• 한국환경과학회지
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• 제6권2호
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• pp.189-194
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• 1997

Hornet venom의 독성 peptide인 mastoparan과 mastoparan-B를 solid phase peptide syn- thesis method로 합성한 후 이들과 phospholipid와의 상호작용, 이들의 항균 활성 및 용혈 활성 을 조사하였다. 두가지 독성 peptide 모두 중성 liposome에서 저 농도에서도 dye release를 유도할 수 있었다. 중성 liposome에 대한 mastoparan-B의 결합 친화도는 산성 liposome에서 보다 작았다. Mastoparan과 mastoparan-B는 두가지 모두 그람 양성 세균에 대하여 강한 항균 활성을 가지고 있었으나 그람 음성 세균에 대해서는 각각 약하거나 유력한 활성을 보였다. Mastoparan과 mastoparan-B는 5$\mu$M의 낮은 농도에서도 적혈구를 분해시키는 독성을 보였다.

• Archives of Pharmacal Research
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• 제28권5호
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• pp.626-635
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• 2005

Liposome as a carrier of topotecan (TPT), a promising anticancer drug, has been reported in attempt to improve the stability and antitumor activity of TPT. However, the biodistr ibution pattern of TPT liposome in vivo and PEG-modified liposome containing TPT have not been studied systemically. In this paper, the in vitro stability and in vivo biodistribution behavior of several liposomes containing TPT with different lipid compositions and PEG-modification were studied. Compared with the 'fluid' liposome (S-Lip) composed of soybean phosphatidylcholine (SPC), the 'solid' liposome (H-Lip) composed of hydrogenated soybean phosphatidylcholine HSPC decreased the leaking efficiency of TPT from liposome and enhanced the stability of liposome in fetal bovine serum (FBS) or human blood plasma (HBP). The results of biodistribution studies in S$_{180}$ tumor-bearing mice showed that liposomal encapsulation increased the concentrations of total TPT and the ratio of lactone form in plasma. Compared with free TPT, S-Lip and H-Lip resulted in 5- and 19- fold increase in the area under the curve (AUC$_{0\rightarrow\propto}$), respectively. PEG- modified H-Lip (H-PEG) showed 3.7-fold increase in AUC$_{0\rightarrow\propto}$ compared with H-Lip, but there was no significant increase in t$_{1/2}$ and AUC$_{0\rightarrow\propto}$ for PEG-modified S-Lip (S-PEG) compared with S-Lip. Moreover, the liposomal encapsulation changed the biodistribution behavior, and H-Lip and H-PEG dramatically increased the accumulation of TPT in tumor, and the relative tumor uptake ratios were 3.4 and 4.3 compared with free drug, respectively. There was also a marked increase in the distribution of TPT in lung when the drug was encapsulated into H-Lip and H-PEG. Moreover, H-PEG decreased the accumulation of TPT in bore marrow compared with unmodified H-Lip. All these results indicated that the membrane fluidity of liposome has an important effect on in vitro stability and in vivo biodistribution pattern of liposomes containing TPT, and PEG-modified 'solid' liposome may be an efficient carrier of TPT.

• 대한화장품학회지
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• 제30권2호
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• pp.201-205
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• 2004

최근 고기능성 화장품이 출시되면서 기능성 원료가 빛, 열, 산소에 매우 불안정하여 다양한 방법으로 안정성을 높이려고 연구되어 지고 있다. 특히, 카테킨은 주름 개선에 탁월한 원료이지만 빛, 열, 산소에 매우 불안정하다. 본 연구에서는 카테킨을 3Dimension화 하여 안정성 및 피부 침투를 높였다. 1 dimension으로 sol-gel method로 실리카를 다공성으로 만들어서 다공성 부문에 카테킨을 흡착시킨다. 2 dimension으로 다공성 실리카에 흡착디어진 카테킨을 non-phospholipid 베지클을 이용하여 solid lipid nanoparticle(SLN)을 만든다. 마지막으로 3dimension은 SLN되어진 카테킨을 skin lipid matrix를 이용하여 lameller phase self organization시킨다. 3 Dimension-카테킨은 일반적인 리포좀에 비해 빛과 열에 대한 color 안정성을 chromameter로 측정한 결과 5-10배 더 안정하였으며, HPLC 분석 결과 카테킨의 생존율이 3-5배 더 개선되었다. 또한 penetration effect를 측정한 결과 일반 리포좀보다 더 깊게 침투되었다. Wrinkle reduction effect를 한달 후에 측정한 결과 일반 리포좀보다 주름이 현저하게 감소되었다. 이러한 여러 가지 실험을 위해서 Laser light scattering system, cryo-SEM, chroma meter, HPLC, image analyzer, microfludizer 등을 사용하였다.

