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Developing Flexible Vertical Micro LED
A KAIST research team led by Professor Keon Jae Lee from the Department of Materials Science and Engineering and Professor Daesoo Kim from the Department of Biological Sciences has developed flexible vertical micro LEDs (f-VLEDs) using anisotropic conductive film (ACF)-based transfer and interconnection technology. The team also succeeded in controlling animal behavior via optogenetic stimulation of the f-VLEDs.
Flexible micro LEDs have become a strong candidate for the next-generation display due to their ultra-low power consumption, fast response speed, and excellent flexibility. However, the previous micro LED technology had critical issues such as poor device efficiency, low thermal reliability, and the lack of interconnection technology for high-resolution micro LED displays.
The research team has designed new transfer equipment and fabricated a f-VLED array (50ⅹ50) using simultaneous transfer and interconnection through the precise alignment of ACF bonding process. These f-VLEDs (thickness: 5 ㎛, size: below 80 ㎛) achieved optical power density (30 mW/mm2) three times higher than that of lateral micro LEDs, improving thermal reliability and lifetime by reducing heat generation within the thin film LEDs.
These f-VLEDs can be applied to optogenetics for controlling the behavior of neuron cells and brains. In contrast to the electrical stimulation that activates all of the neurons in brain, optogenetics can stimulate specific excitatory or inhibitory neurons within the localized cortical areas of the brain, which facilitates precise analysis, high-resolution mapping, and neuron modulation of animal brains. (Refer to the author’s previous ACS Nano paper of “Optogenetic Mapping of Functional Connectivity in Freely Moving Mice via Insertable Wrapping Electrode Array Beneath the Skull.” )
In this work, they inserted the innovative f-VLEDs into the narrow space between the skull and the brain surface and succeeded in controlling mouse behavior by illuminating motor neurons on two-dimensional cortical areas located deep below the brain surface.
Professor Lee said, “The flexible vertical micro LED can be used in low-power smart watches, mobile displays, and wearable lighting. In addition, these flexible optoelectronic devices are suitable for biomedical applications such as brain science, phototherapeutic treatment, and contact lens biosensors.”
He recently established a startup company ( FRONICS Inc. ) based on micro LED technology and is looking for global partnerships for commercialization. This result entitled “ Optogenetic Control of Body Movements via Flexible Vertical Light-Emitting Diodes on Brain Surface ” was published in the February 2018 issue of Nano Energy.
Figure 1. Comparison of μ-LEDs Technology
2018.01.29 View 13369 -
Plasma, an Excellent Sterilizer to Remove Harmful Bacteria
(PhD candidate Joo Young Park, Professor Wonho Choe and PhD researcher Sanghoo Park)
KAIST researchers are using plasma to remove bacteria that are stuck to surfaces of plastic bottles and food. This novel technology will contribute to disinfection in medical settings as well as food and agricultural industries.
Professor Wonho Choe and his team from the Department of Physics developed a technology that removes biofilm, which is comprised of microorganisms, by using plasma as a non-thermal sterilization method.
Plasma contains multiple bactericidal agents, including reactive species. In particular, the chemicals formed in aqueous solution during plasma exposure have the potential for high antibacterial activity against various bacterial infections.
The team treated water with plasma to see how effectively bactericidal agents in the plasma water can remove biofilm comprised of harmful microorganism such as Escherichia coli, Salmonella, and Listeria.
The team identified that reactive species, including hydroxyl radical, hydrogen peroxide, ozone, nitrite, and superoxide produced during plasma treatment, showed considerable ability to remove the biofilm. Hydrogen peroxide showed the strongest effect removing the biofilm; however, the hydroxyl radical also played a significant role in removing biofilm. Despite having a concentration 100 to 10,000 times lower than other reactive species, the hydroxyl radical showed a high biofilm removal efficacy owing to its strong oxidative power.
