1
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Cho Y, Kim J, Park J, Doh J. Surface nanotopography and cell shape modulate tumor cell susceptibility to NK cell cytotoxicity. MATERIALS HORIZONS 2023; 10:4532-4540. [PMID: 37559559 DOI: 10.1039/d3mh00367a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Natural killer (NK) cells are innate cytotoxic lymphocytes exerting cytotoxicity against virally infected cells and tumor cells. NK cell cytotoxicity is primarily determined by biochemical signals received from ligands expressed on target cell surfaces, but it is also possible that biophysical environments of tumor cells, such as nanoscale surface topography typically existing on extracellular matrixes (ECMs) or cell morphology determined by ECM spaces or cell density, regulate NK cell cytotoxicity. In this study, micro/nanofabrication technology was applied to examine this possibility. Tumor cells were plated on flat or nanogrooved surfaces, or micropatterned into circular or elliptical geometries, and the effects of surface topography and tumor cell morphology on NK cell cytotoxicity were investigated. NK cells exhibited significantly higher cytotoxicity against tumor cells on nanogrooved surfaces or tumor cells in elliptical patterns than tumor cells on flat surfaces or tumor cells in circular patterns, respectively. The amounts of stress fiber formation in tumor cells positively correlated with NK cell cytotoxicity, indicating that increased cellular tension of tumor cells, either mediated by nanogrooved surfaces or elongated morphologies, was a key factor regulating NK cell cytotoxicity. These results may provide insight into the design of NK cell-based cancer immunotherapy.
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Affiliation(s)
- Yongbum Cho
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology, 77, Cheongam-ro, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - JangHyuk Kim
- Department of Materials Science and Engineering, Seoul National University, Seoul, South Korea.
| | - Jeehun Park
- SOFT Foundry Institute, Seoul National University, Seoul, South Korea.
| | - Junsang Doh
- Department of Materials Science and Engineering, Seoul National University, Seoul, South Korea.
- SOFT Foundry Institute, Seoul National University, Seoul, South Korea.
- Institute of Engineering Research, BioMAX, Seoul National University, Seoul, South Korea
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2
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Park J, Kim SE, Cho Y, An S, Moon D, Park I, Doh J. Fabrication of 2D and 3D Cell Cluster Arrays Using a Cell-Friendly Photoresist. ACS Biomater Sci Eng 2021; 7:3082-3087. [PMID: 34125522 DOI: 10.1021/acsbiomaterials.1c00655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cells in 3D behave differently than cells in 2D. We develop a new method for the fabrication of 2D and 3D cell cluster arrays on an identical substrate using a cell-friendly photoresist, which enables comparative study between cells in 2D and 3D cell clusters. The fabricated cell cluster arrays maintain their structure up to 3 days with good viability. Using this method, 2D and 3D cancer cell clusters with comparable sizes are fabricated, and natural killer (NK) cell cytotoxicity assays are performed to assess how dimensionality of cancer cell clusters influence their susceptibility to immune cell-mediated killing.
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Affiliation(s)
- Jeehun Park
- Research Institute of Advanced Materials (RIAM), Seoul National University, 1, Gwanak-ro, Seoul 08826, South Korea
| | - Seong-Eun Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77, Cheongam-ro, Pohang, Gyeongbuk 37673, South Korea
| | - Yongbum Cho
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology (POSTECH), 77, Cheongam-ro, Pohang, Gyeongbuk 37673, South Korea
| | - Seongmin An
- Research Institute of Advanced Materials (RIAM), Seoul National University, 1, Gwanak-ro, Seoul 08826, South Korea
| | - Dowon Moon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77, Cheongam-ro, Pohang, Gyeongbuk 37673, South Korea
| | - Inae Park
- Research Institute of Advanced Materials (RIAM), Seoul National University, 1, Gwanak-ro, Seoul 08826, South Korea
| | - Junsang Doh
- Research Institute of Advanced Materials (RIAM), Seoul National University, 1, Gwanak-ro, Seoul 08826, South Korea.,Department of Materials Science and Engineering, Institute of Engineering Research, BioMAX, Seoul National University, 1, Gwanak-ro, Seoul 08826, South Korea
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3
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Park J, Kim T, Choi JC, Doh J. In Situ Subcellular Detachment of Cells Using a Cell-Friendly Photoresist and Spatially Modulated Light. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2019; 6:1900566. [PMID: 31380216 PMCID: PMC6661940 DOI: 10.1002/advs.201900566] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/22/2019] [Indexed: 06/10/2023]
Abstract
Dynamic adhesion and detachment of subcellular regions occur during cell migration, thus a technique allowing precise control of subcellular detachment of cells will be useful for cell migration study. Previous methods for cell detachment were developed either for harvesting cells or cell sheets attached on surfaces with low resolution patterning capability, or for detaching subcellular regions located on predefined electrodes. In this paper, a method that allows in situ subcellular detachment of cells with ≈1.5 µm critical feature size while observing cells under a fluorescence microscope is introduced using a cell-friendly photoresist and spatially modulated light. Using this method, a single cell, regions in cell sheets, and a single focal adhesion complex within a cell are successfully detached. Furthermore, different subcellular regions of migrating cells are detached and changes in cell polarity and migration direction are quantitatively analyzed. This method will be useful for many applications in cell detachment, in particular when subcellular resolution is required.
