A branched TAT cell-penetrating peptide as a novel delivery carrier for the efficient gene transfection

정찬욱,유지상,이대용,김유천 한국생체재료학회 2016 생체재료학회지 Vol.20 No.4

Background: Cell penetrating peptides (CPPs) as one class of non-viral vectors, have been widely explored as a delivery tool due to their cell-penetrating capability with low cytotoxicity. However, CPPs have reported to have low gene transfection efficiency mainly due to the fact that DNA is larger than other biomolecules. On the other hand, the conventional linear CPPs are unstable for constructing the DNA complexes with it. Thus, here we designed a branched CPP using disulfide bridges based on the linear TAT peptide, to enhance the gene delivery efficiency in a better way. Results: The branched TAT (BTAT) was synthesized by the DMSO oxidation method and showed high-molecularweight about 294 kDa. The resulting BTAT was complexed with plasmid green fluorescence protein (pGFP) gene at various N/P ratios. The gene transfection efficiency was assessed on HeLa cells after treating with BTAT/pGFP complexes, showed high gene transfection efficiency as conformed by flowcytometry followed by confocal laser scanning microscopy (CLSM) visualization. Conclusion: The novel BTAT/pGFP complex exhibited significantly higher stability and redox cleavability by reducing agent. In addition, BTAT showed higher transfection efficiency approximately 40-fold than those of the TAT and mTAT complexes. Our primary experiments demonstrated the potential of BTAT as a suitable candidate for gene delivery and it could be applied for various types of gene delivery platforms. Abbreviations: AAS, Antibiotic antimycotic solution; BTAT, Branched TAT; CPPs, Cell penetrating peptides; DMEM, Dulbecco’s Modified Eagle’s Medium; DMSO, Dimethyl sulfoxide; FACS, Fluorescence-activated cell sorting; FBS, Fetal bovine serum; GSH, Glutathione; HEPES, 2-[4-(2-hydroxyethyl) piperazin-1-yl] ethanesulfonic acid; mTAT, Modified TAT; PEI, Poly (ethyleneimine), CLSM, confocal laser scanning microscope; pGFP, Plasmid green fluorescence protein; TEM, Transmission electron microscopy

Development of novel methotrexate delivery nanovector based on near-infrared fluorescent dye

정찬욱,노일구,김유천 한국고분자학회 2017 한국고분자학회 학술대회 연구논문 초록집 Vol.42 No.2

PbO-ZnO-B₂O₃系 Solder Glass의 結晶生成에 關하여

鄭燦旭,朴順子 서울대학교 공과대학 1980 공대연구보고 Vol.12 No.1

Neurons by oxygen-glucose deprivation in organotypic hippocampal slice cultures

정찬욱,홍경식,강지희,장영표 대한소아청소년과학회 2008 Clinical and Experimental Pediatrics (CEP) Vol.51 No.10

Purpose : We intended to observe cell death and apoptotic changes in neurons in organotypic hippocampal slice cultures following oxygen-glucose deprivation (OGD), using propidium iodide (PI) uptake, Fluoro-Jade (FJ) staining, TUNEL staining and immunofluorescent staining for caspase-3. Methods : The hippocampus of 7-day-old rats was cut into 350 µm slices. The slices were cultured for 10 d (date in vitro, DIV 10) and and exposed to OGD for 60 min at DIV 10. They were then incubated for reperfusion under normoxic conditions for an additional 48 h. Fluorescence of PI uptake was observed at predetermined intervals, and the cell death percentage was recorded. At 24 h following OGD, the slices were Cryo-cut into 15 µm thicknesses, and Fluoro-Jade staining, TUNEL staining, and immunofluorescence staining for caspase-3 were performed. Results : 1) PI uptake was restricted to the pyramidal cell layer and DG in the slices after OGD. The fluorescent intensities of PI increased from 6 to 48 h during the reperfusion stage. The cell death percentage significantly increased time-dependently in CA1 and DG following OGD (P<0.05). 2) At 24 h after OGD, many FJ positive cells were detected in CA1 and DG. Some neurons had distinct nuclei and processes while others had fragmented nuclei and disrupted processes in CA1. TUNEL and immunofluorescent staining for caspase-3 showed increased expression of TUNEL labeling and caspase-3 in CA1 and DG at 24 h after OGD. Conclusion : The numerous dead cells in the slice cultures after OGD tended to display apoptotic changes mediated by the activation of caspase-3. Purpose : We intended to observe cell death and apoptotic changes in neurons in organotypic hippocampal slice cultures following oxygen-glucose deprivation (OGD), using propidium iodide (PI) uptake, Fluoro-Jade (FJ) staining, TUNEL staining and immunofluorescent staining for caspase-3. Methods : The hippocampus of 7-day-old rats was cut into 350 µm slices. The slices were cultured for 10 d (date in vitro, DIV 10) and and exposed to OGD for 60 min at DIV 10. They were then incubated for reperfusion under normoxic conditions for an additional 48 h. Fluorescence of PI uptake was observed at predetermined intervals, and the cell death percentage was recorded. At 24 h following OGD, the slices were Cryo-cut into 15 µm thicknesses, and Fluoro-Jade staining, TUNEL staining, and immunofluorescence staining for caspase-3 were performed. Results : 1) PI uptake was restricted to the pyramidal cell layer and DG in the slices after OGD. The fluorescent intensities of PI increased from 6 to 48 h during the reperfusion stage. The cell death percentage significantly increased time-dependently in CA1 and DG following OGD (P<0.05). 2) At 24 h after OGD, many FJ positive cells were detected in CA1 and DG. Some neurons had distinct nuclei and processes while others had fragmented nuclei and disrupted processes in CA1. TUNEL and immunofluorescent staining for caspase-3 showed increased expression of TUNEL labeling and caspase-3 in CA1 and DG at 24 h after OGD. Conclusion : The numerous dead cells in the slice cultures after OGD tended to display apoptotic changes mediated by the activation of caspase-3.

