• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.922-927
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• 2001

In an effort to regulate the mammalian cell behavior in entrapment with a gel, we have functionalized hydrogels with the putative cell-binding (-Arg-Gly-Asp-)(RGD) domain. An adhesion molecule of Gly-Arg-Gly-Asp-Ser (GRGDS) peptides, a cell recognition ligand, was induced into thermo-reversible hydrogels, composed of N-isopropylacrylamide with small amounts of acrylic acid (typically 2-5 $mol\%$ in feed), as a biomimetic extracellular matrix (ECM). The GRGDS containing a p(NiPAAm-co-AAc) copolymer gel was studied in vitro for its ability to promote the spreading and viability of cells by introducing a GRGDS sequence. Hydrogel with no adhesion molecule was a poor ECM for adhesion, permiting spreading of only $3\%$ of the seeded cells for 36h. By immobilizing the peptide linkage into the hydrogel, the conjugation of RGD promoted $50\%$ of proliferation for 36h. However, the GREDS sequence, nonadhesive peptide linkage, conjugated hydrogel showed only $5\%$ of the seeded cell for the same time period. In addition, with the serum-free medium, only GRGDS peptides conjugated to hydrogel was able to promotecell spreading, while there was no cell proliferation in the hydrogel without GRGDS. Thus, the GRGDS peptide-conjugated thermo-reversible hydrogel specifically mediated the cell spreading. This result suggests that utilization of peptide sequences conjugating with the cell-adhesive motifs can enhance the degree of cell surface interaction and influence the long-term formation of ECM in vitro.

• 한국임상수의학회지
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• 제20권1호
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• pp.59-65
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• 2003

This study was performed to investigate the immunopotentiative effects of conjugated linoleic acid on mice immunosuppressed by administratin corticoids. Mice were divided into four groups of 8 mice. Two groups (C, CP) were given diet supplemented with 1% linoleic acid (CLA) and the other two groups (L, LP) were given diet supplemented with 1% linoleic acid (LA) instead of CLA. Prednison was administered to two groups (CP, LP) for immune depression. After feeding diets for 3 weeks containing PDS injection for last 1 week. Serum and gut lumen lavage were taken. Measurement of total Ig were executed using sandwich ELISA. Serum levels of IgA, IgG, and IgM showed some trend which groups fed with CLA were higher than groups fed with LA while IgE was reduced in those fed the CLA intake, and groups administered with PDS were lower than groups administered with saline. However, no significant differences were seen in the proportion of total immunoglobulin in serum. In case of secretory IgA, Group C and CP were significantly higher than group L and LP. Especially between CP and LP, it can be seen effects of CLA. In addition that the CLA treated group weighted a significantly lower level than the one's that have not been treated with CLA. These result support the view that CLA potentiate the immune response and prevent immune depression caused by administrating of corticoids. In conclusion, CLA produced a situation favorable for immunopotentiative effects. Thus, the clinical application of CLA is warranted.

• Macromolecular Research
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• 제14권3호
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• pp.348-353
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• 2006

For enhancing the gene delivery efficiency of polyplexes, a new formulation was developed using PEI conjugated Pluronic F127 copolymer as an effective additive. Low molecular weight, branched polyethylenimine Mw 600 (LMW BPEI 600) was conjugated to the terminal end of Pluronic F127. The PEI-modified Pluronic copolymers formed a micellar structure in aqueous solution, similar to that of unmodified Pluronic copolymer. PEI modification of Pluronic copolymer increased the size of micelles while concomitantly raising the critical micelle concentration (CMC). The PEI-modified Pluronic copolymer was used as a micellar additive to enhance the gene transfection efficiency of pre-formulated polyelectrolyte complex nanoparticles composed of luciferase plasmid DNA and branched PEI Mw 25k (BPEI 25k) or polylysine Mw 39k (PLL 39k). The luciferase gene expression levels were significantly enhanced by the addition of the BPEI-modified Pluronic copolymer for the two formulations of BPEl and PLL polyplexes. The results indicated that the BPEI-modified Pluronic copolymer micelles ionically interacted on the surface of DNA/BPEI (PLL) polyplexes which might facilitate cellular uptake process.

