• Title/Summary/Keyword: MPEG-polyester

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Synthesis of Methoxy Poly(ethylene glycol)/Polyesters Diblock Copolymers and Evaluation of Micellar Characterization as Drug Carrier (메톡시 폴리(에틸렌 글리콜)/폴리에스테르 블록공중합체의 합성 및 미셀 특성 비교)

  • Hyun, Hoon;Yang, Jae-Chan;Kim, Moon-Suk;Lee, Hai-Bang;Khang, Gil-Son
    • Polymer(Korea)
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    • v.30 no.6
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    • pp.464-470
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    • 2006
  • Diblock copolymers consisting of methoxy Poly (ethylene glycol) (MPEG) and poly (${\epsilon}-ca$ prolactone) (PCL), poly(${\delta}-valerolactone$) (PVL), poly(L-lactide) (PLLA), or poly(L-lactide-co-glycolide) (PLGA) were prepared to compare the characterization of diblock copolymers as a drug carrier. MPEG-PCL, MPEG-PVL, MPEG-PLLA, and MPEG-PLGA diblock copolymers were synthesized by the ring-opening polymerization of ${\epsilon}$-caprolactone or ${\delta}$-valerolactone in the presence of $HCl{\cdot}Et_2O$ as a monomer activator at room temperature and by the ring-opening polymerization of L-lactide or a mixture of L-lactide and glycolide in the presence of stannous octoate at $130^{\circ}C$, respectively. The synthesized diblock copolymers were characterized with $^1H-NMR$, GPC, DSC, and XRD. The micellar characterization of MPEG-polyester diblock copolymers in an aqueous phase was carried out by using NMR, dynamic light scattering, AFM, and fluorescence techniques. Most micelles exhibited a spherical shape in AFM. Thus, ore confirmed that the micelles formed with MPEG-polyester diblock copolymers have possibility as a potential hydrophobic drug delivery vehicle because a hydrophobic drug could be preferentially distributed in the micelle core.

Thermosensitive Sol-gel Phase Transition Behavior of Methoxy poly(ethylene glycol)-b-poly($\varepsilon$-caprolactone) Diblock Copolymers (메톡시 폴리(에틸렌 글리콜)-폴리($\varepsilon$-카프로락톤) 공중합체의 온도감응성 솔-젤 전이 거동)

  • 서광수;박종수;김문석;조선행;이해방;강길선
    • Polymer(Korea)
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    • v.28 no.4
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    • pp.344-351
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    • 2004
  • Poly(ethylene glycol)-based diblock and triblock polyester copolymers stimulating to temperature were studied as injectable biomaterials in drug delivery system because of their nontoxicity, biocompatibility and biodegradability. We synthesized the diblock copolymers consisting of methoxy poly(ethylene glycol) (MPEG) (M$_{n}$=750 g/mole) and poly($\varepsilon$-caprolactone) (PCL) by ring opening polymerization of $\varepsilon$-CL with MPEG as an initiator in the presence of HCl . Et$_2$O. The aqueous solution of synthesized diblock copolymers represented sol phase at room temperature and a sol to gel phase transition as the temperature increased from room temperature to body temperature. To confirm the in vivo gel formation, we observed the formation of gel in the mice body after injection of 20 wt% aqueous solution of each block copolymer. After 2 months, we observed the maintenance of gel without dispersion in mice. In this study, we synthesized diblock copolymers exhibiting sol-gel phase transition and confirmed the feasibility as biomaterials of injectable implantation.n.

Osteogenic Differentiation of Bone Marrow Stem Cells Using Thermo-Sensitive Hydrogels (온도감응성 수화젤을 이용한 골수간엽줄기세포의 골분화 유도)

  • Kim, Sun-Kyung;Hyun, Hoon;Kim, Soon-Hee;Yoon, Sun-Jung;Kim, Moon-Suk;Rhee, John-M.;Khang, Gil-Son;Lee, Hai-Bang
    • Polymer(Korea)
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    • v.30 no.3
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    • pp.196-201
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    • 2006
  • Poly (ethylene glycol)-based diblock and triblock thermo- sensitive polyester copolymers were investigated for application on tissue engineering and injectable biomaterials in drug delivery system due to their nontoxicity, biocompatibility and biodegradability. We synthesized the diblock copolymers consisting of methoxy poly (ethylene glycol) (MPEG) (Mn=750 g/mole) and poly $(\varepsilon-caprolactone)$ (PCL) by ring opening polymerization of $\varepsilon-CL$ with MPEG as an initiator in the presence of HCl $Et_2O$. The effect of diblock copolymers on in vivo osteogenic differentiation of rat bone marrow stromal cells (BMSCS) with and without the presence of osteogenic supplements (dexamethasone) was investigated. Thin sections were cut from paraffin embedded tissues and histological sections were stained by H&E, von Kossa, and immunohistochemical staining for osteocalcin. In conclusion, dexamethasone containing thermo- sensitive hydrogel might be improved osteogenic differentiation of BMSCs. We expect the osteoinduction effect to be excellent when it uses stem cell or other osteogenic materials.