Chemical Synthetic Strategy for Single-Layer Transition-Metal Chalcogenides

Yoo, Dongwon,Kim, Minkyoung,Jeong, Sohee,Han, Jeonghee,Cheon, Jinwoo American Chemical Society 2014 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.136 No.42

<P>A solution-phase synthetic protocol to form two-dimensional (2D) single-layer transition-metal chalcogenides (TMCs) has long been sought; however, such efforts have been plagued with the spontaneous formation of multilayer sheets. In this study, we discovered a solution-phase synthetic protocol, called “diluted chalcogen continuous influx (DCCI)”, where controlling the chalcogen source influx (e.g., H<SUB>2</SUB>S) during its reaction with the transition-metal halide precursor is the critical parameter for the formation of single-layer sheets as examined for the cases of group IV TMCs. The continuous influx of dilute H<SUB>2</SUB>S throughout the entire growth period is necessary for large sheet formation through the exclusive <I>a-</I> and <I>b-</I>axial growth processes. By contrast, the burst influx of highly concentrated H<SUB>2</SUB>S in the early stages of the growth process forms multilayer TMC nanodiscs. Our DCCI protocol is a new synthetic concept for single-layer TMCs and, in principle, can be operative for wide range of TMC nanosheets.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2014/jacsat.2014.136.issue-42/ja5079943/production/images/medium/ja-2014-079943_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja5079943'>ACS Electronic Supporting Info</A></P>

Magnetically Triggered Dual Functional Nanoparticles for Resistance‐Free Apoptotic Hyperthermia

Yoo, Dongwon,Jeong, Heeyeong,Noh, Seung‐,Hyun,Lee, Jae‐,Hyun,Cheon, Jinwoo WILEY‐VCH Verlag 2013 Angewandte Chemie Vol.125 No.49

<P><B>Gegen jeden Widerstand</B>: Wärmebehandelte Krebszellen haben einen schützenden Resistenz‐ und Überlebensmechanismus. Resistenzfreie Zelltod‐induzierende magnetische Nanopartikel (RAINs) fördern den hyperthermalen Zelltod, indem sie die Wärmeerzeugung und das Freisetzen von Geldanamycin (GM) zur Hemmung des Hitzschockproteins (Hsp) in einem magnetischen Wechselfeld (AMF) einleiten (siehe Bild) und somit das Überleben der Zelle hindern.</P>

Tuning the Electron Density of Aromatic Solvent for Stable Solid-Electrolyte-Interphase Layer in Carbonate-Based Lithium Metal Batteries

Yoo, Dong-Joo,Yang, Sungyun,Yun, Yang Sik,Choi, Jin Hyeok,Yoo, Dongwon,Kim, Ki Jae,Choi, Jang Wook Wiley (John WileySons) 2018 ADVANCED ENERGY MATERIALS Vol.8 No.33

Theranostic Magnetic Nanoparticles

Yoo, Dongwon,Lee, Jae-Hyun,Shin, Tae-Hyun,Cheon, Jinwoo American Chemical Society 2011 Accounts of chemical research Vol.44 No.10

<P>Early detection and treatment of disease is the most important component of a favorable prognosis. Biomedical researchers have thus invested tremendous effort in improving imaging techniques and treatment methods. Over the past decade, concepts and tools derived from nanotechnology have been applied to overcome the problems of conventional techniques for advanced diagnosis and therapy. In particular, advances in nanoparticle technology have created new paradigms for theranostics, which is defined as the combination of therapeutic and diagnostic agents within a single platform. In this Account, we examine the potential advantages and opportunities afforded by magnetic nanoparticles as platform materials for theranostics.</P><P>We begin with a brief overview of relevant magnetic parameters, such as saturation magnetization, coercivity, and magnetocrystalline anisotropy. Understanding the interplay of these parameters is critical for optimizing magnetic characteristics needed for effective imaging and therapeutics, which include magnetic resonance imaging (MRI) relaxivity, heat emission, and attractive forces. We then discuss approaches to constructing an MRI nanoparticle contrast agent with high sensitivity. We further introduce a new design concept for a fault-free contrast agent, which is a <I>T</I>1 and <I>T</I>2 dual mode hybrid.</P><P>Important capabilities of magnetic nanoparticles are the external controllability of magnetic heat generation and magnetic attractive forces for the transportation and movement of biological objects. We show that these functions can be utilized not only for therapeutic hyperthermia of cancer but also for controlled release of cancer drugs through the application of an external magnetic field. Additionally, the use of magnetic nanoparticles to drive mechanical forces is demonstrated to be useful for molecular-level cell signaling and for controlling the ultimate fate of the cell. Finally, we show that targeted imaging and therapy are made possible by attaching a variety of imaging and therapeutic components. These added components include therapeutic genes (small interfering RNA, or siRNA), cancer-specific ligands, and optical reporting dyes. The wide range of accessible features of magnetic nanoparticles underscores their potential as the most promising platform material available for theranostics.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/achre4/2011/achre4.2011.44.issue-10/ar200085c/production/images/medium/ar-2011-00085c_0012.gif'></P>

Acid-activatable oxidative stress-inducing polysaccharide nanoparticles for anticancer therapy

Yoo, Wooyoung,Yoo, Donghyuck,Hong, Eunmi,Jung, Eunkyeong,Go, Yebin,Singh, S.V. Berwin,Khang, Gilson,Lee, Dongwon Elsevier 2018 Journal of controlled release Vol.269 No.-