These findings reveal that plasma can be used as a no-residual and safe sterilization process alternative to conventional methods. With these outcomes, the team is planning to develop and commercialize a technology that can produce hydroxyl radicals with plasma.
Professor Choe has registered a patent for flexible packaging materials that facilitate plasma and completed the technology transfer to the startup company, named ‘Plasmapp’, which focuses on commercializing bactericidal technology.
“This research outcome will be the foundation for understanding plasma control technology and physicochemical interactions between plasma and microorganisms. It will also become an accelerator for utilizing plasma technology in the medical, food, and agricultural fields,” said Professor Choe.
This research, led by PhD candidate Joo Young Park and PhD researcher Sanghoo Park in collaboration with Professor Cheorun Jo’s team from Seoul National University, was published in ACS Applied Materials and Interfaces on December 20, 2017.
Figure 1. Flexible packaging materials that facilitate plasma
Figure 2. Schematic diagram of biofilm treatment with plasma
Figure 3. Concept of plasma application and evaluation result of reactive species' efficacy
Figure 4. STERPACK, the product launched by Plasmapp
2018.01.25 View 9786 -
Realizing Highly Efficient Quantum Dot LEDs with Metallic Nanostructures
(Professor Yong-Hoon Cho and PhD candidate Hyun Chul Park)
KAIST researchers have discovered a technology that enhances the efficiency of Quantum Dot LEDs.
Professor Yong-Hoon Cho from the Department of Physics and his team succeeded in improving the efficiency of Quantum Dot (QD) Light-Emitting Diodes (LEDs) by designing metallic nanostructure substrates.
QD LEDs possess very small semiconductor light sources and are considered to be the new rising technology for high performance full-color display. However, it is expensive to manufacture displays with QD LED only.
Existing QD-based displays use blue LEDs as a source of light, and they employ a method of color conversion through excitation of green and red QDs.
There are two inconveniences with the existing QD-based displays. As mentioned previously, QD LED is costly, hence the unit price of QD-based displays is higher. Also, the efficiency of a liquid type of QDs is drastically lowered after contact with air.
Professor Cho found the solution in a metallic nanostructure for lowering the production cost while improving the efficiency of QD LEDs.
The team exploited the phenomenon of so-called surface plasmonic resonances when nanoscale metallic structures are exposed to light. Depending on the metal, the size, and the shape, the properties of metallic structures vary.
The team used different metallic nanostructures for each QD LED – silver nanodisks for Red QDs and aluminum nanodisks for Green GDs – to make them more fluorescent.
With brighter QDs, it requires fewer QDs to manufacture QD LEDs, contributing to a lower unit price.
The team used silver and aluminum in this research, but metallic nanostructures can be redesigned according to the desired purposes.
Professor Cho said, “Implementing metallic nanostructures into QD LEDs in a proper manner can reduce the quantity of the QDs required for the system, leading to lower unit prices.”
This research, led by PhD candidate Hyun Chul Park, was chosen as the cover of the international journal, Small, on December 27, 2017.
Figure 1. Cover of the journal
Figure 2. Spectrum showing different fluorescence with and without metallic nanostructure
2018.01.23 View 7169 -
Lifespan of Fuel Cells Maximized Using Small Amount of Metals
(Professor Jung (far right) and his team)
Fuel cells are key future energy technology that is emerging as eco-friendly and renewable energy sources. In particular, solid oxide fuel cells composed of ceramic materials gain increasing attention for their ability to directly convert various forms of fuel such as biomass, LNG, and LPG to electric energy.
KAIST researchers described a new technique to improve chemical stability of electrode materials which can extend the lifespan by employing a very little amount of metals.
