• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1992년도 제2차 학술발표초록집
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• pp.109-110
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• 1992

• 한국재료학회:학술대회논문집
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• 한국재료학회 2005년도 춘계학술발표대회 및 제8회 신소재 심포지엄 논문개요집
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• pp.304-304
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• 2005

• Journal of Pharmaceutical Investigation
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• 제31권3호
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• pp.191-196
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• 2001

Biodegradable polymeric microspheres were studied for their usefulness as carriers for the delivery of vaccine antigens. However, protein antigen could be denatured during microencapsulation processes due to the exposure to the organic phase and stress condition of cavitation and shear force. Therefore this study was carried out to re-evaluate the degree of protein denaturation during microencapsulation with poly(lactide-co-glycolide) (PLGA) copolymer. PLGA microspheres containing ovalbumin (OVA), prepared by W/O/W multiple emulsification method, were suspended in pH 7.4 PBS and incubated with shaking at $37.5^{\circ}C$. Drug released medium was collected periodically and analyzed for protein contents by micro-BCA protein assay. In order to evaluate the protein integrity, release medium was subjected to the analyses of SDS-PAGE and size exclusion chromatography (SEC). And enzyme-linked immunosorbent assay (ELISA) was introduced to measure the immunoreactivity of entrapped OVA and to get an insight into the three-dimensional structure of epitope. The structures of entrapped protein were not affected significantly by the results of SDS-PAGE and SEC. However, immunoreactivity of released antigen was varied, revealing the possibility of protein denaturation in some microspheres when it was evaluate by ELISA method. Therefore, in order to express the degree of protein denaturation, antigenicity ratio (AR) was obtained as follows: amount of immunoreactivity of OVA/total amount of OVA released ${\times}100(%)$. ELISA method was an efficient tool to detect a protein denaturation during microencapsulation and the comparison of AR values resulted in more accurate evaluation for immunoreactivity of entrapped protein.

• Asian-Australasian Journal of Animal Sciences
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• 제21권2호
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• pp.299-306
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• 2008

This study was designed to develop microencapsulated Korean mistletoe extract, to determine the stability in vitro and to examine its application in milk. Coating materials used were polyglycerol monostearate (PGMS) and medium-chain triacylglyderol (MCT). The highest efficiency of microencapsulation was 78.3% with 15:1:40 (w/w/v) as PGMS : mistletoe extract : distilled water and 66.1% with 15:1 (w/w) as MCT : mistletoe extract. The size of microcapsule was about 30.0 and $19.5{\mu}m$ with PGMS and MCT, respectively. When microcapsules of mistletoe extract were incubated in simulated gastric fluid at pH 2 for 60 min, 14.8 and 17.2% of lectin was released from capsules which were coated with PGMS and MCT, respectively. Comparatively, 83.2 and 87.3% of lectin was released in simulated intestinal fluid (pH 8) after 60 min incubation of capsules coated with PGMS and MCT, respectively. The subsequent study determined the changes of physicochemical and sensory characteristics of milk with fortification of the mistletoe extract microcapsules during 12 day storage. TBA value was significantly lower in microcapsule-added groups than in the uncapsulated mistletoe extract-added group during the storage. When 100 ppm microencapsulated mistletoe extract was added, the L-, a- and b- values and viscosity were not significantly different from those of the control. In addition, the release of lectin from mistletoe extract over 12 days was 8.3 and 9.5 mg/100 ml in milk containing microcapsules made by PGMS and MCT, respectively. All sensory attributes showed a significant difference in uncapsulated mistletoe extract-added milk compared with other groups. The present study indicated that microcapsules of Korean mistletoe extract could be applied to milk and microcapsules coated with PGMS were effectively released in a simulated intestinal environment.

