• Journal of Pharmaceutical Investigation
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• 제37권1호
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• pp.15-22
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• 2007

An oil-in-water solvent evaporation method was used to prepare the cyclosporin A (CyA)-loaded nanoparticles varying in poly (D,L-lactide-co-glycolide) (PLGA) polymer (RG 502H, RG 503H) and the amount of additive ethyl myristate (EM) or chitosan (CS). The particles were characterized for drug loading and entrapment efficiency by HPLC, surface morphology by scanning electron microscopy, particle size by dynamic light scattering and surface charge by Zetapotential. The results showed drug loadings ranging from 10.9% to 15.8% with high encapsulation efficiency (82.0-97.8%). SEM and DLS studies showed discrete and spherical particles with smooth surfaces and mean size ranging 257.6-721.7 nm. The additive EM or CS did not change the mean sizes of the nanoparticles, whereas by the coating effect of CS, the Zetapotential values of the CS-added nanoparticles were moved to the more positive direction as the amount of CS was increased. From the pharmacokinetic analysis, the nanoparticles formulations showed the higher bioavailability and MRT than $Neoral^{\circledR}$ While little adding effect of EM or CS was detected in pharmacokinetic profile when RG 503H was used as polymer carrier, more noticeable different pharmacokinetic behaviors could be observed in case of RC 502H. EM incorporation was found to elevate the $K_{el}$, whereas CS coating resulted in the decrease of F and $K_{el}$, which seems to be due to the function of CS as a barrier and a mucoadhesive coating.

• Journal of Korean Neurosurgical Society
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• 제63권6호
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• pp.698-706
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• 2020

Objective : To study the physiochemical characteristics of podophyllotoxin (PPT) conjugated stearic acid grafted chitosan oligosaccharide micelle (PPT-CSO-SA), and evaluate the ability of the potential antineoplastic effects against glioma cells. Methods : PPT-CSO-SA was prepared by a dialysis method. The quality of PPT-CSO-SA including micellar size, zeta potential, drug encapsulation efficiency and drug release profiles was evaluated. Glioma cells were cultured and treated with PPT and PPT-CSO-SA. The ability of glioma cells to uptake PPT-CSO-SA was observed. The proliferation of glioma cells was determined by 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. The apoptosis and morphology of U251 cells were observed by 4',6-Diamidino-2-phenylindole dihydrochloride (DAPI) dye staining. Cell cycle analysis was performed by flow cytometry. The migration ability of U251 cells was determined by wound healing test. Results : PPT-CSO-SA had nano-level particle size and sustained release property. The encapsulation efficiency of drug reached a high level. The cellular uptake percentage of PPT in glioma cells was lower than that of PPT-CSO-SA (p<0.05). The inhibitory effect of PPT-CSO-SA on glioma cells proliferation was significantly stronger than that of PPT (p<0.05). The morphologic change of apoptosis cell such as shrinkage, karyorrhexis and karyopyknosis were observed. The percentage of U251 cells in G2/M phase increased significantly in the PPT-CSO-SA group compared with PPT group (p<0.05). Compared with the PPT group, the cell migration ability of the PPT-CSO-SA group was significantly inhibited after 12 and 24 hours (p<0.05). Conclusion : PPT-CSO-SA can effectively enhance the glioma cellular uptake of drugs, inhibit glioma cells proliferation and migration, induce G2/M phase arrest of them, and promote their apoptosis. It may be a promising anti-glioma nano-drug.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.348-354
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• 2009

Copper(II) complexes with tetraoxo dithia tetraaza macrocyclic ligands; [18]ane$N_4S_2$: 1,4,10,13-tetraaza-5,9,14,18-tetraoxo-7,16-dithia-cyclooctadecane, [20]ane$N_4S_2$: 1,5,11,15-tetraaza-6,10,16,20-tetraoxo-8,18-dithia-cyclocosane,Bzo2[18]ane$N_4S_2$: dibenzo-1,4,10,13-tetraaza-5,9,14,18-tetraoxo-7,16-dithia-cyclooctadecane, Bzo2[20]ane$N_4S_2$: dibenzo-1,5,11,15-tetraaza-6,10,16,20-tetraoxo-8,18-dithia-cyclocosane; were entrapped in the nanopores of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of [bis(diamine)copper(II)] (diamine = 1,2-diaminoethane, 1,3-diaminopropane, 1,2-diaminobenzene, 1,3-diaminobenzene); $[Cu(N-N)_2]^{2+}$-NaY; in the nanopores of the zeolite, and (ii) in situ template condensation of the copper(II) precursor complex with thiodiglycolic acid. The obtained complexes and new host-guest nanocomposite materials; $[Cu([18]aneN_4S_2)]^{2+}-NaY,\;[Cu([20]aneN_4S_2)]^{2+}-NaY,\;[Cu(Bzo_2[18]aneN_4S_2)]^{2+}-NaY,\;[Cu(Bzo_2[20]aneN_4S_2)]^{2+}$-NaY; have been characterized by elemental analysis FT-IR, DRS and UV-Vis spectroscopic techniques, molar conductance and magnetic moment data, XRD and, as well as nitrogen adsorption. Analysis of data indicates all of the complexes have been encapsulated within nanopore of zeolite Y without affecting the zeolite framework structure.