The core factor that determines the performance of solid oxide fuel cells is the cathode at which the reduction reaction of oxygen occurs. Conventionally, oxides with perovskite structure (ABO3) are used in cathodes. However, despite the high performance of perovskite oxides at initial operation, the performance decreases with time, limiting their long-term use. In particular, the condition of high temperature oxidation state required for cathode operation leads to surface segregation phenomenon, in which second phases such as strontium oxide (SrOx) accumulate on the surface of oxides, resulting in decrease in electrode performance. The detailed mechanism of this phenomenon and a way to effectively inhibit it has not been suggested.
Using computational chemistry and experimental data, Professor WooChul Jung’s team at the Department of Materials Science and Engineering observed that local compressive states around the Sr atoms in a perovskite electrode lattice weakened the Sr-O bond strength, which in turn promote strontium segregation. The team identified local changes in strain distribution in perovskite oxide as the main cause of segregation on strontium surface. Based on these findings, the team doped different sizes of metals in oxides to control the extent of lattice strain in cathode material and effectively inhibited strontium segregation.
Professor Jung said, “This technology can be implemented by adding a small amount of metal atoms during material synthesis, without any additional process.” He continued, “I hope this technology will be useful in developing high-durable perovskite oxide electrode in the future.”
The study co-led by Professor Jung and Professor Jeong Woo Han at Department of Chemical Engineering, University of Seoul was featured as the cover of Energy and Environmental Science in the first issue of 2018.
(Figure1.Correlation between the extent of lattice strain in electrode, strontium segregation, and electrode reaction.)
(Figure 2. Cathode surface of solid oxide fuel cell stabilized using the developed technology)
2018.01.18 View 8254 -
Three Professors Named KAST Fellows
(Professor Dan Keun Sung at the center)
(Professor Y.H. Cho at the center)
(Professor K.H. Cho at the center)
The Korean Academy of Science and Technology (KAST) inducted three KAIST professors as fellows at the New Year’s ceremony held at KAST on January 12. They were among the 24 newly elected fellows of the most distinguished academy in Korea. The new fellows are Professor Dan Keun Sung of the School of Electrical Engineering, Professor Kwang-Hyun Cho of the Department of Bio and Brain Engineering, and Professor Yong-Hoon Cho of the Department of Physics.
Professor Sung was recognized for his lifetime academic achievements in fields related with network protocols and energy ICT. He also played a crucial role in launching the Korean satellites KITSAT-1,2,3 and the establishment of the Satellite Technology Research Center at KAIST.
Professor Y.H.Cho has been a pioneer in the field of low-dimensional semiconductor-powered quantum photonics that enables quantum optical research in solid state. He has been recognized as a renowned scholar in this field internationally.
Professor K.H.Cho has conducted original research that combines IT and BT in systems biology and has applied novel technologies of electronic modeling and computer simulation analysis for investigating complex life sciences. Professor Cho, who is in his 40s, is the youngest fellow among the newly inducted fellows.
2018.01.16 View 14290 -
Harnessing the Strength of KAIST Alumni: New Head of KAA Inaugurated
KAIST alumni gathered in Seoul on January 13 to celebrate the New Year and the newly-elected leadership of the KAIST Alumni Association (KAA). More than 300 alumni, including President Sung-Chul Shin who is also an alumnus of KAIST, joined the gala event held at the Lotte Hotel.
Photo: Ki-Chul Cha(left) and Jung Sik Koh(right)
The KAA inaugurated its new president, Ki-Chul Cha, who was preceded by Jung Sik Koh, the former CEO at the Korea Resources Corporation. His term starts from January 2018 to December 2020.
Cha is the CEO of Inbody Co Ltd., a global company specializing in developing and selling medical instruments, such as a body composition analyzers, and medical solutions. He is also an adjunct professor in the Department of Mechanical Engineering at Yonsei University. Cha obtained a master’s degree in Mechanical Engineering at KAIST in 1980, and a Ph.D. in Bioengineering at the University of Utah, before finishing his post-doc fellowship at Harvard Medical School.
Cha plans to explore the idea that alumni engagement, saying, “KAIST stays as a home in the memories of 60,000 alumni. I will dedicate myself to stimulating the alumni association to make KAISTians proud.”
