• Journal of Pharmaceutical Investigation
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• v.40 no.3
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• pp.181-185
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• 2010

The objective of this study was to improve the extent of drug release as well as the dissolution rate of TD49, a novel algicidal agent, via the preparation of solid dispersion (SD). Among the various carriers tested, $Solutol^{(R)}$ HS15 was most effective to enhance the solubility of TD49. Subsequently, SDs of TD49 were prepared by using $Solutol^{(R)}$ HS15 and their solubility, dissolution characteristics and drug crystallinity were examined at various drug-carrier ratios. Solubili ty of TD49 was increased significantly in accordance with increasing the ratio of $Solutol^{(R)}$ HS15 in SDs. Compared to untreated powders and physical mixtures (PMs), SDs facilitated the faster and greater extent of drug release in water. Particularly, SD having the drug-carrier ratio of 1:20 exhibited approximately 90% of drug release within 1 hr. Differential scanning calorimetry (DSC) thermograms and X-ray diffraction (XRD) patterns suggested that SDs might enhance the dissolution of TD49 by changing the drug crystallinity to an amorphous form in addition to the increased solubilization of drug in the presence of $Solutol^{(R)}$ HS15. In conclusion, SD using $Solutol^{(R)}$ HS15 appeared to be effective to improve the extent of drug release and the dissolution rate of poorly water soluble TD49.

• Membrane and Water Treatment
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• v.6 no.2
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• pp.141-160
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• 2015

This study aims to investigate the impacts of chemical cleaning on the performance of a reverse osmosis membrane. Chemicals used for simulating membrane cleaning include a surfactant (sodium dodecyl sulfate, SDS), a chelating agent (ethylenediaminetetraacetic acid, EDTA), and two proprietary cleaning formulations namely MC3 and MC11. The impact of sequential exposure to multiple membrane cleaning solutions was also examined. Water permeability and the rejection of boron and sodium were investigated under various water fluxes, temperatures and feedwater pH. Changes in the membrane performance were systematically explained based on the changes in the charge density, hydrophobicity and chemical structure of the membrane surface. The experimental results show that membrane cleaning can significantly alter the hydrophobicity and water permeability of the membrane; however, its impacts on the rejections of boron and sodium are marginal. Although the presence of surfactant or chelating agent may cause decreases in the rejection, solution pH is the key factor responsible for the loss of membrane separation and changes in the surface properties. The impact of solution pH on the water permeability can be reversed by applying a subsequent cleaning with the opposite pH condition. Nevertheless, the impacts of solution pH on boron and sodium rejections are irreversible in most cases.

• Journal of Pharmaceutical Investigation
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• v.41 no.5
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• pp.295-300
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• 2011

Paclitaxel is a well known anticancer agent and has been a pharmaceutical challenge because of its extremely poor water-solubility and susceptibility to the p-glycoprotein (p-gp)-mediated efflux in multi-drug resistant (MDR) cancer cells. Tributyrin (TB), a triglyceride with relatively short fatty acid chains, was chosen as solubilizing vehicle for paclitaxel based on the solubility study (26.6 mg/mL). Tributyrin (10%) o/w emulsion containing paclitaxel (5%), egg phosphatidylcholine (5%) and pegylated phospholipid (0.5%) was prepared by high pressure homogenization to obtain submicron-sized emulsion. The mean particle size of the resultant TB emulsion was 395.5 nm. Paclitaxel in TB emulsion showed higher anticancer activity against human breast cancer cell line, MCF-7, than free form delivered in DMSO solution. On the other hand, its anticancer activity was significantly reduced in MCF-7/ADR, a MDR variant cancer cell line of MCF-7, and recovered by the presence of verapamil, suggesting of the susceptibility to the p-gp mediated efflux even though paclitaxel was encapsulated into emulsion. The TB emulsion showed great potential as a promising vehicle for water-insoluble anticancer agent, paclitaxel.