• Korean Chemical Engineering Research
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• 제50권3호
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• pp.574-581
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• 2012

OLED 소자는 수분과 산소의 침투에 의하여 유기물이 열화되어 수명이 감소하는 문제점을 가지고 있다. 이러한 문제점을 해결하기 위해서 OLED 소자의 봉지 기술이 최근 연구되고 있다. 현재 유리나 금속 용기를 이용하여 캡슐화 하는 방법이 널리 사용되고 있지만 이러한 방법으로는 유연한(flexible) 소자의 구현이 어렵기 때문에 이를 대체할 수 있는 기술들이 연구되고 있다. 박막 필름을 이용한 OLED의 봉지 기술은 유연한 디스플레이에 적용할 수 있는 기술로 사용될 수 있다. 본 연구에서는 치밀하고 결함이 없는 패시베이션(passivation) 박막을 형성하기 위해서 상온에서 증착이 가능한 PECVD를 이용한 무기 박막 증착 방법을 개발하고 증착 조건과 구조에 따른 OLED의 특성 변화를 분석하였다. 하나의 시스템에서 in-situ로 패시베이션할 수 있는 시스템 및 공정을 구축하였으며 단일 무기 박막의 WVTR(Water Vapor Transmission Rate) 값을 $1{\times}10^{-2}g/m^2{\cdot}day$ 이하로 확보하였고 제작된 박막을 패시베이션막으로 유연한 디스플레이에 적용할 수 있는 가능성을 제시하였다.

• 한국표면공학회지
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• 제50권5호
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• pp.339-344
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• 2017

Highly corrosion resistance performance of CrAlSiN coatings were obtained by applying ultrathin $Al_2O_3$ thin films using atomic layer deposition (ALD) method. CrAlSiN coatings were prepared on Cr adhesion layer/SUS304 substrates by a hybrid coating system of arc ion plating and high power impulse magnetron sputtering (HiPIMS) method. And, ultrathin $Al_2O_3$ passivation layer was deposited on the CrAlSiN/Cr adhesion layer/SUS304 sample to protect CrAlSiN coatings by encapsulating the whole surface defects of coating using ALD. Here, the high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and energy dispersive X-ray spectrometry (EDX) analysis revealed that the ALD $Al_2O_3$ thin films uniformly covered the inner and outer surface of CrAlSiN coatings. Also, the potentiodynamic and potentiostatic polarization test revealed that the corrosion protection properties of CrAlSiN coatings/Cr/SUS304 sample was greatly improved by ALD encapsulation with 50 nm-thick $Al_2O_3$ thin films, which implies that ALD-$Al_2O_3$ passivation layer can be used as an effect barrier layer of corrosion.

• Journal of Microbiology and Biotechnology
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• 제29권7호
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• pp.1096-1103
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• 2019

UCB-1 is the commercial rootstock of pistachio. Reproduction of this rootstock by tissue culture is limited by low levels of proliferation rate. Therefore, any compound that improves the proliferation rate and the quality of the shoots can be used in the process of commercial reproduction of this rootstock. Use of plant growth-promoting bacteria is one of the best ideas. Given the beneficial effects of nanoparticles in enhancement of the growth in plant tissue cultures, the aim of the present study was to investigate the effects of nanoencapsulation of plant growth-promoting rhizobacteria (using silica nanoparticles and carbon nanotubes) and their metabolites in improving UCB1 pistachio micropropagation. The experiment was conducted in a completely randomized design with three replications. Before planting, treatments on the DKW medium were added. The results showed that the use of Pseudomonas fluorescens VUPF5 and Bacillus subtilis VRU1 nanocapsules significantly enhanced the root length and proliferation. The nanoformulation of the VUPF5 metabolite led to the highest root length (6.26 cm) and the largest shoot (3.34 cm). Inoculation of explants with the formulation of the metabolites (both bacterial strains) significantly elevated the average shoot length and the fresh weight of plant compared to the control. The explants were dried completely using both bacterial strains directly and with capsule coating after the three days.

• 식품과학과 산업
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• 제51권3호
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• pp.245-258
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• 2018

Natural and synthetic antibacterial materials are used in foods to avoid bacterial contamination-induced food poison and deterioration. Due to the human and environmental safety, natural products including plant extracts have been extensively added into foods as antibacterial materials. Since some of core molecules comprised in those plant extracts are hardly dissolved in aqueous phases or food matrixes, nanotechnological approaches have been suggested to overcome such obstacles. Here we report domestic and international various types of plant- or non-plant-origin antibacterial materials that have been commercialized and used for the food industry. To improve solubility and stability of such antibacterial materials, nano-encapsulation or nano-complexation methods are also investigated focusing on the utilization of dextrins and proteins as coating materials.

