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Nanoparticle Cluster Manufacturing Technique Using DNA Binding Protein Developed
Professor Hak-Sung Kim of the Department of Biological Sciences at KAIST and Yiseul Ryu, a doctoral candidate, used the Zinc Finger protein that specifically binds to target DNA sequence to develop a new manufacturing technique for size-controllable magnetic Nanoparticle Clusters (NPCs). Their research results were published in Angewandte Chemie International Edition online on 25 November 2014.
NPCs are structures consisting of magnetic nanoparticles, gold nanoparticles, and quantum dots, each of which are smaller than 100 nm (10-9m). NPCs have a distinctive property of collectivity not seen in single nanoparticles.
Specifically NPCS differ in physical and optical properties such as Plasmon coupling absorbance, energy transfers between particles, electron transfers, and conductivity. Therefore, NPCs can be employed in biological and medical research as well as the development of nanoelectric and nanoplasmon devices.
To make use of these novel properties, the size and the composition of the cluster must be exquisitely controlled. However, previous techniques relied on chemical binding which required complex steps, making it difficult to control the size and composition of NPCs.
Professor Kim’s team used Zinc Finger, a DNA binding protein, to develop a NPCs manufacturing technique to create clusters of the desired size easily. The Zinc Finger protein contains a zinc ion and specifically recognizes DNA sequence upon binding, which allows the exquisite control of the size and the cluster composition. The technique is also bio-friendly.
Professor Kim’s team created linear structure of different sizes of NPCs using Zinc Finger proteins and three DNA sequences of different lengths. The NPCs they produced confirmed their ability to control the size and structure of the cluster by using different DNA lengths.
The NPCs showed tripled T2 relaxation rates compared to the existing MRI contrast media (Feridex) and effectively transported to targeted cells. The research findings show the potential use of NPCs in biological and medical fields such as MRI contrast media, fluorescence imaging, and drug transport.
The research used the specific binding property of protein and DNA to develop a new method to create an inorganic nanoparticle’s supramolecular assembly. The technique can be used and applied extensively in other nanoparticles for future research in diagnosis, imaging, and drug and gene delivery.
Figure 1. A Mimetic Diagram of NPCs Manufacturing Technique Using DNA Binding Protein Zinc Finger
Figure 2. Transmission Electron Microscopy Images showing different sizes of NPCs depending on the length of the DNA
2014.12.04 View 11916 -
A Volunteer Project by Students: The Surprise Bus!
GoGeeks, one of the undergraduate student clubs at KAIST, plans to run a bus to take volunteers to places where help is needed such as nursing homes, orphanages, and community centers. This volunteer project is called “Surprise Bus!” Students interested in participating in the project can apply online via a social funding website, http://tumblbug.com, until December 5, 2014. Up to 150 students will be selected.
A total of five buses will leave from Seoul on December 20, 2014 to several places nationwide. Participants will not know their final destination until they arrive at the scene where they will work. GoGeeks was inspired by the “Do Good Bus” project, a volunteer organization that started in the US, through which people meet, and while performing their volunteer activities, they get to know each other.
Bum-Kyu Lee, the President of GoGeeks, who is a senior in the Department of Industrial and Systems Engineering, said, “I’ve encountered many students who want to volunteer, but they are not sure where to go to start. The “Surprise Bus!” is a wonderful volunteer opportunity, and I think participants will have fun and, at the same time, will have a meaningful time. The Christmas season is also an excellent time to do something good for our communities and neighborhoods.”
2014.12.04 View 7338 -
The Bio-Synergy Research Center, KAIST, Hosts an Annual Meeting
The Ministry of Science, ICT and Future Planning of the Republic of Korea founded the Bio-Synergy Research Center (BSRC) at KAIST in 2013 to develop source technology and generate new knowledge by conducting convergence research projects in natural resources with information technology (IT) and biotechnology.
The BSRC hosted an annual meeting on November 21, 2014, at the KAIST campus and reviewed the progress it made this year with the participation of President Steve Kang of KAIST, Commissioner Young-min Kim of KIPO, and Director Doheon Lee of BSRC.
