• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.177-185
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• 2017

In the present work, the interaction of fatty acid with vesicle membrane of phospholipids was investigated using 3 different kinds of fatty acids such as stearic acid (SA), oleic acid (OA) and linoleic acid (LA). Basically, the same trend has been found in 3 fatty acid systems. The addition of fatty acid produced a close packing of liposome due to the penetration of fatty acid molecules into liposome vesicles, which resulted in a decrease in size and an increase in zeta potential of liposome. However, excessive addition of fatty acid produced a transition from liposomes to aggregates of lipid particles having polymorphic structure. The membrane fluidity, characterized by measuring membrane deformability and fluorescence anisotropy ratio of liposomes, was in good agreement with measurement results of transmission electron microscopy (TEM) and particle size. The minimum size and closest packing of liposome with SA, OA and LA were found when the molar ratios of fatty acid to lecithin were 0.70, 0.50, and 0.25 respectively.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.11a
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• pp.81-90
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• 1994

리포좀은 1960년대 초 Bangham등에 의해 혈액응고시 인지질의 영향에 관한 연구 중 우연히 발견하게 되었다. 즉 인지질이 물에 분산되어 2 분자막 (Bilayer)을 형성함을 알았고, 이때 생긴 폐쇄소포체를 리포좀이라 하였다. 이러한 리포좀은 원형질 막이나 세포내의 소기관의 막과 유사한 구조를 갖고 있기 때문에 이것을 이용하여 생화학자나 생물리학자들은 생체막의 모델시스템으로 이용하여 생체막의 기능 연구에 널리 이용하여 왔다. 1970년 초반부터 리포좀을 이용한 약물의 생체내 공급(Drug Delivery System, DDS)에 대하여 많은 연구가 이루어져 왔고, 지금까지도 의약품외 전달매체로 이용할려고 많은 시도를 하고 있는 실정이다. 최근에는 리포좀을 이용하여 항원을 전달하는 면역보조제(Adjuvant System)로 이용하려는 시도를 하고 있다. 현재까지 리포좀을 이용한 상품들은 화장품과 임상용 진단시 약, DNA transfection system (Lipopectin)으로 활용되고 있다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.65-65
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• 1993

봉합율의 최적 조건을 구하기 위해 다양한 방법으로 리포좀을 제조했으며, 인지질과 봉합 약물의 비는 20:1 이상이어야 하고, 리포좀 제조 방법에 따라 봉합율이 차이가 났으며, REV, REV를 freezing-thawing한 것과 SUV를 freezing-thawing한 리포좀에서 봉합율이 좋았다. REV를 freezing-thawing한 리포좀이 가장 좋았다 (66.7%, BPB; 115.7 ug trypsin/mg lipid). 콜레스테롤의 함량은 봉합율과 안정성을 고려하여 인지 질과의 비를 7.3으로 고정시켰다. 안정성은 투과성, light scattering, qucnching 등으로 측정했으며,4$^{\circ}C$,용액 상태에서 두 달 이상동안 보관했을 때 약 10% 정도가 리포좀 내에서 빠져나왔으며, 리포좀의 크기 변화는 거의 일어나지 않았다. Calcein봉합 리포좀을 Vero E6 cell에 투여했을 때, 매우 적은 양이 cell내로 들어가는 것을 형광 현미경으로 확인할 수 있었다.

• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.165-172
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• 2015

Quercetin and its glycoside, rutin, are flavonoids, which are well known as natural antioxidants. In this study, cationic liposomes loaded with flavonoids (quercetin or rutin) were investigated for their effects on cell and skin permeability, and protective effects against UVA. The particle size of the empty cationic liposomes was in the range of 100~130 nm, and the zeta potential was + 33.05 mV. The entrapment efficiency of 0.5R/CL was higher than that of 0.5 Q/CL. The cellular uptake of the cationic liposomes was five-fold higher than that of liposomes. The skin permeability of quercetin and rutin was investigated using Franz diffusion cells. Compared to the initial loading dose, the amount of quercetin or rutin delivered to the skin by cationic liposomes was higher than that delivered by conventional liposomes or phosphate-buffered saline. From the protective effect of cationic liposomes against UVA ($25J/cm^2$), we found that the cell viability in cationic liposomes containing flavonoids was higher than that of using UVA irradiation only. These results indicate that cationic liposomes provide enhanced delivery of flavonoids (quercetin and rutin) into the skin and may be used for antiaging and antioxidant cosmetics.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.1
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• pp.55-60
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• 2011

In this study, DOPC liposomes were prepared with distilled water, phosphate buffer and phosphate buffered saline to evaluate the effects of salt on the stability of DOPC liposome. The changes in physical properties (likeparticle size and zeta potential) of liposome were measured after adding the salt. Liposomes were diluted 40 times and 80 times with hydration solvent to confirm the effect of dilution. Consequently, the stability of liposome was maintained up to 40 times dilution with hydration solvent. The liposome that prepared with distilled water was diluted with distilled water, phosphate buffer and phosphate buffered saline, and the liposome that prepared with phosphate buffer was diluted with phosphate buffer and phosphate buffered saline to evaluate the salt-induced changes in particle size and zeta potentia. As results, the particle size increased slightly and zeta potential became closer to 0 when the salt concentration was increased. In conclusion, particle size and zeta potential of liposome could be reasonable factors to evaluate the stability of liposome. In addition, we suggest that salt concentration of hydration solvent has a significant effect on the stability of liposome.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.549-554
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• 2008

