1
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Guo Z, Yang CT, Chien CC, Selth LA, Bagnaninchi PO, Thierry B. Optical Cellular Micromotion: A New Paradigm to Measure Tumor Cells Invasion within Gels Mimicking the 3D Tumor Environments. SMALL METHODS 2022; 6:e2200471. [PMID: 35764869 DOI: 10.1002/smtd.202200471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/22/2022] [Indexed: 06/15/2023]
Abstract
Measuring tumor cell invasiveness through 3D tissues, particularly at the single-cell level, can provide important mechanistic understanding and assist in identifying therapeutic targets of tumor invasion. However, current experimental approaches, including standard in vitro invasion assays, have limited physiological relevance and offer insufficient insight into the vast heterogeneity in tumor cell migration through tissues. To address these issues, here the concept of optical cellular micromotion is reported on, where digital holographic microscopy is used to map the optical nano- to submicrometer thickness fluctuations within single-cells. These fluctuations are driven by the dynamic movement of subcellular structures including the cytoskeleton and inherently associated with the biological processes involved in cell invasion within tissues. It is experimentally demonstrated that the optical cellular micromotion correlates with tumor cells motility and invasiveness both at the population and single-cell levels. In addition, the optical cellular micromotion significantly reduced upon treatment with migrastatic drugs that inhibit tumor cell invasion. These results demonstrate that micromotion measurements can rapidly and non-invasively determine the invasive behavior of single tumor cells within tissues, yielding a new and powerful tool to assess the efficacy of approaches targeting tumor cell invasiveness.
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Affiliation(s)
- Zhaobin Guo
- Future Industries Institute and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, University of South Australia, Mawson Lakes, SA, 5095, Australia
| | - Chih-Tsung Yang
- Future Industries Institute and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, University of South Australia, Mawson Lakes, SA, 5095, Australia
| | - Chia-Chi Chien
- Future Industries Institute and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, University of South Australia, Mawson Lakes, SA, 5095, Australia
| | - Luke A Selth
- Flinders Health and Medical Research Institute and Freemasons Centre for Male Health and Wellbeing, Flinders University, Bedford Park, SA, 5042, Australia
- Dame Roma Mitchell Cancer Research Laboratories and Freemasons Foundation Centre for Male Health and Wellbeing, Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5000, Australia
| | - Pierre O Bagnaninchi
- Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Benjamin Thierry
- Future Industries Institute and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, University of South Australia, Mawson Lakes, SA, 5095, Australia
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2
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Zhou W, Graham K, Lucendo-Villarin B, Flint O, Hay DC, Bagnaninchi P. Combining stem cell-derived hepatocytes with impedance sensing to better predict human drug toxicity. Expert Opin Drug Metab Toxicol 2018; 15:77-83. [PMID: 30572740 DOI: 10.1080/17425255.2019.1558208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Background: The liver plays a central role in human drug metabolism. To model drug metabolism, the major cell type of the liver, the hepatocyte, is commonly used. Hepatocytes can be derived from human and animal sources, including pluripotent stem cells. Cell-based models have shown promise in modeling human drug exposure. The assays used in those studies are normally 'snap-shot' in nature, and do not provide the complete picture of human drug exposure. Research design and methods: In this study, we employ stem cell-derived hepatocytes and impedance sensing to model human drug toxicity. This impedance-based stem cell assay reports hepatotoxicity in real time after treatment with compounds provided by industry. Results: Using electric cell-substrate impedance Sensing (ECIS), we were able to accurately measure drug toxicity post-drug exposure in real time and more quickly than gold standard biochemical assays. Conclusions: ECIS is robust and non-destructive methodology capable of monitoring human drug exposure with superior performance to current gold standard 'snapshot' assays. We believe that the methodology presented within this article could prove valuable in the quest to better predict off-target effects of drugs in humans.