• Nutrition Research and Practice
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• 제7권5호
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• pp.366-372
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• 2013

The application of polyphenols has attracted great interest in the field of functional foods and nutraceuticals due to their potential health benefits in humans. However, the effectiveness of polyphenols depends on their bioactivity and bioavailability. In the present study, the bioactive component from green tea extract (GTE) was administrated orally (50 mg/kg body weight/day) as free or in a microencapsulated form with maltodextrin in rats fed a high fructose diet. High fructose diet induced features of metabolic syndrome including hypertriglyceridemia, hyperuricemia, increased serum total cholesterol, and retroperitoneal obesity. In addition, myocardial fibrosis was increased. In rats receiving high fructose diet, the lowering of blood triglycerides, total cholesterol, non esterified fatty acid (NEFA) and uric acid, as well as the reduction in final body weight and retroperitoneal fat weight associated with the administration of GTE, led to a reversal of the features of metabolic syndrome (P < 0.05). In particular, the administration of microencapsulated GTE decreased myocardial fibrosis and increased liver catalase activity consistent with a further alleviation of serum NEFA, and hyperuricemia compared to administration of GTE. Taken together, our results suggest that microencapsulation of the bioactive components of GTE might have a protective effect on cardiovasucular system by attenuating the adverse features of myocardial fibrosis, decreasing uric acid levels and increasing hepatic catalase activity effectively by protecting their bioactivities.

• Korea-Australia Rheology Journal
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• 제19권3호
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• pp.157-164
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• 2007

Microencapsulation of cells within microfluidic devices enables explicit control of the membrane thickness or cell density, resulting in improved viability of the transplanted cells within an aggressive immune system. In this study, living cells (3T3 and L929 fibroblast cells) are encapsulated within a semi-permeable membrane (calcium crosslinked alginate gel) in two different device designs, a flow focusing and a core-annular flow focusing geometry. These two device designs produce a bead and a long microfibre, respectively. For the alginate bead, an alginate aqueous solution incorporating cells flows through a flow focusing channel and an alginate droplet is formed from the balance of interfacial forces and viscous drag forces resulting from the continuous (oil) phase flowing past the alginate solution. It immediately reacts with an adjacent $CaCl_2$ drop that is extruded into the main flow channel by another flow focusing channel downstream of the site of alginate drop creation. Depending on the flow conditions, monodisperse microbeads of sizes ranging from $50-200\;{\mu}m$ can be produced. In the case of the microfibre, the alginate solution with cells is extruded into a continuous phase of $CaCl_2$ solution. The diameter of alginate fibres produced via this technique can be tightly controlled by changing both flow rates. Cell viability in both forms of alginate encapsulant was confirmed by a LIVE/DEAD cell assay for periods of up to 24 hours post encapsulation.

• 폴리머
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• 제35권2호
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• pp.152-156
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• 2011

본 연구에서는 페닐아세테이트를 core 물질로 하고 poly(urea-formaldehyde)를 캡슐막 구성물질로 하는 미세캡슐의 제조에 있어서, 교반속도, core/shell 질량비, 계면활성제 농도, 반응시간 등의 고정변수가 캡슐의 크기, 막두께, 표면형태 등의 특성에 미치는 영향을 조사하였다. FTIR 및 TGA에 의하여 원하는 미세캡슐이 제조되었음을 확인하였다. 캡슐의 특성은 광학현미경과 FE-SEM을 사용허여 분석하였다. 교반속도의 증가에 따라 캡슐의 크기와 막두께가 감소하는 것으로 나타났다. 캡슐막 구성물질 질량의 증가는 캡슐막의 두께와 막표면에 부착되는 나노업자의 양을 증가시키는 것으로 나타났다. 계면활성제 농도의 증가에 의해 캡슐크기와 캡슐막 두께가 감소하는 것으로 확연되었다. 반응시간을 증가시키면 캡슐의 수율과 막두께가 증가하는 것이 관찰되었다.

