• Title/Summary/Keyword: Biomaterial

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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 (Poly(D,L-lactide)를 외부 껍질로 하고 Alginate 또는 Chitosan을 내부 코어로 구성한 이중미립구 담체의 약물방출 특성)

  • Kim, Ja Won;Song, Min Jeong;Lee, Sang Min;Lim, So Ryong;Jung, Su Jin;Kim, Hong Sung
    • Polymer(Korea)
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    • v.36 no.6
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    • pp.699-704
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    • 2012
  • Double-layered polymeric carrier was designed for release control of hydrophilic drug in oral administration. Biopolymeric chitosan and alginate were examined as polar absorbents, poly(D,L-lactide) as a hydrophobic shell, and theophylline and diclofenac sodium as loading drugs. The fabrication of the carriers was prepared in the form of double-layered microsphere for delayed and successively extended release, which consisted of outer shell of poly(D,L-lactide) and inner core of alginate or chitosan with drugs. Morphologies and drug-release behaviors of the carriers were investigated, which were influenced by a combination of polarity between carrier and drug. It was confirmed that the relative polarities of the carriers, the drugs, and the environmental pH affected significantly the drug-release property.

Isolation and Characterization of the Colletotrichum acutatum ABC Transporter CaABC1

  • Kim, Suyoung;Park, Sook-Young;Kim, Hyejeong;Kim, Dongyoung;Lee, Seon-Woo;Kim, Heung Tae;Lee, Jong-Hwan;Choi, Woobong
    • The Plant Pathology Journal
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    • v.30 no.4
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    • pp.375-383
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    • 2014
  • Fungi tolerate exposure to various abiotic stresses, including cytotoxic compounds and fungicides, via their ATP-driven efflux pumps belonging to ATP-binding cassette (ABC) transporters. To clarify the molecular basis of interaction between the fungus and various abiotic stresses including fungicides, we constructed a cDNA library from germinated conidia of Colletotrichum acutatum, a major anthracnose pathogen of pepper (Capsicum annum L.). Over 1,000 cDNA clones were sequenced, of which single clone exhibited significant nucleotide sequence homology to ABC transporter genes. We isolated three fosmid clones containing the C. acutatum ABC1 (CaABC1) gene in full-length from genomic DNA library screening. The CaABC1 gene consists of 4,059 bp transcript, predicting a 1,353-aa protein. The gene contains the typical ABC signature and Walker A and B motifs. The 5'-flanking region contains a CAAT motif, a TATA box, and a Kozak region. Phylogenetic and structural analysis suggested that the CaABC1 is a typical ABC transporter gene highly conserved in various fungal species, as well as in Chromista, Metazoans, and Viridiplantae. We also found that CaABC1 was up-regulated during conidiation and a minimal medium condition. Moreover, CaABC1 was induced in iprobenfos, kresoxim-methyl, thiophanate-methyl, and hygromycin B. These results demonstrate that CaABC1 is necessary for conidiation, abiotic stress, and various fungicide resistances. These results will provide the basis for further study on the function of ABC transporter genes in C. acutatum.

Successful Treatment Using Wire-reinforced Interdental Splint for a Puppy with Rostral Mandibular Fractures

  • Kim, Se Eun;Shim, Kyung Mi;Kim, Seung Hyun;Bae, Chun-Sik;Kang, Seong Soo
    • Journal of Veterinary Clinics
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    • v.35 no.4
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    • pp.137-140
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    • 2018
  • A five-month-old toy poodle was referred for treatment of bilateral mandibular fractures. Preoperative skull and dental radiographs showed rostral mandibular fractures and permanent teeth that had not yet erupted. In addition to providing stability for the healing of fractures, it is very important to focus on restoring normal occlusion. The mandibular fractures were repaired using interdental wiring in a dentate area where the deciduous canines and fourth premolars were stable and could be used to anchor the interdental fixation. In the absence of an erupted permanent mandibular first molar, the modified Risdon wiring was performed using the deciduous mandibular fourth premolars as anchor teeth. An intraoral splint was placed on the mandibular teeth using self-curing composite resin. Five months after surgery, the patient had experienced no complications, and the permanent teeth had erupted normally. In this case, which involves a small-breed puppy with deciduous dentition, treatment with a wire-reinforced interdental splint using intact deciduous fourth premolar teeth as anchor teeth can be considered as a suitable method for rostral mandibular fracture restoration.