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Affiliation(s)
- Wenli Zhou
- a Department of Medical Oncology , Changzheng Hospital, Navy medical University , Shanghai , China
| | - Karen Graham
- b MRC Centre for Regenerative Medicine, 5 Little France Drive , University of Edinburgh , Edinburgh , UK
| | - Baltasar Lucendo-Villarin
- b MRC Centre for Regenerative Medicine, 5 Little France Drive , University of Edinburgh , Edinburgh , UK
| | - Oliver Flint
- b MRC Centre for Regenerative Medicine, 5 Little France Drive , University of Edinburgh , Edinburgh , UK
| | - David C Hay
- b MRC Centre for Regenerative Medicine, 5 Little France Drive , University of Edinburgh , Edinburgh , UK
| | - Pierre Bagnaninchi
- b MRC Centre for Regenerative Medicine, 5 Little France Drive , University of Edinburgh , Edinburgh , UK
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3
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Gillies D, Gamal W, Downes A, Reinwald Y, Yang Y, El Haj AJ, Bagnaninchi PO. Real-time and non-invasive measurements of cell mechanical behaviour with optical coherence phase microscopy. Methods 2018; 136:126-133. [PMID: 29080739 DOI: 10.1016/j.ymeth.2017.10.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/12/2017] [Accepted: 10/17/2017] [Indexed: 12/22/2022] Open
Abstract
Cell mechanical behaviour is increasingly recognised as a central biophysical parameter in cancer and stem cell research, and methods of investigating their mechanical behaviour are therefore needed. We have developed a novel qualitative method based on quantitative phase imaging which is capable of investigating cell mechanical behaviour in real-time at cellular resolution using optical coherence phase microscopy (OCPM), and stimulating the cells non-invasively using hydrostatic pressure. The method was exemplified to distinguish between cells with distinct mechanical properties, and transient change induced by Cytochalasin D. We showed the potential of quantitative phase imaging to detect nanoscale intracellular displacement induced by varying hydrostatic pressure in microfluidic channels, reflecting cell mechanical behaviour. Further physical modelling is required to yield quantitative mechanical properties.
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Affiliation(s)
- D Gillies
- MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, EH16 4UU, UK; Institute for Bioengineering, School of Engineering, The University of Edinburgh, Edinburgh, EH9 3DW, UK
| | - W Gamal
- MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - A Downes
- Institute for Bioengineering, School of Engineering, The University of Edinburgh, Edinburgh, EH9 3DW, UK
| | - Y Reinwald
- Institute for Science and Technology in Medicine, Keele University, Keele, ST4 7QB, UK
| | - Y Yang
- Institute for Science and Technology in Medicine, Keele University, Keele, ST4 7QB, UK
| | - A J El Haj
- Institute for Science and Technology in Medicine, Keele University, Keele, ST4 7QB, UK
| | - P O Bagnaninchi
- MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, EH16 4UU, UK.
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4
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Martucci NJ, Morgan K, Anderson GW, Hayes PC, Plevris JN, Nelson LJ, Bagnaninchi PO. Nondestructive Optical Toxicity Assays of 3D Liver Spheroids with Optical Coherence Tomography. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/adbi.201700212] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Nicole J. Martucci
- MRC Centre for Regenerative Medicine; 5 Little France drive Edinburgh EH16 4UU UK
- Hepatology Laboratory; Chancellor's building 49 little France Crescent Edinburgh Eh16 4SB UK
| | - Katie Morgan
- Hepatology Laboratory; Chancellor's building 49 little France Crescent Edinburgh Eh16 4SB UK
| | - Graham W. Anderson
- Hepatology Laboratory; Chancellor's building 49 little France Crescent Edinburgh Eh16 4SB UK
| | - Peter C. Hayes
- Hepatology Laboratory; Chancellor's building 49 little France Crescent Edinburgh Eh16 4SB UK
| | - John N. Plevris
- Hepatology Laboratory; Chancellor's building 49 little France Crescent Edinburgh Eh16 4SB UK
| | - Leonard J. Nelson
- Hepatology Laboratory; Chancellor's building 49 little France Crescent Edinburgh Eh16 4SB UK
- School of Engineering; Institute for Bioengineering; University of Edinburgh; The King's Buildings; Edinburgh EH9 3JL UK
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Leahy M, Thompson K, Zafar H, Alexandrov S, Foley M, O'Flatharta C, Dockery P. Functional imaging for regenerative medicine. Stem Cell Res Ther 2016; 7:57. [PMID: 27095443 PMCID: PMC4837501 DOI: 10.1186/s13287-016-0315-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In vivo imaging is a platform technology with the power to put function in its natural structural context. With the drive to translate stem cell therapies into pre-clinical and clinical trials, early selection of the right imaging techniques is paramount to success. There are many instances in regenerative medicine where the biological, biochemical, and biomechanical mechanisms behind the proposed function of stem cell therapies can be elucidated by appropriate imaging. Imaging techniques can be divided according to whether labels are used and as to whether the imaging can be done in vivo. In vivo human imaging places additional restrictions on the imaging tools that can be used. Microscopies and nanoscopies, especially those requiring fluorescent markers, have made an extraordinary impact on discovery at the molecular and cellular level, but due to their very limited ability to focus in the scattering tissues encountered for in vivo applications they are largely confined to superficial imaging applications in research laboratories. Nanoscopy, which has tremendous benefits in resolution, is limited to the near-field (e.g. near-field scanning optical microscope (NSNOM)) or to very high light intensity (e.g. stimulated emission depletion (STED)) or to slow stochastic events (photo-activated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM)). In all cases, nanoscopy is limited to very superficial applications. Imaging depth may be increased using multiphoton or coherence gating tricks. Scattering dominates the limitation on imaging depth in most tissues and this can be mitigated by the application of optical clearing techniques that can impose mild (e.g. topical application of glycerol) or severe (e.g. CLARITY) changes to the tissue to be imaged. Progression of therapies through to clinical trials requires some thought as to the imaging and sensing modalities that should be used. Smoother progression is facilitated by the use of comparable imaging modalities throughout the discovery and trial phases, giving label-free techniques an advantage wherever they can be used, although this is seldom considered in the early stages. In this paper, we will explore the techniques that have found success in aiding discovery in stem cell therapies and try to predict the likely technologies best suited to translation and future directions.
