• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.266.2-266.2
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• 2013

According to advanced nanotechnology, the nanostructured materials with various kinds and shape are synthesized easily or produced by process. Recently, researches about interaction between the nanostructured materials and biological system have been progressed actively. The surface topography may influence cellular responses, for example cell adhesion, cell morphology. In this work, we synthesized vertically aligned silicon nanowires (SiNWs) on the Au-covered Si(111) wafer by chemical vapor deposition (CVD) method. We accomplished to control of the SiNWs diameter by regulating thickness of Au film such as 1 nm and 10 nm. These substrates did not isolate cells and just provided surface topography for cell culture. Human Embryonic Kidney 293T cells (HEK 293T cells) were cultured on these substrates for 2 days. We studied the nanotopographical effects on cell morphology, adhesion, and growth which are evaluated on each SiNWs substrate comparing bare glass as control.

• 폴리머
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• 제24권6호
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• pp.877-885
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• 2000

본 연구에서는 폴리락타이드 (PLA), 폴리글리콜라이드 (PGA) 그리고 이들의 공중합체인 PLGA 필름을 염소산 혼합용액 [70% 과염소산 (HClO$_4$)/포타슘 클로레이트 (KClO$_3$) 포화 수용액, 3 : 2]으로 처리하여 표면의 젖음성과 세포적합성을 증가시켰다. 표면 처리된 고분자의 표면을 물접촉각 측정과 ESCA, SEM으로 특성결정하였다. 염소산 처리된 PLA, PGA, 및 PLGA의 표면 젖음성은 처리시간이 증가함에 따라 증가되었고 이들 고분자 필름은 기존의 에탄을 전처리와 달리 건조 후에도 친수성 표면을 유지하였다. 세포 점착실험은 섬유아세포를 염소산 처리된 필름의 표면에서 1일 및 2일 배양하였고 표면의 젖음성이 증가함에 따라 세포의 점착도 우세하였다. 결론적으로 본 연구에서는 표면의 젖음성은 세포의 점착과 증식 거동에 중요한 역할을 한다는 것을 증명하였다.

• 미생물학회지
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• 제55권3호
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• pp.199-205
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• 2019

Yeast two-hybrid는 특정 단백질에 대한 상호작용 파트너 단백질의 선별을 위한 방법으로 개발되었다. 하지만 대규모 단백질 상호작용체 분석을 수행하기에 요구되는 노동과 대량의 한천배지 사용에 따른 문제에 의해 널리 사용되지 못하고 있다. 따라서 본 연구에서는 새로운 리포터 시스템을 yeast two-hybrid 방법에 도입하여 fluorescence-activated cell sorting (FACS) 또는 magnetic-activated cell sorting (MACS)를 이용하여 상호작용 파트너 단백질을 포함하는 효모 클론을 손쉽게 선별할 수 있도록 하였다. 새로운 리포터 시스템은 c-myc 항원 결정기가 총 10번 반복되는 형태로 효모 표면에 발현되도록 하였으며, p53과 SV40 T항원을 이용한 실험을 통하여 리포터 단백질의 정상적인 발현을 flow cytometry 분석을 통하여 확인하였다. 따라서, 새로운 리포터 시스템을 도입한 yeast two-hybrid 방법은 대규모 상호작용체 분석을 위해 필요한 노력을 현저히 줄일 수 있을 것으로 기대한다.

• BMB Reports
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• 제56권9호
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• pp.482-487
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• 2023

Hematopoiesis is regulated by crosstalk between long-term repopulating hematopoietic stem cells (LT-HSCs) and supporting niche cells in the bone marrow (BM). Here, we describe the role of KAI1, which is mainly expressed on LT-HSCs and rarely on other hematopoietic stem-progenitor cells (HSPCs), in niche-mediated LT-HSC maintenance. KAI1 activates TGF-β1/Smad3 signal in LT-HSCs, leading to the induction of CDK inhibitors and inhibition of the cell cycle. The KAI1-binding partner DARC is expressed on macrophages and stabilizes KAI1 on LT-HSCs, promoting their quiescence. Conversely, when DARC+ BM macrophages were absent, the level of surface KAI1 on LT-HSCs decreases, leading to cell-cycle entry, proliferation, and differentiation. Thus, KAI1 acts as a functional surface marker of LT-HSCs that regulates dormancy through interaction with DARC-expressing macrophages in the BM stem cell niche. Recently, we showed very special and rare macrophages expressing α-SMA+ COX2+ & DARC+ induce not only dormancy of LT-HSC through interaction of KAI1-DARC but also protect HSCs by down-regulating ROS through COX2 signaling. In the near future, the strategy to combine KAI1-positive LT-HSCs and α-SMA/Cox2/DARC triple-positive macrophages will improve the efficacy of stem cell transplantation after the ablative chemo-therapy for hematological disorders including leukemia.

