Evaluation of 99mTc-MAG3-2-nitroimidazole for hypoxic tumor imaging

Yun Sang Lee,Young Joo Kim,Jae Min Jeong 대한방사성의약품학회 2019 Journal of radiopharmaceuticals and molecular prob Vol.5 No.1

2-Nitroimidazole derivatives have been reported to accumulate in hypoxic tissue. We prepared a novel 99mTc-MAG3-2-nitroimidazole and evaluated the feasibility for hypoxia imaging agent. Bz-MAG3-2-nitroimidazole wassynthesized by direct coupling of Bz-MAG3 and 2-nitroimidazole using dicyclohexylcarbodiimide. Bz-MAG3-2-nitroimidazole was labeled with 99mTc in the presence of tartaric acid and SnCl2-2H2O at 100°C for 30 min. And the reaction mixture was purified by C18 Sep-pak cartridge. The labeling efficiency and the radiochemicalpurity were checked by ITLC-SG/acetonitrile. The tumor was grown in balb/c mice for 8~13 days after thesubcutaneous injection of tumor cells, CT-26 (murine colon adenocarcinoma cell). Biodistribution study andtumor autoradiography were performed in the xenografted mice after i.v injection of 74 kBq/0.1 mL and 19MBq/0.1 mL of 99mTc-MAG3-2-nitroimidazole, respectively. In vivo images of 99mTc-MAG3-2-nitroimidazolein tumor bearing mice were obtained 1.5 hr post injection. The labeling efficiency was 45±20% and theradiochemical purity after purification was over 95%. Paper electrophoresis confirmed negative charge of99mTc-MAG3-2-nitroimidazole. 99mTc-MAG3-2-nitroimidazole was very stable at room temperature and its proteinbinding was 53%. The 99mTc-MAG3-2-nitroimidazole exhibited high uptake in the liver, stomach and intestine. In biodistribution study using tumor bearing mice, the uptakes (% ID/g) of the tumor were 0.5±0.1, 0.4±0.0,0.2±0.1 and 0.1±0.1 at 5, 15, 30 min and 4 hrs. Tumor/muscle ratio were 1.4±0.1, 2.2±0.83, 3.0±0.9, and 3.7(n=2) for 5, 15, 30 min and 4 hrs. The uptake in hypoxic area was found higher than in non-hypoxic area oftumor tissue by autoradiography. In vivo images showed the relatively faint uptake to the hypoxic tumor region. 99mTc-MAG3-2-nitroimidazole was successfully synthesized and found feasible for imaging hypoxia

Evaluation of ^99mTc-MAG₃-2-nitroimidazole for hypoxic tumor imaging

Lee, Yun-Sang,Kim, Young Joo,Jeong, Jae Min Korean Society of Radiopharmaceuticals and Molecul 2019 Journal of radiopharmaceuticals and molecular prob Vol.5 No.1

