• Korean Chemical Engineering Research
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• 제50권6호
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• pp.1064-1067
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• 2012

최근 저가의 풍부한 재생 가능 천연자원인 식물성 오일에 대한 관심이 증가되고 있다. 식물성 오일은 친환경적인 생분해성 고분자 물질들의 원료로서 사용될 수 있다. 본 연구에서는 acrylated epoxidized soybean oil (AESO)과 2-aminoethanol의 중합 반응에 의해 poly(${\beta}$-amino ester)를 합성하였다. AESO와 2-aminoethanol의 몰비를 변화시켜 다양한 비율의 고분자 필름을 제조하였다. FT-IR을 이용하여 poly(${\beta}$-amino ester) 내의 C-N 결합의 생성을 확인하였으며, 98% 이상의 겔함량으로부터 가교 고분자 네트웍이 합성되었음을 확인하였다. 고분자 필름의 인장강도와 신장률은 각각 0.3~1.3 MPa, 32~55%였다. 고분자 필름은 lipase 효소가 첨가된 pH 7.2 완충용액에서 35일 경과 후 2~7%의 질량감소를 보였다.

• Macromolecular Research
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• 제15권5호
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• pp.437-442
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• 2007

Poly(ethylene glycol) methyl ether (PEG)-poly(${\beta}$-amino ester) (PAE) block copolymers were synthesized using a Michael-type step polymerization, and the construction of pH-sensitive polymeric micelles (PM) investigated. The ${\beta}$-amino ester block of the block copolymers functioned as a pH-sensitive moiety as well as a hydrophobic block in relation to the ionization of PAE, while PEG acted as a hydrophilic block, regardless of ionization. The synthesized polymers were characterized using $^1H-NMR$, with their molecular weights measured using gel permeation chromatography. The $pK_b$ values of the pH-sensitive polymers were measured using a titration method. The pH-sensitivity and critical micelle concentration (CMC) of the block copolymers in PBS solution were estimated using fluorescence spectroscopy. The pH dependent micellization behaviors with various bisacrylate esters varied within a narrow pH range. The critical micelle concentration at pH 7.4 decreased from 0.032 to 0.004 mg/mL on increasing the number of methyl group in the bisacrylate from 4 to 10. Also, the particle size of the block copolymer micelles was determined using dynamic light scattering (DLS). The DLS results revealed the micelles had an average size below 100 nm. These pH-sensitive polymeric micelles may be good carriers for the delivery of an anticancer drug.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.263-263
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• 2006

Poly (ethylene glycol)(PEG) - Poly (${\varepsilon}-caprolactone(CL)$) - Poly (D,L lactide(LA) (PCLA-PEG-PCLA) was synthesized by ring-opening polymerization to form temperature sensitive hydrogel triblock copolymer. The triblock copolymer was acrylated by acryloyl chloride. ${\beta}-amino$ ester was used as a pH sensitive moiety, in this study ${\beta}$- amino ester obtained from 1,4-butandiol diacrylate, and 4, 4' trimethylene dipiperidine, it have pKb around 6.6. pH/temperature sensitive penta-block copolymer (PAE-PCL-PEG-PCL-PAE) was synthesized by addition polymerization from acrylated triblock copolymer, 1,4-butandiol diacrylate, and 4, 4' trimethylene dipiperidine. Their physicochemical properties of triblock and penta-block copolymers were characterized by $^1H-NMR$ spectroscopy and gel permeation spectroscopy. Sol-gel phase transition behavior of PAE-PCL-PEG-PCL-PAE block copolymers were investigated by remains stable method. Aqueous media of the penta-block copolymer (at 20 wt%) changed from a sol phase at pH 6.4 and $10^{\circ}C$ to a gel phase at pH 7.4 and $37^{\circ}C$. The sol-gel transition properties of these block copolymers are influenced by the hydrophobic/hydrophilic balance of the copolymers, block length, hydrophobicity, stereo-regularity of the hydrophobic of the block copolymer, and the ionization of the pH function groups in the copolymer depended on the changing of environmental pH, respectively. The degradation and the stabilization at pH 7.4 and $37^{\circ}C$, and the stabilization at pH 6.4 and $10^{\circ}C,\;5^{\circ}C,\;0^{\circ}C$, of the gel were determined. The results of toxicity experiment show that the penta block copolymer can be used for injection drug delivery system. The sol?gel transition of this block copolymer also study by in vitro test ($200{\mu}l$ aqueous solution at 20wt% polymer was injected to mouse). Insulin loading and releasing by in vitro test was investigated, the results showed that insulin can loading easily into polymer matrix and release time is around 14-16days. The PAE-PCL-PEG-PCL-PAE can be used as biomaterial for drug, protein, gene loading and delivery.