• 한국표면공학회지
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• 제15권4호
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• pp.192-207
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• 1982

A study has been made of the interaction parameters of Zn other elements in dilute solutesd solution of molten cadmium alloys over the temperature range of 450 to 570$^{\circ}C$. The experi-mental measurementss were made in a touch instant cell using a fusedd Licl-KCl electrolyte. The activity of zinc in binary and ternary solutions sexhibiteds a strong positive deviation from Raoult's law. The addition of silver, indium or lead increased the activity of zinc whereas addition of copper, bismuth or tin decreased the zinc activity slightly. The results for all the metallic solutions showed a linear dependence of reciprocal of ab-solute temperature over the experimental range. The interaction parameters obtained are as follows.

• 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.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.192-197
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• 2005

The effects of macronutrients $(NO_3^-,\; NH_4^+\;and\;PO_4^{3-})$ on cell growth and triterpenoids production in Centella asiatica cell suspension cultures were analyzed using the Box­Behnken response surface model experimental design. In screening and optimization experiments, $PO_4^{3-}$ as a single factor significantly influenced cell growth where increasing the phosphate level from 0.1 to 2.4 or 2.6 mM, elevated cell growth from 3.9 to $14\~16g/L$. The optimum values predicted from the response surface model are 5.05mM $NH_4^+$, 15.0mM $NO_3^-$ and 2.6mM $PO_4^{3-}$, yielding 16.0g/L cell dry weight with $99\%$ fitness to the experimental data. While the $NH_4^+-NO_3^-$ interaction influenced cell growth positively in the optimization experiment, $NH_4^+$ and $NO_3^-$ as single factors; and interactions of $NO_3^--PO_4^{3-},\;NH_4^+-PO_4^{3-}$ and $NH_4^+-NO_3^-$ were all negative in the screening experiment. Cell growth and the final pH level were positively affected by $PO_4^{3-}$, but negatively affected by $NH_4^+\;and\;NH_4^+-PO_4^{3-}$ interactions. The different effects of factors and their interactions on cell growth and final pH are influenced by a broad or narrow range of macronutrient concentrations. The productions of triterpenoids however were lower than 4mg/g cell dry weight.

• Carbon letters
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• 제9권1호
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• pp.47-60
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• 2008

Understanding the exact structure and surface characteristics of carbon materials is very important for design, synthesis, and utilization of the best carbon form with particular functions and high performance for practical applications such as selective adsorption adsorbents, energy storage materials, catalysts or catalyst supports, etc. This review paper focuses on carbon surface properties and the interaction between gaseous or liquid substances and carbon surface. Catalytic functions of carbon materials are reviewed including recent progress in synthesis and applications of nano-carbons.

• 대한치과보철학회지
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• 제43권3호
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• pp.393-408
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• 2005

Statement of problem. In the process of bone formation, titanium (Ti) surface roughness is an important factor modulating osteoblastic function. Purpose. This study was carried out to determine the effect of different Ti surface on biologic responses of a human osteoblast-like cell line (MG63). Materials and methods. MG63 cells were cultured on S (smooth), SLA (sandblasted largegrit & acid etching), HA (hydroxyapatite) Ti. The morphology and attachment of the cells were examined by SEM. The cDNAs prepared from total RNAs of MG63 were hybridized to a human cDNA microarray (1,152 elements). Results. The appearances of the surfaces observed with SEM were different in the three types of dental substrates. The surface of SLA and HA were shown to be rougher than S. MG63 cells cultured on SLA and HA were cell-matrix interaction. In the expression of genes involved in osseointegration, upregulated genes were bone morphogenetic protein, Villin, Integrin, Insulin-like growth factors in different surfaces. Downregulated genes were fibroblast growth factor receptor 4, Bcl 2-related protein, collagen, CD4 in different surfaces. Conclusion. The attachment and expression of key osteogenic regulatory genes were enhanced by surface roughness of the dental materials.

• Journal of Nutrition and Health
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• 제28권10호
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• pp.1022-1030
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• 1995

Saponins are glycosidic compounds present in many plant foods. They are characterized by their ability to lyse cell membranes due to their surface-active properties. Saponins are believed to interact primarily with cholesterol in the cell membrane. In this study, the interaction of soybean(SS) with cell membrane was investigated using erythrocytes as a model. Mechanisms of interaction was also investigated by measuring their binding capacity with different membrane lipid fractions. Throughout the study, gypsophilla saponin(GS) and quillaja saponin(QS) were used to evaluate the membranolytic activity of soybean saponins. All saponins released hemoglobin in a concentration-dependent manner. SS induced 40% hemolysis at the concentration of 400 ppm, however there was no increase in hemoglobin release above 400ppm concentration. 5ppm of GS and 8 ppm of QS hemolyzed 100% of erythrocytes. Isolation of SS fractions by thin layer chromatography revealed that only one non-polar saponin possesses strong hemolytic activity. When saponins were incubated decreased the release of cholesterol. When the hemolytic activity of saponins was measured in the presence of other major membrane lipid components, sphingomyelin significantly reduced the hemolytic activity of SS, while cholesterol reduced the activity of QS. GS showed high affinity to other component(s) in the incubation media as well as lipids. These results suggest that the membranolytic activity of saponins are related to their specific chemical structure, which determines the interaction behavior between saponins and different membrane components, and thereby influence the biological activity.