• 한국산림과학회지
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• 제98권4호
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• pp.399-408
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• 2009

본 연구는 고로쇠 및 우산고로쇠 수액의 나노입자화를 통한 유용생리활성 증진에 관한 것이다. 먼저 나노입자 수액의 형태 및 크기 확인을 위하여 EF-TEM을 이용한 결과 유상이 주머니처럼 수액을 포집한 리포좀 형태를 띄고 있으며 약 200 nm 크기의 구형으로 형성된 것을 확인할 수 있었으며, 나노입자의 크기와 균일성 및 크기별 분포 측정을 위해 DLS를 이용한 결과 수십 nm에서 수천 nm의 크기를 보였고 그중 약 70%가 100~300 nm의 크기로 형성된 것을 확인하였다. 다음으로 나노입자의 세포독성 실험을 실시하였다. 일반 고로쇠 및 우산고로쇠 수액과 비교하여 큰 차이를 보이지 않았다. 이를 통해 나노입자화를 통한 세포독성의 위험은 없다고 판단하여, 인간 면역세포인 B 세포와 T 세포의 생육증진 실험을 하였다. 5일째 되는 날 가장 많은 세포의 수를 확인할 수 있었고 고로쇠 수액 보다는 우산고로쇠 수액의 면역세포 생육증진효과가 좋았다. 또한 일반 수액보다는 나노입자수액의 생육증진 효과가 크게 나타났다. Cytokine 분비량 및 NK 세포 활성의 경우에서도 위의 실험과 비슷한 결과를 얻을 수 있었다. 면역활성을 확인한 결과를 바탕으로 정상세포 독성 및 항암실험을 하였다. 인간 정상 폐세포인 HEL299에 대한 세포독성 실험 결과 수액 및 나노입자 수액 두 시료 전부 19%이하의 세포독성을 보임으로써 레시틴으로 포집한 수액의 정상세포에서의 안전성을 확인할 수 있었다. AGS, A549, Hep3B에 대한 암세포 생육억제실험결과 3가지 암세포에서 모두 수액에 비해 나노입자수액의 활성이 약 20% 증가 된 것을 확인할 수 있었다. 본 연구에서 수행한 일반 수액 및 나노입자 수액의 연구를 통하여 나노입자 수액의 기능성 소재로서의 활용성을 확인할 수 있었으며, 이를 바탕으로 더욱 다양한 생리활성 연구 및 유용생리활성 물질의 추출에 관한 연구가 이루어져야 할 것으로 생각된다.

• Journal of Pharmaceutical Investigation
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• 제41권6호
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• pp.381-386
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• 2011

Multi-drug resistance (MDR) has been known as a major hurdle in cancer chemotherapy. One of the most clinically significant causes of MDR was the efflux of anticancer agents mediated by p-glycoprotein (p-gp) over-expressed in MDR cancer cells. To overcome MDR, there have been several strategies such as co-administration with p-gp inhibitors and encapsulation of anticancer drugs into drug delivery systems. In the present study, curcumin was evaluated for its potential as p-gp inhibitor and MDR reversal activity when combined with paclitaxel incorporated into lipid nanoparticles (PTX/LN). Western blot assay showed curcumin did not modulate the level of p-gp expression in MCF-7/ADR which is a MDR variant of human breast cancer cell line, MCF-7, and over-expresses p-gp. However, curcumin inhibited p-gp-mediated efflux of calcein in a dose-dependent manner even though it showed lower activity compared to verapamil, a well-known p-gp inhibitor. Incorporation of paclitaxel into lipid nanoparticles partially recovered the anticancer activity of paclitaxel in MCF-7/ADR. The combined use of curcumin and PTX/LN exhibited further full reversal of MDR, suggesting susceptibility of PTX/LN to the efflux system. In conclusion, combined approach of using p-gp inhibitors and incorporation of the anticancer agents into nano-delivery systems would be an efficient strategy to overcome MDR.

• Journal of Dairy Science and Biotechnology
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• 제23권1호
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• pp.19-26
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• 2005

Nanofood can be simply defined as natural polymer particles containing functional food materials in nanoscale that are synthesized by polymerization or emulsification process. They have very uniform diameters in the range of 1 to 100nm and extensive surface areas due to the small particle size in spite of their non-porosity. Although the technique to produce nanofood has not long developing history, many works have been achieved in various fields. Nanofood has a lot of special advantages, such as functionality, diversity, applicability, etc. In case of the domestic food industries, however, the accumulation of related technique is insufficient against developed countries except used food materials. Also, it is difficult to acquire technical know-how from the developed countries that possess those technologies. We have been studied on preparing functional nanofood and developing new production processes since 1999. Last 5 years we have laid the foundation on the preparation of nanofood and now are focusing on developing new processes of nanofood and expending the field of its applications.