• Title/Summary/Keyword: microsphere

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Preparation and Biodegradability of Microsphere Prepared from Biodegradable Microgel (생분해성 Microgel로부터 약물을 담지한 Microsphere의 제조 및 그의 생분해성)

  • Kim, Kong Soo;Kang, Seok Ho;Kim, Jeong Muk
    • Applied Chemistry for Engineering
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    • v.9 no.4
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    • pp.591-594
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    • 1998
  • Biodegradable microsphere containing bovine serum albumine (BSA) as a model drug were prepared with the microgel based on poly(caprolactone diol) by a modified solvent evaporation method. The influence of the stirring speed, the concentration of microgel and the mixing rate but increased with increasing the concentration of microgel in methylene chloride. The biodegradability of microsphere in 100 unit/mL of lipase solution was investigated. A lot of small pores appeared on the surface of microsphere after 3 hours of incubation time and the pores and cracks were developed with increasing the incubation time and microsphere lost their own shape after 36 hours of incubation time.

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Preparation of Silica/collagen Microsphere Composit Doped with Silver Nanoparticles (은 나노입자를 담지한 collagen/silica microsphere 복합체의 제조)

  • Jung, Hyo Jung;Kim, Yeon Bum;Chang, Yoon Ho
    • Korean Chemical Engineering Research
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    • v.46 no.4
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    • pp.722-726
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    • 2008
  • Silica microsphere is a world leading innovative material used in adsorbent packing materials in HPLC technology. The application of microsphere lies in the ability to the surface modification of silica with the special materials such as polymers, metals and bio-active materials. Collagen is a major structural protein of connective tissues and has a good biocompatibility. In this study, we prepared the purified silica porous microsphere, having micro diameters in the range of a pore volume at least 50% by the aggregation procedure of colloidal silica with the polymerization method (PICA). The microspheres were modified by collagen hydrogel to improve the biocompatible properties for biomedical product. The silica/collagen microsphere composite doped with silver nanoparticles was prepared and investigated the capabilities of biomaterial application through the evaluation of the structure characteristics of the microsphere composit.

Preparation and Application of Microcapsule - Preparation and Properties of Suspension-Polymerized Poly(vinyl alcohol) Microsphere with Core-Shell Structure - (마이크로캡슐의 제조와 응용 - 분산중합에 의한 core/shell 구조를 지닌 Poly(vinyl alcohol) Microsphere의 제조와 특성 -)

  • 김혜인;김효정;박수민
    • Textile Coloration and Finishing
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    • v.15 no.4
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    • pp.65-72
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    • 2003
  • Poly(ethylene-co-vinylacetate) (EVA) microspheres were prepared by a thermally induced phase separation. Poly(vinyl Alcohol) (EVAL) microsphere with Core-Shell Structure were synthesized by a saponification on sheath of EVA microspheres. The size of EVA core/EVAL shell microsphere was decreased from $4.09\mu{m}\;to\;2.55\mu{m}$ by partial saponification of $NaOH/Na_2SO_4$/methanol(2 : 1 : 1 by weight) at $60^\circ{C}$ for 4h to produce a saponified surface layer of about 60% of original radius. In this process, the surface layer of EVAL microsphere was dissolved partially and morphology of surface was not showed. Add-on of cotton and silk printed with EVA core/EVAL shell microsphere was increased and that of printed PET was decreased. In case of EVA core/EVAL shell microsphere, Hand of cotton and silk printed was flexible and fullness.

Development of Functional Microsphere( II ) - Surface Modification and Properties of EVA Microsphere - (기능성 microsphere의 개발(II) - EVA Microsphere의 표면개질과 특성 -)

  • Kim Hea-In;Park Heung-Sup;Park Soo-Min
    • Textile Coloration and Finishing
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    • v.17 no.3 s.82
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    • pp.26-33
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    • 2005
  • EVA microsphere was prepared by a thermally induced phase separation. EVAL microsphere was made by a saponification on sheath of EVA microsphere. And microcapsule with EVA core-PU shell structure was synthesized by interfacial polymerization using diisocyanates with PEG in gelatin aqueous solution as the stabilizing agent. The effects of chemical structure of diisocyanate on the average particle size and distribution, morphology, color strength and friction fastness of core-shell particles were investigated to design microcapsule. The friction fastness of the fabrics printed with EVA core-PU shell microcapsules had the 4-5 grade.

Dissolution properties of Chitin or Chitosan Microsphere Containing p-Aminosalicylic Acid (p-Aminosalicylic acid를 포함하고 있는 Chitin, Chitosan-Microsphere의 용출특성)

  • 임정수;김공수
    • Journal of Biomedical Engineering Research
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    • v.10 no.1
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    • pp.59-66
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    • 1989
  • The Applicability of chitin or chitosan microsphere as means to achieve sustained release of p-aminosalicylic acid(PAS) has been examined. The microsphere of chitin or chitosan containing PAS were prepared by coacervation in acidic aqueous system in range of pH 2.0-4.0. The dissolution test of PAS from polymeric drug system was carried out in vitro test. The dissolution rate of PAS from the microsphere with chitin was significanthly lower than that from the microsphere with chitosan.The dissolution rate of PAS from the microsphere was decreased with increasing of concentration of chitin and chitosan. The sustained release of PAS from the microsphere was more effective at pH 1.2 than pH 6.8.