• 폴리머
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• 제36권6호
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• pp.822-830
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• 2012

본 연구에서는 실리카 나노입자를 우수한 내가수분해성을 가지는 dipodal 형태의 bis[3-(trimethoxysilyl)propyl]amine(BTMA) 실란 커플링제로 표면 개질한 후, 실리카에 도입된 BTMA의 2차 아미노기인 N-H기와 마이클 부가반응이 가능한 acrylate기를 1분자당 2개씩 가지는 poly(ethylene glycol)diacrylate(PEGDA)로 표면 처리하여 acrylate기를 실리카 입자 표면에 도입하는 연구를 수행하였다. PEGDA의 몰수 및 3가지 서로 다른 분자량의 PEGDA(M.W. 258, 575, 700) 처리가 실리카 표면에 도입되는 acrylate기의 구조에 미치는 영향을 fourier transform infrared spectroscopy(FTIR), elemental analysis(EA, 원소분석) 및 고체 상태 $^{13}C$ cross-polarization magic angle spinning(CP/MAS) nuclear magnetic resonance spectroscopy(NMR)법을 사용하여 분석하였다. 액체상태의 순수 PEGDA와 순수 BTMA를 같은 몰 비로 반응시키면 PEGDA 1분자당 2개씩 존재하는 acrylate기 중 1개 acrylate기는 순수 BTMA의 N-H기와 1:1의 비율로 마이클 부가반응이 일어나 ${\beta}$-amino acid ester를 형성하고, 나머지 1개의 acrylate기는 남아서 중합반응이 가능한 단량체 합성이 가능하다. 하지만, BTMA로 개질된 실리카 입자를 PEGDA와 반응시키면, PEGDA 1분자당 2개씩 결합있는 acrylate기 대부분이 실리카 입자에 결합되어 있는 BTMA의 N-H기와 마이클 부가반응으로 ${\beta}$-amino acid ester를 형성하여, acrylate기의 C=C기 대부분이 C-C로 변화함을 확인하였다.

• Macromolecular Research
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• 제14권1호
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• pp.117-120
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• 2006

• 폴리머
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• 제35권6호
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• pp.558-564
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• 2011

생체적합하고 생분해성을 갖는 폴리아미노산의 하나인 폴리아스팔트산은 팹타이드 결합으로 이루어진 수용성 합성고분자로서 의료용 소재 및 다양한 응용분야의 연구가 흥미있게 진행되어 왔다. 본 연구에서는 아미노산인 GABA(${\gamma}$-aminobutylic acid)와 ${\beta}$-alanine을 곁사슬에 도입한 폴리아스팔트산 유도체 고분자를 제조하고, 이들을 서로 다른 함량의 ethylene glycol diglycidyl ether(EGDE)를 사용하여 가교시켜 고흡수성 하이드로젤을 제조하였다. 각 하이드로젤에 대해 증류수와 PBS 용액에서 기본적인 팽윤물성, 젤의 가수분해 거동과 모폴로지를 조사하였다. 제조한 하이드로젤은 수용액에서 pH와 염(salt) 농도에 의존하는 민감성 팽윤거동을 보였으며, 또한 비교적 빠른 가수분해 거동을 나타내었다.

• Macromolecular Research
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• 제13권2호
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• pp.147-151
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• 2005

The main objective of this study was to modulate pH-sensitive polymers (poly($\beta-amino esters$)) by controlling their molecular weight during their synthesis. These pH-sensitive and biodegradable polymers were synthesized by Michael-type step polymerization. 1,4-Butane diol diacrylate was used as the unsaturated carbonyl compound and piperazine as the nucleophilic compound. Various molecular weight polymers were obtained by varying the mol ratio of piperazine/1,4-butane diol diacrylate. The synthesized polymers were characterized by $^{1}H-NMR$ and their molecular weights were measured by gel permeation chromatography(GPC). The dependence of the molecular weight on the mol ratio was evaluated by the titration method. Also, the pH dependent turbidity of the polymers was determined by UV-Vis spectrophotometry. This pH dependent property of the polymers could be very useful for preparing drug carriers that are sensitive to pH.

• Macromolecular Research
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• 제17권2호
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• pp.99-103
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• 2009

We evaluated the efficacy of pH-sensitive micelles, formed by methoxy poly(ethylene glycol)-b-poly($\beta$)-amino ester) (PEG-PAE), as carriers for paclitaxel (PIX), a drug currently used to treat various cancers. PTX was successful encapsulated by a film hydration method. Micelles encapsulated more than 70% of the PTX and the size of the PTX-encapsulated micelles (PTX-PM) was less than 150 nm. In vitro experiments indicated that the micelles were unstable below pH 6.5. After encapsulation of PTX within the micelles, dynamic light scattering (DLS) studies indicated that low pH had a similar demicellization effect. An in vitro release study indicated that PTX was slowly released at pH 7.4 (normal body conditions) but rapidly released under weakly acidic conditions (pH 6.0). We demonstrated the safety of micelles from in vitro cytotoxicity tests on HeLa cells and the in vivo anti-tumor activity of PTX-PM in B16F 10 tumor-bearing mice. We concluded that these pH-sensitive micelles have potential as carriers for anti-cancer drugs.