• Journal of Periodontal and Implant Science
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• 제39권2호
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• pp.167-176
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• 2009

Purpose: The purpose of this study is to histologically and histomorphometrically evaluate the effect of PLGA on bone regeneration compared with bone graft material. Methods: The experimental study was conducted in 10 rabbits with 2 different healing periods of 2 and 4 weeks. Following surgical exposure of the calvarium, 4 circular bone defects with a diameter of 4.6mm were formed. Rabbits were divided into control group, test groups I, and II. 10 defects assigned to the test group Ⅰ were grafted with Nu-oss and other 10 defects assigned to the test group II were grafted with PLGA. The rest of the defects were in the negative control group. At 2nd and 4th week after surgery, 10 rabbits were sacrificed through intracardiac perfusion and then specimens were obtained. Histological analysis was performed following staining with trichorme and transversal sectioning of the calvarial bone. Results: A group which used PLGA showed tissue reactions characterized by severe inflammation, rather than distinctive new bone formation. Conclusions: The present experimental investigations have failed to prove any beneficial effects of PLGA. PLGA used in this study exhibited foreign body reactions and a less favorable pattern of new bone formation in comparison to control group. Conclusion: PLGA did not function as scaffold. Further investigations of many types of micro PLGA that could improve its potential in GBR procedures are needed.

• Macromolecular Research
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• 제8권6호
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• pp.276-284
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• 2000

A wettability chemogradient on poly(L-lactide-co-glycolide) (PLGA) films was prepared by treating the films in air with corona from a knife-type electrode whose power increases gradually along the sample length. The PLGA surfaces oxidized gradually with the increasing corona power, and the wettability chemogradient was created on the surfaces as evidenced by the measurement of water contact angles and electron spectroscopy for chemical analysis. The wettability chemogradient PLGA surfaces were used to investigate the interaction of four different types of cells such as hepatoma (Hep G2), osteoblast (MG 63), bovine aortic endothelial (CPAE), and fibroblast (NIH/3T3) cells in terms of the surface hydrophilicity/hydrophobicity of PLGA. The cells adhered and grown on the chemogradient surface along the sample length were counted and observed by scanning electron microscopy. It was observed that the cells were adhered, spread, and grown more onto the positions with moderate hydrophilicity of the wettability chemogradient PLGA surface than the more hydrophobic or hydrophillic positions, regardless of the cell types used. The maximum adhesion and growth of the cells appeared at around water contact angles of 53～55°. This result seems closely related with the serum protein adsorption on the surface; the serum proteins were also adsorbed more onto the positions with moderate hydrophilicity of the wettability chemogradient surface. It seems that the wettability plays important roles for cell adhesion, spreading and growth on the PLGA surface. The surface modification technique used in this study may be applicable tothe area of tissue engineering for the improvement of tissue compatibility of films- or scaffold-type substrates.

• Journal of Pharmaceutical Investigation
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• 제34권3호
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• pp.177-183
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• 2004

Recently, studies on intranasal mucosa delivery of influenza vaccine have been actively developed because of lack of pain and ease of administration. We studied on preparation of nanoparticle delivery system using biodegradable polymer as a poly(DL-lactide-co-glycolide) (PLGA) and their binding characteristics with vaccine. Three kinds of PLGA nanoparticles were prepared by spontaneous emulsification solvent diffusion (SESD) method using sodium dodecyl sulfate and sodium laurate as an anionic surfactant and Lutrol F68 (polyethylene glycol-block-polypropylene glycol copolymer) as a nonionic surfactant. The 5-aminofluorescein labeled vaccine was coated on the surface of nanoparticles by ionic complex. The complexes between vaccine and nanoparticles were confirmed by change of the size. After vaccine coating on the surface of anionic nanoparticles, particle size was increased from 174 to 1,040 nm. However the size of nonionic nanoparticles was not more increased than size of anionic nanoparticles. The amount of coated vaccine on the surface of PLGA nanoparticles was $14.32\;{\mu}g/mg$ with sodium dodecyl sulfate, $12.41\;{\mu}g/mg$ with sodium laurate, and $9.47{\mu}g/mg$ with Lutrol F68, respectively. In conclusion, prepared nanoparticles in this study is possible to use as a virus-like nanoparticles and it could be accept in the field of influenza vaccine delivery system.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.417.1-417.1
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• 2002

