• 제목/요약/키워드: Biomedical polymer

검색결과 318건 처리시간 0.027초

NOVEL CATIONIC POLYMERS DESIGNED FOR NON-VIRAL GENE DELIVERY

  • Zhong Zhiyuan;Lin, Chao;Song, Yan;Lok Martin C.;Jiang Xulin;Christensen Lane V.;Engbersen Johan F.J.;Kim, Sung-Wan;Hennink Wim E.;Feijen Jan
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.44-45
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    • 2006
  • Gene therapy holds great promise for treating various forms of diseases with a genetic origin including cystic fibrosis, different forms of cancer, and cardiovascular disorders. The clinical use of gene therapy treatments is however restricted, mainly because of the absence of safe and efficient gene delivery technologies. In our group, with an aim of developing efficient and nontoxic polymeric gene delivery systems, several novel types of polymeric gene carriers have been designed, synthesized, and evaluated. Herein, I will mainly present our recent work on low molecular weight linear PEI-PEG-PEI triblock copolymers, degradable hyperbranched poly(ester amine)s, and reduction-sensitive poly(amido amine)s.

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Coating defects in polymer-coated drug-eluting stents

  • Bedair, Tarek M.;Cho, Youngjin;Park, Bang Ju;Joung, Yoon Ki;Han, Dong Keun
    • Biomaterials and Biomechanics in Bioengineering
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    • 제1권3호
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    • pp.131-150
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    • 2014
  • Vascular stenting has a great attention as a treatment for coronary arteries diseases as compared with percutaneous balloon angioplasty. In-stent restenosis and thrombosis are side effects resulting from using bare metal stent (BMS). Employing platelet therapy allowed to reduce the rate of thrombosis, however, the rate of restenosis remains a major problem. In 2002, drug-eluting stents (DESs) were introduced as an effort to reduce the restenosis. The commercially available DESs continue to suffer from coating defects that might lead to a series of adverse effects. Most importantly, multiple concerns remain regarding the polymer coating integrity on metal surfaces or the relation of polymer irregularities to longterm adverse events.

전기분사를 이용한 의료용 금속 임플란트의 생분해성 PLGA 고분자 코팅 (Biodegradable PLGA Polymer Coating on Biomedical Metal Implants Using Electrospraying)

  • 조성배;박철호;박귀덕;정동준;한동근
    • 폴리머
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    • 제33권6호
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    • pp.620-624
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    • 2009
  • 의료용 금속 임플란트는 우수한 기계적 강도를 바탕으로 결손된 신체 부위의 보강, 대치, 회복을 위해 임상적으로 사용되고 있지만, 낮은 생체적합성 및 독성 때문에 염증 및 후기 혈전증, 재협착의 문제점을 가지고 있다. 이런 단점을 보안하기 위한 다양한 표면처리 기술 중, 본 연구에서는 금속표면에 생분해성 고분자인 poly (lactic-co-glycolic acid) (PLGA)를 이용하여 전기분사 코팅(electrospray coating) 기술을 검토하였다. 전기분사와 용액 인자들의 기초적인 조사를 바탕으로, 코팅 필름의 표면형상은 방울이 날아가는 거리, 용매의 비등점, 방울의 크기에 밀접한 관련이 있다. 고분자 필름의 두께는 분사량에 선형적으로 비례를 하였다. 이 결과는 전기분사된 고분자 방울이 계속적으로 고분자 필름 위에 적층되는 것을 보여준다. 따라서, 전기분사 코팅기술은 스텐트와 같은 의료용 금속 임플란트에 있어서 표면 형상 조절, 나노/마이크로 두께의 단/다중층의 고분자 필름을 제조하는데 적용될 수 있다.

Femtosecond Laser Ablation of Polymer Thin Films for Nanometer Precision Surface Patterning

  • Jun, Indong;Lee, Jee-Wook;Ok, Myoung-Ryul;Kim, Yu-Chan;Jeon, Hojeong
    • 한국표면공학회지
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    • 제49권1호
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    • pp.20-25
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    • 2016
  • Femtosecond laser ablation of ultrathin polymer films on quartz glass using laser pulses of 100 fs and centered at ${\lambda}=400nm$ wavelength has been investigated for nanometer precision thin film patterning. Single-shot ablation craters on films of various thicknesses have been examined by atomic force microscopy, and beam spot diameters and ablation threshold fluences have been determined by square diameter-regression technique. The ablation thresholds of polymer film are about 1.5 times smaller than that of quartz substrate, which results in patterning crater arrays without damaging the substrate. In particular, at a $1/e^2$ laser spot diameter of $0.86{\mu}m$, the smallest craters of 150-nm diameter are fabricated on 15-nm thick film. The ablation thresholds are not influenced by the film thickness, but diameters of the ablated crater are bigger on thicker films than on thinner films. The ablation efficiency is also influenced by the laser beam spot size, following a $w_{0q}{^{-0.45}}$ dependence.

The Covalent Immobilization of Biomolecules to Polymer Surface by Deep-UV Lithography Using N-Hydroxysuccinimidyl Azidobenzoate

  • 김현정;;;;민병구
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 춘계학술대회
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    • pp.47-50
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    • 1997
  • We synthesized N-Hydroxysuccinimidyl (NHS) azidobenzoate as a cross-linking reagent for immobilization of peptide onto the solid surface. Thin polystyrene(PS) films spin-coated with a NHS azidobenzoate solution were exposed with ultraviolet light at 245nm$(3.3mW/cm^2)$ for 5 min. The NHS active ester groups became covalently attached to the polymer via photogenerated, highly reactive nitrene intermediates derived from NHS azidobenzoate. Using this technique, it is demonstrated that well-defined surface regions can be functionalized with a minimum observable feature size of 1mm for UV exposure. Through reaction of this functionalized PS surface with primary amine-containing biomolecules, biological molecule had been immobilized on the polymer surface.

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