• 제목, 요약, 키워드: Poly(l-lactide)

검색결과 182건 처리시간 0.039초

폴리펩티드-의약 전달체 및 폴리펩티드 공중합체의 합성 및 물성에 관한 연구 (Ⅰ) L-Lactic Acid 와 L-Glutamic Acid 공중합체의 합성 및 그의 물성 (Studies on Synthesis of Block Copolymers Containing Polyester and Polypeptide for Drug Delivery System Ⅰ. Synthesis and Characterization of Copolymer of L-Lactic Acid and L-Glutamic Acid)

  • 김홍범;성용길;정재희;백형게;민태진;김영순
    • 대한화학회지
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    • v.34 no.2
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    • pp.203-210
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    • 1990
  • 의약 전달체에 사용되는 생체분해성 고분자로서 L-lactic acid 와 L-glutamic acid가 각기 다른 조성비로 이루어진 공중합체를 합성하였다. Poly (L-lactide)는 zink oxide를 이용하여 합성하였으며, Poly (L-lactide) 말단에 3-Amino-l-propanol을 도입시킨 다음 이미 합성된 γ-benzyl-L-glutamate-N-carboxyanhydride (γ-BLG-NCA)를 개환중합시켜서 block copoly (L-lactide-γ-benzyl-L-glutamate)를 합성하였다. NMR로써 L-lactide와 γ-BLG-NCA가 서로 일정한 비율로 이루어진 공중합체가 합성되었음을 확인하였으며, 생성된 공중합체들의 열적성질은 시차주사열량계법 및 열무게 측정법으로 조사하였다.

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Synthesis and Properties of Triblock and Multiblock Copolymers Consisting of Poly(L-lactide) and Poly(oxyethylene-co-oxypropylene)

  • Lee, Chan-Woo;Kang, Young-Goo;Kun Jun
    • Macromolecular research
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    • v.9 no.2
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    • pp.84-91
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    • 2001
  • Both A-B-A triblock and multiblock copoly(ester-ether)s consisting of poly(L-Lactide) and poly(oxyethylene-co-oxypropylene) were prepared and characterized. The preparation of the triblock copolymer was done by ring-opening copolymerization of L-lactide with a commercially available telechelic copolyether, Pluronic$\^$TM/(PN) by catalysis of stannous octanoate. The molecular weight and unit composition of the produced copolymers were successfully controlled by changing the L-lactide/PN ratio in feed. However, a high molecular weight copolymer incorporating PN in large amount was not obtained because the molecular weight of the resulting copolymer was limited at a high L-lactide/PN composition. The multiblock copolymer was synthesized by the copolycondensation of oligo(L-lactic acid) prepared by thermal dehydration of L-lactic acid, PN, and dodecanedioic acid as carboxyl/hydroxyl adjusting agent. This polycondensation proceeded by catalysis of stannous oxide to give multiblock copolymers with high molecular weight and wide range of compositions.

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Poly(D,L-lactide)를 외부 껍질로 하고 Alginate 또는 Chitosan을 내부 코어로 구성한 이중미립구 담체의 약물방출 특성 (Drug-release Properties of Double-layered Microspherical Carriers which Consist of Outer Shell of Poly(D,L-lactide) and Inner Core of Alginate or Chitosan)

  • 김자원;송민정;이상민;임소령;정수진;김홍성
    • 폴리머
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    • v.36 no.6
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    • pp.699-704
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    • 2012
  • 경구투여를 통한 친수성 약물의 방출조절을 위하여 이중층으로 된 고분자 담체를 설계하였다. 생체고분자인 alginate와 chitosan은 각각 극성 흡수성분으로, poly(D,L-lactide)는 소수성 피막으로, 그리고 theophylline과 diclofenac sodium은 모델 약물로 사용하였다. 담체는 지연방출과 이어지는 지속방출을 위하여 외부 껍질은 poly(D,L-lactide)로, 내부중심은 약물과 함께 알지네이트 또는 키토산으로 구성되어진 이중층의 미립구 담체로 성형하였다. 담체와 약물간의 극성 조합으로 인한 담체의 모폴로지와 약물방출 거동을 조사하였다. 담체와 약물 그리고 pH 환경의 상대적 극성이 약물방출 특성에 상당한 영향이 있음을 확인하였다.