At the gala event, the KAA awarded the Alumni of the Year honor to six alumni who distinguished themselves in the areas of professional achievement, humanitarianism, and public service. They are the Director of Startup KAIST Professor Byoung Yoon Kim; President of LG Chem Ltd and Head of Battery Research and Development Myung Hwan Kim; Director of INNOX Advanced Materials Co., Ltd Kyung Ho Chang; Vice President of the Korea International Trade Association Jung-Kwan Kim; CEO of Samsung Electro-Mechanics Yun-Tae Lee; and CEO of ENF Technology Jinbae Jung.
Photo: President Shin(far right) poses with six awardees of the Distinguished Alumni Award and the former President of KAA, Koh(far left)
2018.01.16 View 10813 -
One-Step Production of Aromatic Polyesters by E. coli Strains
KAIST systems metabolic engineers defined a novel strategy for microbial aromatic polyesters production fused with synthetic biology from renewable biomass. The team of Distinguished Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering produced aromatic polyesters from Escherichia coli (E. coli) strains by applying microbial fermentation, employing direct microbial fermentation from renewable feedstock carbohydrates.
This is the first report to determine a platform strain of engineered E. coli capable of producing environmentally friendly aromatic polyesters. This engineered E. coli strain, if desired, has the potential to be used as a platform strain capable of producing various high-valued aromatic polyesters from renewable biomass. This research was published in Nature Communications on January 8.
Conventionally, aromatic polyesters boast solid strength and heat stability so that there has been a great deal of interest in fermentative production of aromatic polyesters from renewable non-food biomass, but without success.
However, aromatic polyesters are only made by feeding the cells with corresponding aromatic monomers as substrates, and have not been produced by direct fermentation from renewable feedstock carbohydrates such as glucose.
To address this issue, the team prescribed the detailed procedure for aromatic polyester production through identifying CoA-transferase that activates phenylalkanoates into their corresponding CoA derivatives. In this process, researchers employed metabolic engineering of E. coli to produce phenylalkanoates from glucose based on genome-scale metabolic flux analysis. In particular, the KAIST team made a modulation of gene expression to produce various aromatic polyesters having different monomer fractions.
The research team successfully produced aromatic polyesters, a non-natural polymer using the strategy that combines systems metabolic engineering and synthetic biology. They succeeded in biosynthesis of various kinds of aromatic polyesters through the system, thus proving the technical excellence of the environmentally friendly biosynthetic system of this research. Furthermore, his team also proved the potential of expanding the range of aromatic polyesters from renewable resources, which is expected to play an important role in the bio-plastic industry.
Professor Lee said, “An eco-friendly and sustainable chemical industry is the key global agenda every nation faces. We are making a research focus to a biochemical industry free from petroleum dependence, and conducting diverse research activities to address the issue. This novel technology we are presenting will serve as an opportunity to advance the biochemical industry moving forward.”
This work was supported by the Intelligent Synthetic Biology Center through the Global Frontier Project (2011-0031963) and also by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries (NRF-2012M1A2A2026556 and NRF-2012M1A2A2026557) from the Ministry of Science and ICT through the National Research Foundation of Korea.
Figure: Biosynthesis of aromatic polyesters by metabolically engineered E. coli.This schematic diagram shows the overall conceptualization of how metabolically engineered E. coli produced aromatic polyesters from glucose.
2018.01.09 View 7545 -
Distinguished Alumni Awards 2017 by KAIST Alumni Association
The KAIST Alumni Association announced six Distinguished Alumni Awardees for the year 2017.
Every year, the association selects alumni who have brought honor and distinction to the university through significant contributions to industry, academic achievements, or community service. Since 1992, a total of 95 alumni have been chosen for the distinguished alumni awards.
The recipients are playing major roles in society, and this year is no exception. The award will be given to the alumni during the KAIST New Year Ceremony on January 13 in Seoul.