<P><B>Abstract</B></P> <P>Drug delivery systems have been extensively developed to enhance the therapeutic efficacy of drugs by altering their pharmacokinetics and biodistribution. However, the use of high quantities of drug delivery systems can cause toxicity due to their poor metabolism and elimination. In this study, we developed polysaccharide-based drug delivery systems which exert potent therapeutic effects and could display synergistic therapeutic effects with drug payloads, leading to dose reduction. Cinnamaldehyde, a major component of cinnamon is known to induce anticancer activity by generating ROS (reactive oxygen species). We developed cinnamaldehyde-conjugated maltodextrin (CMD) as a polymeric prodrug of cinnamaldehyde and a drug carrier. Cinnamaldehyde was conjugated to the hydroxyl groups of maltodextrin via acid-cleavable acetal linkages, allowing facile formulation of nanoparticles and drug encapsulation. CMD nanoparticles induced acid-triggered ROS generation to induce apoptotic cell death. Camptothecin (CPT) was used as a model drug to investigate the potential of CMD nanoparticles as a drug carrier and also evaluate the synergistic anticancer effects with CMD nanoparticles. CPT-loaded CMD nanoparticles exhibited significantly higher anticancer activity than empty CMD nanoparticles and CPT alone in the study of mouse xenograft models, demonstrating the synergistic therapeutic effects of CMD with CPT. Taken together, we believe that CMD nanoparticles hold tremendous potential as a polymeric prodrug of cinnamaldehyde and a drug carrier in anticancer therapy.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Double‐Effector Nanoparticles: A Synergistic Approach to Apoptotic Hyperthermia

Yoo, Dongwon,Jeong, Heeyeong,Preihs, Christian,Choi, Jin‐,sil,Shin, Tae‐,Hyun,Sessler, Jonathan L.,Cheon, Jinwoo WILEY‐VCH Verlag 2012 Angewandte Chemie Vol.124 No.50

<P><B>Hoch effiziente</B> apoptotische Hyperthermie ergeben magnetische Nanopartikel, die in einer Doppelfunktion sowohl reaktive Sauerstoffspezies (ROS) als auch Wärme erzeugen. Durch die ROS werden Krebszellen verwundbarer für die anschließende Wärmebehandlung: 100 mm<SUP>3</SUP> große implantierte Tumore in Mäusen werden nach 30 min Hyperthermiebehandlung bei 43 °C binnen 8 Tagen vollständig eliminiert.</P>

감응성 자기공명영상 조영제

유동원(Dongwon Yoo) 한국고분자학회 2018 고분자 과학과 기술 Vol.29 No.3

중국의 신뢰구축조치에 대한 정책과 실천

유동원(Yoo Dongwon) 21세기정치학회 2008 21세기 정치학회보 Vol.18 No.1

Confidence-building measures(CBMs) aim to lessen anxiety and suspicion by making the parties' behavior more predictable. China’s unprecedented economic opening to the world in the early 1980s has drawn Beijing toward the selective use of CBMs. China’s primary reason for employing CBMs is to satisfy its foreign policy objectives of safeguarding China’'s security and regional peace in order to enhance economic growth. China’'s clear preference is to employ bilateral CBMs, the most successful measures implemented to date include border security agreements and troop withdrawals along China’'s border with Russia, neighboring Central Asian states, and India. During the 1990s, however, Beijing has been able to selectively employ various CBMs to help reduce tensions, to facilitate remarkable economic progress. In cases where Beijing sees clear advantages for China, such as agreements with Russia and Central Asia on border demarcations and subsequent troop reductions, Beijing has placed great importance on the use of CBMs. In other cases where Beijing does not see clear advantages for China, such as outstanding issues with Japan, China has been reluctant to pursue CBMs. While China has made headway in utilizing CBMs, Beijing still has several long-standing territorial disputes with India, Japan, and some ASEAN countries, as well as unresolved issues of sovereignty and reunification with Taiwan. China’'s neighbors are concerned that China is becoming more nationalistic and that its growing economic and military power could be used for coercive purposes. They are also concerned that miscalculations on either side of the Taiwan Strait could lead to war, adversely affecting the entire region. By embracing or resisting CBMs in the future, Beijing can help alleviate or affirm lingering suspicions of its future course in the region.

중국의 외교 내러티브(Narrative) 연구

유동원(Yoo Dongwon) 한양대학교 아태지역연구센터 2018 중소연구 Vol.42 No.3

This article examines the China’s diplomatic narratives Under Xi Jinping’s leadership. It focuses on the concept and analyzes the context of this new narrative : Chinese Dream, community of shared destiny for mankind, new model of international relations, and great power diplomacy with Chinese characteristics. Under Xi’s leadership, foreign policy has been named “great power diplomacy with Chinese characteristics,” which confirms that China’s strategic goal of regaining superpower status remains. The Chinese narrative and policy actions are more vigorously spreading all over the world. At the same time, China extensively promotes Asia as a global centre, trying to bypass or ignore the West. Chinese leaders more openly refer to the country’s ancient tradition from a time when China was the world’s centre. China would like to set the tone and lead the world, which indicates that geopolitical competition will become even more apparent. Under “China’s solution,” Xi would like to export Chinese standards, values and principles as more effective and inclusive than those of the West. There is no doubt that China is already exporting its way of thinking worldwide. The PRC is using soft tools(narratives), influencing other countries directly and indirectly. China seems to be effective in convincing others to buy Chinese rhetoric consciously or unconsciously. The Belt and Road Initiative, known and being discussed globally, is a good example.

중러 전략동반자관계와 경제협력

유동원(Yoo, Dongwon) 동아시아국제정치학회 2006 국제정치연구 Vol.9 No.2