Comparison of exosomes and ferritin protein nanocages for the delivery of membrane protein therapeutics

Cho, Eunji,Nam, Gi-Hoon,Hong, Yeonsun,Kim, Yoon Kyoung,Kim, Dong-Hwee,Yang, Yoosoo,Kim, In-San Elsevier 2018 Journal of controlled release Vol.279 No.-

<P><B>Abstract</B></P> <P>Exosomes are small membrane vesicles secreted by most cell types that play an important role in intercellular communication. Due to the characteristic of transferring their biomacromolecules, exosomes have potential as a new alternative for delivering protein therapeutics. Here, we investigate whether exosomes provide crucial advantages over other nanoparticles, in particular protein nanocage formulations, as a delivery system for membrane protein therapeutics. We characterized membrane-scaffold–based exosomes and protein-scaffold–based ferritin nanocages, both harboring SIRPα (signal regulatory protein α), an antagonist of CD47 on tumor cells. The efficacy of these two systems in delivering protein therapeutics was compared by testing their ability to enhance phagocytosis of tumor cells by bone-marrow–derived macrophages and subsequent inhibition of in vivo tumor growth. These analyses allowed us to comprehensively conclude that the therapeutic index of exosome-mediated CD47 blockade against tumor growth inhibition was higher than that of the same dose of ferritin-SIRPα. The results of this analysis reveal the importance of the unique characteristics of exosomes, in particular their membrane scaffold, in improving therapeutic protein delivery compared with protein-scaffold–based nanocages.</P> <P><B>Graphical abstract</B></P> <P>Exosomes harboring membrane-spanning SIRPα proteins antagonize CD47 on cancer cells more effectively than ferritin nanocages containing the SIRPα ectodomain, thereby enhancing tumor phagocytosis by BMDMs.</P> <P>[DISPLAY OMISSION]</P>

Theory and application of 2 omega 7T FT-ICR MS for ultra-high resolution analysis of complex organic mixture

Eunji Cho,Matthias Witt,Sunghwan Kim 한국분석과학회 2016 학술대회논문집 Vol.2016 No.11

Biomolecular condensate assembly of nArgBP2 tunes its functionality to manifest the structural plasticity of dendritic spines

Cho Eunji,Lee Sang Eun,Lee Unghwi,Goh Yuna,Jeong Seonyoung,Choi Junyoung,Jeong Won-Ki,Chang Sunghoe 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

nArgBP2, a candidate gene for intellectual disability, is a postsynaptic protein critical for dendritic spine development and morphogenesis, and its knockdown (KD) in developing neurons severely impairs spine-bearing excitatory synapse formation. Surprisingly, nArgBP2 KD in mature neurons did not cause morphological defects in the existing spines at rest, raising questions of how it functions in mature neurons. We found that unlike its inaction at rest, nArgBP2 KD completely inhibited the enlargement of dendritic spines during chemically induced long-term potentiation (cLTP) in mature neurons. We further found that nArgBP2 forms condensates in dendritic spines and that these condensates are dispersed by cLTP, which spatiotemporally coincides with spine head enlargement. Condensates with CaMKII phosphorylation-deficient mutant or CaMKII inhibition are neither dispersed nor accompanied by spine enlargement during cLTP. We found that nArgBP2 condensates in spines exhibited liquid-like properties, and in heterologous and in vitro expression systems, nArgBP2 undergoes liquid-liquid phase separation via multivalent intermolecular interactions between SH3 domains and proline-rich domains. It also forms coacervates with CaMKIIα, which is rapidly dissembled by calcium/CaMKIIα-dependent phosphorylation. We further showed that the interaction between nArgBP2 and WAVE1 competes with nArgBP2 phase separation and that blocking the nArgBP2-WAVE1 interaction prevents spine enlargement during cLTP. Together, our results suggest that nArgBP2 at rest is confined to the condensates but is released by CaMKIIα-mediated phosphorylation during synaptic plasticity, which regulates its timely interaction with WAVE1 to induce spine head enlargement in mature neurons.