Here are the six distinguished alumni of the year 2017.
The Director of Startup KAIST, Byoung Yoon Kim (M.S. in Physics) is one of the faculty who has brought entrepreneurship to KAIST. Before founding companies, he held the position of assistant professor at Stanford University. In 1995, he founded FiberProf Inc, commercializing research results from KAIST lab for their applications to test and measurement equipment for lab and production lines. He launched Novera Optics, Inc in 1999 which produced broadband access network equipment (WDM-PON) for FTFH application. Since 2014, he has been holding the position of director of KAIST Startup and inspiring entrepreneurship. He is being recognized for playing a crucial role in defining a successful model for technology startup ecosystems.
The President of LG Chem Ltd., and Head of Battery Research and Development, Myung Hwan Kim (M.S. in Chemical and Biomolecular Engineering) succeeded in developing and producing the first lithium ion batteries in Korea. His work contributed to Korea becoming the second most powerful nation in batteries. In particular, he obtained more orders from global automobile companies by successfully commercializing batteries for electronic vehicles, which led elevating national competitiveness. Recently, his company is leading the battery market for automobiles and power storage by developing novel materials and supplying optimal batteries to match each field.
The Director of INNOX Advanced Materials Co., Ltd., Kyung Ho Chang (M.S. in Chemistry and Ph.D. in Materials Science and Engineering) challenged himself in the Flexible Printed Circuit Board (FPCB) industry, which was mostly dominated by Japanese companies in 2001; however, he succeeded in localizing the materials. Now, his company is the number one for FPCB materials in Korea. FPCBs are a component used in most electronic devices, including smartphones and tablet PCs. Localizing the materials has brought about an import substitution effect as well as establishing a foundation for national competitiveness in FPCBs.
The Vice President of the Korea International Trade Association (KITA), Jung-kwan Kim (M.S. in Business) began his career from deputy director in Ministry of Trade, Industry and Energy. Throughout his career at MOTIE, he served as Director for Energy Development, Director General for Energy Industry Policy, Head Officer of Energy and Resources, and finally Vice Minister for MOTIE. Since joining KITA as the vice president in 2015, he has contributed to supporting overseas expansion of new industries and reinforcing trade competitiveness through opening new markets and providing customized consulting.
The CEO of Samsung Electro-Mechanics, Yun-tae Lee (M.S. and Ph.D. in Electrical Engineering) is an expert in designing semiconductors. While serving as Head of System LSI and Head of LCD in Samsung Electronics, he made significant contributions to projects involving semiconductors and displays, which are the company’s engine of growth. Moreover, by utilizing his insights from the component business and making bold decisions, he is leading the future of Samsung Electro-Mechanics.
The CEO of ENF Technology, Jinbae Jung (Ph.D. in Chemical and Biomolecular Engineering) reinforced national industrial competitiveness by developing high-performance chemicals that are used mostly in the production of semiconductors and displays. Especially, he succeeded in applying regeneration technology of thinners and developing various stripping liquidsHe also localized color pastes, which were heavily dependent on Japan, and improved the quality of color accuracy for LCD panels.
Notable Recipient of Distinguished Alumni Award
2018.01.05 View 8537 -
Meet the KAISTian of 2017, Professor YongKeun Park
Professor YongKeun Park from the Department of Physics is one of the star professors in KAIST. Rising to the academic stardom, Professor Park’s daily schedule is filled with series of business meetings in addition to lab meetings and lectures.
The year 2017 must have been special for him. During the year, he published numerous papers in international journals, such as Nature Photonics, Nature Communications and Science Advances. These high performances drew international attention from renowned media, including Newsweek and Forbes. Moreover, recognizing his research performance, he was elected as a fellow member of the Optical Society (OSA) in his mid-30s. Noting that the members’ age ranges from late 50s to early 60s, Professor Park’s case considered to be quite exceptional.
