Prof. Lee Jae-hyun’s Team Develops Layer-Engineered Large-Area Exfoliation of Graphene
Professor Lee Jae-hyun of Ajou University has developed a new graphene exfoliation technique for graphite, a next-generation electron material. A joint research team involving professor Lee Jae-hyun (Department of Materials Science and Engineering, photo), Son Seok-kyun of Mokpo National University, and Cho Sung-ho, director of Samsung Display, announced that the team had developed a new technique of layer-engineered large-area exfoliation of graphene. The study was published in Science Advances on October 28th and titled, “Layer-engineered large-area exfoliation of graphene”. PhD student Moon ji-Yoon and Doctor Kim Min-soo from the University of Manchester participated as lead authors. Graphene, a transparent material with rubber-like flexibility, has received a lot of attention as a “dream material” for its outstanding electrical conductivity. These characteristics make graphene perfect for rollable TVs and smartphone screens. Graphene is a compound integration of carbon atoms that form a beehive shape. This monolayer material is so thin that 100,000 layers are equal to the diameter of a human hair. The conventional method of obtaining graphene sheets from graphite flakes required workers to repeatedly peel off layers of graphite crystals using cellophane tape. This was immensely dependent on worker skill and made it almost impossible to control monolayer graphene area, number of layers and yield. Professor Lee’s team succeeded in controlling, at the atom level, the crack propagation, especially size and direction, produced when peeling off layers using cellophane tape and obtaining the desired area and number of layers. According to Lee’s new method, a specific metal film is attached to graphite to selectively, rather than randomly, control the depth and direction of cracks. The research team’s finding enables production of layer-controlled graphene: from mm2-monolayer to double layer and up to 40 layers. The average area of monolayer graphene exfoliated using the new method is up to approximately 4200 times that of monolayer graphene exfoliated by the standard method. In addition, the density per unit area of monolayer graphene increased by a maximum of 6000 times, which enables higher yield. The recent study is expected to be an alternative method for preparing graphene, as obtaining fine quality exfoliated graphene is essential for commercialization. Research was sponsored by a grant from the Korean Ministry of Science and ICT and the National Research Foundation of Korea as part of their Basic Science and Engineering Lab Program and Beginning Researcher Program. 금필름 Gold Film 자연 흑연으로부터 무결점 그래핀 박리 Exfoliation of top graphene from bulk crystal 원하는 기판으로의 전사 공정 Transfer to target substrate (Top) The exfoliation process of selective monolayer graphene from natural graphite flakes through attachment of gold film. (Bottom) Graphs comparing the size and density of monolayer graphene exfoliated using the conventional method and using the new method with gold film. The average area of monolayer graphene obtained using gold film is up to 4200 times the standard exfoliation method and up to 6000 times the density.
