• Journal of Pharmaceutical Investigation
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• 제38권3호
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• pp.163-169
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• 2008

Liposomes are spherical vesicles composed of lipid bilayer membranes. However, the conventional liposomes have been found to be plagued by rapid opsonization and taken up by the reticuloendothelial system (RES), resulting in shortened circulation time and limited intracellular uptake to target cell. In this study, polyethyleneglycol-cationic liposomes (PCL) containing cationic lipid and DSPE-mPEG were prepared by thin film cast-hydration method. The PEG liposomes had approximately $97.0{\pm}1.3\;nm$ of mean particle diameter and $-21.7{\pm}1.2\;mV$ of zeta potential value. PCL had $96.4{\pm}1.8\;nm$ of mean particle diameter and $-8.7{\pm}1.1\;mV$ of zeta potential value with a decrease of about 10 mV compared to the PEG liposomes. Loading of model drug, doxorubicin (DOX), in liposomes were carried out by using remote loading method and the loading efficiency of DOX in liposomes was about $95.0{\pm}1.9%$. Intracellular uptake and cytotoxicity of PCL were higher than that of PEG liposomes to murine B16F10 melanoma cells. In addition, anti-tumor activity of PCL was similar to that of PEG liposomes on growth of A549 human lung carcinoma in BALB/c mice. Consequently, PCL modified with cationic lipid may be applicable as anticancer drug carriers that can increase intracellular uptake and therapeutic efficacy.

• Biomolecules & Therapeutics
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• 제19권2호
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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.

• Journal of Pharmaceutical Investigation
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• 제26권4호
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• pp.291-297
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• 1996

Liposomes of $pSV-{\beta}-Galactosidase$ vector plasmid DNA with various lipid composition were prepared by the thin-film method. Size distribution, shape and the efficiency of plasmid DNA encapsulation were investigated. Effect of sonication time on the plasmid DNA entrapment in liposomes and stability at $4^{\circ}C$ were also examined. Sizes of neutral liposomes were about 100-200 nm and above $1\;{mu}m$, and those of cationic liposomes were about 400-600 nm and above $1\;{mu}m$. Shapes of liposomes entrapped plasmid DNA were spherical. Proper sonication time for better entrapment was below 15 minutes and stability at $4^{\circ}C$ was decreased rapidly after 1 day. Plasmid DNA entrapments of complex liposomes of various lipids were higher than those of liposomes made from one sort of lipid. Plasmid DNA entrapments of cationic liposomes were higher than those of neutral liposomes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.155-158
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• 1998

MLS capacitor with lipid ultra thin films were deposited by Langmuir-Blodgett (LB) method on the sillicon wafer. The current versus voltage and capacitance versus voltage relationships are depend on the applied voltage, electrode area and electrode materials. LB films deposited were made of L-$\alpha$-DLPC, the 1 layer's thickness of 35$\AA$ was measured by ellipsometer. And MLS capacitor with different electrode materials, the work function of these materials was investigated to increase the leakage current. The result indicated the lower leakage current and very high saturation value of capacitance was reached within 700-800 pF when the two electrode was Ag. And $\varepsilon$$_1$, $\varepsilon$$_2$ versus photon energy showed good film formation.