• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2973-2977
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• 2013

In this study, we developed a liquid crystal (LC)-based optical sensor for monitoring enzymatic activity through orientational changes in liquid crystals (LCs) coupled to the properties of a poly-${\small{L}}$-lysine (PLL)-based polymeric membrane. We prepared a PLL-based polymeric membrane at the planar interface between the thermotropic liquid crystal and aqueous phases. The PLL-based polymeric membrane was obtained by contacting the PLL solution with water immiscible LCs, 4-cyano-4'-pentyl-biphenyl (5CB) doped with adipoyl chloride. We then investigated the membrane properties by examining the permeability of the membrane to phospholipids, 1,2-didodecanoyl-rac-glycero-3-phosphocholine (DLPC). The permeability of the membrane to transport phospholipids was monitored through the orientational transition of 5CB in contact with the dispersions of DLPC. Since trypsin can enzymatically catalyze the hydrolysis of PLL, we incubated an aqueous trypsin solution with the membrane for 2 h at room temperature to cause an increase in the permeability of the polymeric membrane to DLPC. As a result, a bright to dark optical shift of LCs was observed, which implied that an enzymatic reaction between trypsin and PLL-based membrane occurred. Two control experiments using chymotrypsin and bovine serum albumin (BSA) revealed no sign of improved permeability based on the orientational transition of LCs.

• Journal of Pharmaceutical Investigation
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• 제40권6호
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• pp.363-366
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• 2010

Identification of compounds that function as P-glycoprotein (P-gp) substrates or inhibitors can facilitate the selection and optimization of new drug candidates. The purpose of this study is to optimize the experimental conditions for in vitro P-gp assay using LLC-GA5 cells, which is a well-known transformant cell line derived by transfecting LLC-PK1 with human MDR1. The amount of rhodamine123 transported by the LLC-GA5 and LLC-PK1 cells was evaluated under the following experimental conditions: 3 different types of transport media, colchicine pretreatment or nontreatment of the cells in the culture media, and with and without poly-L-lysine coating of the culture plates. The assay sensitivity was found to considerably differ depending on the diluents used in the transport media. P-gp-mediated transport in LLC-GA5 cells was most clearly characterized in the Hanks' balanced salt solution based transport media. The sensitivity of P-gp-mediated transport was not changed by colchicine pretreatment or poly-L-lysine coating of the culture plates.

• 공업화학
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• 제24권1호
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• pp.99-103
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• 2013

유리화탄소전극 위에 탄소나노튜브(CNT), 전하전달체(CTC), 글루코스 산화효소(GOx), 폴리이온복합체(PIC, poly-L-lysine hydrobromiderhk과 poly(sodium 4-styrenesulfonate) 혼합물)를 순차적으로 도포하여 글루코스/산소 바이오전지용 효소전극을 제조하였다. 또한, CNT, bilirubin oxidase (BOD), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 그리고 PIC 등의 층으로 제조한 전극을 바이오캐쏘드로 사용하여 바이오전지를 제조하였다. CNT와 CTC가 전극의 성능에 미치는 영향을 조사하였으며, 글루코스농도 5, 20, 200 mM에서 각각 3.6, 10.1, $46.5{\mu}W/cm^2$의 최대전력밀도를 나타내었으며, 본 연구에서 제시한 전극이 바이오전지 및 바이오센서의 개발에 활용될 수 있다는 것을 보여주었다.

• Macromolecular Research
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• 제14권2호
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• pp.129-131
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• 2006

• 대한화학회지
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• 제42권1호
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• pp.84-91
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• 1998

고분자 전해질 복합체 형성이 poly(N-isopropyl acrylamide)(PNIPAAm) 공중합체의 저임계 용해온도 (lower critical solution temperature, LCST)에 미치는 영향을 조사하기 위하여 N-isopropyl acrylamide (NIPAAm)와 acrylic acid (AAc)를 선택하여 온도 감응성과 pH 감응성을 동시에 지니는 pH/온도감응성 고분자를 합성하였다.합성된 고분자들을 FT-IR과 적정실험을 통해 확인하였다. 고분자전해질로서 poly(allylamine) (PAA)과 poly(L-lysine)(PLL)을 사용하여 pH 2로부터 12에 이르는 넓은 범위의 pH 영역에서 고분자전해질 복합체 형성이 pH/온도감응성 고분자의 LCST에 미치는 영향을 조사하였다. 수용액상에서 poly(NIPAAm-co-AAc)중 PNIPAAm의 LCST는 cloud-point 측정 방법으로 결정하였다. 또한 역적정 실험을 통해 공중합체 중의 AAc 함량을 결정하고 AAc의 이온화 정도가 LCST에 미치는 영향을 조사하였다. 수용액상에서 poly(NIPAAm-co-AAc) 중 PNIPAAm의 LCST는 pH, 고분자전해질의 존재 유무, AAc의 함량, 그리고 고분자 사슬에 존재하는 전하밀도 등에 큰 영향을 받았다. 고분자전해질 복합체는 PAAc의 pKa와 PAA또는 PLL의 pKb 사이인 중성영역에서 형성됐으며 PNIPAAm의 LCST에 미치는 PLL의 영향은 PAA에 비해 크게 나타났다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권5호
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• pp.326-331
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• 2001