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Improved Antigen Delivery Systems with PLGA Microsphere for a Single-Step Immunization (PLGA 미립구를 이용한 새로운 단회 접종 항원 전달 시스템의 개발)

  • Yoon, Mi-Kyeong;Choi, Young-Wook
    • Journal of Pharmaceutical Investigation
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    • v.34 no.1
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    • pp.1-14
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    • 2004
  • A promising approach to the development of a new single-step vaccine, which would eliminate the requirement for multiple injections, involves the encapsulation of antigens into microspheres. Biodegradable poly(lactide-co-glycolide) (PLGA) microspheres gave us a bright insight for controling antigen release in a pulsatile fashion, thereby mimicking two or tree boosting injections. However, in spite of the above merits, the level of immunization induced by a single-shot vaccination is often lower tan two doses of alum-adsorbed antigen. Therefore, optima modification of the microsphere is essential for the development of single-step vaccines. In the review, we discuss the stability of antigen in microsphere, safety and non-toxic in human and encapsulation technology. Also, we attempted to outline relevant physicochemical properties on the immunogenicity of microsphere vaccine and attainment of pulsatile release pater by combination of different microsphere, as well as to analyze immunological data associated with antigen delivery by microsphere. Although a lot of variables are related to the optimized microsphere formulation, we could conclude that judicious choice of proper polymer type, adjustment of particles size, and appropriate immunization protocol along with a suitable adjuvant might be a crucial factor for the generation of long-lasting immune response from a single-step vaccine formulation employing PLGA microsphere.

Development of functional microsphere(II) - Formation and Characteristics of Poly(ethylene-co-vinylacetate) Microsphere with Pigment - (기능성 마이크로스피어의 개발(II) - 안료를 함유한 에틸렌-비닐아세테이트 공중합체의 마이크로스피어 제조와 특성 -)

  • Lee, Shin-Hee;Park, Soo-Min
    • Textile Coloration and Finishing
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    • v.17 no.4 s.83
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    • pp.15-20
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    • 2005
  • Poly(ethylene-co-vinylacetate)(EVA) microspheres were prepared by thermally induced phase separation in toluene. The microsphere formation occurred by the nucleation and growth mechanism in metastable region. The effects of the polymer or pigment weight percentage and cooling rate on microsphere formation were investigated. The microsphere formation and growth were followed by the cloud point of the optical microscope measurement. The microsphere size distribution, which was obtained by particle size analyzer, became broader when the polymer concentration was higher, the pigment concentration and the cooling rate of EVA copolymer solution were lower.

Chemically Bonded Thermally Expandable Microsphere-silica Composite Aerogel with Thermal Insulation Property for Industrial Use

  • Lee, Kyu-Yeon;Phadtare, Varsha D.;Choi, Haryeong;Moon, Seung Hwan;Kim, Jong Il;Bae, Young Kwang;Park, Hyung-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.26 no.2
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    • pp.23-29
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    • 2019
  • Thermally expandable microsphere and aerogel composite was prepared by chemical compositization. Microsphere can produce synergies with aerogel, especially an enhancement of mechanical property. Through condensation between sulfonated microsphere and hydrolyzed silica sol, chemically-connected composite aerogel could be prepared. The presence of hydroxyl group on the sulfonated microsphere was observed, which was the prime functional group of reaction with hydrolyzed silica sol. Silica aerogel-coated microsphere was confirmed through microstructure analysis. The presence of silicon-carbon absorption band and peaks from composite aerogel was observed, which proved the chemical bonding between them. A relatively low thermal conductivity value of $0.063W/m{\cdot}K$ was obtained.

Preparation and Application of Functional Microsphere (II) Formation and Characteristics of Poly(ethylene-co-vinylacetate) Microsphere with Disperse Dye (기능성 마이크로스피어의 제조와 응용(II) 분산염료를 함유한 에틸렌-비닐아세테이트 중합체의 마이크로스피어 제조와 특성)

  • Lee, Shin-Hee;Cho, Hyun;Park, Soo-Min
    • Fashion & Textile Research Journal
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    • v.10 no.3
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    • pp.371-376
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    • 2008
  • Poly(ethylene-co-vinylacetate) (EVA) microspheres were prepared by thermally induced phase separation (TIPS) in toluene. The microsphere formation occurred by the nucleation and growth mechanism in metastable region. The effects of the concentration and component of the polymer and cooling rate on microsphere formation were investigated. The microsphere formation and growth were followed by the cloud point of the optical microscope measurement. The microsphere size distribution, which was obtained by particle size analyzer, became broader when the polymer concentration was higher, the content of vinyl acetate in EVA copolymer was higher, the cooling rate of EVA copolymer solution were lower. The content of disperse dye in EVA microsphere was obtained by TGA thermal analysis, the dye content of EVA15 and EVA18 were 3.5 and 2.0 wt% respectively.

Synthesis of Magnetic Polystyrene-Polyimide Core-Shell Microsphere (자성 폴리스티렌-폴리이미드 Core-Shell 마이크로스피어의 합성)

  • Ahn, Byung-Hyun
    • Elastomers and Composites
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    • v.47 no.2
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    • pp.168-173
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    • 2012
  • Polystyrene-polyimide core-shell microsphere was prepared by dispersion polymerization using poly(amic acid) as the stabilizer. Iron oxide was formed at the microsphere by thermal decomposition of iron pentacarbonyl impregnated in the microsphere. The magnetic polystyrene-polyimide microsphere was monodisperse and the size was about 500 nm. The magnetic polystyrene-polyimide microsphere had 40% of iron oxide, which was identified as $Fe_3O_4$ by X-ray diffraction.