• Polymer(Korea)
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• v.28 no.6
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• pp.502-508
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• 2004

Cationic liposomes for cancer treatment have been developed in the field of chemotharpy. It was well combined on the surface of anionic tumor cell membrane by electrostatic interaction. Thus, the object of this study was to prepare the cationic liposomes capable of forming an ionic complex with the anionic cell membrane. To prepare the cationic liposomes, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE) as a cationic lipid material and polyethylenimine (PEI) as a cationic polymer were synthesized. Ionic property on the surface of liposomes was determined by the zeta potential. The adsorption characteristics of plasma protein for liposome in bovine serum were determined by the particle size and turbidity change. To estimate the stability of liposome in buffered solution, the change of particle size was measured at room temperature for seven days. The cationic liposomes were absorbed a large amount of plasma protein in bovine serum because plasma protein having anionic charge was fixed on the surface of cationic liposomes. This result indicate that the modification on the surface of liposomes using cationic polyethylenimine enhances the protein adsorption in bovine serum. Additionaly, cationic liposomes showed good stability in buffered solution for seven days.

• Journal of Pharmaceutical Investigation
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• v.40 no.3
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• pp.187-192
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• 2010

We aimed to evaluate the effect of temperature, pH, and light conditions on the stability of porcine placental extract (PPE)-loaded liposomes with different surface charges. The size distribution profiles and in vitro release patterns were investigated by dynamic light scattering method and spectrophotometry. The stability of PPE-loaded liposomes was affected by the surface charges of the liposomes. As compared to neutral and anionic liposomes, cationic liposome formulations showed significantly lower physical stability. At the test storage conditions of different temperatures and pHs, the mean sizes of cationic PPE-loaded liposomes substantially increased. In contrast, neutral and anionic liposomes did not reveal significant changes in mean sizes upon various storage conditions. The neutral and anionic liposomes showed no significant differences in the release profiles of PPE after storage at various temperatures and pHs. Our results indicate that anionic and neutral liposome compositions might be more suitable for the formulations of PPE providing the higher stability.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.131-135
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• 2013

A DOTAP analog labeled by NBD on the head group (DTNBD) was designed and synthesized to label DOTAP liposome. The structure was confirmed by $^1H$ NMR and FAB-MS, and the fluorescence of the newly synthesized DT-NBD was observed by fluorescent microscopy. The transfection efficiency of DOTAP liposome containing DT-NBD was comparable to commonly used NBD PE in COS7 and MCF7 cells. Furthermore, the level of cellular uptake and fluorescent intensity of fluorescent liposome containing DT-NBD was higher than NBD PE. Therefore, the novel NBD-labeled DOTAP analog seems to be effectively used for investigation of the cellular interaction and transfection mechanism of DOTAP liposome.

• KSBB Journal
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• v.13 no.4
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• pp.418-423
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• 1998

Cellular transfections with cationic liposomes are widely empolyed for gene and oligonucleotide transfer in vitro because of their safety and ease of use. However, they still suffer from the low transfection efficiency comparing with viral vectors. Substantial effort shave been focused on increasing transfection efficiency by supplementing the liposome/DNA complexes(lipoplex) with various components. In this work, we tired three kinds of supplements, Poly-L-lysine(PLL), transferrin and a mixture of anionic lipids(PS/PE/PC), to study their effects on gene transfer yield and gene expression efficiency. PLL, a polycationic polymer, enhanced gene transfer yield by 3 times but the gene expression efficiency was increased only by 1.5 times. this result implies that PLL can enhance the transfection efficiency mainly by increasing the rate of outermembrane transport of lipoplex into the cells. On the other hand, transferrin which can facilitate the gene transfer via ligand-receptor interaction gave not only increased gene transfer yield but also enhanced gen expression efficiency by 2.8 times. Transferrin seems to contribute to the escape of plasmid from endosomes through ligand-receptor recycle mechanism. When the cells were treated with a mixture of anionic lipids for 3 hours before the transfection, gene transfer yield was slightly decreased but the gene expression efficiency was enhanced by 1.9 times. This is presumably due to the accelerated liposome-plasmid dissociation by the anionic lipids, and the increased delivery of plasmid to the nucleus. According to these results, it is clear that the supplementation to ameliorate transfection efficiency with cationic liposomes should be contrived in the direction of increasing delivery of plasmid.