• The Journal of Pediatrics of Korean Medicine
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• v.19 no.1
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• pp.11-23
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• 2005

Objectives : In the present study, the authors intended to investigate whether two oriental medical prescriptions named chwiyeon-tang and chihyosan-gamibang significantly affect much release from cultured hamster tracheal surface epithelial HTSE cells. Methods : Confluent HTSE cells were metabolically radiolabeled with 3H-glucosamine for 24 hrs and chased for 30 min in the presence of chwiyeon-tang or chihyosan-gamibang to assess the effect of each agent on 3H-mucin release. Possible cytotoxicities of each agent were assessed by measuring lactate dehydrogenase LDH release. Also, the effect of chwiyeon-tang and chihyosan-gamibang on contractility of isolated tracheal smooth muscle were investigated. Results : (1) Chwiyeon-tang significantly inhibited mucin release from cultured HTSE cells, with significant cytotoxicity ; (2) Chihyosan-gamibang significantly stimulated mucin release from cultured HTSE cells, with minute cytotoxicity ; (3) Chwiyeon-tang and Chihyosan-gamibang did not affect contractility of isolated tracheal smooth muscle. Conclusions : We suggest that the effects of Chwiyeon-tang and Chihyosan-gamibang with their components should be further investigated and it is of great value to find, from oriental medical prescriptions, noel agents which might regulate mucin secretion from airway goblet cells.

• The Journal of Pediatrics of Korean Medicine
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• v.20 no.1
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• pp.93-107
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• 2006

Objective : To investigate the effectiveness of two oriental medical prescriptions named Sigoungcheongpyetang(SCPT) and Tonggyutanggamibang(TGT) for mucin release from cultured hamster tracheal surface epithelial(HTSE) cells. Method : Confluent HTSE cells were metabolically radiolabeled with $^{3}H-glucosamine$ for 24hrs and chased for 30 min in the presence of SCPT or TGT to assess the effect of each agent $^{3}H-mucin$ release. Possible cytotoxicities of each agent were assessed by measuring lactate dehy drogenase(LDH) release. Also, the effects of SCPT and TGT on contrectility of isolated tracheal smooth muscle were investigated. Results : (1) SCPT and TGT significantly increased mucin release from cultured HTSE cells, with significantly cytotoxicity ; SCPT did not affect contractility of isolated tracheal smooth muscle and TGT inhibited Ach-induced contraction of isolated tracheal smooth muscle. Conclusion : We suggest that the effects of SCPT and TGT with their components should be further investigated and it is of great value to find, from oriental medical prescriptions, novel agents which might regulate mucin secretion from airway goblet cells.

• Journal of the Korean Applied Science and Technology
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• v.27 no.2
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• pp.129-136
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• 2010

A series of noble poly(amide-imide)s and copoly(amide-imide)s bearing 1,2-bis(4-phenoxy)benzene units were synthesized by the direct polycondensation of 1,2-bis(4-trimellitimidophenoxy)benzene[1,2-PTPB] with a combination of commercially available aromatic diamines and diacids such as m-phenylene diamine, p-phenylene diamine(PPD), isophthalic acid and terephthalic acid(TA) in N-methyl-2-pyrrolidone(NMP) using triphenyl phosphite and pyridine as a condensing agent in the presence of dehydrating agent ($CaCl_2$). The resulting polymers had inherent viscosities in the range of 0.37~0.78 dL/g and most of them were soluble m common organic solvents including NMP, dimethylacetamide, dimethylsulfoxide, dimethylformamide, and m-cresol. Wide-angle X-ray diffractograms revealed that the copoly(amide-imide) derived from PPD with mixed acids of 1,2-BTPB and TA, showed crystalline nature, whereas all of the other polymers were found to be amorphous. The glass transition temperatures of the polymers occurred over the temperature range of $270{\sim}323^{\circ}C$ in their differential scanning calorimetry curves and their 10% weight loss temperature, determined by thermogravimetric analysis in air and nitrogen atmosphere, were in the range $465{\sim}535^{\circ}C$, $500{\sim}550^{\circ}C$, respectively, indicating their good thermal stability.

