Pohang University of Science and Technology (POSTECH)

10 articles published in JoVE

• Bioengineering

  
  3D Cell-Printed Hypoxic Cancer-on-a-Chip for Recapitulating Pathologic Progression of Solid Cancer Wonbin Park*¹, Mihyeon Bae*¹, Minseon Hwang¹, Jinah Jang², Dong-Woo Cho¹, Hee-Gyeong Yi^{1,3 1}Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), ²Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), ³Department of Rural and Biosystems Engineering, College of Agriculture and Life Sciences, Chonnam National University Hypoxia is a hallmark of tumor microenvironment and plays a crucial role in cancer progression. This article describes the fabrication process of a hypoxic cancer-on-a-chip based on 3D cell-printing technology to recapitulate a hypoxia-related pathology of cancer.

• Engineering

  
  Demonstration of Spin-Multiplexed and Direction-Multiplexed All-Dielectric Visible Metaholograms Inki Kim¹, Dasol Lee¹, Junsuk Rho^{1,2 1}Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), ²Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH) We present a protocol for fabrication of spin- and direction-multiplexed visible metaholograms, then conduct an optical experiment to verify their function. These metaholograms can easily visualize encoded information, so they can be used for projective volumetric display and information encryption.

• Cancer Research

  
  Culture, Manipulation, and Orthotopic Transplantation of Mouse Bladder Tumor Organoids Yubin Kim*¹, Juhee Lee*¹, SungEun Kim*¹, Kunyoo Shin^{1 1}Department of Life Sciences, Pohang University of Science and Technology This protocol provides detailed experimental steps to establish a three-dimensional in vitro culture of bladder tumor organoids derived from carcinogen-induced murine bladder cancer. Culture methods including passaging, genetic engineering, and orthotopic transplantation of tumor organoids are described.

• Bioengineering

  
  Pancreatic Tissue-Derived Extracellular Matrix Bioink for Printing 3D Cell-Laden Pancreatic Tissue Constructs Jaewook Kim*¹, Myungji Kim*², Dong Gyu Hwang², In Kyong Shim³, Song Cheol Kim^3,4, Jinah Jang^{1,2,5 1}Department of Mechanical Engineering, Pohang University of Science and Technology, ²School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, ³Asan Institute for Life Science, University of Ulsan College of Medicine and Asan Medical Center, ⁴Division of Hepato-Biliary and Pancreatic Surgery, Department of Surgery, University of Ulsan College of Medicine and Asan Medical Center, ⁵Department of Creative IT Engineering, Pohang University of Science and Technology Decellularized extracellular matrix (dECM) can provide suitable microenvironmental cues to recapitulate the inherent functions of target tissues in an engineered construct. This article elucidates the protocols for the decellularization of pancreatic tissue, evaluation of pancreatic tissue-derived dECM bioink, and generation of 3D pancreatic tissue constructs using a bioprinting technique.

• Engineering

  
  Demonstration of Equal-Intensity Beam Generation by Dielectric Metasurfaces Gwanho Yoon¹, Dasol Lee¹, Junsuk Rho^{1,2,3 1}Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), ²Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), ³National Institute of Nanomaterials Technology (NINT) A protocol for the fabrication and optical characterization of dielectric metasurfaces is presented. This method can be applied to the fabrication of not only beam splitters, but also of general dielectric metasurfaces, such as lenses, holograms, and optical cloaks.

• Biochemistry

  
  Studying Protein Import into Chloroplasts Using Protoplasts Junho Lee¹, Hyangju Kang¹, Inhwan Hwang^{1,2 1}Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, ²Department of Life Sciences, Pohang University of Science and Technology Here we describe a protocol to express proteins into protoplasts by using PEG-mediated transformation method. The method provides easy expression of proteins of interest, and efficient investigation of protein localization and the import process for various experimental conditions in vivo.

• Engineering

  
  Demonstration of a Hyperlens-integrated Microscope and Super-resolution Imaging Dasol Lee*¹, Minkyung Kim*¹, Sunae So*¹, Inki Kim¹, Gwanho Yoon¹, Kyunghoon Kim², Junsuk Rho^{1,3 1}Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), ²School of Mechanical Engineering, Sungkyunkwan University, ³Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH) The use of a hyperlens has been regarded as a novel super-resolution imaging technique due to its advantages in real-time imaging and its simple implementation with conventional optics. Here, we present a protocol describing the fabrication and imaging applications of a spherical hyperlens.

• Engineering

  
  Measurement of Outgassing Rates of Steels Chongdo Park¹, Se-Hyun Kim¹, Sanghoon Ki¹, Taekyun Ha¹, Boklae Cho^{2 1}Accelerator Division, Pohang Accelerator Laboratory, POSTECH, ²Center for Advanced Instrumentation, Korea Research Institute of Standards and Science A protocol for the measurement of outgassing rates of hydrogen from ordinary steel vacuum chambers using the rate-of-pressure rise method is presented.

• Chemistry

  
  Synthesis of Poly(N-isopropylacrylamide) Janus Microhydrogels for Anisotropic Thermo-responsiveness and Organophilic/Hydrophilic Loading Capability Kyoung Duck Seo¹, Andrew Choi¹, Junsang Doh^1,2, Dong Sung Kim^{1 1}Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), ²School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology (POSTECH) We present a protocol to synthesize Janus microhydrogels composed entirely of the same base material, poly(N-isopropylacrylamide) (PNIPAAm), with a clearly compartmentalized structure base on the phase separation of a supersaturated NIPAAm monomer solution. The synthesized Janus microhydrogels show unique properties such as anisotropic thermo-responsiveness and organophilic/hydrophilic loading capability.

• Bioengineering

  
  Photoacoustic Cystography Mansik Jeon^1,2, Jeehyun Kim³, Chulhong Kim^{1,2 1}Department of Biomedical Engineering, University at Buffalo, The State University of New York, ²Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), ³School of Electrical Engineering and Computer Science, Kyungpook National University Photoacoustic cystography (PAC) has a great potential to map urinary bladders, a radiation sensitive internal organ in pediatric patients, without using any ionizing radiation or toxic contrast agent. Here we demonstrate the use of PAC for mapping urinary bladders with an injection of optical-opaque tracers in rats in vivo.