Improvement of Rheological Properties of Soy-based Spread-type Cheese by Alternation of Organic Acid Coagulants

Eunji Cho,Youngwan Kim 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

The purpose of this study is to develop a plant-based cheese substitute with properties similar to commercial dairy spread cheese through coagulation by acid or lactic acid bacteria fermentation. In the analysis of spread-type cheese, the target range of rheological properties was set by puncture, spreadability and frequency sweep tests. A soy-based spread-type cheese (SSC) that reached these ranges was selected as the final product. The most important thing in the rheological properties of spread-type cheese is the viscoelasticity measured by rheometer. In this study, it was found that the viscoelasticity is greatly affected by the coagulant that reduces the pH of soymilk. Organic acid was more effective than GDL in improving viscoelasticity. In addition, the viscoelastic properties of SSC reached 68-80.5% of the average of commercial animal spread cheese through the organic acid produced during the fermentation by L. plantarum 11B02. It is expected that fermentation will contribute to enhancing the functionality of the product as well as improving the rheological properties of cheese substitutes.

Application of FT-ICR MS Equipped with Quadrupole Detection for Analysis of Crude Oil

Cho, Eunji,Witt, Matthias,Hur, Manhoi,Jung, Maeng-Joon,Kim, Sunghwan American Chemical Society 2017 ANALYTICAL CHEMISTRY - Vol.89 No.22

<P>Resolving power is a critical factor determining the quality of ultrahigh-resolving power mass spectra of crude oil. In this study, 7T Fourier-transform ion cyclotron mass spectrometry (FT-ICR MS), equipped with quadrupole detection, was applied and evaluated for crude oil analysis for the first time. Four spectra were obtained from two oil samples using two ionization methods. Resolving power of 1500000 was observed at <I>m</I>/<I>z</I> 400 with 4 s transient signal. Comparison with literature reports revealed that the achieved resolving power was comparable with or superior to those obtained from instruments using higher magnetic fields but without quadrupole detection. A total of 6000–10000 peaks with an S/N ratio of 3 or higher were observed from the obtained spectra and over 97% of the peaks could be assigned to appropriate chemical formulas with an error within 1 ppm. Double bond equivalents vs carbon number plots generated from the obtained data agreed well with those previously reported without quadrupole detection. Mass accuracy values of the assigned elemental formulas were examined and the average root-mean-square error was calculated to be only 160 ppb. Low unassignment rate of the observed peaks and strong agreement with previously reported results suggests that unwanted harmonics of reduced frequency are not significant for the data obtained with quadrupole detection. Overall, the data presented in this study show that FT-ICR MS equipped with quadrupole detection can be a powerful tool to examine complex mixtures like crude oil. To the best of our knowledge, this is the first paper reporting application of FT-ICR MS equipped with quadrupole detection for the oil analysis.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2017/ancham.2017.89.issue-22/acs.analchem.7b02644/production/images/medium/ac-2017-02644t_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac7b02644'>ACS Electronic Supporting Info</A></P>

Protons are One of the Limiting Factors in Determining Sensitivity of Nano Surface-Assisted (+)-Mode LDI MS Analyses

Cho, Eunji,Ahn, Miri,Kim, Young Hwan,Kim, Jongwon,Kim, Sunghwan Springer US 2013 Journal of the American Society for Mass Spectrome Vol.24 No.10

<P>A proton source employing a nanostructured gold surface for use in (+)-mode laser desorption ionization mass spectrometry (LDI-MS) was evaluated. Analysis of perdeuterated polyaromatic hydrocarbon compound dissolved in regular toluene, perdeuterated toluene, and deuterated methanol all showed that protonated ions were generated irregardless of solvent system. Therefore, it was concluded that residual water on the surface of the LDI plate was the major source of protons. The fact that residual water remaining after vacuum drying was the source of protons suggests that protons may be the limiting reagent in the LDI process and that overall ionization efficiency can be improved by incorporating an additional proton source. When extra proton sources, such as thiolate compounds and/or citric acid, were added to a nanostructured gold surface, the protonated signal abundance increased. These data show that protons are one of the limiting components in (+)-mode LDI MS analyses employing nanostructured gold surfaces. Therefore, it has been suggested that additional efforts are required to identify compounds that can act as proton donors without generating peaks that interfere with mass spectral interpretation.</P> [FIG OMISSION]</BR>

Non-target and effect directed assay analyses of unknown toxic substance mixtures in house hold chemical products by using Liquid Chromatography and ultra high resolution mass spectrometry

Eunji Cho,Sunghwan Kim 한국분석과학회 2020 학술대회논문집 Vol.2020 No.11

Analysis of coffee bean with laser desorption ionization high‐resolution mass spectrometry

Cho Eunji,Acter Thamina,Uddin Nizam,Kim Sunghwan 대한화학회 2022 Bulletin of the Korean Chemical Society Vol.43 No.3

This study evaluates the application of laser desorption ionization highresolution mass spectrometry (LDI-HRMS) to identify coffee components. The coffee analysis was performed based on origins, roasting temperatures, and extraction methods. The LDI-HRMS experimental results were compared with electrospray ionization (ESI) HRMS analysis, which revealed major compositional differences of coffee ingredients between LDI and ESI data. It was also observed that bitter components in coffee increased with the increasing roasting temperature, and espresso was found to have more carbohydratederived compounds. This study clearly shows that coffee components can efficiently be identified with LDI. Moreover, a more systematic database can be constructed by combining it with LDI-imaging because LDI is simple, fast, and requires small amount sample consumption.