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Affiliation(s)
- Martin Leahy
- Tissue Optics & Microcirculation Imaging Group, School of Physics, National University of Ireland (NUI), Galway, Ireland. .,Chair of Applied Physics, National University of Ireland (NUI), Galway, Ireland.
| | - Kerry Thompson
- Centre for Microscopy and Imaging, Anatomy, School of Medicine, National University of Ireland (NUI), Galway, Ireland
| | - Haroon Zafar
- Tissue Optics & Microcirculation Imaging Group, School of Physics, National University of Ireland (NUI), Galway, Ireland
| | - Sergey Alexandrov
- Tissue Optics & Microcirculation Imaging Group, School of Physics, National University of Ireland (NUI), Galway, Ireland
| | - Mark Foley
- Medical Physics Research Cluster, School of Physics, National University of Ireland (NUI), Galway, Ireland
| | - Cathal O'Flatharta
- Regenerative Medicine Institute (REMEDI), National University of Ireland (NUI), Galway, Ireland
| | - Peter Dockery
- Centre for Microscopy and Imaging, Anatomy, School of Medicine, National University of Ireland (NUI), Galway, Ireland
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6
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Yang CT, Méjard R, Griesser HJ, Bagnaninchi PO, Thierry B. Cellular micromotion monitored by long-range surface plasmon resonance with optical fluctuation analysis. Anal Chem 2015; 87:1456-61. [PMID: 25495915 DOI: 10.1021/ac5031978] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Long-range surface plasmon resonance (LRSPR) is a powerful biosensing technology due to a substantially larger probing depth into the medium and sensitivity, compared with conventional SPR. We demonstrate here that LRSPR can provide sensitive noninvasive measurement of the dynamic fluctuation of adherent cells, often referred to as the cellular micromotion. Proof of concept was achieved using confluent layers of 3T3 fibroblast cells and MDA-MB-231 cancer cells. The slope of the power spectral density (PSD) of the optical fluctuations was calculated to determine the micromotion index, and significant differences were measured between live and fixed cell layers. Furthermore, the performances of LRSPR and conventional surface plasmon resonance (cSPR) were compared with respect to micromotion monitoring. Our study showed that the micromotion index of cells measured by LRSPR sensors was higher than when measured with cSPR, suggesting a higher sensitivity of LRSPR to the micromotion of cells. To investigate further this finding, simulations were conducted to establish the relative sensitivities of LRSPR and cSPR to membrane fluctuations. Increased signal intensity was predicted for LRSPR in comparison to cSPR, suggesting that membrane fluctuations play a significant role in the optical micromotion measured in LRSPR. Analogous to cellular micromotion measured using impedance techniques, LRSPR micromotion has the potential to provide important biological information on the metabolic activity and viability of adherent cells.
