• 공업화학
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• 제7권2호
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• pp.252-260
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• 1996

막의 기능설계를 하기 위하여 DPPC(dipalmitoylphosphatidylcholine)인 지질로 제조한 liposome과 DPPC와 DTAB(dodecyltrimethylammonium bromide)를 혼합하여 liposome을 제조하여 그 구조변화를 조사하였다. 막 구조의 변화는 CF(carboxylfluorescein)를 이용하여 DPPC의 상전이 온도($t_c=41^{\circ}C$) 이상과 이하에서 측정하여 평가하였다. DPPC liposome에 함유된 CF의 유출에 의한 형광강도는 $45^{\circ}C$에서 증가되었지만 $20^{\circ}C$에서는 그 변화는 관측되지 않았다. 동등한 조건에서 DPPC/DTAB liposome에서 CF 유출에 의한 형광강도의 변화는 DPPC liposome에 비하여 큰 것이 관측되었다. 이 결과는 DPPC/DTAB liposome이 불규칙한 배열을 하고 있다는 것을 시사한다. 한편 $Ca^{2+}$ 존재하에서 DPPC liposome과 DTAB/DPPC liposome에서 Quin 2의 형광강도는 $45^{\circ}C$에서 현저히 증가되었지만 $20^{\circ}C$에서는 거의 변화하지 않았다. 그리고 형광강도의 변화는 DPPC/DTAB liposome보다 DPPC liposome 쪽이 더 크게 나타났다. 이것은 DPPC/DTAB liposome의 구조가 DPPC liposome보다 더 안정하다는 것을 의미한다. 또한 형광물질인 ANS를 이용하여 막 표면의 양상을 조사한 결과 DPPC liposome과 DPPC/DTAB liposome에서 ANS의 형광강도는 $45^{\circ}C$와 $20^{\circ}C$에서 다른 양상을 보였다. 이 양상은 상전이 온도의 이상과 이하에서 DPPC liposome과 DPPC/DTAB liposome의 막유동성을 의미하고 그 변화량은 DPPC liposome이 DPPC/DTAB liposome보다 더 컸다. 또한 DSC에 의해 측정된 상전이 온도는 DPPC liposome의 경우 $41^{\circ}C$이었으며 DPPC/DTAB liposome의 경우에는 $32^{\circ}C$이었다. 이상의 결과로 DPPC/DTAB liposome의 분자배열 상태가 불규칙한 것을 의미한다. 그러므로 DPPC/DTAB liposome은 불규칙하게 배열되어 있지만 안정된 구조를 갖고 있다고 생각된다.

• Biomolecules & Therapeutics
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• 제18권1호
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• pp.99-105
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• 2010

The purpose of this study was to evaluate relative bioavailability of the coenzyme Q10 (CoQ10) in emulsion and three liposome formulations after a single oral administration (60 mg/kg) into rats. Emulsion formulation of CoQ10 was prepared by conventional method using Phospholipon 85G as an emulsifier, and three liposome formulations (neutral, anionic, and cationic) of CoQ10 were prepared by traditional lipid film hydration technique using Phospholipon 85G, cholesterol, and charge carrier lipids (1,2-dioleoyl-3-trimethylammonium-propane chloride salt for cationic liposome and 1,2-dimyristoyl-sn-glycero-3-phosphate monosodium salt for anionic liposome). Mean particle size of all CoQ10-loaded liposome was less than a micron, and size distribution of the liposome population was homogeneous. Bioavailability of CoQ10 in emulsion was 1.5 to 2.6-fold greater than liposome formulations in terms of $AUC_{0-24\;h}$. $T_{max}$ was 3 h when administered as emulsion while it was greater than 6 h in liposome formulations. Notably, it was approximately 8 h in cationic liposome. $C_{max}$ was highest in emulsion and was significantly decreased when administered as liposome. Charged liposome showed even lower $C_{max}$ than neutral liposome, especially in cationic liposome. In conclusion, therefore, it is suggested that clinicians and patients consider bioavailability issue a primary concern when choosing a CoQ10 product, especially when very high plasma level is required such as in the treatment of heart failure and Parkinson's disease.

• 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.