Thermal Decomposition Kinetics of Copolymers Derived from p-dioxanone, L-lactide and Poly(ethylene glycol)

  • Bhattarai Narayan;Khil Myung Seob;Oh Seung Jin;Kim Hak Yong;Kim Kwan Woo
    • Fibers and Polymers
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    • v.5 no.4
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    • pp.289-296
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    • 2004
  • The kinetic parameters, including the activation energy E, the reaction order n, and the pre-exponential factor Z, of the degradation of the copolymers based on the poly(L-lactide) (PLLA) or poly(p-dioxanone-co-L-lactide) (PDO/PLLA) and diol-terminated poly(ethylene glycol) (PEG) segments have been evaluated by the single heating methods of Friedman and Freeman-Carroll. The experimental results showed that copolymers exhibited two degradation steps under nitrogen that can be ascribed to PLLA or PDO/PLLA and PEG segments, respectively. However, copolymers exhibited almost single degradation step in air. Although the values of initial decomposition temperature were scattered, copolymers showed the lower maximum weight loss rate and degradation-activation energy in air than in nitrogen whereas the higher value of temperature at the maximum rate of weight loss was observed in air.

전기방사에 의한 이성질 폴리락타이드 블렌드의 섬유제조와 분해거동에 관한 연구 (Studies of Degradation Behavior of Stereochemical Poly(lactide) Blend Fibers Prepared by Electrospinning)

  • 정의습;이원기
    • Journal of Environmental Science International
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    • v.23 no.3
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    • pp.473-481
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    • 2014
  • Poly(lactide)s(PLA) is an attractive material to solve the problem of waste plastic accumulation in nature because of its biodegradability. The lactide exists in three stereoisomeric configurations: L-lactide, D-lactide, and meso-lactide. PLA stereocomplexes, formed by the mixing of two enantiomers, poly(L-lactide)(PLLA) and poly(D-lactide)(PDLA), have many favorable characteristics because the stereocomplex showed $50^{\circ}C$ higher melting point than each enantiomeric polymer and the resistance toward degradation increased. In this study, we investigated the influence of the composition and the optical purity of each component on the formation of stereocomplexes. Also, the nanofibers of stereochemical PLA and their blends were prepared by electrospinning method. The properties of the obtained fibers were analyzed by differential scanning calorimetry and scanning electron microscopy. The results showed that a degree of stereocomplex was controlled by change of optical purity of each component. The enzymatic degradation of the fibers were strongly dependent on the stereocomplex.

Poly(L-lactide-co-p-dioxanone) 세그먼트와 블록 공중합체의 합성 및 in-vitro물성 비교 (Synthesis of Segmented and Block Poly(L-lactide-co-p-dioxanone) Copolymers and Comparison of in-vitro Behavior of the Copolymers)

  • 김학용;이상욱;이덕래;길명섭
    • 한국섬유공학회지
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    • v.39 no.2
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    • pp.167-172
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    • 2002
  • The segmented and block copolymers of poly(L-lactide-co-p-dioxanone)(PDO) and L-lac-tide were prepared successfully by ring-opening polymerization in the presence of lauryl alcohol with stannous octoate catalyst. The products were characterized by SEM, $^1$H-NMR, $^{13}$ C-NMR, and scanning electron microscopy. The hydrolytic degradation of copolymers was studied in a phosphate buffer solution at pH=7.4 and 37$^{\circ}C$. The degradation behavior was evaluated by analyzing the morphological changes. The weight loss, pH, and inherent viscosity changes suggested diffusion of low molecular weight chain segments into the reaction medium as a consequence of the cleavage of ester bonds On the material. Surface morphological changes observed using SEM suggest a heterogeneous degradation mechanism.