Generation of a Pulse Plasma and its Application to Polysilicon Etching

정찬욱,K. K. Chi,Y. B. Koh,M. Y. Lee 대한전자공학회 1997 대한전자공학회 학술대회 Vol.1997 No.1

Tetrazole염을 기반으로 한 고에너지형 로켓추진제의 합성 및 특성평가

정찬욱,최성호 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0

이전까지의 로켓추진 연료-산화제 조합 시스템은 외부 자극을 주어서 점화시키기때문에 복잡한 반면에, 현재 진행중인 연구들은 연료와 산화제의 접촉을 통한 자발적 점화 시스템을 사용하여 로켓 엔진설계를 간단하게 할 수 있는 장점을 가지고 있다. 질소 원자를 다량으로 함유하는 energetic ionic salt 물질은 이온성 로켓 추진제로서 기존 물질과 비교하여 안정성이 좋아 취급 저장이 용이하고, 산화제와 반응하여 자연발화 할 수 있으며, 독성물질의 발생량을 줄일 수 있다는 장점을 가지고 있다. 또한, high-nitrogen energetic ionic salt는 로켓 추진제로서 적용성이 매우 높고, 군사분야에서도 탄두 미사일 혹은 고성능 폭약 등으로의 응용성을 기대 할 수 있다. 본 연구에서, 환경 친화적 고에너지형 이온성 추진제를 합성하기 위해, 1,5-diamino-4-methyl-tetrazolium을 기반으로 한 고에너지형 이온성 염을 합성하였다. 합성된 고에너지 염은 1H-NMR과 IR을 통해 화학적 구조를 확인하였고 DSC와 산화제와의 반응을 통해 열적 안정성 및 점화 특성을 평가하였다. 또한 이론화학적인 연구를 통해 열역학적 특성에 대해 계산하였다.

Injury of Neurons by Oxygen-Glucose Deprivation in Organotypic Hippocampal Slice Culture

정찬욱,홍경식,강지희,장영표,Chung, David Chanwook,Hong, Kyung Sik,Kang, Jihui,Chang, Young Pyo The Korean Pediatric Society 2008 Clinical and Experimental Pediatrics (CEP) Vol.51 No.10