High-Level Secretory Expression of Human Procarboxypeptidase B by Fed-Batch Cultivation of Pichia pastoris and its Partial Characterization

  • Kim, Mi-Jin;Kim, Sang-Hyuk;Lee, Jae-Hyung;Seo, Jin-Ho;Lee, Jong-Hwan;Kim, Jong-Hyun;Kim, Yeon-Hee;Nam, Soo-Wan
    • Journal of Microbiology and Biotechnology
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    • v.18 no.12
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    • pp.1938-1944
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    • 2008
  • The procpb gene encoding human procarboxypeptidase B (proCPB, GeneBank access code AJ224866) was cloned and its Pichia expression plasmid, $pPIC9{\alpha}$/hproCPB (9.2 kb), was constructed, in which procpb was under the control of the AOXl promoter and connected to the downstream of the mating factor ${\alpha}$-1 ($MF{\alpha}1$) signal sequence. The plasmid was linearized by digestion with Sacl, and integrated into the genome of P. pastoris strain GS115. By culturing of Pichia transformant on methanol medium, the human proCPB was successfully expressed and secreted into the culture supernatant. Moreover, Western blot analysis of the extracellular proteins showed proCPB bands clearly at a molecular mass of 45 kDa, confirming the expression of proCPB with its right size. The CPB activity reached about 3.5 U/ml and 12.7 U/ml in the flask and fermentor batch cultures of Pichia transformant, respectively. No CPB enzyme activity was found in the intracellular fraction. When the fed-batch cultivation was performed with methanol and glycerol mixture as a feeding medium, the extracellular CPB activity was increased to 42.0 U/ml, which corresponds to a 3.3-fold higher level of CPB activity than that of batch culture. The $K_m$ and $k_{cat}$ values of recombinant human CPB enzyme for hippuryl-$_L$-Arg as a substrate were estimated to be 0.16 mM and $11.93\;sec^{-1}$, respectively.

Induction of Apoptotic Cell Death by Methanol Extract of Houttuynia cordata Thunb. in A549 Human Lung Carcinoma Cells (어성초 메탄올 추출물에 의한 A549 인체 폐암세포 사멸유도에 관한 연구)

  • Hong, Su-Hyun;Park, Cheol;Hong, Sang-Hoon;Choi, Byung-Tae;Lee, Yong-Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.6
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    • pp.1584-1592
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    • 2006
  • Houttuynia cordata Thunb, well known as 'E-Sung-Cho' in Korea, is traditional medicinal plant generally used in Oriental medicine therapy. We previously reported that the water extract of H. cordata inhibited cell proliferation and induced apoptosis in human breast carcinoma cells. In the present study, we investigated the biochemical mechanisms of anti-proliferative effects by the methanol extract of H. cordata (MEHC) in human lung carcinoma A549 cells. It was found that MEHC could inhibit the cell growth in a dose-dependent manner, which was associated with morphological change and apoptotic cell death as determined by formation of apoptotic bodies, DNA fragmentation and increased populations of apoptotic-sub G1 phase cells. Apoptosis of A549 cells by MEHC was also connected with a down-regulation of anti-apoptotic Bcl-2 and inhibitor of apoptosis proteins (IAPs) expression. MEHC treatment induced the proteolytic activation of caspase-3, caspase-8 and caspase-9, and a concomitant inhibition of poly(ADP-ribose) polymerase (PARP), ${\beta}$-catenin and phospholipase (PLC)-${\gamma}$1 protein expression. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of H. cordata.

