• Journal of Sensor Science and Technology
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• v.13 no.1
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• pp.47-55
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• 2004

This paper presents drug release properties of active drug delivery system (DDS) using volume change of polypyrrole (PPy). The incorporation of various chemical substances into the PPy and controlling its release with the externally applied voltage to the PPy are possible. In order to confirm possibility for drug delivery system qualitatively, indicator(phenol red) was examined as a dopant of PPy. The applied voltage to the PPy electrode was set to -2 V and this negative voltage makes the anionic indicator released in saline solution. After qualitative analysis, in order to confirm quantitative drug release characteristic of PPy, salicylate which is one of the aspirin substance was used as a dopant of PPy. As a result, the salicylate release characteristics with time was thoroughly investigated while varying the electrode area, polymerization time, the applied voltage for drug release. Based on these quantitative results, a preliminary experiment was carried out to check the feasibility of the PPy applicable to the neuronal system.

• Biomedical Science Letters
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• v.25 no.2
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• pp.159-169
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• 2019

Breast cancer stem cells (BCSCs) in breast cancer cells have self-renewal ability and differentiation potential. They are also resistant to drugs after chemotherapy. To overcome this resistance, we designed negatively charged 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG)-based liposomes for drug delivery. These liposomes have enhanced the therapeutic effects of a range of antitumor therapies by increasing the cellular uptake and improving drug delivery to targets sites. In this study, we investigated whether DMPG-POPC liposomes, including the neutral lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholin (POPC), can specifically bind to MCF-7 breast cancer cells and increase cellular uptake compared with that by CHOL-POPC liposomes. We also estimated the cytotoxicity of DMPG-POPC liposomes encapsulated with both metformin (Met) and sodium salicylate (Sod) against breast cancer cells and BCSCs compared with that of the free drugs. Our results demonstrated that these dual drug-encapsulated liposomes significantly enhanced the cytotoxic and anti-colony formation abilities compared with individual drug-encapsulated liposomes or free drugs in BCSCs. Overall, our results suggest that DMPG-POPC liposomes containing two drugs (Met + Sod) show promise for synergistic anti-cancer therapy of breast cancer by increasing drug delivery efficiency into breast cancer cells and BCSCs.

• Applied Microscopy
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• v.18 no.1
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• pp.92-102
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• 1988

The ototoxic effects of salicylate on the ultrastructure of spiral ganglion cells were examined. Sodium salicylate($50{\sim}60\/kg$ body weight, once a day for 7 days) were injected subcutaneously to $5{\sim}6$ week-old fifteen Sprague-Dawley rats. Animals were sacrificed 24 hours (group 1), 6 weeks (group 2) or 10 weeks (group 3) after the last injection. In group 1 animals, distention of membranous cisternae was found in the cytoplasm of ganglion cells, satellite cells and Schwann cells in which enlargement or multicystic cytosome formation of the mitochondria were shown. In group 2 animals, membranous cisternae became larger or fused to form larger vacuoles or cysts. Shrinkage of spiral ganglion cell cytoplasm and loosening of myelin sheath were seen. In group 3 animals, extensive swelling or loss of nerve fibers were shown along with the folding or partial loss of myelin sheath which caused leakage of ganglion cell cytoplasm. It was concluded that the ototoxicity of salicy-late caused the ultrastructral changes of the spiral ganglion cells which became more severe in group 2 and 3 animals. The possibility of retrograde degeneration following the sensory cell changes was suggested.

• YAKHAK HOEJI
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• v.30 no.2
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• pp.96-99
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• 1986

Absorption enhancing effect of 5 MSA-Na at the mucous memberanes of the rectum and duodenum was studied via in vitro sac test. There were no significant differences between two membranes. Effect of 5MSA-Na on the transfer of CMZ to the tissue was also studied via in situ loop method. There was no significant difference at the duodenum, compared to the control when CMZ was administered intravenously. Transfer of CMZ to the loop of the rectum was increased in the presence of 5MSA-Na compared to the control, which might be attributed to the enhanced permeability of the mucous memberane of the rectum.

• Journal of the Korean Chemical Society
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• v.37 no.12
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• pp.1080-1086
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• 1993

• Bulletin of the Korean Chemical Society
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• v.9 no.1
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• pp.17-21
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• 1988

A mechanistic study on the chemiluminescence resulting from the reaction between bis(2,4,6-trichlorophenyl)oxalate(TCPO) and hydrogen peroxide in the presence of fluorescent polycyclic aromatic hydrocarbons in a viscous phthalate medium has been conducted. The rate determining step, decay rate constants, and relative quantum efficiencies yielded by varying the concentration of reagents generally support an existing mechanism. However, a reaction between TCPO and sodium salicylate was not observed.

