatty Acids, Monounsaturated; Feasibility Studies; Ferric Compounds; HeLa Cells; Humans; Hydrophobic and Hydrophilic Interactions; Magnetic Resonance Imaging; Male; Metal Nanoparticles; Mice; Mice, Inbred BALB C; Micelles; Neuroblastoma; Particle Size; Phosphatidylethanolamines; Polyethylene Glycols; Prostatic Neoplasms; Quaternary Ammonium Compounds; Rhodamines

Neurodegenerative diseases as a class do not have effective pharmacotherapies. This is due in part to a poor understanding of the pathologies of the disease processes, and the lack of effective medications. Gene delivery is an attractive possibility for treating these diseases. For the paradigm to be effective, efficient, safe and versatile vectors are required. In this study we evaluated three plasmid delivery systems for transgene expression in the rat hippocampus. Two of these systems were designed to have enhanced intracellular biodegradability. It was hypothesized that this system would be less toxic and could increase the free (non-vector) associated plasmids within the cell, leading to increased transgene activity. Polyethylenimine (PEI) and r-AAV-2 (recombinant adeno associated virus-2) were used as positive, non-viral and viral controls respectively, in the in vivo experiments. The results from the studies indicate there is a distinct difference between the various vectors in terms of total cells transfected, type of cell transfected, and toxicity. Non-viral systems were effective at transfecting both neurons and glia cells within the hippocampus, while the r-AAV-2 transfected mainly neurons. In summary, plasmid-mediated systems are effective for transgene expression within the brain and deserve further study.

Topics: Animals; Biodegradation, Environmental; Cations; Cholesterol; Dependovirus; Drug Delivery Systems; Drug Evaluation, Preclinical; Gene Transfer Techniques; Genetic Therapy; Hippocampus; Humans; Male; Microscopy, Confocal; Neuroblastoma; Neurodegenerative Diseases; Phosphatidylethanolamines; Plasmids; Polyethyleneimine; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; Transduction, Genetic; Transfection; Tumor Cells, Cultured

We report a new class of amphiphilic gemini surfactants as vehicles for gene delivery into cells, and the beginnings of a systematic structure-activity study. Preliminary results suggest that combining gemini surfactants with dioleoylphosphatidylethanolamine (DOPE) should allow the preparation of liposomes of various sizes and lipid compositions. Control of such colloidal changes could be as significant as the changes in the molecular composition of the gemini surfactants in delivering optimum gene expression in animal models.

Topics: Amino Acid Sequence; Animals; Cells, Cultured; CHO Cells; Cricetinae; DNA; Gene Transfer Techniques; Genetic Vectors; Humans; Liposomes; Luciferases; Lysine; Magnetic Resonance Spectroscopy; Membrane Lipids; Mice; Microscopy, Electron; Molecular Structure; Muscles; Neuroblastoma; Peptides; Phosphatidylethanolamines; Serine; Structure-Activity Relationship; Surface-Active Agents; Tumor Cells, Cultured

Cationic lipid formulations consisting of 3beta [N-(N', N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and the helper lipid dioleoylphosphatidylethanolamine (DOPE) (1.5: 1 molar ratio) were prepared by solvent evaporation and sized by high pressure extrusion. Liposomes made of 1:1 molar ratio 1 ,2-dioleoyl-3-trimethyl-ammonium-propane (DOTAP)/DOPE were used as controls in the study. The two formulations were characterized and evaluated for their efficiency in transfecting SKnSH (neuroblastoma) and primary rat neuronal cell lines. DC-Chol/DOPE liposomes were more efficient at transfecting both the SKnSH and the primary rat neuronal cells and also less toxic compared to the DOTAP/DOPE liposomes. The cellular-associated signal of rhodamine-labeled DC-Chol/DOPE liposomes into SKnSH and primary rat neuronal cells was higher than the rhodamine-labeled DOTAP/DOPE liposomes. These results demonstrate that DC-Chol/DOPE cationic liposomes provide an efficient vehicle for the delivery of plasmids into SKnSH and primary neuronal cells compared to DOTAP/DOPE liposomes. DC-Chol/DOPE liposomes may provide a good non-viral candidate for transfecting primary rat neuronal cells.

Topics: Animals; Cholesterol; Flow Cytometry; Fluorescent Dyes; Gene Transfer Techniques; Genetic Vectors; Humans; Liposomes; Neuroblastoma; Neurons; Phosphatidylethanolamines; Plasmids; Rats; Rhodamines; Tumor Cells, Cultured