Adding to his academic achievement, he has launched two startups powered of his own technologies. One is called Tomocube, a company specialized in 3-D imaging microscope using holotomography technology. His company is currently exporting the products to multiple countries, including the United States and Japan. The other one is The.Wave.Talk which has technologies for examining pre-existing bacteria anywhere and anytime.
His research career and entrepreneurship are well deserved recipient of many honors. At the 2018 kick-off ceremony, Professor Park was awarded the KAISTian of 2017 in recognition of his developing holographic measure and control technology as well as founding a new field for technology application.
KAISTian of the Year, first presented in 2001, is an award to recognize the achievements and exemplary contribution of KAIST member who has put significant effort nationally and internationally, enhancing the value of KAIST.
While receiving the award, he thanked his colleagues and his students who have achieved this far together. He said, “I would like to thank KAIST for providing environment for young professors like me so that we can engage themselves in research. Also, I would like to mention that I am an idea seeder and my students do the most of the research. So, I appreciate my students for their hard works, and it is very pleasure to have them. Lastly, I thank the professors for teaching these outstanding students. I feel great responsibility over this title. I will dedicate myself to make further progress in commercializing technology in KAIST.”
Expecting his successful startup cases as a model and great inspiration to students as well as professors, KAIST interviewed Professor Park.
Q What made you decide to found your startups?
A I believed that my research areas could be further used. As a professor, I believe that it is a university’s role to create added value through commercializing technology and creating startups.
Q You have co-founded two startups. What is your role in each company?
A So, basically I have two full-time jobs, professor in KAIST and CTO in Tomocube. After transferring the technology, I hold the position of advisor in The.Wave.Talk.
(Holographic images captured by the product Professor Park developed)
Q Do your students also participate in your companies or can they?
A No, the school and companies are separate spaces; in other words, they are not participating in my companies. They have trained my employees when transferring the technologies, but they are not directly working for the companies.
However, they can participate if they want to. If there’s a need to develop a certain technology, an industry-academia contract can be made. According to the agreement, students can work for the companies.
Q Were there any hardships when preparing the startups?
A At the initial stage, I did not have a financial problem, thanks to support from Startup KAIST. Yet, inviting capital is the beginning, and I think every step I made to operate, generate revenue, and so on is not easy.
Q Do you believe KAIST is startup-friendly?
A Yes, there’s no school like KAIST in Korea and any other country. Besides various programs to support startup activities, Startup KAIST has many professors equipped with a great deal of experience. Therefore, I believe that KAIST provides an excellent environment for both students and professors to create startups.
Q Do you have any suggestion to KAIST institutionally?
A Well, I would like to make a comment to students and professors in KAIST. I strongly recommend them to challenge themselves by launching startups if they have good ideas. Many students wish to begin their jobs in government-funded research institutes or major corporates, but I believe that engaging in a startup company will also give them valuable and very productive experience.
Unlike before, startup institutions are well established, so attracting good capital is not so hard. There are various activities offered by Startup KAIST, so it’s worthwhile giving it a try.
Q What is your goal for 2018 as a professor and entrepreneur?
A I don’t have a grand plan, but I will work harder to produce good students with new topics in KAIST while adding power to my companies to grow bigger.
By Se Yi Kim from the PR Office
2018.01.03 View 11733 -
Ultra-Low Power Flexible Memory Using 2D Materials
(Professor Choi and Ph.D. candidate Jang)
KAIST research team led by Professor Sung-Yool Choi at School of Electrical Engineering and Professor Sung Gap Im at the Department of Chemical and Biomolecular Engineering developed high-density, ultra-low power, non-volatile, flexible memory technology using 2D materials. The team used ultrathin molybdenum disulfide (MoS2) with atomic-scale thickness as the channel material and high-performance polymeric insulator film as the tunneling dielectric material. This research was published on the cover of Advanced Functional Materials on November 17. KAIST graduate Myung Hun Woo, a researcher at Samsung Electronics and Ph.D. candidate Byung Chul Jang are first authors.