Prof. Jeon Sang-min’s Research Team Suggests a Paradigm Shift in the Role of NRF2
A team led by Ajou University Professor Jeon Sang-min has found that a specific gene formerly considered helpful in prevention and treatment of cancer, in fact, stimulates its development and progression. Professor Jeon Sang-min (College of Pharmacy, photo) discovered that, contrary to traditional understanding, Nuclear factor E2-related factor 2 (NRF2) is a gene that stimulates cancer development and is also related to poor clinical outcomes, not at all a tumor suppressor gene. His study was published in Clinical Cancer Research on October 19th and entitled, “NRF2 activation promotes aggressive lung cancer and associates with poor clinical outcomes”. Professor Jeon Sang-min, PhD student Choi Eun-ji, US company Genentech, and a research team from Johns Hopkins Medical Institutions participated in the recent study, which was sponsored with a grant from the Korea National R&D Program for Cancer Control (Ministry of Health and Welfare) and the Basic Science Research Program (Individual Basic Science & Engineering Research Program) under the Ministry of Science, ICT and Future Planning. NRF2 has long been considered helpful in preventing and treating cancer as it was believed to reduce reactive oxygen species (ROS) once it is processed into a transcription factor that activates anti-oxidation pathways. However, several recent findings have suggested that NRF2 may actually contribute to tumor development, because in many cases of cancer, including cancer of the lung, NRF2 was activated. Another study also found that, in lung cancer cases, NRF2 activation occurred along with the mutation of STK11/LKB1, which are other tumor suppressor genes. Accordingly, the joint research team conducted experiments based on a genetically modified lung cancer mouse model (Kras/Keap1/Stk11-KO) and analyzed the results of the latest large-scale lung cancer clinical trials (OAK, IMpower131). The research team identified that, in the genetically modified mouse model, the activation of NRF2 stimulated lung cancer development and lowered survival rates. The team also found that the STK11 gene mutation increased ROS and stimulated the progression of lung cancer development. When STK11 mutation and NRF1 activation were both taking place, they suppressed ROS, further promoted lung cancer development and significantly lowered survival rates. The research team discovered that the reason NRF2 activation and STK11 mutation happen simultaneously in lung cancer cases is because NRF2 activation reduces oxidative stress incurred by STK11 mutation leading to cancer cell survival and growth. In conclusion, the study produced meaningful findings proving that NRF2 is a tumor oncogene, not a tumor suppressor gene. The team also analyzed recent clinical trials and found that lung cancer patients with active NRFs were highly likely to have poorer chemotherapy and immunotherapy outcomes than those who didn’t have active NRFs, and had significantly lower survival rates. Professor Jeon Sang-min stated “The study suggests a paradigm shift in the role of NRF2 in cancer. […] Many attempts have been made to develop an NRF2 stimulant for cancer prevention and treatment. However, our research has set the record straight and contributed to increasing interest on the development of an NRF2 inhibitor.” Professor Jeon’s research team is continuing efforts to be the first in developing such an NRF2 inhibitor drug. Professor Jeon participated in joint creation of SCL Therapeutics, a bio start-up, for clinical development of the self-discovered NRF2 inhibitor candidate. Currently, the lab is conducting pre-clinical trials.
Chemical Engineering 1985 Alumni Member Makes “Love Ajou” Relay Donation
<Photo: From left: EP Global CEO Kang Won-gu, Paint Wall Mart CEO Kwon Hoe-jung, RAY Star CEO Kwon Soon-ho, Ajou University president Park Hyung-ju and dean of the Chemical Engineering Department, Kim Ju-hyung> The Chemical Engineering 1985 Alumni Association continues giving to the university. Its donation relay campaign began in 2016 and has continued every year. This year, Kwon Soon-ho, member of the Chemical Engineering 1985 Alumni Association, continued the relay with a monetary gift to the university. RAY Star CEO, Kwon Soon-ho started his undergraduate studies in the Ajou University Department of Chemical Engineering in 1985. He donated 10 million won towards establishment of a commemorative hall celebrating Ajou’s 50th anniversary, becoming the fifth “runner” in the relay donation campaign. The donation hand-over ceremony was held at the president’s office on October 21st. Park Hyung-ju, President of Ajou University, extended his gratitude on behalf of the Ajou family and held a luncheon. The previous donors to the relay donation campaign also participated. The campaign was introduced by the alumni association of the Chemical Engineering department and began with EP Global CEO Kang Won-gu in 2016. This year celebrates the fifth year of continued donations: Innofiltech CEO Kim Jung-woo in 2017, EKC CEO Kang Min-gu in 2018, and Paint Wall Mart CEO Kwon Hoe-jung in 2019 all contributed 10 million won. The alumni are now one step closer to their goal of donating 100 million won within a decade thanks to the recent donation made by Kwon Soon-ho. Kang Won-gu directed his donation to the Ajou University Central Library, Kim Jung-woo contributed to further development of the Electrical and Computer Engineering Department, while gifts from Kang Min-gu and Kwon Hoe-jung went towards advancement of the Chemical Engineering Department.