The Korean Intellectual Property Office (KIPO) provided BSRC with its database in Korean traditional medicine that includes a vast amount of information about disease symptoms, native medicinal herbs and plant extracts, prescriptions, and chemical compounds used for medication. The database, “Compound Combination-Oriented Natural Product Database with Unified Terminology (COCUNUT),” holds approximately one million data sets in four major categories: prescriptions, medicinal resources, medicine components and functions, and diseases.
Based on COCUNUT, BSRC has been working on the standardization of Korean traditional medicine such as the development of data mapping and text mining technology and the analysis of big data in accordance with the said categories. Using IT and biotechnology, the center has also created a virtual human body to explain how traditional medicine works in human body, thereby contributing to the development of new natural materials for medicine.
2014.12.03 View 7469 -
Broadband and Ultrathin Polarization Manipulators Developed
Professor Bumki Min from the Department of Mechanical Engineering at KAIST has developed a technology that can manipulate a polarized light in broadband operation with the use of a metamaterial.
It is expected that this technology will lead to the development of broadband optical devices that can be applied to broadband communication and display.
When an object or its structure is analyzed by using a polarized light such as a laser, the results are generally affected by the polarized state of the light. Therefore, in an optics laboratory, the light is polarized by various methods.
In such cases, researchers employ wave plates or photoactive materials. However, the performance of these devices depend vastly on wavelength, and so they are not suitable to be used as a polarizer, especially in broadband.
There were many attempts to make artificial materials that are very photoactive by using metamaterials which have a strong resonance. Nonetheless, because the materials had an unavoidable dispersion in the resonance frequency, they were not adequate for broadband operation.
Professor Min’s research team arranged and connected helical metamaterials that are smaller than the wavelength of light. They verified theoretically and experimentally that polarized light can be constantly rotated regardless of the wavelength by super-thin materials that have thickness less than one-tenth of the wavelength of the light. The experiment which confirmed the theory was conducted in the microwave band.
Broadband polarized rotational 3D metamaterials were found to rotate the polarized microwave within the range of 0.1 GHz to 40 GHz by 45 degrees regardless of its frequency. This nondispersive property is quite unnatural because it is difficult to find a material that does not change in a wide band.
In addition, the research team materialized the broadband nondispersive polarized rotational property by designing the metamaterial in a way that it has chirality, which determines the number of rotations proportional to the wavelength.
Professor Min said, “As the technology is able to manipulate ultrathin polarization of light in broadband, it will lead to the creation of ultra-shallow broadband optical devices.”
Sponsored by the Ministry of Science, ICT and Future Planning of the Republic of Korea and the National Research Foundation of Korea, this research was led by a PhD candidate, Hyun-Sung Park, under the guidance of Professor Min. The research findings were published online in the November 17th issue of Nature Communications.
Figure 1 – Broadband and Ultrathin Polarization Manipulators Produced by 3D Printer
Figure 2 – Concept of Broadband and Ultrathin Polarization Manipulators
2014.12.03 View 10489 -
SmileGate Membership Program for Students and Video Game Industry in Korea
The Office of University and Industry Cooperation at KAIST and SmileGate, a video game developer based in Korea, agreed in June 2014 to cooperate in the development of talents for the video game industry in Korea and to support students’ startup efforts.
The company established the SmileGate Studio at the KAIST campus in 2010 and has been supporting KAIST students who are interested in video game design and development, such as hosting design competitions and offering networking opportunities as well as consulting services for startups.
The Studio launched a scholarship program called the “SmileGate Membership” in November this year to offer 12 students research funding, equipment and tools for game design and development, and mentoring services for eight months. Participating students will also receive free space for research and development, legal services for business development, investment advice, and assistance in networking with the global community after the completion of the program.
Professor Joongmyeon Bae, the Dean of the KAIST Office of University and Industry Cooperation, said, “This is a great opportunity for our students because they can actually utilize their passion and creativity to make their own games. KAIST and SmileGate will continue to lead the video game industry in Korea through close collaboration.”