The surge of new technologies such as Internet of Things (IoT), Artificial Intelligence (AI), and cloud server led to the paradigm shift from processor-centric computing to memory-centric computing in the industry, as well as the increase in demand of wearable devices. This led to an increased need for high-density, ultra-low power, non-volatile flexible memory. In particular, ultrathin MoS2 as semiconductor material has been recently regarded as post-silicon material. This is due to its ultrathin thickness of atomic-scale which suppresses short channel effect observed in conventional silicon material, leading to advantages in high- density and low-power consumption. Further, this thickness allows the material to be flexible, and thus the material is applicable to wearable devices.
However, due to the dangling-bond free surface of MoS2 semiconductor material, it is difficult to deposit the thin insulator film to be uniform and stable over a large area via the conventional atomic layer deposition process. Further, the currently used solution process makes it difficult to deposit uniformly low dielectric constant (k) polymeric insulator film with sub-10 nm thickness on a large area, thus indicating that the memory device utilizing the conventional solution-processed polymer insulator film cannot be operated at low-operating voltage and is not compatible with photolithography.
The research team tried to overcome the hurdles and develop high-density, ultra-low power, non-volatile flexible memory by employing a low-temperature, solvent-free, and all-dry vapor phase technique named initiated chemical vapor deposition (iCVD) process. Using iCVD process, tunneling polymeric insulator film with 10 nm thickness was deposited uniformly on MoS2 semiconductor material without being restricted by the dangling bond-free surface of MoS2. The team observed that the newly developed MoS2-based non-volatile memory can be operated at low-voltage (around 10V), in contrast to the conventional MoS2-based non-volatile memory that requires over 20V.
Professor Choi said, “As the basis for the Fourth Industrial revolution technologies including AI and IoT, semiconductor device technology needs to have characteristics of low-power and flexibility, in clear contrast to conventional memory devices.” He continued, “This new technology is significant in developing source technology in terms of materials, processes, and devices to contribute to achieve these characteristics.”
This research was supported by the Global Frontier Center for Advanced Soft Electronics and the Creative Materials Discovery Program by funded the National Research Foundation of Korea of Ministry of Science and ICT.
( Figure 1. Cover of Advanced Functional Materials)
(Figure 2. Concept map for the developed non-volatile memory material and high-resolution transmission electron microscopy image for material cross-section )
2018.01.02 View 9368 -
Technology to Find Optimum Drug Target for Cancer Developed
(Professor Kwang-Hyun Cho (right) and lead author Dr. Minsoo Choi)
A KAIST research team led by Professor Kwang-Hyun Cho of the Department of Bio and Brain Engineering developed technology to find the optimum drug target according to the type of cancer cell. The team used systems biology to analyze molecular network dynamics that reflect genetic mutations in cancer cells and to predict drug response. The technology could contribute greatly to future anti-cancer drug development.
There are many types of genetic variations found in cancer cells, including gene mutations and copy number variations. These variations differ in cancer cells even within the same type of cancer, and thus the drug response varies cell by cell. Cancer researchers worked towards identifying frequently occurring genetic variations in cancer patients and, in particular, the mutations that can be used as an index for specific drugs. Previous studies focused on identifying a single genetic mutation or creating an analysis of the structural characteristics of a gene network. However, this approach was limited in its inability to explain the biological properties of cancer which are induced by various gene and protein interactions in cancer cells, which result in differences in drug response.
Gene mutations in cancer cells not only affect the function of the affected gene, but also other genes that interact with the mutated gene and proteins. As a consequence, one mutation could lead to changes in the dynamical properties of the molecular network. Therefore, the responses to anti-cancer drugs by cancer cells differ. The current treatment approach that ignores molecular network dynamics and targets a few cancer-related genes is only effective on a fraction of patients, while many other patients exhibit resistance to the drug.