• Applied Biological Chemistry
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• 제37권5호
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• pp.343-348
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• 1994

A. tumafaciens C58로부터 $^3H-thymidine$으로 표지한 Ti plasmid를 분리하여 lyophilization-rehydration법으로 octadecyl rhodamine B로 표지한 liposome에 내포시켰다. Liposome조제에 사용한 지질은 phosphatidylserine(PS)을 사용한 PS liposome과, PS와 cholesterol(Chol)을 같은 mole비로 섞은 PS-Chol이었다. 꽃담배 원형질체는 0.1% macerozyme과 1.5% cellulase를 처리하여 유리시키고 불연속성 농도구배 원심분리로 정제하였다. $^3H-Ti plasmid$를 포함하고 있는 liposome$(1\;{\mu}mole\;PS)$을 5 mM $Ca^{2+}$과 10% PEG로 처리하여 꽃담배 원형질체$(10^6)$과 융합시켰다. 원형질체와 융합한 liposome의 양은 rhodamine B의 형광으로 측정하고 원형질체에 도입된 Ti plasmid의 양은 tritium의 방사능으로 측정하였다. 이때 PS liposome에서는 7.9%가 PS-Chol liposome에서는 7.2%의 liposome이 원형질체와 융합하였는데 융합과정에서 PS liposome서는 약 60%의 내용물이 유실되었고 PS-Chol liposome에서는 약 30%의 내용물이 유실되었다. 따라서 Ti plasmid를 식물원형질체에 도입하는데는 PS 보다는 PS-Chol로 구성된 liposome이 효율적인 것으로 나타났다. PS-Chol liposome을 사용할 경우에 1개의 원형질체에 약 1,700개의 Ti plasmid가 결합하고 있음으로 lyophilization-rehydration법을 사용하여 Ti plasmid를 식물원형질체에 도입할 경우에 식물의 형질전환 효율을 높일 수 있을 것임을 시사하여 준다.

• KSBB Journal
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• 제7권4호
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• pp.302-307
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• 1992

protein phosphatase 2A는 bovine brain homogenate의 세포질 fraction에서 얻어졌다. 기질로서 인산화된 histione H1을 이용하여 측정한 phosphatase 의 활성은 dipalmitoyIphophatidylcholine(DPPC) 혹은 phosphatidylserine/DPPC의 혼합물로 구성된 liposome의 존재하에서 저해되었다. Protein phosphatase 2A의 lipid membrane에의 결합은 다중층 지질막의 혼합물 계에서 liposome 의 양이 증가함에 따라서 상등액 중의 phosphatase의 활성이 감소하는 것으로 확인할 수 있었다. 또한 [$^{125}I$]protein phosphatase 2A가 liposome과 동시에 용출되는 것으로도 확인되었다. 그러나 liposome에 대한 protein phosphatase의 친화력은 높지 않았다. 한편, okadaic acid와 liposome은 협동으로 phosphatase의 활성을 감소시켰다. 이것은 okadaic acid가 lipid membrane이나 membrane에 결함한 phosphatase에는 결합하지 않는다는 것을 의미한다. 그러므로 lipid membrane에 의한 protein phosphatase 2A의 활성 저해 효과는 phosphatase 2A와 lipid membrane과의 결합에 의한 것이라고 설명될 수있다.

• 한국식품영양과학회지
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• 제22권1호
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• pp.91-95
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• 1993

Vibrio vulnificus가 생산하는 용혈독소의 단백화학적, 면역화학적 연구에 이용할 목적으로 이 균의 용혈독소에 대한 항혈청을 간편하게 만드는 방법을 실험한 결과는 다음과 같다. Vibrio vulnificus가 생산하는 조용혈독소를 인위적으로 만든 liposome (cholesterol-phos-phatidyl-liposome)에 혼합하여 반응시킨 결과 분자량 50kD의 단백질인 용혈독소만 선택적으로 liposome에 결합되었다. 그러므로 liposome에 결합시킨 조용혈독소를 면역원으로 하고 이 면역원을 토끼의 등근육에 주사하여 항혈청을 간편하게 만들 수 있었으며 이 항혈청은 용혈독소에 대한 특이성이 높았다. 환자와 환경에서 분리된 Vibrio vulnificus의 용혈독소와 liposome를 이용하여 제조한 항혈청을 gel 내 침강반응으로 확인한 결과 단일 침강선을 형성하였다.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.61-72
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• 2003

