• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.570-573
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• 2005

The spray method was chiefly used to prepare alginate microspheres. Additionally due to formation at mild conditions, the alginate microspheres were coated with chitosan. The particle size of alginate microspheres increased when the sodium alginate increased. Release pattern of OVA in alginate microspheres was evaluated at PBS buffer(pH 7.4) and HCl buffer(pH 1.2). Release rate of OVA from chitosan/alginate microsphere was also lower than that with the concentration of alginate in the microspheres, the amount of OVA released from alginate microspheres increased from alginate micorsphere. Therefore, the alginate microspheres can be prepared by spray rozzle for a protein drug delivery. OVA release from the alginate microspheres was controlled by a coating with chitosan.

• Fashion & Textile Research Journal
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• v.10 no.2
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• pp.254-259
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• 2008

Poly(ethylene-co-vinylacetate)(EVA) microspheres were prepared by a thermally induced phase separation. The microsphere formation occurred by the nucleation and growth mechanism in the metastable region. The diluents used were toluene. The microsphere formation and growth was followed by the cloud point of the optical microscope measurement. The microsphere size, which was obtained by SEM observation and particle size analyzer, became decreased when the titanium dioxide($TiO_2$) concentration was higher. The deodorizing function of the prepared fabrics was studied by the determination of the decomposing capability for $NH_3$. The deodorant activity of these deodorizing fabrics was measured by chromogenic gas detector tubes. The deodorant activity of $NH_3$ increased with increasing $TiO_2$ concentration of EVA microsphere.

• Journal of the Korean Ceramic Society
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• v.41 no.7
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• pp.513-517
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• 2004

Porous alumina ceramics with aligned plate-shaped pores were fabricated by using thermoplastic microsphere in order to show the anisotropy in thermal conductivity. The mixed powder of alumina and microsphere was pressed under 15 MPa till 20$0^{\circ}C$ to deform polymer into platelet-shape and sintered at 1,00$0^{\circ}C$ for 1 h. The sintered specimen with 10 wt% microsphere has 45.3% porosity and the bending strength of 44 MPa. The microstructural investigation confirmed the pore structure of platelet-shape, the thermal conductivities for vertical and parallel directions are 3.803 W/mK and 7.818 W/mK, respectively, the ratio between two directions exceeds 2.

• Journal of Veterinary Clinics
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• v.19 no.2
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• pp.228-235
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• 2002

Mastitis is the most costly disease results in lost milk production, decreased milk quality, milk discard, early culling of cows, drug costs and labor costs in dairy cow. Until now, a antibiotic administration at the end of lactation, dry cow therapy has been known the most effective and widely used mastitis control method. However, dry cow therapy do not control a new infection in the late dry and prepartum period because dry cow products have only persistent activity in the early dry period. Therefore, this study was conducted to evaluate clinical effect of sustained released biodegradable cephalexin microsphere using PLGA in bovine mastitis control during dry period. PLGA has been approved as controlled drug release system because of non-toxic, non-tissue reactive and bioerodible characteristics. This study revealed that cephalexin microsphere had a spherical shape with characteristic porous structure on the surface. Also, in vitro drug release studies are clearly observed that the release rate of cephalexin from PLGA microsphere decrease during the first 21 days after initial burst and then increase again between 3 and 4 weeks showing pulsatile releasing pattern. On the other hand, as tried in field the new infection rate, cure rate and mean SCC after parturition in cephalexin microsphere infused group were significantly differenced as compared to the control group. Accordingly, a sustained release of cephalexin from a biodegradable microsphere could make dry cow therapy more efficiently by preventing a new infection and decreasing the number of existing infection of mammary gland during dry period.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.157-160
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• 1992

표면에 여러 가지 기능성기를 가지는 microspheres는 immunoassay, drug delivery system, cell separation등 의용공학분야에 응용이 기대되고 있다. 이들 분야의 응용을 위하여 유화제를 사용하지 않으면서, 기존의 회분식, 반회분식, seed 중합법등의 문제점을 극복한 two stage shot growth technique올 개발하여 여러 가지 기능성기가 표면에 도입된 microspheres를 제조하였으며, 응용의 전단계로서 이들 microspheres에 대한 모델 단백질(BSA)의 흡착실험을 pH, 기능 성기의 종류와 양, BSA농도를 변수로 행하여 최대 흡착량을 보이는 조건을 결정하였다.