Aerobic Composting Process of Garbage using Thermoacidophilic Bacillus sp. SJ-15. (고온.내산성 Bacillus sp. SJ-15를 이용한 음식물 쓰레기의 호기적 퇴비화)

  • Kim, Choon-Hee;Nam, Soo-Wan;Choi, Woo-Bong;Lee, Jong-Hwan;Kang, Byoung-Won;Kim, Hweh-Su;Jeon, Sung-Jong
    • Journal of Life Science
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    • v.17 no.5 s.85
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    • pp.735-739
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    • 2007
  • A thermoacidophilic bacterium was isolated from the compost and designated as Bacillus sp. SJ-15 by physiological and biochemical characteristics. The optimum temperature and pH for growth were at $55^{\circ}C$ and pH 5.0, respectively. The strain SJ-15 was adapted in process of accelerated high-temperature composting of garbage. The highest viable cell count of composting process reached to $9.2{\times}10^9/ml$ in 16 hours. After running times of 100 days, the composting process showed a reduction rate of approximately 88%, and the concentrations of components were sufficiently high or low to satisfied the standard of organic compost except for salinity.

Estimating Material Parameters of Rubber-liked Material Similar to Biomaterial (생체 유사재료를 설명하는 물질 상수 추정)

  • Kang, Taewon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.1
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    • pp.45-49
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    • 2013
  • It is important to have a well developed strain energy function in order to understand the mechanical behavior of biomaterial like the blood vessel of artery. However, since it is not possible to have a complete form of strain energy function of artery, theoretical framework describing the behaviour of Rubber-like material which is similar to blood vessel is applied to infer useful forms of strain energy function of biomaterial. Based on Chuong-Fung model and Mooney-Rivlin model, material parameters are estimated based on experimental data. From the results, it can be inferred that the estimated parameters can be used to explain the difference of mechanical characteristics between normal vessel and vessel with stent.

Ultra-thin Film Assembly of a Novel Biomaterial Containing Protein and Functionalized Polymer for Sensor Application

  • Lim, Jeong-Ok;Sohn, Byung-Ki;Huh, Jeung-Soo
    • Journal of Sensor Science and Technology
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    • v.4 no.4
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    • pp.81-87
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    • 1995
  • A novel biomaterial capable of incorporating biotinylated biomolecule has been synthesized. Our strategy is to biotinylate one-dimensional electroactive polymers and use a bridging streptavidin protein on Langmuir-Blodgett (LB) organized films. These copolymers are derivatized with long alkyl chains and biotin moieties to bind, respectively, to the hydrophobic surface and the biotinylated species, through the biotin and streptavidin complexation. We utilize the polymer assembly approach to attach a signal transducing biomolecule biotinylated phycoerythrin (B-PE) into this novel biomaterial by binding the unoccupied biotin binding sites on the bound streptavidin (4 sites total). The pressure-area isotherm of the protein injected monolayer showed area expansion. A characteristic fluorescent emission peak at 576nm was detected from the monolayer transferred onto a solid substrate. These observations demonstrated the promise of the organized thin polymer assemblies for their application to the sensor system.

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Characterization of Cyclofructans from Inulin by Saccharomyces cerevisiae Strain Displaying Cell-Surface Cycloinulooligosaccharide Fructanotransferase

  • Kim, Hyun-Jin;Lee, Jae-Hyung;Kim, Hyun-Chul;Lee, Jin-Woo;Kim, Yeon-Hee;Nam, Soo-Wan
    • Journal of Microbiology and Biotechnology
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    • v.17 no.4
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    • pp.695-700
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    • 2007
  • The cycloinulooligosaccharide fructanotransferase (CFTase) gene (cft) from Paenibacillus macerans (GenBank access code AF222787) was expressed on the cell surface of Saccharomyces cerevisiae by fusing with Aga2p linked to the membrane-anchored protein Aga1p. The surface display of CFTase was confirmed by immunofluorescence microscopy and enzymatic assay. The optimized reaction conditions of surface-displayed CFTase were as follows; pH, 8.0; temperature, $50^{\circ}C$; enzyme amount, 30 milliunit; substrate concentration, 5%; inulin source, Jerusalem artichoke. As a result of the reaction with inulin, cycloinulohexaose was produced as a major product along with cycloinuloheptaose and cycloinulooctaose as minor products.