2014.12.03 View 8082 -
Structure of Neuron-Connecting Synaptic Adhesion Molecules Discovered
A research team has found the three-dimensional structure of synaptic adhesion molecules, which orchestrate synaptogenesis. The research findings also propose the mechanism of synapses in its initial formation. Some brain diseases such as obsessive compulsive disorder (OCD) or bipolar disorders arise from a malfunction of synapses. The team expects the findings to be applied in investigating pathogenesis and developing medicines for such diseases.
The research was conducted by a Master’s candidate Kee Hun Kim, Professor Ji Won Um from Yonsei University, and Professor Beom Seok Park from Eulji University under the guidance of Professor Homin Kim from the Graduate School of Medical Science and Engineering, KAIST, and Professor Jaewon Ko from Yonsei University. Sponsored by the Ministry of Science, ICT and Future Planning and the National Research Foundation of Korea, the research findings were published online in the November 14th issue of Nature Communications.
A protein that exists in the neuronal transmembrane, Slitrk, interacts with the presynaptic leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs) and forms a protein complex. It is involved in the development of synapses in the initial stage, and balances excitatory and inhibitory signals of neurons.
It is known that a disorder in those two proteins cause a malfunction of synapses, resulting in neuropsychosis such as autism, epilepsy, OCD, and bipolar disorders. However, because the structure as well as synaptogenic function of these proteins were not understood, the development of cures could not progress.
The research team discovered the three-dimensional structure of two synaptic adhesion molecules like Slitrk and LAR-RPTPs and identified the regions of interaction through protein crystallography and transmission electron microscopy (TEM). Furthermore, they found that the formation of the synapse is induced after the combination of two synaptic adhesion molecules develops a cluster.
Professor Kim said, “The research findings will serve as a basis of understanding the pathogenesis of brain diseases which arises from a malfunction of synaptic adhesion molecules. In particular, this is a good example in which collaboration between structural biology and neurobiology has led to a fruitful result.” Professor Ko commented that “this will give new directions to synaptic formation-related-researches by revealing the molecular mechanism of synaptic adhesion molecules.”
Figure 1: Overview of the PTPd Ig1–3/Slitrk1 LRR1 complex.
Figure 2: Representative negative-stained electron microscopy images of Slitrk1 Full ectodomain (yellow arrows indicate the horseshoe-shaped LRR domains). The typical horseshoe-shaped structures and the randomness of the relative positions of each LRR domain can be observed from the two-dimensional class averages displayed in the orange box.
Figure 3: Model of the two-step presynaptic differentiation process mediated by the biding of Slitrks to LAR-RPTPs and subsequent lateral assembly of trans-synaptic LAR-RPTPs/Slitrik complexes.
2014.11.28 View 10932 -
Breakthrough in Flexible Electronics Enabled by Inorganic-based Laser Lift-off
Flexible electronics have been touted as the next generation in electronics in various areas, ranging from consumer electronics to bio-integrated medical devices. In spite of their merits, insufficient performance of organic materials arising from inherent material properties and processing limitations in scalability have posed big challenges to developing all-in-one flexible electronics systems in which display, processor, memory, and energy devices are integrated. The high temperature processes, essential for high performance electronic devices, have severely restricted the development of flexible electronics because of the fundamental thermal instabilities of polymer materials.
A research team headed by Professor Keon Jae Lee of the Department of Materials Science and Engineering at KAIST provides an easier methodology to realize high performance flexible electronics by using the Inorganic-based Laser Lift-off (ILLO).
The ILLO process involves depositing a laser-reactive exfoliation layer on rigid substrates, and then fabricating ultrathin inorganic electronic devices, e.g., high density crossbar memristive memory on top of the exfoliation layer. By laser irradiation through the back of the substrate, only the ultrathin inorganic device layers are exfoliated from the substrate as a result of the reaction between laser and exfoliation layer, and then subsequently transferred onto any kind of receiver substrate such as plastic, paper, and even fabric.
This ILLO process can enable not only nanoscale processes for high density flexible devices but also the high temperature process that was previously difficult to achieve on plastic substrates. The transferred device successfully demonstrates fully-functional random access memory operation on flexible substrates even under severe bending.
