• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.203-204
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• 2006

Studies on some biodegradable polymers and other materials such as hydrogels have shown the promising potential for a variety of surgical applications. Postoperative adhesion caused by the natural consequence of surgical wound healing results in problems of the repeated surgery. Recently, scientists have developed absorbable anti-adhesion barriers that can protect a tissue from adhesion in case they are in use; however, they are dissolved when no longer needed. Although these approaches have been attempted to fulfill the criteria for adhesion prevention, none can perfectly prevent adhesions in all situations. Overall of this work, a new method to fabricate an anti-adhesion membrane using biodegradable polymer and hydrogel has been developed. The ideal barrier for preventing postoperative adhesion would have the following properties; it should be (i) resorbable (ii) non-reactive (iii) easy to apply (iv) capable of being fixed in position. In order to fulfill these properties, we adopted solid freeform fabrication method combined with surface modification which includes the hydrogel coating, therefore, inner or outer structure can be controlled and the property of anti adhesion can be improved.

• Membrane Journal
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• v.15 no.3
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• pp.213-223
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• 2005

We prepared an anti-adhesion membrane made of sodium hyaluronate/sodium carboxymethylcellulose (HA/CMC) and evaluated its effectiveness for adhesion prevention in a rat model. The anti-adhesion membrane was prepared by lyophilizing HA/CMC solution and cross-linking properly with 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC). In a cecum/abdominal wall abrasion model of Sprague-Dawley rat, cecal serosa and abdominal wall were abraded in $1\times2\;(cm^2)$ with a bone burr after peritoneal midline incision and sutured at 3 points around the injured surface. The denuded cecum was covered with HA/CMC membrane (experimental group), or nothing (control group) and apposed to the abdominal wall. Most of the control group represented 3 or more of adhesion grade at POD 7, 14, 21, and 28, whereas $60\~70\%$ of the experimental group was 2 or less of adhesion grade at 14, 21, and 28. It was similar in the adhesion strength. In a general manner, the adhesion grade and strength showed gradual increasing until POD 14, almost same or a little increasing POD 21, but decreasing POD 28. Also the control group was much higher in adhesion grade, strength, and area than the experimental group. It is expected that the anti-adhesion membrane will have a good clinical result in postoperative adhesion prevention.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.4 s.193
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• pp.138-146
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• 2007

Some biodegradable polymers and other materials such as hydrogels have shown the promising potential for surgical applications. Post surgical adhesion caused by the natural consequence of surgical wound healing results in repeated surgery and harmful effects. Recently, scientists have developed absorbable anti-adhesion barriers that can protect a tissue from adhesion in case they are in use; however, they are dissolved when no longer needed. Although these approaches have been attempted to fulfill the criteria for adhesion prevention, none can perfectly prevent adhesions in all situations. Overall, we developed a new method to fabricate an anti-adhesion membrane using biodegradable polymer and hydrogel. It employed a highly accurate three-dimensional positioning system with pressure-controlled syringe to deposit biopolymer solution. The pressure-activated microsyringe was equipped with fine-bore nozzles of various inner-diameters. This process allowed that inner and outer shapes could be controlled arbitrarily when it was applied to a surgical region with arbitrary shapes. In order to fulfill the properties of the ideal barriers f3r preventing postoperative adhesion, we adopted the pre-mentioned method combined with surface modification with the hydrogel coating by which anti-adhesion property was improved.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.129-130
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• 2006

• Membrane Journal
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• v.15 no.4
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• pp.289-296
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• 2005

In the MBR process, the membrane fouling occurs seriously on the membrane surface. In general, the membrane fouling is attributed to factors such as deposition or adhesion of sludge floc. The occurrence of fouling is a main cause of a decrease in membrane module fluk. At this study, our MBR membrane is manufactured by nano-particle with excellent anti-fouling character. The fine nano-material which can repel the sludge Hoc from the membrane surface is distributed in the membrane surface. We confirm anti-fouling effect, test continuously in the pilot site.

• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.119-121
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• 1999

Tumor cell interaction with the extracellular matrix is defined as the critical event of tumor invasion that signals the initiation of a metastatic cascade. Sesquicillin has been identified as an inhibitor of melanoma cell adhesion to the components of the extracellular matrix (ECM) in cultured broth of fungal strain F60063. Sesquicillin strongly inhibited the adhesion of B16 melanoma cells to laminin, fibronectin, and typeIV collagen. It also inhibited B16 melanoma cell invasion of reconstituted basement membrane Matrigel in vitro in a dose-dependent manner. These results suggest that sesquicillin is a new class of nonpeptidic ECM adhesion inhibitor having anti-invasive activity.

