• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.251-251
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• 1994

1차년도에서 이미 확립한 다양한리포좀의 제조 방법에 따라간세포를표 적하기 위해 이들 리포좀의 조성에 galactocercbroside를 함유시켜 targeted liposomes을 제조하였다. 표적리포좀의 제조 방법에 따른 봉합율 (cncapsulation)과 안정성을 조사했을 때, freezing-thawing 과정을 거친 리포좀이 encapsulation 과 stability가 가장 뛰어남을 알 수 있었다. In vitro 간세포 표적능력을 in vitro cell culture system에서 간세포 cell line (Hep G2, 2.2.15과 다른 cell line (Vero E6, J82)에 대한 표적리포좀과 control liposomes의 uptake를 FTTC 또는 CF 형광으로 측정했을 때, 표적리포좀이 간세포 cell line에 더 많이 uptake하는 것을 알았다. In vivo 실험에서는 6 - 8 주령의 mouse tail vain에 표적리포좀과 control liposomes을 주사하여 각 장기에 존재하는 리포좀의 양을 형광으로 측정했을 때, 표적리포좀 (targetcd liposomes)이 다른 장기에 비해 liver에 선택적으로 많이 분포함을 알수있었다. 또한 간암의 효과적인 치료를 위해 간세포와 암세포를 동시에 표적할 수는 double targeting liposomes을 design 하였다.

• Textile Coloration and Finishing
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• v.33 no.4
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• pp.338-347
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• 2021

In the case of occlusive dressings currently used in dressings for burn treatment, it is impossible to confirm the replacement time, so replacement is delayed, resulting in additional infection. To solve this problem, liposomes capable of bacterial sensing were prepared using 5(6)-Carboxyfluorescein, Phosphatidylcholine, 1,2-Dipalmitoyl-sn-glycero-3-phosphocholine, Cholesterol, and 10,12-Tricosadiynoic acid. In this study, evaluation of changes in drug encapsulation rate in liposomes according to changes in three types of phosphatidylcholine phospholipids during liposome production, high-performance phosphatidylcholine phospholipids selected through vesicle size analysis, low and high temperature stability evaluation, bacterial sensitization ability evaluation, animals cell responses were assessed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.66-67
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• 2020

The synthesis of stearic acid composite phase change material (PCM) was investigated and the samples produced were characterized for use in latent heat storage, using a simple chemical sol-gel process. The PCM was encapsulated to tetraethyl orthosilicate by various preparation ratios of stearic acid (5, 10, 15, 20, 30 and 50%). Fourier transformation infrared spectroscope (FT-IR) and X-Ray diffraction (XRD) were performed to determine the chemical structure and crystalloid phase of the microencapsulated PCM. SATEOS1 (5%) shows the best proportion for the PCM. With the presence of stearic acid as core materials and SiO2 as the supporting materials, it does not show any chemical reaction between both of them. SATEOS1 shows promising potential for thermal energy storage as it shows a better encapsulation efficiency and good thermal stability.

• Polymer(Korea)
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• v.31 no.3
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• pp.215-220
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• 2007

The control of the surface energy by electrohydrodynamic force provides electrospraying with various potential advantages such as simple particle size control, mono-dispersity, high recovery, and mild processing conditions. The advantages are quite helpful to improve the stability of protein drug and control its release. Herein, the nano-encapsulation of protein drugs using electrospraying was investigated. Albumin as a model protein was processed using uniaxial and co-axial electrospraying, and chitosan, polycaporlactone (PCL), and poly (ethylene glycol) (PEG) were used as encapsulation materials. The major processing parameters such as the conductivity of spraying liquids, flow rate, the distance of electrical potential gradient, etc were measured to obtain the maximum efficiency. In the chitosan systems, mean particles size decreases as flow rate and the distance between nozzle and the collecting part decreases. In the uniaxial technique of the PCL systems, mean particles size decreases as flow rate decreases. In the coaxial technique of the PCL systems, it was found that the particles size gets larger under the application of the higher ratio of inner-to-outer liquid flow rates. The primary particles formed out of an electrospraying nozzle showed narrow particle size distribution, but once they arrived to the collecting part, aggregation behavior was observed obviously. Efficient nano-encapsulation of albumin with PCL, PEG, and chitosan was conveniently achieved using electrospraying at above 12 kV.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.170-174
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• 2006

For the purpose of developing a high quality agricultural microbial inoculant, methods and materials for improving encapsulation were investigated. Preparation of capsule was conducted by improving extrusion system with micro-nozzle and peristaltic pump. The sodium alginate was selected because of its cheapness, stability of cells, and gel formation ability. The yields, physical properties and gel formation abilities of extractable alginate from sea tangle were investigated by hot water extractable and alkali soluble methods. The extraction yields of hot water extractable alginate (HWEA) and alkali soluble alginate (ASA) from sea tangle were 8 and 20%, respectively. The HWEA was almost not viscous even in 1.5% of the sample solution, whereas the ASA was very highly viscous in above 3% sample solution. The gel formation ability of each samples varied from 1.5% to 5% and the ASA showed a good gel formation ability at 3% solution as commercial alginate (CA). The soil microbial inoculant, Bacillus thuringiensis, Bacillus subtilis, Lactobacillus plantarum and Geotrichum candidum encapsulated sodium alginate with starch and zeolite for stabilizer. The survivability of encapsulated soil microbial inoculant using alginate without stabilizer appeared to be 66, 52, 70 and 50%, respectively. Inclusion of starch and zeolite with alginate bead increased viabilities in Bacillus sp. and Geotrichum candidum by 81-83% and 89%, respectively.