The in vitro release of rhGH from PLGA microspheres was characterized. rhGH-loaded PLGA microspheres were prepared with 50:50 poly(D.L-lactide-co-glycolide) (PLGA) polymers using a double emulsion process. To simulate rhGH release under physiological conditions. the microspheres were suspended in a physiological buller at 37$^{\circ}C$. Quantification of the rhGH released and its molecular form analysis were carried out using SE-HPLC. (omitted)

• 폴리머
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• 제36권3호
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• pp.326-331
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• 2012

본 연구에서는 혈액투석 시 필요한 혈관접근통로로 활용되는 expanded poly(tetrafluoro ethylene)(ePTFE) 인공혈관을 표면 개질하였다. 생분해성 합성고분자인 poly(D,L-lactide-$co$-glycolide)(PLGA)와 함께 항암제로서 뿐만아니라 항증식제제로서 널리 쓰이고 있는 파클리탁셀을 인공혈관 표면에 코팅함으로써 PLGA가 생분해됨에 따라 파클리탁셀을 서방할 수 있도록 고안하였다. 인공혈관의 다공구조 특성을 유지하면서 인공혈관 표면에 1.96 mg/$cm^2$의 PLGA가 코팅되었음을 ATR-FTIR을 통해 확인하였다. 또한 0.263 mg/$cm^2$의 파클리탁셀이 인공혈관에 코팅되었음을 HPLC로 확인하였다. PLGA를 코팅함으로써 인공혈관의 모듈러스는 감소하였으나 인장강도는 향상되었다. 약물방출 실험 결과 PLGA의 생분해거동에 동반하여 코팅된 파클리탁셀의 약 35%가 28일 동안 지속적으로 방출되었다. 이러한 지속적인 파클리탁셀의 방출은 장기간에 걸쳐 신내막 과형성증을 억제하여 혈관의 개존율을 향상시킬 것으로 기대된다.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.417.2-418
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• 2002

The rhGH-loaded PLGA microsphere formulation was prepared using a double emulsion process from hydrophilic 0:50 poly(D.L-lactide-co-glycolide) (PLGA) polymers. To investigate the sustained efficacy of this formulation, ts pharmacodynamic characteristics were analyzed. It showed particle size of ca 53.1 $\mu\textrm{m}$ with high drug ncorporation efficiency and it was sucutaneously administrated to hypophysectomized rats and whole body rowth responses of this formulation were compared to those of the different dosing patterns of rhGH. (omitted)

• 폴리머
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• 제34권2호
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• pp.178-183
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• 2010

의료용 금속스텐트는 관상동맥계 심장질환을 앓고 있는 환자에 시술되어 상대적으로 생존율을 높여 준다. 그러나, 재협착 및 후기 혈전증으로 인하여 새로운 스텐트의 개발이 시급하게 되었다. 이러한 문제점을 해결하기 위해서 신생내막 과대증식을 막을 수 있는 것으로 알려진 alpha lipoic acid(ALA)를 생분해성 고분자인 poly(lactide-coglycolide)(PLGA), poly(L-lactide)(PLLA) 및 poly($\varepsilon$-caprolactone)(PCL)과 혼합하여 전기분사 방식으로 스테인레스 스틸 표면 위에 코팅하였다. 코팅된 고분자로부터 약물방출 거동은 고분자의 종류와 농도, 용출속도 및 용매의 종류에 따라서 조사하였다. 약물방출 속도는 유리전이온도($T_g$)가 낮은 PCL에서 가장 빨랐으며 PLGA, PLLA 순서를 보였다. 고분자 표면의 거친정도는 용출속도가 증가함에 따라서 증가하였고, 용매의 비등점의 차이에 의해서 약물방출속도가 변화됨을 알 수 있었다. 이러한 약물방출 거동을 조절함으로써 ALA가 담지된 생분해성 고분자로 코팅된 약물방출 스텐트를 실제 임상적용이 가능할 것으로 기대된다.