• Journal of Oral Medicine and Pain
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• v.24 no.3
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• pp.235-244
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• 1999

The present study was performed to investigate the binding between salivary proteins(low-molecular-weight mucin;MG2, amylase, proline-rich proteins;PRPs) and oral pathogens(Streptococcus gordonii, Actinomyces viscosus, Staphylococcus aureus) by using solid-phase assay. In the case of transferring proteins to Immobilon-P, S. gordonii binds to MG2. A. viscosus binds to MG2, amylase, and PRPs, and S. aureus binds to MG2 and amylase. On nitrocellulose membrane, S, gordonii and A. viscosus bind to MG2, amylase, and PRPs. S. aureus binds to MG2 and PRPs. However, rabbit anti-A. viscosus antisera and rabbit anti-S. aureus antisera showed cross reactivity to PRPs adsorbed to only nitrocellulose membrane in negative control experiments, which were done without bacterial overlay. The results were different according to the membrane used as solid-phase, which reflected the assay-sensitive nature of binding experiment. PRPs and amylase are known to be components of tooth enamel pellicle. In addition, there was experimental evidence that PRPs and MG2 may covalently bind to oral mucosal epithelium. Considering above facts, the results of the present study can provide information on the interactions between salivary proteins and oral bacteria on tooth and oral mucosal surfaces.

• Molecules and Cells
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• v.25 no.1
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• pp.131-137
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• 2008

Crk-associated substrate (CAS) is a focal adhesion protein that is involved in integrin signaling and cell migration. CAS deficiency reduces the migration and spreading of cells, both of which are processes mediated by Rac activation. We examined the functions of v-Crk, the oncogene product of the CT10 virus p47gag-crk, which affects cell migration and spreading, membrane ruffling, and Rac activation in CAS-deficient mouse embryonic fibroblasts (CAS-/- MEFs). CAS-/- MEFs showed less spreading than did CAS+/+ MEFs, but spreading was recovered in mutant cells that expressed v-Crk (CAS-/-v-Crk MEF). We observed that the reduction in spreading was linked to the formation of membrane ruffles, which were accompanied by Rac activation. In CAS-/- MEFs, Rac activity was significantly reduced, and Rac was not localized to the membrane. In contrast, Rac was active and localized to the membrane in CAS-/-v-Crk MEFs. Lamellipodia protrusion and ruffle retraction velocities were both reduced in CAS-/- MEFs, but not in CAS-/-v-Crk MEFs. We also found that microinjection of anti-gag antibodies inhibited the migration of CAS-/-v-Crk MEFs. These findings indicate that v-Crk controls cell migration and membrane dynamics by activating Rac in CAS-deficient MEFs.

• Korean Chemical Engineering Research
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• v.47 no.4
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• pp.501-505
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• 2009

In this study, we evaluated the effect of soluble EPCR(Soluble Endothelial Protein C Receptor, sEPCR) on the anti-inflammatory activities by activated protein C(APC) in endothelium. We demonstrated that sEPCR inhibited the barrier protective activity, the inhibition of neutrophils adhesion toward endothelial cells and the inhibition of transendothelial migration by APC in endothelial cells. Interestingly, sEPCR also blocked the mechanism by which APC inhibited the expression of cell adhesion molecules(CAM) by TNF-alpha in endothelial cells. These results suggested that the anti-inflammatory activities of APC was inhibited by sEPCR which blocked the binding motifs of Gla domain of APC to membrane bound EPCR. This finding will provide the important evidence in the development of new medicine for the treatment of severe sepsis and inflammatory diseases and good clue for understanding unknown mechanisms by which APC showed the anti-inflammatory activities in endothelium.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1332-1338
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• 2018

In the course of studies to discover natural products with anti-angiogenic properties, two cyclic octapeptides, octaminomycins A (1) and B (2), were isolated from the cultures of Streptomyces sp. RK85-270. Octaminomycins suppressed the vascular endothelial growth factor (VEGF)-induced proliferation, adhesion, tube formation, migration, and invasion of HUVECs. Anti-angiogenic activity was futher confirmed in vivo by the chicken chorioallantoic membrane assay. We also identified that 1 and 2 inhibited the phosphorylation of VEGF receptor 2, AKT, and ERK1/2 and the expression and activities of MMP-2 and MMP-9. These results suggest that 1 and 2 may serve as potential scaffolds for the development of therapeutic agents to angiogenesis-dependent diseases.