In cosmetic area, retinol is prominent ingredient for anti-wrinkle but unstable against light, heat, oxygen and so on. Therefore the stabilization of retinol is required. Here, we capsulated doubly retinol in the SLM(Skin Lipid Matrix) that makes three dimensional lamellar structure similar to skin, after formation of primary liposome (retinol-nanoemulsion). First, we make primary liposome from retinol / hydrogenated lecithin / polysorbate20 / caprylic ＆ capric triglyceride / ethanol / and so on, and the mean diameter to 70 nm, using microfluidizer passed three times at 800 Bar, repeatedly. Then we produce DC-liposome (doubly capsulated-liposome) that was encapsulated primary liposome with SLM made of hydrogenated phosphatidyl choline / caprylic ＆ capric triglyceride / 1, 3-butylene glycol / ceramide3 / cholesterol /etc. We measured for color stability against light and heat with chromameter. As a result of this experiment, we observed DC-liposome was more than from 1.5 to 3 times as stable as general liposome. Livability of retinol has improved from 2 to 6 times when we analyzed it by HPLC. Also, penetration effect of DC-liposome has improved.

• Journal of Ginseng Research
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• 제14권3호
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• pp.379-384
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• 1990

In order to study the lipid peroxidation caused by light and the protective action it in biological memberane, reverse-phase evaporation liposome (REV) was employed as a model memberance and the effect of several antioxidants and ginseng water extracts were tested. In the presence of photosensitizer, liposome was oxidized easily and the oxidation index dut to the peroxidation was increased. The oxidation index of liposome was increased according to the increase in temperature. When dl-${\alpha}$-tocopherol, ${\beta}$-carotene or L-ascorbic acid was added into the reaction mixture, the photooxidation of liposome was inhibited. Ginseng water extract and crude saponin inhibited the rate of oxidation index of liposome in low concentration but increase in high concentration. On the other hand, when lipid hydroperoxide of liposome was tested by ferrothiocyanate method, ginseng water extract and crude saponin acted as antioxidants.

• 대한핵의학회지
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• 제24권2호
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• pp.317-324
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• 1990

Liposome was labelled with $^{99m}Tc$ after negative charged liposome was formed with combination of a few lipid components. $^{99m}Tc$ liposome was injected through the tail vein of C3H mice bearing fibrosarcoma and biodistribution of $^{99m}Tc$ liposome was evaluated. The results were as follows: 1) We confirmed formation of liposome which was small unillamellar and multilamellar vesicles. 2) In this experiment the optimal concentration of $SnCl_2$ was $156{\mu}g/ml$ to label liposome with $^{99m}Tc$ and labelling efficiency was 95%. 3) The labelled liposome was stable when it was incubated with human serum for 24 hours. Mean labelling efficiency was 94% at 24 hour. 4) The main uptake sites of Tc-99m liposome were liver and spleen. It showed significantly higher uptake than $^{99m}Tc$ HSA (p < 0.001). 5) $^{99m}Tc$ liposome uptake in tumor tissue was not significantly higher than $^{99m}Tc$ HSA uptake. In conclusion, $^{99m}Tc$ liposome disclosed high labelling efficiency and was highly stable. Liver and spleen were main uptake sites of $^{99m}Tc$ liposome. The uptake mechanism of $^{99m}Tc$ liposome also seemed to be different from that of $^{99m}Tc$ HSA. We conclude that $^{99m}Tc$ liposome would be a promising agents for the imaging of some tumor.

• BMB Reports
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• 제29권1호
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• pp.81-87
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• 1996

The relationship of S-thiolation and oxidation of glycogen phosphorylase b and peroxidation of phosphatidyl choline liposome by xanthine oxidase (XOD), 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH), and 2,2'-azobis(dimethylvaleronitrile) (AMVN)-generated free radicals was investigated, Glycogen phosphorylase b was S-thiolated in the presence of glutathione and oxidized in the absence of it by XOD, AAPH and AMVN. In XOD-initiated reaction, the rates of S-thiolation and oxidation of phosphorylase were very similar and addition of liposome to the reaction mixture showed little inhibition of the modifications. In AAPH-initiated reaction, the rate of oxidation was higher than that of S-thiolation and addition of liposome increased oxidation of the protein but had no effect on S-thiolation. In AMVN-initiated reaction, S-thiolation was higher than oxidation and addition of liposome increased S-thiolation remarkably but showed no effect on oxidation. The effect of liposome on modifications of protein in AAPH and AMVN reaction seemed to be caused by certain reactive degradation products or intermediates of liposome by free radical attack. Peroxidation of liposome was not observed in XOD-initiated reaction. Liposome was gradually peroxidized by AAPH reaction. The peroxidation was inhibited by addition of GSH and phosphorylase. Peroxidation of liposome by AMVN was extreamly fast, and was not affected by GSH and phosphorylase.