• Biomedical Science Letters
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• v.15 no.4
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• pp.265-272
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• 2009

Recently, mesenchymal stem cells (MSCs) began to be utilized as a vehicle for ex vivo gene therapy based on their plasticity. Effective and safe transfection of therapeutic genes is a critical step for genetic modification of MSCs. Therefore, optimization of in vitro gene delivery into MSCs is essential to provide genetically modified stem cells. In this study, various cationic liposomes, O,O'-dimyristyl-N-lysyl aspartate (DMKD), DMKD/cholesterol, O,O'-dimyristyl-N-lysyl glutamate (DMKE), DMKE/cholesterol, and N-[1-(2,3-dioleoyloxy)]-N,N,N-trimethylammonium propane methyl sulfate (DOTAP)/cholesterol, were mixed with plasmid DNA encoding luciferase (pAAV-CMV-Luc) at varied ratios, and then used for transfection to MSCs under varied conditions. The MSCs were also transfected by electroporation under varied conditions, such as voltage, pulse length, and pulse interval. According to the experimental results, electroporation-mediated transfection was more efficient than cationic liposome-mediated transfection. The best MSC transfection was induced by electroporation 3 times pulses for 2 ms at 200 V with 10 seconds of a pulse interval.

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.292.2-292.2
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• 2001

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.426.2-426.2
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• 2002

Various strategies have been attempted to design efficient protocols for ovarian cancer gene therapy but there has been little progress in their clinical application. In this study, we formulated and evaluated a new cationic liposome composed of dioleoyltrimethylaminopropane (DOTAP), 1.2-dioleoyl-3-phosphophatidylethanolamine (DOPE). and cholesterol (Chol) (DDC) for plasmid DNA transfer into ovarian cancer cells. The DOC liposome was prepared by mixing DOTAP. DOPE. and Chol using extrusion method. (omitted)

• Polymer(Korea)
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• v.29 no.3
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• pp.277-281
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• 2005

Recently, various curriers prepared by the modification both cationic polymers and liposomes have been examined. In this work, we prepared the lipid with polyethylenimine (PEI) to investigate the possibility as effective DNA carrier. Cationic lipid (PEI-DSPE) was synthesized by the reaction of PEI and 1,2-diacyl-sn-glycero-3-phosphoetha-nolamine (DSPE). The liposomes were prepared by the concenoation changes of PEI-DSPE for a mixture of 1,2-disteanyl-sn-glycero-3-phosphocholine (DSPC), L-$\alpha$-phosphatidylcholine, hydrogenated (HSPC) and cholesterol (CHOL). Particle size decreased as PEI-DSPE concentration increased. In addition, the charge of liposome surface increased to positive value according to increasing the relative of PEI-DSPE concentration. The complexation of DNA was confirmed by gel retardation assay and fluorescence measurement. The surface charge of liposome/DNA complexes increased as the liposome concentration or surface charge of liposome increased. In conclusion, we confirmed that the prepared liposomes have the possibility as a DNA carrier.

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.231-236
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• 2011

The aim of this study was to investigate the effect of charge carrier lipid on the skin penetration, retention, and hair growth of topically applied finasteride-containing liposomes. Finasteride-containing liposomes were prepared by traditional thin film hydration method using Phospholipon$^{(R)}$ 85 G and cholesterol with or without charge carrier lipid (1,2 dimyristoyl-sn-glycero-3-phosphate or 1,2-dioleoyl-trimethylammonium-propane for anionic and cationic charge, respectively). Freshly prepared finasteride-containing liposome suspension was applied on the hairless mouse skin, and skin penetration and retention were measured using Keshary-Chien diffusion cell. Non-liposomal formulation (ethanol 10% solution containing 0.5 mg/ml of FNS) was also used as a control. The amount of finasteride in the diffusion cell and mouse skin was measured by HPLC. The hair growth was evaluated using depilated male C57BL/6N mice. Mean particle size of all finasteride-containing liposomes was less than a micron, and polydispersity index revealed size homogeneity. Skin penetration and retention studies showed that significantly less amount of finasteride was penetrated when applied as anionic liposome while more amount of the drug was retained. Specifically, in liposome prepared with 10% anionic charge carrier lipid, penetration was 12.99 ${\mu}g/cm^2$ while retention was 79.23 ${\mu}g/cm^2$ after 24 h of application. In hair growth study, finasteride-containing anionic liposomes showed moderate efficacy, but the efficacy was not found when applied as cationic liposomes. In conclusion, topical application of finasteride using anionic liposome formulation appears to be useful option for the treatment of androgenetic alopecia to avoid systemic side effects of the drug.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.425.3-426
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• 2002

Cationic lipids have been used as one of the major components for making most promising non-viral gene delivery systems. whereas sodium cholate. an edge activator has been used as a surfactant in making ultradeformable and ultraflexible liposomes called Transfersomes. Using both a cationic lipid, DOTAP and sodium cholate. a newly formulated ultradeformable cationic liposome has been prepared. The average particle size of this formulation was approximately 80nm. (omitted)