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Affiliation(s)
- Jeehun Park
- School of Interdisciplinary Bioscience and Bioengineering (I‐Bio)Pohang University of Science and Technology77, Cheongam‐roPohangGyeongbuk37673South Korea
| | - Taeyup Kim
- Department of Mechanical EngineeringPohang University of Science and Technology77, Cheongam‐roPohangGyeongbuk37673South Korea
| | - Jong Chul Choi
- Department of Mechanical EngineeringPohang University of Science and Technology77, Cheongam‐roPohangGyeongbuk37673South Korea
| | - Junsang Doh
- Department of Materials Science and EngineeringSeoul National University1 Gwanak‐roGwanak‐guSeoul08826South Korea
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4
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Kweon S, Song KH, Park H, Choi JC, Doh J. Dynamic Micropatterning of Cells on Nanostructured Surfaces Using a Cell-friendly Photoresist. ACS APPLIED MATERIALS & INTERFACES 2016; 8:4266-4274. [PMID: 26760679 DOI: 10.1021/acsami.6b00318] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cellular dynamics under complex topographical microenvironments are important for many biological processes in development and diseases, but systematic investigation has been limited due to the lack of technology. Herein, we developed a new dynamic cell patterning method based on a cell-friendly photoresist polymer that allows in situ control of cell dynamics on nanostructured surfaces. Using this method, we quantitatively compared the spreading dynamics of cells on nanostructured surfaces to those on flat surfaces. Furthermore, we investigated how cells behaved when they simultaneously encountered two topographically distinct surfaces during spreading. This method will allow many exciting opportunities in the fundamental study of cellular dynamics.
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Affiliation(s)
- SoonHo Kweon
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio) and ‡Department of Mechanical Engineering, Pohang University of Science and Technology , San31, Hyoja-dong, Nam-Gu, Pohang, Gyeongbuk 790-784, South Korea
| | - Kwang Hoon Song
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio) and ‡Department of Mechanical Engineering, Pohang University of Science and Technology , San31, Hyoja-dong, Nam-Gu, Pohang, Gyeongbuk 790-784, South Korea
| | - HyoungJun Park
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio) and ‡Department of Mechanical Engineering, Pohang University of Science and Technology , San31, Hyoja-dong, Nam-Gu, Pohang, Gyeongbuk 790-784, South Korea
| | - Jong-Cheol Choi
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio) and ‡Department of Mechanical Engineering, Pohang University of Science and Technology , San31, Hyoja-dong, Nam-Gu, Pohang, Gyeongbuk 790-784, South Korea
| | - Junsang Doh
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio) and ‡Department of Mechanical Engineering, Pohang University of Science and Technology , San31, Hyoja-dong, Nam-Gu, Pohang, Gyeongbuk 790-784, South Korea
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5
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Matsuzaki T, Ito K, Masuda K, Kakinuma E, Sakamoto R, Iketaki K, Yamamoto H, Suganuma M, Kobayashi N, Nakabayashi S, Tanii T, Yoshikawa HY. Quantitative Evaluation of Cancer Cell Adhesion to Self-Assembled Monolayer-Patterned Substrates by Reflection Interference Contrast Microscopy. J Phys Chem B 2016; 120:1221-7. [PMID: 26845066 DOI: 10.1021/acs.jpcb.5b11870] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Adhesion of cancer cells with different metastatic potential and anticancer drug resistance has been quantitatively evaluated by using self-assembled monolayer (SAM)-patterned substrates and reflection interference contrast microscopy (RICM). Cell-adhesive SAM spots with optimized diameter could prevent cell-cell adhesion and thus allowed the systematic evaluation of statistically reliable numbers of contact area between single cancer cells and substrates by RICM. The statistical image analysis revealed that highly metastatic mouse melanoma cells showed larger contact area than lowly metastatic cells. We also found that both cancer cell types exhibited distinct transition from the "strong" to "weak" adhesion states with increase in the concentration of (-)-epigallocatechin gallate (EGCG), which is known to exhibit cancer preventive activity. Mathematical analysis of the adhesion transition revealed that adhesion of the highly metastatic mouse melanoma cells showed more EGCG tolerance than that of lowly metastatic cells. Moreover, time-lapse RICM observation revealed that EGCG weakened cancer cell adhesion in a stepwise manner, probably via focal adhesion complex. These results clearly indicate that contact area can be used as a quantitative measure for the determination of cancer phenotypes and their drug resistance, which will provide physical insights into the mechanism of cancer metastasis and cancer prevention.