Professor Lee said, “By selecting an optimized set of inorganic exfoliation layer and substrate, a nanoscale process at a high temperature of over 1000 °C can be utilized for high performance flexible electronics. The ILLO process can be applied to diverse flexible electronics, such as driving circuits for displays and inorganic-based energy devices such as battery, solar cell, and self-powered devices that require high temperature processes.”
The team’s results were published in the November issue of Wiley’s journal, ‘ Advanced Materials, ’ as a cover article entitled “ Flexible Crossbar-Structured Resistive Memory Arrays on Plastic Substrates via Inorganic-Based Laser Lift-Off.”
( http://onlinelibrary.wiley.com/doi/10.1002/adma.201402472/abstract )
This schematic picture shows the flexible crossbar memory developed via the ILLO process.
This photo shows the flexible RRAM device on a plastic substrate.
2014.11.26 View 9639 -
Elsevier Selects a KAIST Graduate's Paper as the Top Cited Papers in 2011-2012
Dr. Myung-Won Seo, a graduate from the Department of Chemical and Bimolecular Engineering at KAIST, published a paper in January 2011 in Chemical Engineering Journal, which was entitled “Solid Circulation and Loop-seal Characteristics of a Dual Circulating Fluidized Bed: Experiments and CFD Simulation.” His paper was selected by Elsevier as the Top Cited Papers of 2011-2012. The Chemical Engineering Journal is a renowned peer-reviewed journal issued by Elsevier.
Dr. Seo published another paper, “CFD Simulation with Experiments in a Dual Circulating Fluidized Bed Gasifier,” in January 2012 in Computers & Chemical Engineering, which was also selected as the Most Downloaded Papers in 2012-2013.
Dr. Seo graduated with a doctoral degree from KAIST in 2011. He is currently working at the Clean Fuel Laboratory, the Korea Institute of Energy Research, Daejeon, as a researcher. His research areas are coal gasification, upgrading, and liquefaction, as well as energy and chemical production from low-grade fuels such as biomass and wastes.
2014.11.24 View 8745 -
KAIST Robotic Art: Exhibit called "Artificial Brain, Robots Evolve"
It is not difficult to find the desire to create a Neoanthropinae in the history of mankind. Humans evolve through man-made extensions and live by self-training them. This is Seung Hyun Son’s description which encourages us to discuss the changes man-made humanoids would bring to our future lives. He depicts this in “Theory of Evolution: From mankind to humanoid” in the “Artificial Brain, Robots Evolve” exhibition in the KI Building, KAIST, from 21 November 2014 to 8 February 2015.
KAIST's Art and Design Committee (led by President Myung Seok Kim) is holding the third experimental art exhibition based on the integration of science and art. The previous exhibition themes were “See the Sky” in 2012 and “Life is Beautiful” in 2013. The exhibition is divided into five subtopics: Move, Feel, Think, Express, and Experiment in Imagination.
The exhibits are by 17 artists including Nam June Paik, Nancy Lang, and KAIST Professor Myung Seok Kim. The main exhibits include “Cloud Face,” by Seung Baek Shin and Yong Hoon Kim, that shows up as error on computer but can be seen by human eyes and “Brains in Vat," by Boo Rok Lee and Myung Chul Kim based on KAIST's robotic lab’s materials and motif. Also, “The May of My Life” by Professor Myung Seok Kim’s lab reminds us of the relationship between robot and human.
President Myung Seok Kim said, “The range of content in cultural art will inspire students’ imagination.” He continued, “I hope this exhibition will awaken both scientific ideas and artistic sense.”
The opening ceremony of the exhibition will be held from 14:00, 21 November. The “Artificial Brain, Robots Evolve” exhibition is hosted by the Daejeon Museum of Art and sponsored by National Museum of Modern and Contemporary Art and Soma Museum.
Pictures from top to bottom are Cloud Face, Brains in Vat, The May of My Life_1, and The May of My Life_2.
2014.11.21 View 7308 -
The 2014 Wearable Computer Competition Takes Place at KAIST
“This is a smart wig for patients who are reluctant to go outdoors because their hair is falling out from cancer treatment.”