• Membrane Journal
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• v.17 no.1
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• pp.67-79
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• 2007

Uniform microcapsules containing ionic model drugs were prepared by controlling various conditions of emulsification procedure using a lab-scale membrane emulsification system with a SPG (Shirasu porous glass) tubular membrane. We observed the effects of various emulsification parameters [concentration and molecular weight of polycaprolatone (PCL) polymer, transmembrane pressure and emulsifier concentration in disperse phase and continuous phase, stirring speed] on the mean size and size ditribution of microcapsules containing lidocaine hydrochloride (cationic drug), sodium salicylate (nonionic drug) and 4-acetaminophen (anionic drug) used as a model drugs. Also, release characteristics of a model drugs from PCL microcapsules were investigated. Controlling membrane emulsification parameters, uniform PCL microcapsules with about $5\;{\mu}m$ of the mean size were finally prepared. The release rate and the burst effect of microcapsules were decreased in condition of the acidic solution, but it was increased in condition of the base solution.

• Journal of Pharmaceutical Investigation
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• v.23 no.3
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• pp.41-50
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• 1993

The iontophoretic delivery across rat skin of quaternary ammonium salts (isopropamide: ISP, pyridostigmine: PS), which are positively charged over a wide pH range, was measured ill vitro. The study showed that: (a) iontophoresis significantly enhanced delivery of ISP and PS compared to respective passive transport; (b) delivery of ISP and PS was directly proportional to the applied continuous direct current density over the range of $0-0.69\;mA/cm^2;$ (c) delivery of ISP and PS was also proportional to the drug concentration in the donor compartment over the range of $0-2{\time}l0^{-2}M:$ (d) sodium ion in the donor compartment inhibited the drug transport possibly due to decreasing the electric transference number of the drug; (e) delivery of ISP and PS increased as the pH of the donor solution increased over the pH range 2-7 suggesting permselective nature of the epidermis, and inhibition of the transference number of the drugs by hydronium ion; (f) some organic anions such as taurodeoxycholate, salicylate and benzoate which form lipophilic ion-pair complexes with ISP inhibited the delivery of ISP. The degree of inhibition by the organic anions was linearly proportional to the extraction coefficient $(K_e)$ of ISP from the partition system with each counteranion between phosphate buffer (pH 7.4) and n-octanol. For PS, however, taurodeoxycholate, but not salicylate and benzoate inhibited the iontophoretic delivery. It suggests that not only sodium ion and hydronium ion but also the counteranions which form lipophilic ion-pairs with quaternary ammonium drugs are not favorable components in formulating the donor solution of the drugs to achieve an effective iontophoretic delivery.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1439-1446
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• 2009

Isocarbophos is a widely used organophosphorus insecticide that has caused environmental pollution in many areas. However, degradation of isocarbophos by pure cultures has not been extensively studied, and the degradation pathway has not been determined. In this paper, a highly effective isocarbophos-degrading strain, scl-2, was isolated from isocarbophos-polluted soil. The strain scl-2 was preliminarily identified as Arthrobacter sp. based on its morphological, physiological, and biochemical properties, as well as 16S rDNA analysis. The strain scl-2 could utilize isocarbophos as its sole source of carbon and phosphorus for growth. One hundred mg/l isocarbophos could be degraded to a non detectable level in 18 h by scl-2 in cell culture, and isofenphos-methyl, profenofos, and phosmet could also be degraded. During the degradation of isocarbophos, the metabolites isopropyl salicylate, salicylate, and gentisate were detected and identified based on MS/MS analysis and their retention times in HPLC. Transformation of gentisate to pyruvate and fumarate via maleylpyruvate and fumarylpyruvate was detected by assaying for the activities of gentisate 1,2-dioxygenase (GDO) and maleylpyruvate isomerase. Therefore, we have identified the degradation pathway of isocarbophos in Arthrobacter sp. scl-2 for the first time. This study highlights an important potential use of the strain scl-2 for the cleanup of environmental contamination by isocarbophos and presents a mechanism of isocarbophos metabolism.

• Molecules and Cells
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• v.28 no.2
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• pp.105-109
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• 2009

We reported previously that overexpression of a salicylic acid (SA) methyltransferase1 gene from rice (OsBSMT1) or a SA glucosyltransferase1 gene from Arabidopsis thaliana (AtSAGT1) leads to increased susceptibility to Pseudomonas syringae due to reduced SA levels. To further examine their roles in the defense responses, we assayed the transcript levels of AtBSMT1 or AtSAGT1 in plants with altered levels of SA and/or other defense components. These data showed that AtSAGT1 expression is regulated partially by SA, or nonexpressor of pathogenesis related protein1, whereas AtBSMT1 expression was induced in SA-deficient mutant plants. In addition, we produced the transgenic Arabidopsis plants with RNAi-mediated inhibition of AtSAGT1 and isolated a null mutant of AtBSMT1, and then analyzed their phenotypes. A T-DNA insertion mutation in the AtBSMT1 resulted in reduced methyl salicylate (MeSA) levels upon P. syringae infection. However, accumulation of SA and glucosyl SA was similar in both the atbsmt1 and wild-type plants, indicating the presence of another SA methyltransferase or an alternative pathway for MeSA production. The AtSAGT1-RNAi line exhibited no altered phenotypes upon pathogen infection, compared to wild-type plants, suggesting that (an)other SA glucosyltransferase(s) in Arabidopsis plants may be important for the pathogenesis of P. syringae.