• The Journal of Internal Korean Medicine
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• v.27 no.4
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• pp.895-904
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• 2006

Objectives : In the present study, the author intended to investigate whether two oriental medical prescriptions named Socheongryongtang-ga-seoggo (SCTS) and Prescription D (P-D) significantly affect mucin release from cultured hamster tracheal surface epithelial (HTSE) cells. Materials and Methods : Confluent HTSE cells were metabolically radiolabeled with 3H-glucosamine for 24 hrs and chased for 30 min in the presence of SCTS or P-D to assess the effect of each agent on 3H-mucin release. Possible cytotoxicities of each agent were assessed by measuring lactate dehydrogenase (LDH) release. Also, the effects of SCTS and P-D on contractility of isolated tracheal smooth muscle were investigated. Results : SCTS did not affect mucin release from cultured HTSE cells, without cytotoxicity. However, P-D significantly increased mucin release from cultured HTSE cells. with significant cytotoxicity. SCTS inhibited Ach-induced contraction of isolated tracheal smooth muscle. P-D also inhibited Ach-induced contraction of isolated tracheal smooth muscle. Conclusions : The author suggests that the effects of SCTS and P-D with their components should be further investigated and it is valuable to find, from oriental medical prescriptions, novel agents which might regulate mucin secretion from airway goblet cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.1-1
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• 2011

We developed a new generalized synthetic procedure, called as "heat-up process," to produce uniform-sized nanocrystals of many transition metals and oxides without a size selection process. We were able to synthesize uniform magnetite nanocrystals as much as 1 kilogram-scale from the thermolysis of Fe-oleate complex. Clever combination of different nanoscale materials will lead to the development of multifunctional nano-biomedical platforms for simultaneous targeted delivery, fast diagnosis, and efficient therapy. In this presentation, I would like to present some of our group's recent results on the designed fabrication of multifunctional nanostructured materials based on uniform-sized magnetite nanoparticles and their medical applications. Uniform ultrasmall iron oxide nanoparticles of <3 nm were synthesized by thermal decomposition of iron-oleate complex in the presence of oleyl alcohol. These ultrasmall iron oxide nanoparticles exhibited good T1 contrast effect. In in vivo T1 weighted blood pool magnetic resonance imaging (MRI), iron oxide nanoparticles showed longer circulation time than commercial gadolinium complex, enabling high resolution imaging. We used 80 nm-sized ferrimagnetic iron oxide nanocrystals for T2 MRI contrast agent for tracking transplanted pancreatic islet cells and single-cell MR imaging. We reported on the fabrication of monodisperse magnetite nanoparticles immobilized with uniform pore-sized mesoporous silica spheres for simultaneous MRI, fluorescence imaging, and drug delivery. We synthesized hollow magnetite nanocapsules and used them for both the MRI contrast agent and magnetic guided drug delivery vehicle.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.442-446
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• 2003

Over two hundred fungal strains from Korean soil were tested for the production of cholesterol-lowering agent, lovastatin. Each fungal strain was cultivated in the rapeseedmeal production medium (RPM). After growing for 7 days, the presence of lovastatin in the culture was examined by TLC analysis and HPLC. Nine different fungal strains were determined to produce detectable amounts of lovastatin, among which one fungal strain isolated from barnyard manure of Kanghwa island produced 25.58 mg/L of lovastatin in the production medium. The morphological observation combined with the determination of 18S-rRNA sequence suggested that the selected strain belongs to a member of Aspergillus sp..

• Biomolecules & Therapeutics
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• v.4 no.3
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• pp.224-231
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• 1996

DA-5018, a non-narcotic analgesic agent, was examined for mutagenicity in the reverse mutation test on bacteria, chromosomal aberration test on cultured mammalian cells and micronucleus test on mice. The reverse mutation test was performed by a plate incorporation method with or without a metabolic activation system(S9 mix) using Salmonella typhimurium strain TA100, TA1535, TA98 and TA1537. DA-5018 did not significantly increase revertant colonies in any of the test strains under any conditions at concentrations ranging from 0.0049 to 1.25 mg/plate, compared with the vehicle control. In the chromosomal aberration test using cultured Chinese Hamster Lung(CHL) cells, DA-5018 did not increase the number of aberrant cells in the presence or absence of S9 mix at concentrations of 0.016 mM/plate to 0.25 mM/plate, compared with the vehicle control. In the micronucleus test, male ICR mice were given DA-5018 intraperitoneally at a dose level of 0.55, 1.10 and 2.20 mg/kg. The incidence of bone marrow micronucleated polychromatic erythrocytes in the DA-5018 treated mice was not significantly different from that of the vehicle control. These results indicate that DA-5018 does not have mutagenic potential under the present test conditions.