A graduate student from Sungkyunkwan University, Jee-Hoon Lee enthusiastically explains his project at the KAIST KI Building where the 2014 Wearable Computer Competition was held. He said, “The sensor embedded inside the wig monitors the heart rate and the body temperature, and during an emergency, the device warns the patient about the situation. The product emphasizes two aspects; it notifies the patient in emergency situations, and it encourages patients to perform outdoor activities by enhancing their looks.”
The the tenth anniversary meeting of the 2014 Wearable Computer Competition took place at the KAIST campus on November 13-14, 2014.
A wearable computer is a mobile device designed to be put on the body or clothes so that a user can comfortably use it while walking. Recently, these devices that are able to support versatile internet-based services through smartphones are receiving a great deal of attention.
Wearable devices have been employed in two categorizes: health checks and information-entertainment. In this year’s competition, six healthcare products and nine information-entertainment products were exhibited.
Among these products, participants favored a smart helmet for motorcycle drivers. The driver can see through a rear camera with a navigation screen of the smartphone and text messages through the screen installed in the front glass of the helmet. Another product included a uniform that can control presentation slides by means of motion detection and voice recognition technology. Yet another popular device offered an insole to guide travelers to their destination with the help of motion sensors.
The chairman of the competition, Professor Hoi-Jun Yoo from the Department of Electrical Engineering at KAIST said, “Wearable devices such as smart watches, glasses, and clothes are gaining interest these days. Through this event, people will have a chance to look at the creativity of our students through the display of their wearable devices. In turn, these devices will advance computer technology.”
The third annual wearable computer workshop on convergence technology of wearable computers followed the competition. In the workshop, experts from leading information technology companies such as Samsung Electronics, LG Electronics, and KT Corporation addressed the convergence technology of wearable computers and trends in the field.
2014.11.19 View 9482 -
3D Printer Developed by KAIST Undergraduate Students
More than 100 Pre-orders Prior to Product Launch Made
KAIST undergraduate students received more than 100 pre-orders before the launch for 3D printers they developed and became a hot topic of interest.
KAIST Research Institute for Social Technology and Innovations (Head Hong-Kyu Lee) had a launch party at Daejeon Riviera Hotel on 17 November 2014 for “Commercial Delta 3D Printer” developed by KAIST undergraduate students inviting around 50 businesses, buyers and representatives of 3D Printing Industry Association.
“3D Printer” uses blueprints of products such as toys, mug cups and chairs to make 3D objects and is thought to be revolutionary technology in manufacturing industry. The interest has grown as recent printers could print even fruits and cosmetics.
The printing structure of 3D printer can be divided roughly into horizontal Mendel method and Delta method. KAIST students focused on the Delta method to give a differentiated product from 90% of commercial products that use Mendel method.
First, the students focused on lowering the cost of unit price by using self-developed components. The carriage (transport machine) of the product is replaced by self-developed components instead of bearing to reduce the noise and the linking method was changed to beads from loop guide to increase the completeness of the printed product. Also, an auto-levelling is loaded to ensure the nozzle and the bed is parallel and hence increasing convenience for the users. Further, the printer, designed by a product designer in Germany, is linked to a smartphone application for blueprints.
A student in the development team, Seokhyeon Seo (Department of Computer Science, 3rd Year Undergraduate) said, “The biggest merits of the product are lowering the price to a 1/3 by using self-developed components and reducing the noise.” He continued, “By using a smartphone application, anyone can easily design the product. So it is applicable to use for education or at home”
In the exhibit, “3D Printing Korea 2014,” in Coex, Seoul the printer had a preview demonstration, and received more than 100 pre-orders from educational and business training institutions. Further, buyers from Canada and the US requested opening agencies in their countries.
KAIST Research Institute for Social Technology and Innovations Head Hong-Kyu Lee said, “3D printing is an innovative technology that could bring the 3rd industrial revolution.” He continued, “It is still early days but the demand will increase exponentially.”
