• Title, Summary, Keyword: nanoprecipitation

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All-trans Retinoic Acid Release from Surfactant-free Nanoparticles of Poly(DL-lactide-co-glycolide)

  • Jeong, Young-Il;Kim, Don-Gon;Jang, Mi-Kyeong;Nah, Jae-Woon;Kim, Yong-Bae
    • Macromolecular Research
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    • v.16 no.8
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    • pp.717-724
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    • 2008
  • In this study, we prepared all-trans retinoic acid (ATRA)-encapsulated, surfactant-free, PLGA nanoparticles. The nanoparticles were formed by nanoprecipitation process, after which the solvent was removed by solvent evaporation or dialysis method. When a nanoparticle was prepared by the nanoprecipitation - solvent evaporation method, the nanoparticles were bigger than the nanoparticles of the nanoprecipitation - dialysis method, despite the higher although loading efficiency. Nanoparticles from the nanoprecipitation - dialysis method were smaller than 200 nm in diameter, while the loading efficiency was not significantly changed. Especially, nanoparticles prepared from DMAc, 1,4-dioxane, and DMF had a diameter of less than 100 nm. In the transmission electron microscopy (TEM) observations, all of the nanoparticles showed spherical shapes. The loading efficiency of ATRA was higher than 90% (w/w) at all formulations with exception of THF. The drug content was increased with increasing drug-feeding amount while the loading efficiency was decreased. In the drug release study, an initial burst was observed for $2{\sim}6$ days according to the variations of the formulation, after which the drug was continuously released over one month. Nanoparticles from the nanoprecipitation - dialysis method showed faster drug release than those from the nanoprecipitation - solvent evaporation method. The decreased drug release kinetics was observed at lower drug contents. In the tumor cell cytotoxicity test, ATRA-encapsulated, surfactant-free, PLGA nanoparticles exhibited similar cytotoxicity with that of ATRA itself.

Formation of Poly(ethylene glycol)-Poly($\varepsilon$-caprolactone) Nanoparticles via Nanoprecipitation

  • Lee, Jae-Sung;Hwang, Su-Jong;Lee, Doo-Sung;Kim, Sung-Chul;Kim, Duk-Joon
    • Macromolecular Research
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    • v.17 no.2
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    • pp.72-78
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    • 2009
  • Size control of therapeutic carriers in drug delivery systems has become important due to its relevance to biodistribution in the human body and therapeutic efficacy. To understand the dependence of particle size on the formation condition during nanoprecipitation method, we prepared nanoparticles from biodegradable, amphiphilic block copolymers and investigated the particle size and structure of the resultant nanoparticles according to various process parameters. We synthesized monomethoxy poly(ethylene glycol)-poly($\varepsilon$-caprolactone) block copolymer, MPEG-PCL, with different MPEG/PCL ratios via ring opening polymerization initiated from the hydroxyl end group of MPEG. Using various formulations with systematic change of the block ratio of MPEG and PCL, solvent choice, and concentration of organic phase, MPEG-PCL nanoparticles were prepared through nanoprecipitation technique. The results indicated that (i) the nanoparticles have a dual structure with an MPEG shell and a PCL core, originating from self-assembly of MPEG-PCL copolymer in aqueous condition, and (ii) the size of nanoparticles is dependent upon two sequential processes: diffusion between the organic and aqueous phases and solidification of the polymer.

Preparation of Valuable Compounds Encapsulated Polymer Nanoparticles with High Payload Using Core-crosslinked Amphiphilic Polymer Nanoparticles (코아 가교 양친성 고분자 나노입자를 이용한 고함량 유용 약물 담지 고분자 나노입자 제조)