인공지능 기반 전장상황 분석을 위한 가상 전장상황 데이터 셋 생성 연구

조은지(Eunji Cho),진소연(Soyeon Jin),신유경(Yukyung Shin),이우신(Woosin Lee) 한국컴퓨터정보학회 2022 韓國컴퓨터情報學會論文誌 Vol.27 No.6

기존의 지능형 지휘통제체계 연구에서는 지휘관의 전장 상황 질문에 대한 분석 결과를 지식베이스 기반 상황 데이터에서 정보를 추출하여 제공해주고 있다. 하지만, 다양한 표현의 자연어가 사용된 정·첩보를 문맥에 맞게 분석하는 것이 상황 분석에 있어 중요해지면서 인공지능을 사용한 전장 상황 분석 연구가 진행되고 있다. 본 논문에서는 전장 상황 분석용 인공지능 개발에 필요한 데이터 셋을 제공하기 위해 전장 상황 모의 시나리오 기반 가설 데이터 셋 생성 방법을 제안한다. 가설 데이터 셋은 실제 전장 환경이 고려된 모의 시나리오에서 전장 지식요소를 식별하여 생성한다. 먼저 후보가설을 생성하면 자동으로 단위가설이 생성된다. 단위가설을 조합하여 유사 식별 가설 조합을 만들고, 연관된 후보가설을 그룹화하여 집합가설을 생성한다. 제안하는 방법으로 데이터 셋을 생성할 수 있음을 확인하기 위해 생성기 SW를 구현하였고, 생성기 SW로 가설 데이터 셋을 생성할 수 있음을 확인하였다. In the existing intelligent command control system study, the analysis results of the commander’s battlefield situation questions are provided from knowledge-based situation data. Analysis reporters write these results in various expressions of natural language. However, it is important to analyze situations about information and intelligence according to context. Analyzing the battlefield situation using artificial intelligence is necessary. We propose a virtual dataset generation method based on battlefield simulation scenarios in order to provide a dataset necessary for the battlefield situation analysis based on artificial intelligence. Dataset is generated after identifying battlefield knowledge elements in scenarios. When a candidate hypothesis is created, a unit hypothesis is automatically created. By combining unit hypotheses, similar identification hypothesis combinations are generated. An aggregation hypothesis is generated by grouping candidate hypotheses. Dataset generator SW implementation demonstrates that the proposed method can be generated the virtual battlefield situation dataset.

전기로를 이용한 응집특성에 관한 실험적 연구

길은지(EunJi Gil),정수화(SooHaw Jeong),조천현(CheonHyeon Cho),서수빈(SuBeen Seo),안석기(SeokGi An),조현호(HyeonHo Cho),정성묵(SeongMook Jeong) 한국신재생에너지학회 2021 한국신재생에너지학회 학술대회논문집 Vol.2021 No.7

최근, 순환유동층보일러는 바이오매스 등 저품질의 연료를 효율적으로 연소하는 발전방법으로 주목을 받고 있다. 일반적으로 바이오매스는 포타슘(K)이나 소듐(Na)와 같은 알칼리 금속을 함유하고 있는데 이들 성분이 고온에서 층물질인 모래 성분(si)과 만나 용융화합물이 생성되면 녹는점이 낮아져 agglomeration(응집현상)이 일어난다. 이러한 agglomeration이 발생하면 연소가스 및 유동사의 정상적인 흐름을 방해하여 연소상태이상 및 설비효율 저하를 초래한다. 따라서 본 실험에서는 반응온도 및 혼합비율(바닥재, 석탄 그리고 KOH)에 따른 agglomeration 특성을 파악하였다. 반응온도는 820, 850, 그리고 880℃ 3가지 조건에서 시료의 표면형상과 응집물의 양을 관찰하였으며, 온도가 높을수록 응집물의 양이 증가하는 결과를 확인하였고 KOH의 함량이 증가할수록 응집물이 크게 형성되는 것을 관찰하였다.