Professor Cho’s team integrated a large-scale computer simulation using super-computing and cellular experiments to analyze changes in molecular network dynamics in cancer cells.
This led to development of technology to find the optimum drug target according to the type of cancer cells by predicting drug response. This technology was applied to the molecular network of known tumor suppressor p53. The team used large-scale cancer cell genomic data available from The Cancer Cell Line Encyclopedia (CCLE) to construct different molecular networks specific to the characteristics of genetic variations.
Perturbation analysis on drug response in each molecular network was used to quantify changes in cancer cells from drug response and similar networks were clustered. Then, computer simulations were used to analyze the synergetic effects in terms of efficacy and combination to predict the level of drug response. Based on the simulation results from various cancer cell lines including lung, breast, bone, skin, kidney, and ovary cancers were used in drug response experiments for compare analysis.
This technique can be applied in any molecular network to identify the optimum drug target for personalized medicine.
The research team suggests that the technology can analyze varying drug response due to the heterogeneity of cancer cells by considering the overall modulatory interactions rather than focusing only on a specific gene or protein. Further, the technology aids the prediction of causes of drug resistance and thus the identification of the optimum drug target to inhibit the resistance. This could be core source technology that can be used in drug repositioning, a process of applying existing drugs to new disease targets.
Professor Cho said, “Genetic variations in cancer cells are the cause of diverse drug response, but a complete analysis had not yet been made.” He continued, “Systems biology allowed the simulation of drug responses by cancer cell molecular networks to identify fundamental principles of drug response and optimum drug targets using a new conceptual approach.”
This research was published in Nature Communications on December 5 and was funded by Ministry of Science and ICT and National Research Foundation of Korea.
(Figure 1. Drug response prediction for each cancer cell type from computer simulation and cellular experiment verification for comparison)
(Figure 2. Drug response prediction based on cancer cell molecular network dynamics and clustering of cancer cells by their molecular networks)
(Figure 3. Identification of drug target for each cancer cell type by cellular molecular network analysis and establishment for personalized medicine strategy for each cancer patient)
2017.12.15 View 7153 -
A Glance at the 2017 KAIST Literary Awards Ceremony
Since KAIST is a university specializing in science and engineering, people may think that the students rarely engage in literary activities. But KAIST students also excel in writing literature.
The 23rd KAIST Literary Award Ceremony was held on December 14 on the KAIST main campus. The award was established in 1995 to encourage students’ creative activities and to promote literary attainment. It is open to all KAIST students from undergraduate to masters and PhD students. This year, 43 students submitted a total of 68 literary works in the genres of poetry, novel, critique, and scenario.
KAIST professors Dong Ju Kim, Bong Gwan Jun, and Yunjeong Jo from the School of Humanities & Social Sciences participated as judges for the awards and they were joined by writers from the 8th Endless Road Program who served as invited judges for the novels and scenarios.
The Endless Road Program is a KAIST project for supporting artists who are engaged in literary works including scenarios, novels, webtoons, and movies by providing residences and funds. Novelists Jin Young Choi and Hak Chan Kim participated as judges for the novels and a drama scriptwriter, Joo Kim, as a judge of the scenarios.
After thorough evaluation, four submissions were chosen as awardees.
Section
Award
Name
Poetry
Winner
Sung Gil Moon (PhD candidate from the College of Business)
Runner-up
Jong Ik Jeon (Undergraduate student)
Novel
Winner
Joo Hwan Kim
(Undergraduate from the Dept. of Chemical and Biomolecular Engineering)
Runner-up
-
Essay & Critique
Winner
-
Runner-up
Jung Joon Park
(PhD candidate from the Dept. of Bio and Brain Engineering)
Scenario
Winner
-
Runner-up
-
The literary works as well as a review of the awards will be published in the KAIST Times in 2018.
2017.12.15 View 7997