• Journal of Pharmaceutical Investigation
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• 제24권4호
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• pp.201-215
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• 1994

Recent development in the immunochemical technique has resulted in a new ultrasensitive analytical method known as liposome immunoassay (LIA). Liposome is a key element in performing liposome immunoassays, specifically designed to participate in immune reactions. A variety of markers can be encapsulated in liposomes and used as quantitative indicators of reactions. Liposome immunoassay based on agglutination, complement-mediated Iysis, cytolysin-mediated Iysis, detergent-mediated Iysis or destabilization of the liposomal membrane have been reviewed. The quantity of markers released from liposomes should be proportional to the concentration of the analytes. Therefore, liposomal agglutination and Iysis which are essential to liposomal Iysis are critically reviewed to provide a better understanding of liposome immunoassay. Based on the literature review of recent advances in liposome immunoassay for bioactive substances, this assay method may provide a convenient, specific and highly sensitive method for detecting and measuring trace amount of clinically relevant substances in the future.

• 한국미생물·생명공학회지
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• 제40권3호
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• pp.215-219
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• 2012

Although the antioxidant capacity of carotenoids and their role in regulating membrane fluidity have been well studied, their ability to confer resistance to hypoosmotic shock is poorly understood. In this work, we analyzed the effect of a mixture of carotenoid pigments obtained from an Antarctic microorganism belonging to the genus Pedobacter on liposomal resistance to hypoosmotic conditions. Intercalation of pigments into liposomal structures resulted in an improvement of membrane resistance by decreasing the percentage of calcein released in comparison to that by liposomes without pigments. Due to these properties, such pigments could be useful for biotechnological applications.

• Journal of Pharmaceutical Investigation
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• 제36권5호
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• pp.293-297
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• 2006

Curcumin is a phytochemical compound with anticancer activity. Although curcumin has substantial pharmacological effect against various cancers, the low solubility of curcumin has hindered its development. For an organic solvent-free injectable formulation, we encapsulated curcumin in various liposomes. Due to its lipophilic property, curcumin was placed in the membrane region of liposomes. Curcumin was stably encapsulated in all formulations tested in this study. The cellular uptake of curcumin delivered in liposomal formulations or free form was measured in K562 human leukemia cell lines using a flow cytometry and MTT viability assay, respectively. Although all the liposomes could solubilize curcumin, the cellular levels and the anticancer effects of liposomal curcumin varied with the composition of liposomes. Moreover, liposomal curcumin down-regulated the expression of Notch-1, the molecule involved in the carcinogenesis, to the similar extent to free curcumin dissolved in dimethyl sulfoxide. These results warrant the development of liposomal curcumin as an injectable formulation for leukemia treatment.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2001년도 10주년 기념 국제학술 심포지움 및 추계학술대회
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• pp.39-39
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• 2001

• 한국영양학회:학술대회논문집
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• 한국영양학회 2001년도 춘계연합학술대회 초록
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• pp.315.1-315
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• 2001

• 한국영양학회:학술대회논문집
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• 한국영양학회 2001년도 춘계연합학술대회 초록
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• pp.301.1-301
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• 2001

• Journal of Life Science
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• 제10권2호
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• pp.27-32
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• 2000

To understand the effects of the fraction from Chrysanthemum coronarium L. (CC), we prepared five different types of samples, denoted here as CCMM, CCMH, CCMEA, CCMB and CCMA. We studied the effects of these samples on the phase transition of liposomal membranes by high-sensitivity differential scanning calorimetry (nano-DSC). We used dipalmitoylphosphatidylcholine (DPPC) bilayers which make most stable liposomes among the other phosphatidylcholines. When the samples were added to the bilayers, the phase transition temperatures of DPPC liposomes incorporated with CCMH and CCMEA were decreased by 1.5 and 2^{\circ}C$, while the other three fractions showed less tendencies. The CCMH and CCMEA fractions markedly affected the thermotropic properties of DPPC liposomes, broadened and shifted the thermograms of DSC. It also significantly reduced the size of cooperative unit of the transition. In all cases, there was no change in enthalpy of transition within the concentration range of the CC fractions studied. We concluded that the incorporation of the CCMH and CCMEA into DPPC liposomes was preferentially located in the hydrophobic core of DPPC bilayers compared to the other three fractions CCMM, CCMB and CCMA. These results suggest that certain substances in CCMH and CCMEA fractions might have biologically significant effects on the fluidity of biological membrane.