• 폴리머
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• 제37권1호
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• pp.94-99
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• 2013

폴리디아세틸렌(polydiacetylene, PDA)은 자기조립된 디아세틸렌(diacetylene) 단량체의 광중합에 의해 만들어진다. 디아세틸렌 단량체들이 조직적으로 배열되면 254 nm의 자외선 노광에 의해 1,4-첨가 중합이 일어나 고분자 주사슬에 이중결합과 삼중결합이 교대로 존재하는 폴리디아세틸렌이 만들어진다. 폴리디아세틸렌 수용액은 일반적으로 약 640 nm에서 최대흡수파장을 지니는 청색을 띠게 되며 여기에 온도나 pH의 변화, 다른 물질의 결합 등 외부 자극에 의해 약 550 nm의 최대 흡수 파장을 띠는 적색으로 색 전이가 일어나게 된다. 본 연구에서, 우리는 고체상 펩티드 합성을 이용하여 PCDA(10,12-pentacosadyinoic acid) 리포좀의 표면에 양이온성 올리고펩티드를 도입하였다. 또한 다양한 몰 비율로 리포좀 수용액을 제조하여 동물 세포에 트랜스펙션한 결과, 향상된 유전자 전달 효율과 낮은 독성을 보이는 것을 확인하였고, PCDA의 특성을 이용하여 세포에 처리 후 세포 관련 비표지 형광을 관찰하였다.

• Journal of Pharmaceutical Investigation
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• 제35권1호
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• pp.25-31
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• 2005

Depot system for local drug delivery using chitosan hydrogel has been developed to enhance the therapeutic efficacy and to prevent the severe side effect in whole body. Thus, we have prepared an injectable chitosan hydrogel containing liposomes to treat cancers clinically. Anionic liposomes incorporated to improve sustained release efficiency within chitosan hydrogel. The chitosan solution containing liposomes was designed to form a hydrogel complex at body temperature. The released behavior of doxorubicin from liposomes in chitosan hydrogel showed sustained-release caused by diffusion of doxorubicin from temperature responsive liposome into chitosan hydrogel. The chitosan hydorgel containing liposomes enhanced the therapeutic potency for the solid tumor in vivo system. Our results indicate that the liposomes in chitosan hydrogel represent a depot system for local drug delivery.

• BMB Reports
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• 제35권4호
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• pp.358-363
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• 2002

Chemical and photochemical processes during storage and preparation rapidly degrade retinol, the most active form of vitamin A. therefore, the efficacy of incorporation into liposomes in order to modulate the kinetics of retinol degradation was investigated. Retinol was readily incorporated into multilamellar liposomes that were prepared form soybean phosphatidylcholine; the extent of the incorporation was 98.14±0.93% at pH 9.0 at a ratio of 0.01 : 1 (wt:wt) retinol : phospholipid. It was only marginally lower at higher retinol concentrations. The pH of the hydration buffer had a small effect. The incorporation efficiency ranged from 99.25±0.47% at pH 3 to 97.45±1.13% at pH 11. The time course of the retinol degradation in the aqueous solution in liposomes was compared to that of free retinol and free retinol with α-tocopherol under a variety of conditions of pH(3, 7, and 11), temperature(4, 25, 37, and 50℃), and light exposure(dark, visible, and UV). The retinol that was incorporated into the liposomes degraded significantly slower than the free retinol or retinol with α-tocopherol at pH 7 and 11. At pH 3, where the free retinol degrades rapidly, the degradation kinetics were similar in liposomes and the presence of α-tocopherol. At pH 7.0 and 4℃ in the light, for example, free aqueous retinol was completely degraded within 2 days, while only 20% of the retinol in the liposomes were degraded after 8 days. In general, the protective effect of the liposome incorporation was greater at low temperatures, at neutral and high pH, and in the dark. The results suggest that protection is greater in the solid, gel phase than in the fluid liquid crystalline phase lipids. These results indicate that the incorporation into liposomes can extend the shelf-life of retinol under a variety of conditions of temperature, pH, and ambient light conditions.