• Journal of Microbiology and Biotechnology
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• 제32권9호
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• pp.1209-1216
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• 2022

To better understand the effects of PEGylation and biotinylation on the delivery efficiency of proteins, the cationic protein lysozyme (LZ) and anionic protein bovine serum albumin (BSA) were chemically conjugated with poly(ethylene glycol) (PEG) and biotin-PEG to primary amine groups of proteins using N-hydroxysuccinimide reactions. Four types of protein conjugates were successfully prepared: PEGylated LZ (PEG-LZ), PEGylated BSA (PEG-BSA), biotin-PEG-conjugated LZ (Bio-PEG-LZ), and biotin-PEG-conjugated BSA (Bio-PEG-BSA). PEG-LZ and Bio-PEG-LZ exhibited a lower intracellular uptake than that of LZ in A549 human lung cancer cells (in a two-dimensional culture). However, Bio-PEG-BSA showed significantly improved intracellular delivery as compared to that of PEG-BSA and BSA, probably because of favorable interactions with cells via biotin receptors. For A549/fibroblast coculture spheroids, PEG-LZ and PEG-BSA exhibited significantly decreased tissue penetration as compared with that of unmodified proteins. However, Bio-PEG-BSA showed tissue penetration comparable to that of unmodified BSA. In addition, citraconlyated LZ (Cit-LZ) showed reduced spheroid penetration as compared to that of LZ, probably owing to a decrease in protein charge. Taken together, chemical conjugation of targeting ligands-PEG to anionic proteins could be a promising strategy to improve intracellular delivery and in vivo activity, whereas modifications of cationic proteins should be more delicately designed.

• 한국표면공학회지
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• 제56권1호
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• pp.40-54
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• 2023

In this work, we synthesized a novel electrochemical sensing materials based on tetracarboxylic copper phthalocyanine (TcCuPtc) conjugated PANI (TcCuPtc@PANI). The synthesized materials were employed to modify the screen-printed carbon electrode (SPCE) for the selective sensing of 4-nitrophenol. The TcCuPtc was conjugated with conducting polymer of PANI through the electrostatic interaction and π-π electron conjugation, the polymer film of PANI to inhibit the leakage of TcCuPtc from the surface of the electrode. The prepared TcCuPtc@PANI were characterized and confirmed by scanning electron microscopy (SEM) with EDX, ATR-IR, UV-vis absorption spectroscopy, cyclic voltammetry, and differential pulse voltammetry techniques. The prepared TcCuPtc@PANI/SPCE showed an excellent electrocatalytic sensing of 4-NP in the linear concentrations from 3 to 500 nM with a LOD of 0.03 nM and a sensitivity of 8.8294 ㎂/nM cm^-2. However, the prepared TcCuPtc@PANI/SPCE showed selective sensing of 4-NP in the presence of other interfering species. The practical applicability of the TcCuPtc@PANI/SPCE was employed for the sensing of 4-NP in different water samples by standard addition method and showed satisfactory recovery results.

• Asian-Australasian Journal of Animal Sciences
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• 제21권10호
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• pp.1458-1465
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• 2008

Effects of soybean oil or whole cotton seed addition on conjugated linoleic acid (CLA) and performance of fattening Brahman$\times$Thai-Native cattle were studied. Eighteen fattening cattle averaging $241{\pm}24kg$ body weight and approximately 1 year old were stratified by live weight into three groups and randomly assigned by group to one of three dietary treatments. The treatments were control (concentrated 14% crude protein), control and supplemented with 170 g/d soybean oil, control plus 170 g/d of oil from whole cotton seed. All animals were weighed before and after the experimental period and 4 cattle per treatment were randomly slaughtered then carcass measurements were obtained. There were no statistically significantly differences in the final body weight, average daily gain and dry matter intake among treatments. However, the crude protein intake was significantly decreased (p<0.01) when whole cotton seed was fed compared with control and soybean oil treatments. The carcass composition and carcass characteristics were not significantly different in Longissimus and Semimembranosus muscle by feeding soybean oil and whole cotton seed compared with the control treatment. Supplementation of soybean oil increased (p<0.01) cis-9, trans-11 CLA by 116% in Longissimus muscle and by 240% in Semimembranosus muscle. However, whole cotton seed did not increase cis-9, trans-11 CLA in both muscles. The present study successfully increased cis-9, trans-11 CLA content of muscle lipids by soybean oil but not by whole cotton seed.