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Affiliation(s)
| | | | - Kentaro Masuda
- School of Science and Engineering, Waseda University , Okubo 3-4-1, Shinjuku, Tokyo 169-855, Japan
| | - Eisuke Kakinuma
- School of Science and Engineering, Waseda University , Okubo 3-4-1, Shinjuku, Tokyo 169-855, Japan
| | - Rumi Sakamoto
- School of Science and Engineering, Waseda University , Okubo 3-4-1, Shinjuku, Tokyo 169-855, Japan
| | | | - Hideaki Yamamoto
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University , 6-3 Aramakiazaaoba, Aoba, Sendai, Miyagi 980-8578, Japan
| | | | | | | | - Takashi Tanii
- School of Science and Engineering, Waseda University , Okubo 3-4-1, Shinjuku, Tokyo 169-855, Japan
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6
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Abstract
Recent advances in dynamic biointerfaces enable spatiotemporal control over cell position and migration after attachment using substrates that employ chemical, optical, thermal, or electrical triggers. This review focuses on flexible and accessible methods for the fabrication of cellular arrays or co cultures for fundamental studies of cell biology or regenerative medicine.
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Affiliation(s)
| | - Carlos C Co
- University of Cincinnati, Cincinnati, OH 45221
| | - Chia-Chi Ho
- University of Cincinnati, Cincinnati, OH 45221
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7
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Kim M, Doh J. Complex micropatterning of proteins within microfluidic channels. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:782-5. [PMID: 25570075 DOI: 10.1109/embc.2014.6943707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Microfluidic channels containing protein micropatterned surfaces are useful in many bioanalytical and biological applications. In this study, we developed a new method to integrate microfluidics and protein micropatterning by attaching poly(dimethylsiloxane) (PDMS) microfluidic channels to bio-friendly photoresist films via poly(dopamine) (PDA) adhesive. A bio-friendly photoresist poly(2,2-dimethoxy nitrobenzyl methacrylate-r-methyl methacrylate-r-poly(ethylene glycol) methacrylate) (PDMP) was synthesized and used. By performing microscope projection photolithography (MPP) to the PDMP thin films within PDMS microchannels, complex micropatterns of proteins were successfully generated within microfluidic channels.
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8
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Micropatterning strategies to engineer controlled cell and tissue architecture in vitro. Biotechniques 2015; 58:13-23. [PMID: 25605576 DOI: 10.2144/000114245] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 12/26/2014] [Indexed: 11/23/2022] Open
Abstract
Micropatterning strategies, which enable control over cell and tissue architecture in vitro, have emerged as powerful platforms for modelling tissue microenvironments at different scales and complexities. Here, we provide an overview of popular micropatterning techniques, along with detailed descriptions, to guide new users through the decision making process of which micropatterning procedure to use, and how to best obtain desired tissue patterns. Example techniques and the types of biological observations that can be made are provided from the literature. A focus is placed on microcontact printing to obtain co-cultures of patterned, confluent sheets, and the challenges associated with optimizing this protocol. Many issues associated with microcontact printing, however, are relevant to all micropatterning methodologies. Finally, we briefly discuss challenges in addressing key limitations associated with current micropatterning technologies.
