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RISS 인기검색어
- 검색키워드
- 저자 : Park Youmie (검색결과 87 건)
- 무료
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Park, Youmie Korean Society of ToxicologyKorea Environmental Mu 2014 Toxicological Research Vol.30 No.3
This review covers general information regarding the green synthesis of antibacterial silver nanoparticles. Owing to their antibacterial properties, silver nanoparticles are widely used in many areas, especially biomedical applications. In green synthesis practices, the chemical reducing agents are eliminated, and biological entities are utilized to convert silver ions to silver nanoparticles. Among the various biological entities, natural plant extracts have emerged as green reducing agents, providing eco-friendly routes for the preparation of silver nanomaterials. The most obvious merits of green synthesis are the increased biocompatibility of the resulting silver nanoparticles and the ease with which the reaction can be carried out. This review summarizes some of the plant extracts that are used to produce antibacterial silver nanoparticles. Additionally, background information regarding the green synthesis and antibacterial activity of silver nanoparticles is provided. Finally, the toxicological aspects of silver nanoparticles are briefly mentioned.
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Park, Ji Su,Ahn, Eun-Young,Park, Youmie DOVE MEDICAL PRESS 2017 INTERNATIONAL JOURNAL OF NANOMEDICINE Vol.12 No.-
<P>Mangosteen (<I>Garcinia mangostana</I>) pericarp waste extract was used to synthesize gold and silver nanoparticles by a green strategy. The extract was both a reducing and stabilizing agent during synthesis. Phytochemical screening of the extract was conducted to obtain information regarding the presence/absence of primary and secondary metabolites in the extract. The in vitro antioxidant activity results demonstrated that the extract had excellent antioxidant activity, which was comparable to a standard (butylated hydroxy toluene). Spherical gold nanoparticles (gold nanoparticles green synthesized by mangosteen pericarp extract [GM-AuNPs]) with an average size of 15.37±3.99 to 44.20±16.99 nm were observed in high-resolution transmission electron microscopy (HR-TEM) images. Most interestingly, the silver nanoparticles (silver nanoparticles green synthesized by mangosteen pericarp extract [GM-AgNPs]) had asymmetric nanodumbbell shapes where one tail grew from a spherical head. The average head size was measured to be 13.65±5.07 to 31.08±3.99 nm from HR-TEM images. The hydrodynamic size of both nanoparticles tended to increase with increasing extract concentration. Large negative zeta potentials (−18.92 to −34.77 mV) suggested that each nanoparticle solution possessed excellent colloidal stability. The reaction yields were 99.7% for GM-AuNPs and 82.8% for GM-AgNPs, which were assessed by inductively coupled plasma optical emission spectroscopy. A high-resolution X-ray diffraction pattern confirmed the face-centered cubic structure of both nanoparticles. Based on phytochemical screening and Fourier transform infrared spectra, the hydroxyl functional groups of carbohydrates, flavonoids, glycosides, and phenolic compounds were most likely involved in a reduction reaction of gold or silver salts to their corresponding nanoparticles. The in vitro cytotoxicity (based on a water-soluble tetrazolium assay) demonstrated that GM-AgNPs were toxic to both A549 (a human lung cancer cell) and NIH3T3 (a mouse fibroblast cell). The cytotoxicity of GM-AgNPs on A549 cells was related to apoptotic cell death. However, GM-AuNPs did not show any significant cytotoxicity to either cell. These results suggest that GM-AuNPs have the potential to be drug delivery vehicles or carriers for pharmaceutical and biomedical applications.</P>
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A furanquinone from Paulownia tomentosa stem for a new cathepsin K inhibitor
Park, Youmie,Kong, Jae Yang,Cho, Heeyeong John Wiley Sons, Ltd. 2009 Phytotherapy research Vol.23 No.10
<P>In the search for novel inhibitors of cathepsin K, a new furanquinone compound, methyl 5-hydroxy-dinaphtho[1,2-2′3′]furan-7,12-dione-6-carboxylate (1a), showed in vitro inhibitory activities for cathepsin K. Compound 1a was isolated originally from Paulownia tomentosa stem and its derivatives were synthesized. Furanquinone compounds (1a, 1b, 1c and 1d) were also found to be capable of inhibiting cathepsin L, which is closely related to cathepsin K. The inhibitory activity of the parent compound 1a (IC50 = 21 µm) for cathepsin K was slightly higher than those of the other three derivatives that have a methoxy (1b), propoxy (1c) or acetoxy (1d) group (IC50 = 33–66 µm) in the 5-position of compound 1a. This implies that the 5-hydroxyl functional group of 1a may have favorable effects on the reduction potential which are related to the cathepsin K inhibitory activities of furanquinone compounds. Therefore, the cathepsin K inhibitory activity of a new furanquinone compound is proposed. Copyright © 2009 John Wiley & Sons, Ltd.</P>
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Youmie Park 한국독성학회 2014 Toxicological Research Vol.30 No.3
This review covers general information regarding the green synthesis of antibacterial silver nanoparticles. Owing to their antibacterial properties, silver nanoparticles are widely used in many areas, especially biomedical applications. In green synthesis practices, the chemical reducing agents are eliminated, and biological entities are utilized to convert silver ions to silver nanoparticles. Among the various biological entities, natural plant extracts have emerged as green reducing agents, providing eco-friendly routes for the preparation of silver nanomaterials. The most obvious merits of green synthesis are the increased biocompatibility of the resulting silver nanoparticles and the ease with which the reaction can be carried out. This review summarizes some of the plant extracts that are used to produce antibacterial silver nanoparticles. Additionally, background information regarding the green synthesis and antibacterial activity of silver nanoparticles is provided. Finally, the toxicological aspects of silver nanoparticles are briefly mentioned.