With the aim of developing of pH-sensitive controlled drug release system, a poly(Llysine) (PLL) based cationic semi-interpenetrating polymer network (semi-IPN) has been synthesized. This cationic hydrogel was designed to swell at lower pH and de-swell at higher pH and therefore be applicable for achieving regulated drug release at a specific pH range. In addition to the pH sensitivity, this hydrogel was anticipated to interact with an ionic drug, providing another means to regulate the release rate of ionic drugs. This semi-IPN hydrogel was prepared using a free-radical polymerization method and by crosslinking of the polyethylene glycol (PEG)-methacrylate polymer through the PLL network. The two polymers were penetrated with each other via interpolymer complexation to yield the semi-IPN structures. The PLL hydrogel thus prepared showed dynamic swelling/de-swelling behavior in response to pH change, and such a behavior was influenced by both the concentrations of PLL and PEG-methacrylate. Drug release from this semi-IPN hydrogel was also investigated using a model protein drug, streptokinase. Streptokinase release was found to be dependent on its ionic interaction with the PLL backbones as well as on the swelling of the semi-IPN hydrogel. These results suggest that a PLL semi-IPN hydrogel could potentially be used as a drug delivery platform to modulate drug release by pH-sensitivity and ionic interaction.

• 폴리머
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• 제27권5호
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• pp.397-404
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• 2003

조직공학적 지지체에서의 골수유래 간엽줄기세포의 점착과 성장에 있어서 세포 점착성 단백질과 폴리펩타이드와의 상호작용을 조사하였다. 세포 점착성 물질로 알려진 단백질이나 폴리펩타이드는 락타이드-글리콜라이드 공중합체인 PLGA 필름과 지지체에 흡착하여 코팅되었으며, 이에 골수유래 간엽줄기 세포의 점착과 성장 거동을 비교하였다. 이들 단백질과 폴리펩타이드는 콜라겐 IV형과 피브리노겐, 라미닌, 젤라틴, 피브로넥틴, 폴리(L-라이신)이 사용되었다. 이중 폴리(L-라이신)을 제외한 단백질과 폴리펩타이드는 PLGA 필름 표면에 거의 단층으로 덮어져 흡착되었으며, PLGA 필름과 지지체에서 골수유래 간엽줄기세포가 1일과 2일, 4일간 배양되었다. 세포의 점착과 성장 거동은 sulforhodamine B법으로 평가하였다. PLGA 필름과 지지체에 단백질이나 폴리펩타이드가 흡착되지 않은 표면보다는 흡착된 표면에서의 세포의 점착과 성장이 우수하였다.

• Journal of Plant Biology
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• 제32권4호
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• pp.215-226
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• 1989

The effects of Ca2+ on polyamines on callose contents of carrot suspension cultured cells were studied. The regeneration process of the cell wall of carrot protoplast observed through the electron microscope. Treatment of the carrot suspension cultured cells with Ca2+ and polyamines resulted in considerable increase on callose contents at 0.1 mM of Ca2+ and polyamines, particulary spermidine. Poly-L-lysine and poly-L-ornithine increased about 30% and 100% of callose contents than that of the control respectively, whereas verapamil and flunarizine markedly decreased the callose contents. These effects of Ca2+ of free ion rather than as Ca2+-calmodulin complex. During the cultivation of the protoplast, the regeneration of the cell wall was somewhat observed on the 4th day, however, it was inhibited by verapamil. These results suggested that the promotive action of Ca2+ and polyamines were manifested in the callose contents and the regeneraton of the cell wall.

• 폴리머
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• 제28권6호
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• pp.538-544
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• 2004

Z-라이신 올리고머를 사슬연장제로 하고 D-다이페닐이소시아네이트와 폴리테트라메틸글리콜을 반응시켜 주사슬에 L-라이신 분절을 함유하는 폴리우레틴 (PULL)을 합성하였다. PULL 표면의 아민기와 인슐린의 공유 결합으로 인슐린 고정화 폴리우레탄 (PULL-In)을 제조하였다. Bradfold법으로 측정한 고정화 인슐린의 양은 약 0.30 nmol/$\textrm{cm}^2$이였다. $^3$H-thymidine 분석방법과 광학 현미경법으로 NIH/3T3 섬유아세포와 표면 개질된 PULL의 상호작용을 조사하였다. 그 결과 PULL-In 필름 표면에서의 세포 성장 속도는 다른 기질에서보다 높았다. 또한 고정화된 인슐린에서의 세포증식이 배양액에 용해된 인슐린에서와 거의 유사한 특성을 나타내었다.

• The Korean Journal of Physiology and Pharmacology
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• 제7권3호
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• pp.143-147
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• 2003

Poly-L-lysine (PLL) was reported to suppress mucin release from airway goblet cells during 30 min treatment period. In this study, we investigated whether PLL consistently suppresses mucin release from cultured airway goblet cells during 24 h after 30 min treatment and also specifically suppresses the release of mucin without any effects on the other releasable glycoproteins. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled with $^3H$-glucosamine for 24 h and chased for 30 min in the presence of varying concentrations of PLL to assess the effects on $^3H$-mucin release and on the total elution profile of the treated culture medium. The total mucin content during 24 h after 30 min treatment of PLL was assesed to investigate the consistency of effects. PLL did not affect the release of the other releasable glycoproteins whose molecular weights were less than mucin, and decreased the total mucin content during 24 h after 30 min treatment. We conclude that PLL can specifically suppress mucin release from cultured airway goblet cells and the suppression on mucin release is consistent. This finding suggests that PLL might be used as a specific airway mucin-regulating agent by directly acting on airway mucin-secreting cells.