• Preventive Nutrition and Food Science
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• 제12권1호
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• pp.58-63
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• 2007

Bifidobacteria are probiotic organisms that provide both flavor and health benefits when incorporated as live cultures into commercial dairy products. Because bifidobacteria are very sensitive to environmental conditions (acids, temperature, oxygen, bile salts, the presence of other cultures, etc.), their viability in human gastrointestinal tract is limited. The microencapsulation of bifidobacteria is a process to protect them against harsh environmental conditions, thereby increasing their viability while passing through human gastrointestinal tract. To confirm the survival rate of microencapsulated Bifidobacterium breve CBG-C2 in milk, their survival rate was compared with several kinds of free bifidobacteria and lactic acid bacteria in commercial yogurt products under simulated gastric and small intestinal conditions. Double-microencapsulation of the bacteria was employed to increase the survival rate during digestion. The outer layer was covered with starch and gelatin to endure gastric conditions, and the inner layer was composed of a hard oil for the upper small intestinal regions. Almost all microencapsulted bifidobacteria in the milk survived longer than the free bifidobacteria and lactic acid bacteria in the commericial yogurt products under the simulated gastric conditions. Numbers of surviving free bifidobacteria and lactic acid bacteria in the commercial products were significantly reduced, however, the viability of the microencapsulated bificobacteria in the milk remained quite stable under gastric and small intestine conditions over 3$\sim$6 hrs. Thus double-microencapsualtion of bifidobacteria in milk is a promising method for improving the survival of bifidobacteria during the digestive process.

• Archives of Pharmacal Research
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• 제28권7호
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• pp.859-865
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• 2005

This study was designed to develop a microencapsulated, water-soluble isoflavone for application into milk and to examine the hypocholesterolemic effect of such a milk product in a rat diet. The coating material was medium-chain triglyceride (MCT) and the core material was watersoluble isoflavone. The microencapsulation efficiency was 70.2% when the ratio (w/w) of coating material to core material was 15:1. The isoflavone release from the microcapsules was 8% after 3-day storage at $4^{\circ}C$. In in vitro study, 4.0-9.3% of water-soluble isoflavone in simulated gastric fluid was released in the pH range of 2 to 5 after 60 min incubation; however, in simulated intestinal fluid at pH 8, 87.6% of isoflavone was released from the capsules after 40 min incubation time. In sensory analysis, the scores of bitterness, astringency, and off-taste in the encapsulated isoflavone-added milk were slightly, but not significantly, different from those in uncapsulated, isoflavone-added milk. In blood analysis, total cholesterol was significantly decreased in the isoflavone-added group compared with that in the control after 6-week feeding. Therefore, this study confirmed the acceptability of MCT as a coating material in the microencapsulation of water-soluble isoflavone for application into milk, although a slight adverse effect was found in terms of sensory attributes. In addition, blood total cholesterol was lowered in rats which had been fed a cholesterol-reduced and microencapsulated, isoflavoneadded milk for 6 weeks.

• 한국식품과학회지
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• 제29권6호
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• pp.1322-1326
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• 1997

미세캡슐화를 위한 기초 연구로 다양한 다당류의 점도를 측정하고, 분무건조법을 이용하여 미세캡슐을 제조하여 특성을 비교하였다. 10% maltodexrin의 점도는 2.2 mPa.s, 10% gum arabic은 9.2 mPa.s, 10% dextran은 13.0 mPa.s, 1% gum locust bean은 4660.0 mPa.s, 1% gum karaya는 77.0 mPa.s로 측정되었다. 분무건조기를 이용하여 제조한 각종 다당류의 미세캡슐을 전자현미경으로 관찰한 결과, gum arabic은 20%의 농도에 비하며 30%에서 입자가 크게 형성되었으나 40%에서는 섬유상의 늘어진 형태가 관찰되었다. Maltodextrin 30%메서 고른 분포의 원형 입자가 관찰되었으며, 40%의 농도에서는 다양한 크기의 입자가 뭉쳐서 관찰되었다. Dextran은 20%에서 구형의 캡슐이 골고루 관찰되었으나, 30%이상의 농초에 서는 섬유상의 형태가 관찰되었다. Gum arabic : maltodextrin (1:3, w/w) 경우에서는 20%, 30%, 40%농도에서 구형의 캡슐이 고르게 관찰되었고 농도가 높을수록 입자의 크기가 증가하였다.