2-Nitroimidazole derivatives have been reported to accumulate in hypoxic tissue. We prepared a novel $^{99m}Tc-MAG_3$-2-nitroimidazole and evaluated the feasibility for hypoxia imaging agent. $Bz-MAG_3$-2-nitroimidazole was synthesized by direct coupling of $Bz-MAG_3$ and 2-nitroimidazole using dicyclohexylcarbodiimide. $Bz-MAG_3$-2-nitroimidazole was labeled with $^{99m}Tc$ in the presence of tartaric acid and $SnCl_2-2H_2O$ at $100^{\circ}C$ for 30 min. And the reaction mixture was purified by $C_{18}$ Sep-pak cartridge. The labeling efficiency and the radiochemical purity were checked by ITLC-SG/acetonitrile. The tumor was grown in balb/c mice for 8~13 days after the subcutaneous injection of tumor cells, CT-26 (murine colon adenocarcinoma cell). Biodistribution study and tumor autoradiography were performed in the xenografted mice after i.v injection of 74 kBq/0.1 mL and 19 MBq/0.1 mL of $^{99m}Tc-MAG_3$-2-nitroimidazole, respectively. In vivo images of $^{99m}Tc-MAG_3$-2-nitroimidazole in tumor bearing mice were obtained 1.5 hr post injection. The labeling efficiency was $45{\pm}20%$ and the radiochemical purity after purification was over 95%. Paper electrophoresis confirmed negative charge of $^{99m}Tc-MAG_3$-2-nitroimidazole. $^{99m}Tc-MAG_3$-2-nitroimidazole was very stable at room temperature and its protein binding was 53%. The $^{99m}Tc-MAG_3$-2-nitroimidazole exhibited high uptake in the liver, stomach and intestine. In biodistribution study using tumor bearing mice, the uptakes (% ID/g) of the tumor were $0.5{\pm}0.1$, $0.4{\pm}0.0$, $0.2{\pm}0.1$ and $0.1{\pm}0.1$ at 5, 15, 30 min and 4 hrs. Tumor/muscle ratio were $1.4{\pm}0.1$, $2.2{\pm}0.83$, $3.0{\pm}0.9$, and 3.7 (n=2) for 5, 15, 30 min and 4 hrs. The uptake in hypoxic area was found higher than in non-hypoxic area of tumor tissue by autoradiography. In vivo images showed the relatively faint uptake to the hypoxic tumor region. $^{99m}Tc-MAG_3$-2-nitroimidazole was successfully synthesized and found feasible for imaging hypoxia.

Geometric effect of the hydrogel grid structure on in vitro formation of homogeneous MIN6 cell clusters.

Bae, Chae Yun,Min, Mun-kyeong,Kim, Hail,Park, Je-Kyun Royal Society of Chemistry 2014 Lab on a chip Vol.14 No.13

<P>A microstructure-based hydrogel was employed to study the relationship between spatial specificity and cellular behavior, including cell fate, proliferation, morphology, and insulin secretion in pancreatic β-cells. To effectively form homogeneous cell clusters in vitro, we made cell-containing hydrogel membrane constructs with an adapted grid structure based on a hexagonal micropattern. Homogeneous cell clusters (average diameter: 83.6 14.2 μm) of pancreatic insulinoma (MIN6) cells were spontaneously generated in the floating hydrogel membrane constructs, including a hexagonal grid structure (size of cavity: 100 μm, interval between cavities: 30 μm). Interestingly, 3D clustering of MIN6 cells mimicking the structure of pancreatic islets was coalesced into a merged aggregate attaching to each hexagonal cavity of the hydrogel grid structure. The fate and insulin secretion of homogeneous cell clusters in the hydrogel grid structure were also assessed. The results of these designable hydrogel-cell membrane constructs suggest that facultative in vitro β-cell proliferation and maintenance can be applied to biofunctional assessments.</P>