목 적: 해마 절편 배양에서 산소-포도당 박탈(oxygen-glucose deprivation, OGD)에 의한 세포 사망과 신경 세포 사멸을 propidium iodide(PI) 섭취, Fluoro-Jade(FJ) 염색, TUNEL 염색, caspase-3 면역형광염색 방법으로 관찰하고자 하였다. 방 법: 생후 7일된 Sprague-Dawley 흰쥐의 해마를 MacIlwain chopper로 $350{\mu}m$ 두께의 절편으로 절단하였다. 해마 절편을 6-well plate의 insert 내의 반 유공(sem-porous) 막 위에서 membrane-interface technique으로 10일 동안 배양하였다. 배양된 해마 절편에 산소-포도당 박탈을 60분 동안 가한 후 재산소-재관류하에 기초 배양액에서 48시간 배양하였다. 재산소-재관류 동안 PI 섭취 형광 정도를 시간에 따라 형광 현미경으로 관찰하고 세포사망 백분율(percent cell death)을 측정하였다. 산소-포도당 박탈 직전과 24 시간 후에 해마 절편을 $15{\mu}m$ 두께로 냉동 절단 후 FJ 염색, TUNEL 염색, caspase-3 면역형광염색을 시행하여 세포 사망을 관찰하였다. 결과: OGD 후 PI 섭취 는 해마 절편의 CA1과 DG에 한정되어있었다. OGD 후 재산소-재관류 동안 6시간에서 48시간까지 PI 섭취 형광 강도는 시간이 증가함에 따라 증가하였다. 세포 사망 백분율은 CA1과 DG에서 모두 OGD 후 재산소-재관류 시간이 증가함에 따라 의미 있게 증가하였다(P<0.05). OGD 후 24시간에 세포 변성을 의미하는 많은 FJ 염색 양성 신경 세포 들이 CA1과 DG에서 관찰되었다. 고배율 confocal laser 현미경으로 관찰한 CA1에서의 신경 세포들 중 일부는 명확한 핵과 돌기를 가지고 있는 것을 보여 주었으며, 다른 신경 세포들은 핵의 분절화, 돌기의 손실 등을 보여 주었다. TUNEL 염색과 caspase-3 염색은 OGD 후 24시간에 CA1과 DA에서 TUNEL 양성 발현을 증가시키고 caspase-3 발현을 증가시켰다. 결 론: 해마 절편 배양에서 산소-포도당 박탈 에 의한 다수의 세포 사망을 관찰할 수 있었다. 사망한 세포 들은 주로 신경 세포의 caspase-3 활성화에 의해 매개된 사멸을 보였다. Purpose : We intended to observe cell death and apoptotic changes in neurons in organotypic hippocampal slice cultures following oxygen-glucose deprivation (OGD), using propidium iodide (PI) uptake, Fluoro-Jade (FJ) staining, TUNEL staining and immunofluorescent staining for caspase-3. Methods : The hippocampus of 7-day-old rats was cut into $350{\mu}m$ slices. The slices were cultured for 10 d (date in vitro, DIV 10) and and exposed to OGD for 60 min at DIV 10. They were then incubated for reperfusion under normoxic conditions for an additional 48 h. Fluorescence of PI uptake was observed at predetermined intervals, and the cell death percentage was recorded. At 24 h following OGD, the slices were Cryo-cut into $15{\mu}m$ thicknesses, and Fluoro-Jade staining, TUNEL staining, and immunofluorescence staining for caspase-3 were performed. Results : 1) PI uptake was restricted to the pyramidal cell layer and DG in the slices after OGD. The fluorescent intensities of PI increased from 6 to 48 h during the reperfusion stage. The cell death percentage significantly increased time-dependently in CA1 and DG following OGD (P<0.05). 2) At 24 h after OGD, many FJ positive cells were detected in CA1 and DG. Some neurons had distinct nuclei and processes while others had fragmented nuclei and disrupted processes in CA1. TUNEL and immunofluorescent staining for caspase-3 showed increased expression of TUNEL labeling and caspase-3 in CA1 and DG at 24 h after OGD. Conclusion : The numerous dead cells in the slice cultures after OGD tended to display apoptotic changes mediated by the activation of caspase-3.

ERRATUM: Neurons by oxygen-glucose deprivation in organotypic hippocampal slice cultures

정찬욱,홍경식,강지희,장영표,Jeong, Chan-Uk,Hong, Gyeong-Sik,Gang, Ji-Hui,Jang, Yeong-Pyo 대한소아청소년과학회 2008 Clinical and Experimental Pediatrics (CEP) Vol.51 No.12