This project was a research project of KAIST Research Institute for Social Technology and Innovations led by a development team consisting of 4 undergraduate students of KAIST, one student from University of Oxford and one German product designer.
Students in the picture below are Won-Hoi Kim (Department of Mechanical Engineering), Sung-Hyun Cho (Department of Mechanical Engineering), and Suk-Hyun Seo (Department of Computer Science) from left to right.
2014.11.19 View 10088 -
Eggshell-like Cell Encapsulation and Degradation Technology Developed
Some bacteria form endospores on cell walls to protect their DNA in case of nutrient deficiency. When an endospore meets a suitable environment for survival, the cell can revert to the original state from which it can reproduce.
The technique that can artificially control such phenomenon was developed by an international team of researchers. At first, a cell is wrapped and preserved like an egg. When the cell is needed, the technique allows the endospore to decompose while it is alive. Future applications for this technique include cell-based biosensor, cell therapy, and biocatalyst processes.
Professors Insung Choi and Younghoon Lee from the Department of Chemistry at KAIST as well as and Professor Frank Caruso from the University of Melbourne developed this technique which permits a cell to stay alive by coating it with film on a nanometer scale and then to be decomposed while it is alive.
The research finding was published in the November 10th issue of Angewandte Chemie International Edition as the lead article.
Cell encapsulation allows researchers to capture a cell in a tight capsule while it is alive. It is highly recognized in cell-based applications where the control of cell stability and cell-division is the biggest issue.
Traditional cell encapsulation methods utilized organic film or inorganic capsules that are made of organic film moldings. Although these films tightly closed around the cell, because they were not easily decomposable, it was difficult to apply the method.
The research team succeeded in encapsulating each cell in a metal-polyphenol film by mixing tannic acid and iron ion solution with yeast cells.
Usually extracted from oak barks or grape peels, tannic acid is a natural substance. It forms a metal-polyphenol film within ten seconds when it meets iron ions due to its high affinity with cells. Cells encapsulated with this film presented high survival rates. Since the film forms quickly in a simple manner, it was possible to obtain large amount of encapsulated cells.
The research team also found that the metal-polyphenol film was stable in neutral pH, but is easily degradable under a weak acidic condition. Using this property, they were able to control cell division by restoring the cell to its pre-encapsulated state at a desired moment.
Protecting the cell from the external environment like an egg shell, the metal-polyphenol film protected the cell against foreign conditions such as lytic enzymes, extended exposure to UV radiation, and silver nanoparticles. The research indicated that the encapsulated cells had a high survival rate even under extreme environments.
Professor Lee said that “not only the cells remain alive during the encapsulation stage, but also they can be protected under extreme environment.” He added, “This is an advanced cell encapsulation technology that allows controlling cell-division of those cells through responsive shell degradation on-demand.”
Professor Choi commented, “Although the cell encapsulation technology is still in its infancy, as the technology matures the application of cell-manipulation technology will be actualized.” He highlighted that “it will serve as a breakthrough to problems faced by cell-based applications.”
Sponsored by the Ministry of Science, ICT and Future Planning and the National Research Foundation of Korea, the research was led by two Master’s candidates, Ji Hun Park and Kyung Hwan Kim, under the joint guidance of research professors from KAIST and the University of Melbourne.
Figure 1: Lead article of Angewandte Chemie
Background: Shows a live native yeast (in green) encapsulated in a metal-polyphenol film (in red) illustrating the vitality of the yeast
Front: A native yeast at each encapsulation stage
Pictured on the bottom left is a cell prior to encapsulation. Following the red arrow, the native yeast is in purple to show metal-polyphenol film formed around the cell. The cell after the green arrow is a visualization of the degradation of the film in weak acidic condition.
Figure 2: A mimetic diagram of cell encapsulation with a metal-polyphenol film
Top: A native yeast before encapsulation
Middle: A native yeast encapsulated with Tannic Acid-Fe (III) Nanoshell – cell-division of the encapsulated cell is controlled by pH and the shell is protected against silver nanoparticle, lytic enzyme, and UV-C
Bottom: Shell degradation on-demand depending on pH
2014.11.18 View 9612