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Park, Youmie,Noh, Hwa Jung,Han, Lina,Kim, Hyun-Seok,Kim, Yong-Jae,Choi, Jae Sue,Kim, Chong-Kook,Kim, Yeong Shik,Cho, Seonho American Scientific Publishers 2012 Journal of Nanoscience and Nanotechnology Vol.12 No.9
<P>We report a green synthesis of silver nanoparticles that uses extracts from the aerial part of Artemisia capillaris. Both water and 70% ethanol extracts successfully generated silver nanoparticles. The formation of silver nanoparticles was confirmed by surface plasmon resonance bands, Fourier transform-infrared spectra, high resolution-transmission electron and atomic force microscopic images. Various shapes of silver nanoparticles were generated with an average diameter of 29.71 nm with water extract and 29.62 nm with 70% ethanol extract. An improvement in antibacterial activity (MIC 8.35-16.7 microg/mL) was observed against a total of twenty different strains of Gram-negative and Gram-positive bacteria. A remarkable enhancement (approximately 12-fold) was observed against Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, and Klebsiella areogenes when compared with the extract alone. Silver nanoparticles produced by the 70% ethanol extract showed slightly higher antibacterial activity than those generated with the water extract. The correlation between total flavonoid content of each extract and the antibacterial activity did not exert any significant relationships. This report suggests that plant extracts have the potential to be used as powerful reducing agents for the production of biocompatible silver nanoparticles possessing enhanced antibacterial activities.</P>
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Potential nanocarriers of chondroitinase for the treatment of spinal cord injury
Youmie Park 한국당과학회 2008 한국당과학회 학술대회 Vol.2008 No.1
Recent studies have shown the potential therapeutic uses of chondroitinase to recover loss of function in spinal cord injuries by regenerating neuronal growth. Upon injury to the spinal cord there is an up-regulation of chondroitin sulfate proteoglycans (CSPG). These CSPG help create an intertwined matrix within the glial scar, which can inhibit the advancement of neuronal growth between the sites of injury. Chondroitinase is able to degrade the chondroitin sulfate (CS) chains on the proteoglycans, thus eliminating obstacles for efficient neuron growth. In various animal models, the use of chondroitinase within injury sites allows the animal to regain the ability to walk. However, due to the instability of this enzyme, administration requires continuous, invasive, injections over a long period of time, which can further aggravate the injured site. Immobilization of chondroitinase onto a nano-solid support system could eliminate some of the problems currently faced, by increasing thermal stability, reducing immune responses, and limiting the migration of the enzyme to other parts of the body. Various methods of enzyme immobilization are used and have been shown to increase the activity of the enzymes in the literature. This technology could eventually be used for efficient treatment of spinal cord injury to recover the loss of function. Carbon nanotubes (cellulose-coated) and gold nanoparticles (citrate-reduced) were used for immobilization of chondroitinase ABC (Proteus vulgaris and Bacteroides thetaitaomicron) in the current study. While performing the immobilization process, we noticed a difference in the action pattern of both Proteus and Bacteroides enzymes. LC-ESI-MS to study the action pattern of these enzymes will be also discussed.
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Catalytic reduction of 4-nitrophenol with gold nanoparticles synthesized by caffeic acid
Seo, Yu Seon,Ahn, Eun-Young,Park, Jisu,Kim, Tae Yoon,Hong, Jee Eun,Kim, Kyeongsoon,Park, Yohan,Park, Youmie SPRINGER SCIENCE + BUSINESS MEDIA 2017 NANOSCALE RESEARCH LETTERS Vol.12 No.1
<P>In this study, various concentrations of caffeic acid (CA) were used to synthesize gold nanoparticles (CA-AuNPs) in order to evaluate their catalytic activity in the 4-nitrophenol reduction reaction. To facilitate catalytic activity, caffeic acid was removed by centrifugation after synthesizing CA-AuNPs. The catalytic activity of CA-AuNPs was compared with that of centrifuged CA-AuNPs (<I>cf</I>-CA-AuNPs). Notably, <I>cf</I>-CA-AuNPs exhibited up to 6.41-fold higher catalytic activity compared with CA-AuNPs. The catalytic activity was dependent on the caffeic acid concentration, and the lowest concentration (0.08 mM) produced CA-AuNPs with the highest catalytic activity. The catalytic activities of both CA-AuNPs and <I>cf</I>-CA-AuNPs decreased with increasing caffeic acid concentration. Furthermore, a conversion yield of 4-nitrophenol to 4-aminophenol in the reaction mixture was determined to be 99.8% using reverse-phase high-performance liquid chromatography. The product, 4-aminophenol, was purified from the reaction mixture, and its structure was confirmed by <SUP>1</SUP>H-NMR. It can be concluded that the removal of the reducing agent, caffeic acid in the present study, significantly enhanced the catalytic activity of CA-AuNPs in the 4-nitrophenol reduction reaction.</P>
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