• Journal of Photoscience
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• 제1권2호
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• pp.83-88
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• 1994

The synergic effect of iron plus blue light on the peroxidation of membrane lipid was investigated, using liposomes made of phospholipid. While strong irradiation did not affect Fe$^{+2}$-promoted lipid peroxidation that turned out to be O$_2$-dependent, ferric iron in bright light exerted a pronounced effect on the initiation of lipid peroxidation: this combined action of light and Fe$^{+3}$ on liposomal membranes was apparently independent of O$_2$. When liposomal samples containing Fe$^{+3}$ were subjected to irradiation, some portions of Fe$^{+3}$ were converted into Fe$^{+2}$. The extent of the Fe$^{+3}$-Fe$^{+2}$ conversion increased with increasing time of irradiation, which resembled the dependence of Fe$^{+3}$-promoted lipid peroxidation on irradiation. Further, it was observed that the effect of irradiation in liposomal samples containing Fe$^{+2}$ was strikingly mimicked by that of Fe$^{+2}$ addition to the same samples. The obligatory requirement of a suitable Fe$^{+3}$/Fe$^{+2}$ ratio for the genesis of iron-dependent lipid peroxidation, a controversial proposition, was also confirmed by the observation that lipid peroxidation was substantially enhanced by the addition of a mixture of Fe$^{+3}$ and Fe$^{+2}$, as compared to the addition of Fe$^{+3}$ or Fe$^{+2}$ alone. The results obtained in this study not only suggest that light acts as an effector for initiating lipid peroxidation, when Fe$^{+3}$ is present in membrane systems, but also imply that any chemical or physical factor that influences the redox states of iron in membranes can play a role in lipid peroxidation reactions.

• 한국식품영양과학회지
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• 제21권4호
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• pp.381-385
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• 1992

Egg 인지질 liposome에 미치는 대두 saponin의 항산화 작용에 대한 영향을 흡광분석법으로 검토하였다. ${\alpha}-tocopherol$이 함유된 egg 인지질 liposomed의 산화지수와 산화속도가 순수 eff 인지질 liposome의 산화지수와 산화속도에 비하여 현저하게 감소되었다. Liposome내 함유된 ${\alpha}-tocopherol$은 순수 egg 인지질 liposome의 산화를 지연시켰다. 특히 대두 saponine은 egg 인지질 liposome에 대한 ${\alpha}-tocopherol$의 항산화 효과를 촉진시켰다. 이러한 결과로 보아 대두 saponine이 egg 인지질 liposome에 대한 ${\alpha}-tocopherol$의 항산화 작용에 영향을 미치는 것으로 사료된다.

• Archives of Pharmacal Research
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• 제10권2호
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• pp.94-99
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• 1987

By using the former equation (8), we modified the equation which can show the dissimilar osmotic behavior of liposome with composition change. The slope of the new equation was presented as the ratio of osmotically active volume (V$_{act}$= ) to the total volume (V$_{totel}$= $_{acl}$+ V$_{dead}$ ; V$_{dead}$ is osmotically inactive volume) of loposomes, we defined is as a Z-value, which can elucidate the dissimilarity of the osmotic activity of multilamellar liposomes with the change of phospholipid composition and the differences of physicochemical properties of liposomes. Z-value was applied for studying the physico-chemical properties of liposomal membrane. The factor that affects on the Z-value was not the lipid concentration of liposome stock dispersion but the lipid composition of liposomal membrane. As the content of dicetylphosphate, the negative charged phospholipid, was increased, the osmotic activity, represented by Z-value, of multilamellar liposome was decreased. Using the hypertonic conditions (shrinking region), Z-value steadily increased and reached a maximum at 10 mole percent cholesterol with increasing the cholesterol content.