纖維强化 Plastics의 切削加工에 관한 硏究

金元鎰,李允景,姜渭民 慶南大學校 附設 工業技術硏究所 1991 硏究論文集 Vol.9 No.-

本 硏究에서는 유리纖維 强化樹脂의 旋消時 각 切削 條件에 따른 超音波 振動切削과 常用切削時 나타나는 加工特性을 考察하기 위하여 眞圓度, 表面粗度을 中心으로 比較, 檢討한 結果 다음과 같은 結論을 얻을 수 있었다. 1. 眞圓度의 값은 切削條件 및 振幅에는 많은 影響을 받지 않고, 纖維角이 60˚인 경우 V=60m/min, f=0.08mm/rev, t=0.05mm일때 眞圓度 값이 10㎛로 가장 良好하였고, 纖維角이 90˚인 경우에는 振動切削에서는 19㎛, 常用切削에서는 37㎛로 가장 높은 값이 나타났으며, 振動切削이 常用切削 보다 약 2배 改善되었다. 2. 表面眺度는 纖維角이 60˚인 경우가 가장 良好하고, V=20m/min에서는 振動切削과 常用切削의 값은 거의 變化가 없으며 V=30m/min이상에서는 振動切削이 顯著하게 改善되었다. 3. 工具傾斜角은 眞圓度에는 많은 影響을 미치지 않지만 表面粗度는 0˚보다 6˚가 약간 改善됨을 알 수 있다. 4. 振動切削은 硏削에서 얻을 수 있는 加工精度를 旋削에서도 쉽게 얻을 수 있어 精密度와 生産性을 向上시키는 加工法이라 할 수 있다. In this paper, under different cutting condition on G.F.R.P, ultrasonic vibration cutting and the characteristics in conventional cutting have been studied. So the following conclusion centered on comparison, examination of roundess, surface roughness has been reached. 1. The value of surface roundess doesn't get much effect from amplitude as well as cutting conditions. With 60˚of fiber angle, v=60m/min, f=0.08mm/rev, t=0.05mm, the value of surface roundess, 10㎛, was the best. In case of 90˚, the highest value was 19㎛ in vibration cutting and 37㎛ in conventional cutting vibration cutting has improved about twice as high as conventional cutting. 2. In case the fiber angle was 60˚, surface roundess was little difference between vibeation and conventional cutting. Under v=30m/min and above, vibration cutting has remarkably improved. 3. Even if the tool rake angle doesn't affect the roundess, surface roughness has improved a little more at 6˚than at 0˚. 4. Vibration cutting helps to gain as lathe turing working precision as in grinding, Consequently, it's considered a good working method to improve precision and productivity.

클로르헥시딘이 초음파 치석제거기에 의해 발생된 에어로졸 내 세균 수에 미치는 영향

손우경,신승윤,계승범,양승민,Son, Woo-Kyung,Shin, Seung-Yun,Kye, Seung-Beom,Yang, Seung-Min 대한치주과학회 2009 Journal of Periodontal & Implant Science Vol.39 No.3

Purpose: The aerosol generated by ultrasonic scaler can contain bacteria or virus which can penetrate into body through respiratory systems of dentists, dental hygienist or patients. The aim of this study is to evaluate the effect of chlorhexidine digluconate as preoperative mouthrinse or lavage for ultrasonic scaler on the reduction of viable organisms in aerosol produced during periodontal treatment using ultrasonic scaler. Methods: 30 patients with moderate chronic periodontitis were included and divided into 3 groups: Control (no preoperative mouthrinse and tap water as lavage), CHG (preoperative mouthrinse with 0.1% chlorhexidine digluconate and tap water as lavage), CHL (no preoperative mouthrinse and 0.1% chlorhexidine digluconate as lavage). Each patient received scaling or subgingival curettage for 30 min. In CHG group, mouthrinse with chlorhexidine digluconate was performed for 1 min. before treatment. Before, during and after scaling or subgingival curettage, air sampling was performed for 7 min. each (1000 L/7 min.) with trypticase-soy agar plate. Agar plates were incubated in $37^{\circ}C$ aerobically. The numbers of colony-forming units (CFU) were counted and compared. Results: The numbers of CFUs of the samples obtained during treatment were $97{\pm}14.0$ in control, $73.1{\pm}14.9$ in CHG group and $44.5{\pm}9.0$ in CHL group. The difference among the 3 groups was determined to be statistically significant (one-way ANOVA with Bonferroni's correction, p-value: 0.0003). In contrast, the numbers of CFU of samples obtained before and after treatment were not significantly different among the groups. Conclusions: Chlorhexidine digluconate used as preoperative mouthrinse or lavage for ultrasonic scaler can reduce the microorganisms in aerosol produced during periodontal treatment using ultrasonic scaler. Less number of microorganisms were detected when chlorhexidine was used as lavage for ultrasonic scaler.