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9
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Yamahira S, Yamaguchi S, Kawahara M, Nagamune T. Collagen surfaces modified with photo-cleavable polyethylene glycol-lipid support versatile single-cell arrays of both non-adherent and adherent cells. Macromol Biosci 2014; 14:1670-6. [PMID: 25195937 DOI: 10.1002/mabi.201400312] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 07/25/2014] [Indexed: 11/09/2022]
Abstract
Cell patterning on photo-responsive materials are a promising tool for preparing unique single-cell arrays. However, most conventional single-cell arrays on such smart materials can be applied only to adherent cells and limit cellular functions such as extension and migration within the patterned adhesive surfaces. In this study, a versatile single cell array that works with both non-adherent and adherent cells was constructed using a photo-cleavable polyethylene glycol (PEG)-lipid/collagen surface. On this single-cell array, cells behaved similar to their native functions without limitation from the patterned surface. Furthermore, quantitative imaging analyses of cellular motility and morphological changes were performed in a high-throughput manner.
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Affiliation(s)
- Shinya Yamahira
- Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
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10
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Kang J, Choi JC, Kim M, Jung HR, Doh J. Photopatterning with a printed transparency mask and a protein-friendly photoresist. Methods Cell Biol 2014; 119:55-72. [PMID: 24439279 DOI: 10.1016/b978-0-12-416742-1.00004-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Microscope projection photolithography (MPP) based on a protein-friendly photoresist is a versatile tool for the fabrication of protein- and cell-micropatterned surfaces. Photomasks containing various features can be economically produced by printing features on transparency films. Features in photomasks are projected by the objective lens of a microscope, resulting in a significant reduction of the feature size to as small as ~1 μm, close to the practical limit of light-based microfabrication. A fluorescence microscope used in most biology labs can be used for the fabrication process with some modifications. Using such a microscope, multistep MPP can be readily performed with precise registration of each micropattern on transparency film masks. Here, we describe methods of the synthesis and characterization of a protein-friendly photoresist poly(2,2-dimethoxy nitrobenzyl methacrylate-r-methyl methacrylate-r-poly(ethylene glycol) methacrylate) and the setups of fluorescence microscopes and the MPP procedures. In addition, we describe the protocols used in the micropatterning of multiple lymphocytes and the dynamic micropatterning of adherent cells.
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Affiliation(s)
- Jiwoo Kang
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology, Pohang, Gyeongbuk, South Korea
| | - Jong-Cheol Choi
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, South Korea
| | - Miju Kim
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology, Pohang, Gyeongbuk, South Korea
| | - Hong-Ryul Jung
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology, Pohang, Gyeongbuk, South Korea
| | - Junsang Doh
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology, Pohang, Gyeongbuk, South Korea; Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, South Korea
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11
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Song KH, Kwon KW, Choi JC, Jung J, Park Y, Suh KY, Doh J. T cells sense biophysical cues using lamellipodia and filopodia to optimize intraluminal path finding. Integr Biol (Camb) 2014; 6:450-9. [DOI: 10.1039/c4ib00021h] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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12
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Choi JC, Jung HR, Doh J. Dynamic modulation of small-sized multicellular clusters using a cell-friendly photoresist. ACS APPLIED MATERIALS & INTERFACES 2013; 5:12757-12763. [PMID: 24256472 DOI: 10.1021/am404134u] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Dynamics of small-sized multicellular clusters is important for many biological processes including embryonic development and cancer metastasis. Previous methods to fabricate multicellular clusters depended on stochastic adhesion and proliferation of cells on defined areas of cell-adhering islands. This made precise control over the number of cells within multicellular clusters impossible. Variation in numbers may have minimal effects on the behavior of multicellular clusters composed of tens of cells but would have profound effects on groups with fewer than ten cells. Herein, we report a new dynamic cell micropatterning method using a cell-friendly photoresist film by multistep microscope projection photolithography. We first fabricated single cell arrays of partially spread cells. Then, by merging neighboring cells, we successfully fabricated multicellular clusters with precisely controlled number, composition, and geometry. Using this method, we generated multicellular clusters of Madin-Darby canine kidney cells with various numbers and initial geometries. Then, we systematically investigated the effect of multicellular cluster sizes and geometries on their motility behaviors. We found that the behavior of small-sized multicellular clusters was not sensitive to initial configurations but instead was determined by dynamic force balances among the cells. Initially, the multicellular clusters exhibited a rounded morphology and minimal translocation, probably due to contractility at the periphery of the clusters. For 2-cell and 4-cell clusters, single leaders emerged over time and entire groups aligned and comigrated as single supercells. Such coherent behavior did not occur in 8-cell clusters, indicating a critical group size led by a single leader may exist. The method developed in the study will be useful for the study of collective migration and multicellular dynamics.