Liposomes were prepared from egg yolk phospholipids to study their physical properties and stability at various storage conditions. Under storage conditions at different pH levels, the particle sizes of liposomes increased at the range of pH 1-2, and the absolute values of $\xi$-potentials were reduced at the range of pH 1-4. The leakage of sulforhodamine B (SRB), a fluorescent dye which is encapsulated in the liposome, increased greatly at pH 2-4. At different storage temperatures, the particle size of liposomes increased from the 10 days of storage at $4^{\circ}C$ and the 40 days at 20 and $35^{\circ}C$. The $\xi$-potentials decreased slightly later during storage under 4, 20 and $35^{\circ}C$. At the storage temperature of $50^{\circ}C$, the leakage of SRB was the greatest. Therefore, we concluded that the pH conditions lower than pH 6 and high temperature of $50^{\circ}C$ are not conducive to storing liposomes. The results obtained here may prove helpful in developing liposome-based encapsulation and diagnostic reagents.

• KSBB Journal
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• v.10 no.2
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• pp.204-211
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• 1995

A target-sensitive liposome was prepared by using a dioleoyl-phosphatidylethanolamine(DOPE) and a palmitic acid coupled antibody(p-IgG). For the preparation of stable PE-liposomes, the key factors such as antibody modification method with palmitic acrid, molar ratio of p-IgG to lipid and the amount of various additives, were examined. The optimum molar ratio of p-IgG to lipid was found to be $2.5{\times}10^{-4}$ and the final concentration of deoxycholate for the stable liposome formation was about 0.09%. Two kinds of target-sensitive liposomes, containing polyclonal anti-SRBC(Sheep Red Blood Cell)-antibody and monoclonal anti-${\beta}$-HCG(Human Chorionic Gonadotropin)-antibody, were successfully prepared. The destabilization of liposomes was examined by measuring the release of calcein entrapped in the liposome vesicles. Calcein was released only when the liposomes were contacted with the specific target cells. The calcein release with non-specific target cells was negligible. From this result, it is clear that p-IgG is indispensible for the maintenance of stable PE-liposome and the calcein release is mainly due to the specific interactions between the liposomes containing antibody and the target cells containing antigen.

• Journal of the Korean Chemical Society
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• v.47 no.3
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• pp.257-264
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• 2003

This study has investigated the temperature-sensitive liposomes, which release anticancer drug(doxorubicin) at the hyperthermia temperature$(~40^{\circ}C)$. The temperature-sensitive liposomes were modified with a copolymers of N-isopropylacrylamide(NIPAAm) and acrylamide(AAm), which exhibit a lower critical solution temperature (LCST) at the hyperthermia temperature. The release of doxorubicin from the modified liposomes was determined by measuring the fluorescence intensity with changing temperature and time. The release of doxorubicin from liposomes modified with poly(NIPAAm-co-AAm) copolymer was increased significantly, because poly(NIPAAm-co-AAm) could undergo the conformational transition in the narrow hyperthermia temperature region$(~40{\pm}2^{\circ}C)$. Moreover, we observed that doxorubicin released from liposomes within 5 minutes, and the size of modified liposomes was 120~170 nm. In this study, we have prepared temperature-sensitive liposomes which could be controlled by temperature. They can be applied in the field of a drug delivery system for tumor targeting by temperature control.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.428-434
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• 2016

In this study, benzyltrialkylammonium chlorides with different alkyl chain length were synthesized and applied to liposome. Prepared cationic surfactant embedded liposomes were measured particle size, zetapotential, release property and antibacterial activity. The average particle size of liposomes was 120~140 nm. As alkyl chain length was increased, the liposome size was increased. Zetapotential for the solution of liposomes added cationic surfactants were in the range of +80~90 mV. In release test, collagen release rate could be controlled by alkyl chain length. liposome embedded long alkyl chain surfactant had enhanced sustained release property. Entrapment efficiency of hydrophilic collagen were 25.9~27.5%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.5
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• pp.864-868
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• 2004

Iron is an essential ingredient for all metabolism in a living body However, because of the very low content of the iron in foods, many researches have been performed about iron-fortified food additives. We developed an iron-fortified food additive using the liposome that contain ferrous sulfate and hemin. For preventing the autoxidation of the ferrous sulfate, ascorbic acid was applied. Also, to prevent the oxidation of the liposome induced by the added ferrous sulfate and/or hemin, $\alpha$ -tocopherol was additionally applied. Though the effect of the added aqueous ascorbic acid did not show the antioxidative activity on the liposome containing ferrous sulfate and/or hemin, the added $\alpha$ -tocopherol in the phospholipid bilayer could retard the oxidation of the liposome. These results support that the liposome containing ferrous sulfate, hemin and ascorbic acid with the incorporated $\alpha$ -tocopherol could be applied in the food industry as an iron-fortified additive.