유화처리 바이오디젤이 도포된 콘크리트의 침투깊이 판정

백철 ( Baek Cheol ),김태우 ( Kim Tae-woo ),이재진 ( Lee Jae-jin ),이동윤 ( Lee Dong-yun ),한민철 ( Han Min-cheol ),한천구 ( Han Cheon-goo ) 한국건축시공학회 2017 한국건축시공학회 학술발표대회 논문집 Vol.17 No.2

This study is to provide a evaluation method for the penetration depth of emulsified refined bio diesel(ERBD)applied to a surface of the concrete by using water absorption capability of the concrete. The concrete applied with ERBD was immersed at water for 1 min., 5min., and 10 min. and then was checked the brightness with elapse of time. Test results indicated that there was clear difference between ERBD part and non ERBD part in concrete specimen after measuring the brightness until 120min.

Loop와 HPLC Purification 방법보다 더 높은 비방사능을 보여주는 카트리지 Methylation과 Purification을 이용한 손쉬운 [ ¹¹C]PIB 합성

이용석,조용현,이홍재,이윤상,정재민,Lee, Yong-Seok,Cho, Yong-Hyun,Lee, Hong-Jae,Lee, Yun-Sang,Jeong, Jae Min 대한핵의학기술학회 2018 핵의학 기술 Vol.22 No.2

$[^{11}C]PIB$는 베타아밀로이드($A{\beta}\;plague$)라는 변성 단백질에 결합하여 뇌의 기능과 기억력을 서서히 감퇴시키는 비가역적인 질환인 치매를 조기에 감별할 수 있는 대표적인 방사성의약품이다. 지금까지 많은 실험실에서 $[^{11}C]PIB$는 자동화합성장치에서 $[^{11}C]methyl\;iodide$나 $[^{11}C]methyl\;triflate$를 만든 다음 loop나 vial 방법을 사용하여 methylation을 한 다음 HPLC로 정제를 하는 것이다. 하지만 기존의 보고된 방법은 시간이 오래 걸리며, HPLC와 같은 복잡한 시스템을 필요로 하여 소규모 실험실에서 합성하기에 적합하지 않으며, 최종 product에서 에탄올 함량이 높다는 단점이 있었다. 이러한 단점을 보완하기 위하여 카트리지만을 사용하여 카트리지에서 methylation과 purification을 동시에 실시함으로써 합성 시간을 단축하고, 비방사능이 높고, 낮은 에탄올 함량을 가진 $[^{11}C]PIB$를 합성 가능한지 확인하고자 하였다. 가장 널리 사용하는 카트리지 6종(CM, HLB, Alumina, C18, tC18, tC18 environmental을 선택하여 screening test를 실시하였다. 6-OH-BTA-0 1 mg을 c-HXO에 녹인 다음 6개의 카트리지에 loading를 한 다음 0.5 M MSP(pH 5.1) 20 mL로 정제를 한 다음 최종 fraction을 받아서 analytical HPLC로 전구체 잔류량을 측정한 결과 hydrophobicity가 낮은 계열(CM, HLB, Alumina)의 카트리지에서는 완충액으로 정제를 하였을 때 잔류전구체의 양이 많았으나, 탄소함량이 많은 계열의 카트리지(C18, tC18, tC18 environmental)에서는 잔류전구체의 양이 CM, HLB, Alumina 카트리지에 비하여 상대적으로 적었다. 완충액의 정제 농도와 부피를 최적화 하기 위하여 screening test에서 가장 좋은 결과를 나타낸 C18 series cartridge를 가지고 추가 실험을 진행하였다. 인산완충액 농도를 10 mM, 20 mM, 30 mM, 40 mM, 50 mM, 250 mM, 500 mM로 변화시켰으며, 에탄올 함량은 20%와 30%로 하여 용출액을 분석하여서, $[^{11}C]PIB$를 카트리지로 합성하기 위한 최적의 조합은 tC18 environmental cartridge와 0.5 M MSP 20 mL인 것을 알 수 있었다. 기존에 보고된 방법과 cartridge를 비교한 결과, 합성시간에서는 각각 15 ~ 18min, 8 ~ 9 min이 소요되었으며, product activity는 각각 $4.1{\pm}1.4\;GBq$ (n=41), $3.8{\pm}0.9\;GBq$ (n=3), 방사화학적 수율(based on HPLC analysis of the crude product)에서는 $13.9{\pm}4.4%$ (n=41), $12.3{\pm}2.2%$ (n=3)로 별다른 차이가 없었으며, 비방사능에 있어서는 HPLC purification method가 $78.7{\pm}39.7\;GBq/{\mu}mol$ (n=41), cartridge method가 $420.6{\pm}20.4\;GBq/{\mu}mol$ (n=3)로 카트리지 방법이 기존 방법보다 더 좋은 결과를 나타내었다. 또한, 잔류 용매(c-HXO)도 vial or loop method와 별다른 차이가 없었으며, 에탄올 함량에 있어서는 70%(기존 방법)에서 30%(카트리지 방법)로 두 배 이상 함량이 적다는 사실을 알 수 있었다. 지금까지 알아본바와 같이 cartridge method는 reported method(HPLC purification)에 비하여 더 향상된 결과를 보여준다는 사실을 확인하였다. $[^{11}C]PIB$ synthesis has been performed by a loop-methylation and HPLC purification in our lab. However, this method is time-consuming and requires complicated systems. Thus, we developed an on-cartridge method which simplified the synthetic procedure and reduced time greatly by removing HPLC purification step. We compared 6 different cartridges and evaluated the $[^{11}C]PIB$ production yields and specific activities. $[^{11}C]MeOTf$ was synthesized by using TRACERlab FXC Pro and was transferred into the cartridge by blowing with helium gas for 3 min. To remove byproducts and impurities, cartridges were washed out by 20 mL of 30% EtOH in 0.5 M $NaH_2PO_4$ solution (pH 5.1) and 10 mL of distilled water. And then, $[^{11}C]PIB$ was eluted by 5 mL of 30% EtOH in 0.5 M $NaH_2PO_4$ into the collecting vial containing 10 mL saline. Among the 6 cartridges, only tC18 environmental cartridge could remove impurities and byproducts from $[^{11}C]PIB$ completely and showed higher specific activity than traditional HPLC purification method. This method took only 8 ~ 9 min from methylation to formulation. For the tC18 environmental cartridge and conventional HPLC loop methods, the radiochemical yields were $12.3{\pm}2.2%$ and $13.9{\pm}4.4%$, respectively, and the molar activities were $420.6{\pm}20.4GBq/{\mu}mol$ (n=3) and $78.7{\pm}39.7GBq/{\mu}mol$ (n=41), respectively. We successfully developed a facile on-cartridge methylation method for $[^{11}C]PIB$ synthesis which enabled the procedure more simple and rapid, and showed higher molar radio-activity than HPLC purification method.