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Affiliation(s)
- Jong-Cheol Choi
- Department of Mechanical Engineering, ‡School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology , San31, Hyoja-dong, Nam-Gu, Pohang, Gyeongbuk, 790-784, Korea
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13
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Directing GPCR-transfected cells and neuronal projections with nano-scale resolution. Biomaterials 2013; 34:10065-74. [DOI: 10.1016/j.biomaterials.2013.09.070] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 09/20/2013] [Indexed: 12/18/2022]
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Andrews RN, Mun KS, Scott C, Ho CC, Co CC. Rapid Prototyping of Heterotypic Cell-Cell Contacts. J Mater Chem B 2013; 1:5773-5777. [PMID: 24466428 PMCID: PMC3899713 DOI: 10.1039/c3tb21038c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Disparities in cellular behaviour between cultures of a single cell type and heterogeneous co-cultures require constructing spatially-defined arrays of multiple cell types. Such arrays are critical for investigating cellular properties as they exist in vivo. Current methods rely upon covalent surface modification or external physical micromanipulation to control cellular organization on a limited range of substrates. Here, we report a direct approach for creating co-cultures of different cell types by microcontact printing a photosensitive cell resist. The cell-resistant polymer converts to cell adhesive 0 with light exposure, thus the initial copolymer pattern dictates the position of both cell types. This strategy enables straightforward preparation of tailored heterotypic cell-cell contacts on materials ranging from polymers to metallic substrates.
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Affiliation(s)
- Ross N. Andrews
- Department of Chemical Engineering, University of Cincinnati, 2901 Woodside Drive, Cincinnati, OH 45221
| | - Kyu-Shik Mun
- Department of Chemical Engineering, University of Cincinnati, 2901 Woodside Drive, Cincinnati, OH 45221
| | - Carl Scott
- Department of Chemical Engineering, University of Cincinnati, 2901 Woodside Drive, Cincinnati, OH 45221
| | - Chia-Chi Ho
- Department of Chemical Engineering, University of Cincinnati, 2901 Woodside Drive, Cincinnati, OH 45221
| | - Carlos C. Co
- Department of Chemical Engineering, University of Cincinnati, 2901 Woodside Drive, Cincinnati, OH 45221
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Cheong BHP, Liew OW, Ng TW. MRT letter: Micro- to nanoscale sample collection for high throughput microscopy. Microsc Res Tech 2013; 76:767-73. [PMID: 23733610 DOI: 10.1002/jemt.22238] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/19/2013] [Accepted: 04/26/2013] [Indexed: 11/12/2022]
Abstract
In high throughput microscopy, it is often assumed that the objects under investigation are fixed spatially. In addition, it is also presumed that the objects are sufficiently populated, otherwise there will be need to search through vast tracks of field of views before any recording can be done. The ability to collect objects at one location in the hydrated state is thus desirable and this is a challenge when the density of target objects in a sample is very low. In this work, we report that the generation of a squeezing flow from a circular coverslip compressing on suspensions is able to collect particulate (microbeads, fluorescent nanobeads and live algal cells) and non-particulate (EGFP) objects at the rim region of the coverslip. With a coverslip of 13 mm diameter, volumes between 2 µL and 4 µL were found to completely fill the coverslip without breaching the rims. Sample compression speeds between 100 µm/s and 1000 µm/s did not have any effect on object collection outcomes. In effect, the simple placement of coverslips on top the drop of sample by hand without a motorized translator was found to produce similar collection outcomes. Quantitative measurements confirmed that all the objects investigated were displaced and relocated at the rim regions to a very high degree.
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16
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Koga H, Sada T, Fujigaya T, Nakashima N, Nakazawa K. Tailor-made cell patterning using a near-infrared-responsive composite gel composed of agarose and carbon nanotubes. Biofabrication 2013; 5:015010. [DOI: 10.1088/1758-5082/5/1/015010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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