poly(D,L-lactide-co-glycolide) nanoparticles제조와 약물방출 거동 및 생분해도

  • 유정준;정영일;오동석;임균택
    • 한국생물공학회:학술대회논문집
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    • pp.550-553
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    • 2000
  • The polymeric matrices made with poly(D,L-lactide-co-glycolide) were prepared using copolymer of poly(D,L-lactide) and poly(ethylene glycol) for application of drug delivery systems. Catalyst made use of stannous actoate. Particle size were differ greatly$(435.3{\pm}11.2{\sim}2284.1{\pm}188.5)$ that nanoparticle made use of according to solvent of various kinds. Polymer could a sharp distinction with copolymerized among LE-1, LE-2 and LE-3 of PLA and PEG of content that to examine $^1H-NMR$ of copolymer make refine and reprecipitation. Drug delivery effect at PLGA nanoparticle : PLA amount more then proved highly drug delivery amount that each LE-1, LE-2, LE-3, drug and solvent was 40mg, 20mg and 10mg. Drug delivery effect proved higher 20mg that change(10mg, 20mg, 40mg) at drug feeding amount with LE-2. The first a lot of drug proved delivery. LE-3 most lactide content proved much delivery since biodegradable on PLGA copolymer result from lactide. Also biodegradable rate was highest at LE-3 much of lactide content, because influence at biodegradable effect of lactide by inclusive of soft PEG.

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마이크로캡슐의 제조와 그 응용(폴리락티드 마이크로캡슐) (Preparation of Microcapsules and Their Application (Poly (L-lactide) Microcapsule))

  • 홍기정;박수민
    • 한국염색가공학회지
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    • v.10 no.2
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    • pp.29-36
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    • 1998
  • Poly(L-lactide) microcapsules containing hydrophilic penetrate were prepared by interfacial precipitation method through solvent evaporation from w/o/w emulsion. Effect of four determinative process parameters on the particle size distributions, morphologies, and release properties of microcapsules coated with poly(L-lactide) was investigated. Moreover, susceptible functional cotton fabrics treated with the mentioned microcapsules were prepared and laundry test up to 15 times were done to determine fastness properties. As a result, the prepared poly(L-lactide) microcapsules with a more sharp-distributive, rounder, and more permeable membranes could be prepared by means of protective colloid concentration, solution volume and stirring rate.

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Glycidol을 개시제로 이용한 L-lactide 개환중합 (Ring-Opening Polymerization of L-lactide with Glycidol as Initiator)

  • 임진형;김다희;고영수
    • 폴리머
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    • v.37 no.5
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    • pp.606-612
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    • 2013
  • $Al(O-i-Pr)_3$을 촉매로 이용하고 중합 개시제로 glycidol을 사용하여 L-lactide를 개환중합하여 glycidol-poly(lactide)(Gly-PLA)를 얻었다. $^1H$ NMR 분석 결과 glycidol의 말단에 존재하는 수산기가 Gly-PLA에는 존재하지 않았고 이를 통해 glycidol의 말단에 존재하는 OH기가 개시제의 역할을 하여 중합이 진행되었음을 확인하였다. Llactide용액중합과 벌크중합을 진행하였으며, L-lactide/glycidol 몰비, 중합 온도와 시간에 따라 생성된 Gly-PLA의 분자특성을 관찰하였다. L-lactide/glycidol 몰비가 증가할수록 수율과 분자량은 증가하였다. 또한 L-lactide/glycidol 몰비가 증가할수록 저분자량에 해당하는 낮은 녹는점 피크는 줄어들고, 고분자량에 해당하는 높은 녹는점 피크가 증가하였다.

Assessment of Biodegradability of Polymeric Microspheres in vivo: Poly(DL-lactic acid), poly(L-lactic acid) and poly(DL-lactide-co-glycolid) microspheres

  • Oh, In-Joon;Oh, Jhin-Yee;Lee, Kang-Choon
    • Archives of Pharmacal Research
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    • v.16 no.4
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    • pp.312-317
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    • 1993
  • To confirm a new evaluation tedhnique for biodegradability of biopolymer microsphers in vivo condition, magnetic microsphere sytem was adopted for tracing the microspheres injected and lodged in micr. Microsphers of poly(DL-lactic acid), poly(L-alctic acid) and poly(DL-lactide-coglycolide)(PLGA) were prepared by solvent-extraction method and their organ distribution and biodegradation in mice was examined. Magnetic microspheres lodged in mice organs were recollected from the homogenates of mice organs with a constant flow magnetic separation apparatus. Recollected microspheres were observed by scanning electron microscopy and also were assayed for their magnetite ocntent by atomic absorption spectrophotometry to evaluate the biodegradability of polymeric microspheres. This method seems to be practical and simple to estimate the biodegradability of biopolymers over the conventional methods.

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