Effect of Chromatin Changes in the Germinal Vesicle on the Development of Porcine Embryos In Vitro

Min‐Gu Lee,Rong‐xun Han,Jin‐Yu zhang,Yun‐Fei Diao,Reza K. Oqani,Dong‐Il Jin 한국동물생명공학회(구 한국동물번식학회) 2011 발생공학 국제심포지엄 및 학술대회 Vol.2011 No.1

In all the studies of mammalian species, chromatin in the germinal vesicle (GV) is initially decondensed with the nucleolus not surrounded by heterochromatin (the NSN configurations). During oocyte growth, the GV chromatin condenses into perinucleolar rings (the SN configurations) or other corresponding configurations with or without the perinucleolar rings, depending on species. During oocyte maturation, the GV chromatin is synchronized in a less condensed state before germinal vesicle breakdown (GVBD) in species that has been minutely studied. As not all the species show the SN configuration and gene transcription always stops at the late stage of oocyte growth, it is suggested that a thorough condensation of GV chromatin is essential for transcriptional repression. Because the GV chromatin status is highly correlated with oocyte competence, oocytes must end the NSN configuration before they gain the full meiotic competence and they must take on the SN/corresponding configurations and stop gene transcription before they acquire the competence for early embryonic development. In this study, we firstly investigated whether the layer of cumulus cells and size of oocytes could determine chromatin configurations in porcine oocytes. Using Hoechst3342 staining, the GV nucleolus and chromatin of porcine oocytes was classified into SN and NSN configurations. Next, we examined the changes in GV chromatin configurations during growth and maturation of porcine oocytes. In addition, the maturation and parthenogenetic development abilities in vitro were significant different between the SN and NSN configurations oocytes. These results indicated that chromatin changes in GV oocytes affect the development potential of parthenogenetic embryos.