• 대한의용생체공학회:의공학회지
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• 제41권1호
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• pp.62-66
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• 2020

Controlled drug release is important for effective treatment of cancer. Poly(DL-lactide-co-glycolide) acid (PLGA) is a Food and Drug Administration (FDA) approved polymer and have been extensively studied as drug delivery carriers with biodegradable and biocompatible properties. However, PLGA drug delivery carriers are limited due to the initial burst release of drug. Certain drugs require an early rapid release, but in many cases the initial rapid release can be inefficient, reducing therapeutic effects and also increasing side effects. Therefore, sustained release is important for effective treatment. Poly Lactic Acid stereo complex (PLA SC) is resistant to hydrolysis and has high stability in aqueous solutions. Therefore, in this work, PLGA based discoidal polymeric particles are modified by Poly Lactic Acid stereocomplex (PLAsc DPPs). PLAsc DPPs are 3 ㎛ in diameter, also showing a relatively sustained release profile. Fluorescein 5(6)-isothiocyanate (FITC) released from PLAsc DPPs was continuously observed until 38 days, which showed the initial release of FITC from PLAsc DPPs was about 3.9-fold reduced as compared to PLGA based DPPs at 1 hour.

• 폴리머
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• 제32권3호
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• pp.246-250
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• 2008

본 연구에서는 분해성 고분자의 종류와 제조조건에 따른 나노입자의 분산 안정성을 평가하기 위하여 광산란 입도 분석기를 이용하여 입자 크기 변화를 조사하였다. 이를 위해 생분해성 고분자인 폴리(D,L-락타이드-co-글리콜라이드) 단독과 폴리(L-락타이드)와의 블렌드, 그리고 폴리(L-락타이em)-g-폴리(에틸렌 글리콜)과의 블렌드, 세 종류를 개선된 자발적 에멀션/용매 확산 방법을 이용하여 나노입자를 제조하였다. 제조조건의 영향을 파악하기 위하여서는 나노입자의 제조시에 대표적인 분산 안정제인 폴리(비닐 알코올)(PVA)의 사용 유무의 영향을 조사하였다. 시간이 진행함에 따라 분산 안정제가 적용되지 않은 경우에서는 나노입자의 분해와 분해를 통해 붕괴된 입자의 응집에 의하여 입자의 크기가 bimodal 분포를 나타내었다. 나노입자가 분산된 수용액에 단백질 용액을 투입한 경우에는 분산 안정제인 PVA의 사용 유무에 의해 극명한 차이를 나타내었으며 PVA가 분산 안정성에 크게 기여함을 확인할 수 있었다. 또한 낮은 분자량의 폴리(에틸렌 글리콜)이 그래프트 고분자를 미량 블렌드함에 따라 입자의 단백질 흡착에 대한 분산 안정성은 침전이 일어나지 않고 1일 정도 분산 상태를 유지하는 것으로부터 일부 향상됨을 확인하였다.

• 폴리머
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• 제26권5호
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• pp.680-690
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• 2002

골 재흡수 치료를 목적으로 파미드로네이트를 지속적으로 방출하는 제형으로 제조하기 위하여 락타이드-글리콜라이드 공중합체 (PLGA, 락타이드 : 글리콜라이드 몰비 = 75 : 25, 분자량 20000 g/mole 및 90000 g/mole)를 이용하여 직접압축 성형방법으로 생분해성 웨이퍼를 제조하였다. 약물과 고분자의 함량비 웨이퍼의 두께, PLGA 분자량 등을 조절하여 PLGA 웨이퍼를 제조하였고 이들의 형태학적 특성과 방출거동 및 분해거동을 살펴보았다. 웨이퍼의 제조는 혼합된 분말을 웨이퍼 제작용 몰드에 넣은 후 프레스를 이용하여 일정 압력으로 일정시간 동안 상온에서 가압하여 제조하였다. 제조된 웨이퍼는 약물의 초기함량이 증가할수록 방출속도가 빠르게 나타났으며, 제형의 두께가 두꺼워질수록 시간이 경과함에 따라 약물의 방출속도가 증가하였다. 또한 고분자의 분자량이 큰 것이 작은 것에 비해 상대적으로 초기 약물 방출량이 적고 방출되는 속도 또한 느려져. 저분자보다 오랫동안 약물이 방출되었다. 이러한 약물전달 시스템은 압축성형방법에 의해 제조하므로 제조가 간단하고 약물방출속도를 정확하게 제어할 수 있으므로 이식을 위한 제형으로 제조시 유용하게 쓰일 것으로 예상되었다.