O4O 서비스의 지속 사용의도 및 실제사용에 영향을 미치는 요인 분석

정찬욱,이원준 국제e-비즈니스학회 2022 e-비즈니스 연구 Vol.23 No.2

Research Purpose: The main purpose is to identify the behavior of O4O service users. To identify behaviors, intending to reveal the antecedent factors of continuous use intention and actual use as final variables. Research Methods: The data were analyzed crosswise by conducting a questionnaire. To collect high-quality sample, data collection was requested from the largest professional research institute in Korea, and PLS-SEM was used as the methodology. Results in Research: It was found that all variables like Convenience, Accessibility, Synchronization except Personalization had a significant effect on perceived usefulness, and all variables except Accessibility had no significant effect on user satisfaction. In addition, Perceived usefulness had a significant effect on user satisfaction, continuous use intention, and actual use. Continuous use intention had a significant level of relationship with actual use. Research Conclusion: This study is meaningful in that it empirically analyzed O4O users, who have not been actively analyzed so far. Suggestions in Research: In future research, it would be beneficial to obtain more in-depth results by reflecting demographic information as a control variable. Also this study proposes to conduct a longitudinal study to observe and explain the dynamic behavior of O4O users. 코로나 바이러스가 전 세계적으로 확산되면서 비대면 방식으로 소비를 유도하는 ‘언택트’ 마케팅이 확대· 진행되고 있으며 기업들은 O2O(Online to Offline)를 넘어 O4O(Online for Offline) 마케팅에 주력하고 있다. 이러한 시점에서 O4O 서비스를 지속적으로 사용 및 실제사용 하려는 의도에 미치는 요인을 규명하는 연구는상당히 중요하다. 본 연구에서는 기술수용모형과 기대일치모형 및 이론적 배경에서 도출된 4개의 온-오프라인 통합채널의서비스 특성인 편이성, 접근성, 개인화, 동시성을 독립변수로 제시하였다. 통계 분석을 위해서 실제로 O4O 서비스 사용자들을 대상으로 설문 자료를 수집하였다. 분석결과 개인화를 제외한 모든 변수가 지각된 유용성에 유의한 영향을 미치는 것으로 나타났으며 접근성을 제외한 모든 변수가 사용자 만족도에 유의한 영향을미치지 못하는 것으로 나타났다. 또한 지각된 유용성은 사용자 만족도, 지속 사용의도 및 실제사용 모두에서유의한 영향을 주었으며 사용자 만족도는 지속 사용의도에 유의한 영향을 미치지만, 실제사용에는 유의한영향을 미치지 않는다. 지속적 사용의도는 실제 사용에 유의한 영향을 미치는 것으로 분석되었다. 본 연구는 현재까지 활발히 분석되지 못했던 O4O 사용자들을 대상으로 실증적으로 분석하였다는 점에서의의가 있다. 분석 결과, 제안한 선행 요인 중에서 접근성은 지각된 유용성과 사용자 만족을 모두 촉진하는역할을 하기 때문에 경영진과 개발자들은 특히 우선적으로 감안해야 할 것이다. 향후 연구에서는 인구 통계학적 정보를 통제 변수로 반영하여 더 심도 있는 결과를 얻으면 유익할 것이다. 또한, O4O 사용자들을 동적인행위를 관찰하고 설명하기 위해서 향후 종단적인 연구를 수행할 것을 제안한다.

Flat TDR 시스템을 이용한 지반의 물리적 특성 및 전단파속도 예측

정찬욱,김대현 대한지질공학회 2022 지질공학 Vol.32 No.1

In this study, the shear wave velocity of the ground was measured using Flat TDR, and the precision analysis of the measured value and the verification of field applicability were performed. The shear wave velocity measurement value was derived in the field using the piezo-stack combined in the Flat TDR. analyzed. As a result of the experiment, the average value of the change in shear wave speed at the time of grout material injection was 10.15 m/s at the beginning of age, and the average value of the change in shear wave speed after the 7th to 14th days was 65.99 m/s, showing a tendency to increase with age. Also, it was found that dry density and shear wave speed increased as the water content increased on the dry side, and that the dry density and shear wave rate decreased as the water content increased on the wet side as the water content increased. The shear modulus value derived from the field test was confirmed to be a minimum of 17.36 MPa and a maximum of 28.13 MPa, confirming a measurement value similar to the reference value. Through this, it can be seen that the measured value of the shear modulus using Flat TDR is reliable data, and it can be determined that the compaction management of the site can be effectively managed in the future. 본 연구에서는 Flat TDR을 이용하여 지반의 전단파속도를 측정하였고 측정값의 정밀도 분석 및 현장적용성에 대한 검증을 수행하였다. Flat TDR 내 결합되어 있는 Piezo-stack을 이용하여 현장에서의 전단파속도 측정값을 도출하였고, 도출한 값의 검증을 위해서 들밀도시험, 동적콘관입시험(DCPT), 문헌조사 등을 적용하여 비교 ‧ 분석하였다. 실험결과 그라우트재 주입시 재령 초기 전단파속도 변화의 평균값은 10.15 m/s이며, 7~14일차 이후의 전단파속도 변화의 평균값은 65.99 m/s로 재령일 증가하는 경향을 보였다. 또한 OMC를 기준으로 건조 측에서는 함수비가 증가할수록 건조밀도와 전단파속도가 증가하고, 습윤 측에서는 함수비가 증가할수록 건조밀도와 전단파속도가 감소하는 것을 알 수 있었다. 현장시험 결과 도출된 전단탄성계수 값이 최소 17.36 MPa에서 최대 28.13 MPa로 확인되어 참고문헌 값과 유사한 측정값을 확인하였다. 이를 통해 Flat TDR을 이용한 전단탄성계수의 측정값이 신뢰성이 있는 데이터임을 알 수 있고, 추후 현장 지반의 다짐관리를 효과적으로 할 수 있음을 판단할 수 있다.