Effects of hydrogen plasma treatment on SnO2:F substrates for amorphous Si thin film solar cells

Min-Seung Choi,Young-Ju Lee,Jung-Dae Kwon,Yongsoo Jeong,Ju-Yun Park,강용철,Pung Keun Song,Dong-Ho Kim 한국물리학회 2013 Current Applied Physics Vol.13 No.8

We investigated the effects of hydrogen plasma treatment on the physical and electrical properties of fluorine-doped tin oxide (FTO) films used for amorphous silicon (a-Si) thin film solar cells. A slight increase in carrier concentration by the hydrogen doping effect was observed for the FTO film exposed to the hydrogen plasma for 5 min. For further exposure to the plasma, the chemical reduction became prominent and resulted in deterioration of the electrical and optical properties of the film. XPS analysis revealed that the chemical reduction of SnO2 to Sn metallic state occurs on the surface region. It was found that the defects formed by hydrogen plasma act as recombination centers at the interface between FTO electrode and p-layer of a-Si solar cells. This phenomenon resulted in the deterioration of the cell performance. The averaged conversion efficiency (6.82%) of the cells on pristine FTO hydrogen substrate was decreased to 5.81% for the cells on FTO treated for 5 min, which is mainly attributed to the decrease in short-circuit current density.

Energy storage capabilities of nitrogen-enriched pyropolymer nanoparticles fabricated through rapid pyrolysis

Yun, Young Soo,Kim, Yu Hyun,Song, Min Yeong,Kim, Na Rae,Ku, Kyojin,An, Ji Su,Kang, Kisuk,Choi, Hyoung Jin,Jin, Hyoung-Joon Elsevier 2016 Journal of Power Sources Vol.331 No.-

<P><B>Abstract</B></P> <P>Nanostructured pyropolymers contain significant amounts of redox-active heteroatoms, have high specific surface areas, and a defective carbon microstructure, indicating good potential for pseudocapacitive charge storage. In this study, nitrogen-enriched pyropolymer nanoparticles (N-PNs-50) are fabricated from polyaniline nanotubes through rapid pyrolysis at 50 °C min<SUP>−1</SUP>. N-PNs-50 exhibit a nitrogen content of 9.8 wt%, a high specific surface area of 875.8 m<SUP>2</SUP> g<SUP>−1</SUP>, and an amorphous carbon structure with an I<SUB> <I>D</I> </SUB>/I<SUB> <I>G</I> </SUB> intensity ratio of 0.95. These unique characteristics lead to good electrochemical performances, in which reversible capacities of 660 and 255 mAh g<SUP>−1</SUP> are achieved for Li-ion and Na-ion storage, respectively, with favorable voltage characteristics (<1.5 V for Li-ions and <1.2 V for Na-ions). This study provides a more feasible production method for nitrogen-doped pyropolymers and their practicable electrochemical performances for use as an anode in energy storage devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanostructured pyropolymers (N-PNs-50) were fabricated by rapid pyrolysis. </LI> <LI> N-PNs-50 exhibited a nitrogen content of 9.8 wt% and amorphous carbon structure. </LI> <LI> N-PNs-50 exhibited a high specific surface area of 875.8 m<SUP>2</SUP> g<SUP>−1</SUP>. </LI> <LI> 660 and 255 mAh g<SUP>−1</SUP> were achieved for Li-ion and Na-ion storage, respectively. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Nitrogen-enriched pyropolymer nanoparticles (N-PNs-50) were fabricated from polyaniline nanotubes through rapid pyrolysis at 50 °C min<SUP>−1</SUP>, showing superior electrochemical performances.</P> <P>[DISPLAY OMISSION]</P>