• KSBB Journal
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• v.25 no.3
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• pp.297-302
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• 2010

Ketoprofen is one of the propionic acid class of nonsteroidal anti-inflammatory drug with analgesic and antipyretic effects. The most common side effects from ketoprofen after oral administration are gastrointestinal irritation, diarrhea, abdominal pain and retention of fluid. Ketoprofen was formulated as water-soluble gels to reduce these side effects. To increase the skin permeability of ketoprofen, microsphere containing ketoprofen was prepared with chitosan and ploy-$\varepsilon$-caprolactone. And then prepared microsphere was manufactured as an adhesive hydrogel with polyvinylpyrrolidone K-25, polyethylene glycol 4000, and various permeation enhancers. The flux and permeability of ketoprofen were evaluated. As the concentration of tween 80 and enhancers increased, the flux of ketroprofen was accelerated. Also the permeation rate was facilitated by enhancers, but did not affect the lag time. From these results, the adhesive hydrogel using microsphere could be a good delivery system for ketoprofen to improve the skin permeation.

• Textile Coloration and Finishing
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• v.15 no.4
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• pp.57-64
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• 2003

Poly(ethylene-co-vinyl acetate)(EVA) microspheres were prepared by a thermally induced phase separation. The microsphere formation occurred by the nucleation and growth mechanism in the metastable region. The diluent used was toluene. The microsphere formation and growth was followed by the cloud point of the optical microscope measurement. The microsphere size distribution, which was obtained by SEM observation and particle size analyzer, became broader when the polymer concentration was higher, the content of vinyl acetate in EVA copolymer was higher, and the cooling rate of EVA copolymer solution was lower.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5299-5303
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• 2013

Poly(butyl methacrylate-co-polyethyleneglycol methacrylate) (Poly(BMA-co-PEGMA)) microsphere was prepared by precipitation copolymerization of PEGMA and butyl methacrylate in ethanol solution. Microspheres were controlled by experimantal conditions 140nm to 210nm. The particle size of Poly(BMA-co-PEGMA) microspheres was decreased with increasing the concentration of PEGMA and increased with BMA of monomer.

• Journal of Life Science
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• v.17 no.12
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• pp.1754-1759
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• 2007

This study is performed to assess the preparation and characterization of lactic acid bacteria (Sterpoccoccus thermophilus) loaded with alginate microsphere using alginate and chitosan for the efficient delivery of lactic acid bacteria to large intestine. Size and morphology of alginate microsphere were confirmed $6{\sim}10{\mu}m$ with spherical shape by scanning electronic microscope (SEM). Biodegradation study of alginate was investigated at different buffer solutions (pH 1.2 and 7.4). This result showed that alginate microsphere did not degrade at pH 1.2 buffer solution but it's degradation occurred from first day at pH 7.4 buffer solution. Survivability test of lactic acid bacteria in alginate microsphere showed that it was keeping activity of lactic acid bacteria by chroma meter. Therefore, the introduction of alginate microsphere might be a potential system to efficiently delivery lactic acid to large intestine.

• Environmental Mutagens and Carcinogens
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• v.22 no.2
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• pp.65-69
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• 2002

To elucidate the effect of microsphere coinjection on the administration of oligodeoxynucleotides (ODN), we have investigated biodistribution of ［S-35］-labeled antisense ODN targeted to cAMP-dependent protein kinase (PKA) RI-$\alpha$ subunit in nude mice xenografted with WiDr (human colon cancer, ATCC CCL218). The strategy of using microsphere has been proposed for cancer treatment as a carrier of therapeutic ODN so that it could offer an advantage with respect to maintaining constant ODN levels in blood and obtaining higher therapeutic ODN concentration at tumor sites. Comparative biodistribution studies were performed in nude mice (female, 20 g of body weight, n = 4-6) xenografted with WiDr cancer cells, when 0.1 $\mu$Ci (specific activity, 2.94 mCi/$\mu$mole) of ［S-35］-labeled RI-$\alpha$ antisense ODN was injected alone or with microsphere (PLG-18, polylactic copolymer with cationic surfactant DDAB18). Peak tumor uptake of ［S-35］-labeled ODN was significantly increased from 17.7% (at 6 h) of injected dose per gram of tissue (ID/g) to 42.5% (at 24 h) ID/g when microsphere was coinjected with ODN. The different biodistribution in the kidney accumulation (e.g., 100.2% ID/g for ODN alone and 54.9%/ID/g for microshpere coinjection) may contribute to higher blood concentration (e.g., 21.5%ID/$m\ell$ for ODN alone and 37.5%ID/$m\ell$ for microsphere coinjection) of radiolabeled ODN. Of importance is the fact that the whole body retention of radioactivity increased with microsphere coinjection from 50.8%ID/g to 68.0%ID/g after 24-h of injection. This decreased kidney accumulation and increased whole body retention of ［S-35］-labeled ODN resulted in a significant improvement of ODN targeting to the tumor site. In conclusion, the coinjection of microsphere appears to be an important carrier system in vehiculation of antisense oligonucleotide to the tumor tissue in vivo.