• 한국환경과학회지
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• 제12권1호
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• pp.77-80
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• 2003

The interaction of mastoparan B, a cationic tetradecapeptide amide isolated from the hornet Vespa basalis, with phospholipid bilayers was studied with synthetic mastoparan B and its analogue with Ala instead of hydrophobic 12th amino acid residue in mastoparan B. MP-B and its derivative, [12-Ala]MP-B were synthesized by the solid-phase peptide synthesis method. MP-B and its analogue, [12-Ala]MP-B adopted an unordered structure in buffer solution. In the presence of neutral and acidic liposomes, the peptides took an $\alpha$-helical structure. The two peptides interacted with neutral and acidic lipid bilayers. These results indicated that the hydrophobic face in the amphipathic $\alpha$-helix of MP-B critically affected the biological activity and helical content.

• 한국응용과학기술학회지
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• 제26권3호
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• pp.233-239
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• 2009

A reaction device raising a generation yield by efficiently removing water generated in an esterified reaction between diethylene glycol monoethyl ether and succinic acid with mixture of an azeotropic point was newly developed as a new product in development of more stabilized emulsifier with a semi-solid phase(cream) in an emulsified phase of interfacial activity. The bis-(diethylene glycol monoethyl ether succinate(hereinafter, called as BDGS) with a high yield of more than 95% was obtained. As this has a property containing amphoteric emulsified functions such as W/O type or O/W type, etc., and has a merit that can be used regardless of any emulsified phase, there is no need using other emulsified surfactant. therefore, as this has excellent skin wetability in the cosmetics industry, a product having a wider range in quality compatibility or cost saving, etc. as a humectant has been developed.

• Journal of Pharmaceutical Investigation
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• 제26권4호
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• pp.245-256
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• 1996

Solid lipid nanoparticles (SLN) have been developed as a new drug delivery system. Although many particulate drug carriers, such as microsphere, liposome, niosome, emulsion, etc. have been introduced, they have some disadvantage; low efficiency of incorporation and stability, lack of reproducibility, and so on. Meanwhile, SLN as a new drug delivery system is known to entrap rugs with a high efficiency and a good reproducibility. Moreover, small size SLN can circulate in blood for a prolonged time. Although many preparation methods were introduced, microfluidization method is recommended to be the most useful. This study was attempted to prepare and evaluate ketoprofen-incorporated SLNs (keto-SLN), which were prepared by two methods, ultrasonication and microfluidization. Keto-SLN was evaluated by measurement of particle size and zeta potential, efficacy of entrapment, sedimentation volume, in virto release pattern. The mean particle size was about $0.1\;{\mu}m$, and the size was dependent on the type and the amount of emulsifier. Zeta potential was negative, $-9{\sim}-13mV$ and entrapment efficacy was very high and stability was good for at least 60 days in the respect of particle size and sedimentation volume ratio. Analgesic effect was also determined as well as pharmacokinetic parameters. The former was comparable to that of that of ketoprofen loaded suspension (keto-sus) and the latter revealed that consistent with the delayed release of keto-SLN. $T_{max}$ was longer than keto-sus. Therefore, keto-SLN was favourable dosage forms in the field of drug delivery system such as anti-cancer, analgesics and anti-inflammatory agents.

• BMB Reports
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• 제37권4호
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• pp.460-465
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• 2004

A 16-residue polypeptide model with the sequence acetyl-YALSLAATLLKEAASL-OH was derived by rational de novo peptide design. The designed sequence consists of amino acid residues with high propensity to adopt an alpha helical conformation, and sequential order was arranged to produce an amphipathic surface. The designed sequence was chemically synthesized using a solid-phase method and the polypeptide was purified by reverse-phase liquid chromatography. Molecular mass analysis by electro-spray ionization mass spectroscopy confirmed the correct designed sequence. Structural characterization by circular dichroism spectroscopy demonstrated that the peptide adopts the expected alpha helical conformation in 50% acetonitrile solution. Liposome binding assay using Small Unilamellar Vesicle (SUV) showed a marked release of entrapped glucose by interaction between the lipid membrane and the tested peptide. The channel-forming activity of the peptide was revealed by a planar lipid bilayer experiment. An analysis of the conducting current at various applied potentials suggested that the peptide forms a cationic ion channel with an intrinsic conductance of 188 pS. These results demonstrate that a simple rational de novo design can be successfully employed to create short peptides with desired structures and functions.