• Preventive Nutrition and Food Science
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• 제8권3호
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• pp.253-259
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• 2003

Conjugated linoleic acid (CLA) is a class of positional, geometric conjugated dienoic isomers of linoleic acid (LA). CLA activates the immune system, protects against tumorigenesis, and reduces the incidence of atherosclerosis. Trans-10, cis-12 CLA has specific effects on lipid metabolism, it has been shown to reduce body fat gain and regulates some adipocyte secreted proteins in vivo and in vitro. Here we report that a CLA mixture affects cytokine secretion from rat primary adipocytes. Rat primary adipocytes were treated with 1 mM, 100 $\mu$M, 1 $\mu$M or 100 nM CLA mixture doses; and leptin, tumor necrosis factor alpha (TNF a ), interleukin-6 (IL-6) and glycerol levels in the medium were measured. Leptin secretion was lower, TNF $\alpha$ secretion higher and IL-6 secretion did not change in response to the CLA mixture. Leptin and TNF $\alpha$ secretions did not change with CLA mixture treatment in a dose-dependent manner. In addition, the CLA mixture did not appear to enhance lipolysis in rat primary adipocytes. In conclusion, our study demonstrates that the decrease in leptin and increase in TNF $\alpha$ secretion in adipocytes treated with CLA mixture may be due to the apoptotic effect and to a reduction in peroxisome proliferator-activated receptor gamma (PPAR ${\gamma}$ ) ligands.

• 한국식품과학회지
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• 제32권1호
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• pp.62-68
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• 2000

본 연구는 CLA를 이용한 다기능성 육제품의 제조 가능성을 알아보고자 첨가하는 지방의 일부를 CLA로 대체하여 돈육 patty를 제조하여 실험하였다. 제조된 patty를 $4^{\circ}C$의 냉장온도에서 11일 동안 저장하면서 이화학적 성질, 지방산 조성, 콜레스테롤 및 CLA 함량을 조사하였다. 조단백, 조지방은 유의적인 차이를 나타내지 않았지만, 조회분과 함유수분을 CLA 첨가 수준이 증가할수록 유의적으로 낮아지는 경향을 보였다. TBARS는 대조구에 비하여 CLA 첨가구가 유의적으로 낮은 결과를 보였으며, 저장기간이 경과함에 따라 모든 처리구가 유의적으로 증가하였다. Nitrite 함량은 CLA 첨가량이 증가할수록 유의적으로 감소하였으며, 콜레스테롤 함량은 CLA 첨가수준이 증가할수록 유의적으로 감소하는 경향을 나타내었고, CLA 첨가량이 증가할수록 CLA 축적량은 증가하였다. 이상의 결과 patty 제조시 CLA 첨가는 제품특성에 영향을 미치지 않으면서 제품의 저장기간의 연장, 콜레스테롤 함량 감소, nitrite 함량의 감소효과를 나타내어 고급 patty생산이 가능하리라 사료된다.

• Bulletin of the Korean Chemical Society
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• 제6권4호
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• pp.210-214
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• 1985

Urokinase, a plasminogen activator, was conjugated with dextran by the cyanogen bromide activation-coupling method. The resulting water-soluble conjugate was purified by gel permeation chromatography on Sephadex G-200. The maximal activity was obtained when the ratio of urokinase/dextran was 1/20 for the coupling. The final preparation showed 5 CTA units/mg conjugate, 300 CTA units/mg protein, 8.4 % activity retention, and 47 % protein retention. The urokinase-dextran conjugate had good thermal, pH and storage stabilities. In addition, it showed greater resistance to the inhibitory effect of human plasma than native urokinase. Also in vitro biological half-life of urokinase increased 40 times by this conjugation. In view of activity, excellent stability and increased half-life, the conjugate can be a potential fibrinolytic agent in an injectable form.

• Asian-Australasian Journal of Animal Sciences
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• 제28권8호
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• pp.1095-1104
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• 2015

To evaluate the effects of the pelleting and the addition of sodium monensin on production, the chemical and lipid composition of milk and butter physical characteristics, 4 Holstein dairy cows (135 days of lactation) with an average milk production of 14.7 kg/d, were supplemented with a concentrate containing ground canola seeds. The cows were assigned to a $4{\times}4$ Latin square design with a $2{\times}2$ factorial arrangement of treatments: i) ground maize, soybean meal, mineral and vitamin supplements, and ground canola seeds (CG); ii) CG concentrate with 31.5 mg of monensin added per kg of dry matter (DM); iii) CG pelleted concentrate; iv) CG concentrate with monensin addition pelleted. There was no difference in milk production and composition. The addition of monensin increased milk concentration of polyunsaturated fatty acids (PUFA), the PUFA/saturated fatty acids (SFA) ratio, and omega 6. The pelleting increased the concentration of monounsaturated fatty acids, the PUFA/SFA ratio, and the omega 6/omega 3 ratio, but decreased the concentration of SFA. The association between pelleting and the addition of monensin increased the concentration of conjugated linoleic acids by 46.9%. The physical characteristics of butter were not affected by the evaluated diets. We concluded that the concentrate with 31.5 mg of monensin added per kg DM basis combined with the pelleting improves the lipid composition of milk from Holstein cows that are on pasture and supplemented with ground canola seeds, without changing the production, milk composition, and spreadability of butter.