• Journal of Dairy Science and Biotechnology
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• v.39 no.1
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• pp.27-35
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• 2021

The aim of this research was to investigate the potential application of casein phospho-peptide (CPP)/chitosan oligosaccharide (CSO) nanocomplexes to dairy foods. The physical stability of CPP/CSO nanocomplexes during storage in model dairy foods including milk and yogurt was assessed by measuring the size and polydispersity index of the nanocomplexes. Encapsulation efficiency and in vitro vitamin D release from CPP/CSO nanocomplexes during gastrointestinal digestion were determined using HPLC. CPP/CSO nanocomplexes with increased CPP concentrations and decreased pH displayed significantly increased average particle size. During storage in model dairy foods, CPP/CSO nanocomplexes prepared with lower CPP concentrations and raised pH exhibited excellent physical stability. Vitamin D encapsulation efficiency increased significantly (p<0.05) as CPP concentration and/or pH decreased. Less than 3% vitamin D were released under gastric digestion conditions in vitro, while 91% of encapsulated vitamin D was released by 2 h of incubation under intestinal conditions, indicating that CPP/CSO nanocomplexes could effectively protect vitamin D from gastric conditions for delivery to the intestines. In conclusion, CPP/CSO nanocomplexes can be applied to dairy foods as an effective vitamin D delivery system.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.17-24
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• 2021

Perovskite solar cells (PSCs) can be fabricated through solution process economically with variable bandgap that is controlled by composition of precursor solution. Tandem cells in which PSCs combined with silicon solar cells have potential to reach high power conversion efficiency over 30%, however, lack of long-term stability of PSCs is an obstacle to commercialization. Degradation of PSCs is mainly attributed to the mass transport of halide and metal electrode materials. In order to ensure the long-term stability, the mass transport should be inhibited. In this study, we confirmed degradation behaviors due to the mass transport in PSCs and designed buffer layers with LiF and/or SnO₂ to improve the long-term stability by suppressing the mass transport. Under high-temperature storage test at 85℃, PSCs without the buffer layers were degraded by forming PbI₂, AgI, and the delta phase of the perovskite material, while PSCs with the buffer layers showed improved stability with keeping the original phase of the perovskite. When the LiF buffer and encapsulation were applied to PSCs, superior long-term stability on 85℃-85% RH dump heat test was achieved; efficiency drop was not observed after 200 h. It was also confirmed that 90.6% of the initial efficiency was maintained after 200 hours of maximum power tracking test under AM 1.5G-1SUN illumination. Here, we have demonstrated that the buffer layer is essential to achieve long-term stability of PSCs.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.667-674
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• 2007

Phase behavior for the mixed aqueous surfactant systems of cationic octadecyl trimethyl ammonium chloride (OTAC)/anionic ammonium dodecyl sulfate (ADS)/water was examined. Below the total surfactant concentrations of 1.5 m molal, mixed micelles were formed. At the total surfactant concentrations higher than 1.5 m molal, there appeared a region where mixed micelles and vesicles coexist. As the surfactant concentration increased, the systems looked very turbid and much more vesicles were observed. The vesicles were spontaneously formed in this system and their existence was observed by negative-staining transmission electron microscopy (TEM), small-angle neutron scattering (SANS) and encapsulation efficiency of dye. The vesicle region was where the molar fraction α of ADS to the total mixed surfactant was from 0.1 to 0.7 and the total surfactant concentration was above 5 × 10-4 molality. The size and structure of the vesicles were determined from the TEM microphotographs and the SANS data. Their diameter ranged from 450 nm to 120μm and decreased with increasing total surfactant concentration. The lamellar thickness also decreased from 15 nm to 5 nm with increasing surfactant concentration and this may be responsible for the decrease in vesicle size with the surfactant concentration. The stability of vesicles was examined by UV spectroscopy and zeta potentiometry. The vesicles displayed long-term stability, as UV absorbance spectra remained unchanged over two months. The zeta potentials of the vesicles were large in magnitude (40-70 mV) and the observed longterm stability of the vesicles may be attributed to such high ζ potentials.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.3
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• pp.225-231
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• 2013

Oil in water nanoemulsion of astaxanthin was prepared by high pressure homogenization. The emulsifying conditions including emulsifier type, concentration and astaxanthin concentration were optimized. Stability of nanoemulsion was measured using zetasizer, freeze-fracture scanning electron microscope (FF-SEM), particle analyzer and colorimeter. The mean diameter of the dispersed particles containing astaxanthin ranged from 160 to 190 nm. Size distribution was unimodal and extended from 40 to 200 nm. The nanoemulsion prepared by glyceryl citrate/lactate/linoleate/oleate had smaller particle size and narrow size distribution. Stable incorporation of astaxanthin in nanoemulsion was performed and checked using high performance liquid chromatography (HPLC), freeze-fracture scanning electron microscope (FF-SEM). Physical stability of nanoemulsion was not significantly changed during storage at both light and thermal condition for a month with zeta potential value of -41 mV meaning stable colloid.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.653-653
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• 2013

In this study, ITO extended gate reduced graphene oxide field effect transistor (rGO FET) was demonstrated as a transducer for a proton sensing application. In this structure, the sensing area is isolated from the active area of the device. Therefore, it is easy to deposit or modify the sensing area without affecting on the device performance. In this case, the ITO extended gate was used as a gate electrode as well as a proton sensing material. The proton sensing properties based on the rGO FET transducer were analyzed. The rGO FET device showed a high stability in the air ambient with a TTC encapsulation layer for months. The device showed an ambipolar characteristic with the Dirac point shift with varying the pH solutions. The sensing characteristics have offered the potential for the ion sensing application.