  • Kim, Nahae;Kim, Juyoung
    • Applied Chemistry for Engineering
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    • v.27 no.1
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    • pp.26-34
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    • 2016
  • In this study, core-crosslinked amphiphilic polymer (CCAP) nanoparticles prepared using a reactive amphiphilic polymer precursor (RARP) were used for preparing some valuable compounds encapsulated polymer nanoparticles with high payload through nanoprecipitation process. Various solvents (acetone, ethanol, and THF) having different polarity and CCAP nanoparticles prepared using different amphiphilicity were used for the preparation of ${\alpha}$-tocopherol encapsulated polymer nanoparticles to investigate their effects on the encapsulation efficiency, payload, nanoparticle size, and stability. CCAP dissolved in hydrophobic solvent, THF, could form ${\alpha}$-tocopherol encapsulated polymer nanoparticles dispersed in water with the high payload of ${\alpha}$-tocopherol and encapsulation efficiency. Because of their physically and chemically robust nano-structure originated from crosslinking of the hydrophobic core, CCAP nanoparticles could encapsulate ${\alpha}$-tocopherol with the high payload (33 wt%) and encapsulation efficiency (97%), and form 70 nm-sized stable nanoparticles in water.

Synthesis of methoxy poly(ethylene glycol)-b-poly(ᴅʟ-lactide-co-glycolide) copolymer via diselenide linkage and fabrication of ebselen-incorporated nanoparticles for radio-responsive drug delivery

  • Choi, Changyong;Lee, Hyo Young;Jeong, Young-Il;Nah, Jae-Woon
    • Journal of Industrial and Engineering Chemistry
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    • v.47
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    • pp.112-120
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    • 2017
  • The ebselen has radio-protective effect. In this study, we investigate radio-protective effect of ebselen-incorporated nanoparticles using methoxy poly(ethylene glycol)-b-poly($\text\tiny{DL}$-lactide-co-glycolide) copolymer (LEsese). Ebselen-incorporated LEses nanoparticles were fabricated by nanoprecipitation and dialysis method. Their radio-protective effect was assessed under irradiation conditions in vitro and in vivo. The diameter was around 100 nm with spherical shapes. The ebselen release from nanoparticles was accelerated by irradiation dose. It compensated radiation damage against cells. Especially, ebselen-incorporated nanoparticles have superior radio-protective effects against animal's whole body irradiation trials. We suggest that LEsese nanoparticles are good candidate for radiation-responsive drug delivery and radioprotection application.

Preparation of Hydrophobic Antimicrobal Compounds Encapsulated Nanoparticles Using Alkoxysilane-functionalized Amphiphilic Polymer Precursor and Their Antimicrobial Properties (실란 기능화 양친성 고분자 전구체를 이용한 소수성 항균물질 담지 나노 입자 제조 및 항균 특성)

  • Kim, Nahae;Kim, Juyoung
    • Journal of Adhesion and Interface
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    • v.18 no.1
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    • pp.13-24
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    • 2017
  • In this study, nanoparticles which encapsulated hydrophobic antimicrobial compounds with 50wt% of payload and 70%of solid content were prepared. These nanoparticles could be dispersed at water as well as various medium. Water dispersible organic-inorganic (O-I) hybrid nanoparticles were first prepared using alkoxysilane-functionalized amphiphilic polymer precursors through a conventional sol-gel process. Hydrophobic antimicrobial compound, Eugenol encapsulated nanoparticles were prepared using these O-I hybrid nanoparticles through a new nanoprecipitation process. The effect of various preparation on the size of nanoparticles, amount of payload, antimicrobial activity, and release rate of encapsulated compounds was investigated. All eugenol-encapsulated O-I nanoparticles regardless of preparation condition showed the same minimal inhibitory concentration (MIC) (50mg/ml) and 99% of antimicrobial activity for every strain. Their antimicrobial activity could maintain longer than two weeks. Especially, eugenol-encapsulated O-I nanoparticles prepared using tetraethoxysilane (TEOS) exhibited the highest payload (50wt%) and the lowest release rate which was owing to higher inorganic content in the O-I nanoparticles. And these O-I nanoparticles dispersed in hexanediol (HD) showed the highest antimicrobial activity and solid content (70wt%) because HD acted as a solvent as well as a antimicrobial agent.