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Affiliation(s)
- Chih-Tsung Yang
- Ian Wark Research Institute, University of South Australia , Mawson Lakes Campus, Mawson Lakes, South Australia 5095, Australia
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7
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Ryu S, Hyun KA, Heo J, Jung HI, Joo C. Label-free cell-based assay with spectral-domain optical coherence phase microscopy. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:046003. [PMID: 24711152 DOI: 10.1117/1.jbo.19.4.046003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 03/10/2014] [Indexed: 06/03/2023]
Abstract
Quantitative measurement of dynamic responses of unstained living cells is of great importance in many applications ranging from investigation of fundamental cellular functions to drug discoveries. Conventional optical methods for label-free cell-based assay examine cellular structural changes proximal to sensor surfaces under external stimuli, but require dedicated nanostructure-patterned substrates for operation. Here, we present a quantitative imaging method, spectral-domain optical coherence phase microscopy (SD-OCPM), as a viable optical platform for label-free cell-based assay. The instrument is based on a low-coherence interferometric microscope that enables quantitative depth-resolved phase measurement of a transparent specimen with high phase stability. We demonstrate SD-OCPM measurement of dynamic responses of human breast cancer cells (MCF-7) to 2-picolinic acid (PA) and histamine.
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Holmes C, Daoud J, Bagnaninchi PO, Tabrizian M. Polyelectrolyte multilayer coating of 3D scaffolds enhances tissue growth and gene delivery: non-invasive and label-free assessment. Adv Healthc Mater 2014; 3:572-80. [PMID: 24030932 DOI: 10.1002/adhm.201300301] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Indexed: 01/06/2023]
Abstract
Layer-by-layer (LbL) deposition is a versatile technique which is beginning to be be explored for inductive tissue engineering applications. Here, it is demonstrated that a polyelectrolyte multilayer film system composed of glycol-chitosan (Glyc-CHI) and hyaluronic acid (HA) can be used to coat 3D micro-fabricated polymeric tissue engineering scaffolds. In order to overcome many of the limitations associated with conventional techniques for assessing cell growth and viability within 3D scaffolds, two novel, real-time, label-free techniques are introduced: impedance monitoring and optical coherence phase microscopy. Using these methods, it is shown that LbL-coated scaffolds support in vitro cell growth and viability for a period of at least two weeks at levels higher than uncoated controls. These polyelectrolyte multilayer coatings are then further adapted for non-viral gene delivery applications via incorporation of DNA carrier lipoplexes. Scaffold-based delivery of the enhanced green fluorescent protein (EGFP) marker gene from these coatings is successfully demonstrated in vitro, achieving a two-fold increase in transfection efficiency compared with control scaffolds. These results show the great potential of Glyc-CHI/HA polyelectrolyte multilayer films for a variety of gene delivery and inductive tissue engineering applications.
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Affiliation(s)
- Christina Holmes
- Department of Biomedical Engineering; McGill University; Montreal H3A 2B4 Canada
| | - Jamal Daoud
- Department of Biomedical Engineering; McGill University; Montreal H3A 2B4 Canada
| | - Pierre O. Bagnaninchi
- MRC Centre for Regenerative Medicine; University of Edinburgh; Edinburgh EH16 4SB Scotland
| | - Maryam Tabrizian
- Department of Biomedical Engineering and Faculty of Dentistry; McGill University; Montreal H3A 2B4 Canada
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9
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Pai JH, Liu T, Hsu HY, Wedding AB, Thierry B, Bagnaninchi PO. Molecular photo-thermal optical coherence phase microscopy using gold nanorods. RSC Adv 2014. [DOI: 10.1039/c4ra03041a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A new evolution of OCT is termed molecular OCPM, which is capable of imaging the expression of molecular markers at the cellular level by using functionalized gold nanorods as imaging agents.
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Affiliation(s)
- Jing-Hong Pai
- School of Engineering
- University of South Australia
- Mawson Lakes, Australia
- Ian Wark Research Institute
- University of South Australia
| | - Tianqing Liu
- Ian Wark Research Institute
- University of South Australia
- Mawson Lakes, Australia
| | - Hung-Yao Hsu
- School of Engineering
- University of South Australia
- Mawson Lakes, Australia
| | - A. Bruce Wedding
- School of Engineering
- University of South Australia
- Mawson Lakes, Australia
| | - Benjamin Thierry
- Ian Wark Research Institute
- University of South Australia
- Mawson Lakes, Australia
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10
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Holmes C, Tabrizian M, Bagnaninchi PO. Motility imaging via optical coherence phase microscopy enables label-free monitoring of tissue growth and viability in 3D tissue-engineering scaffolds. J Tissue Eng Regen Med 2013; 9:641-5. [DOI: 10.1002/term.1687] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 09/10/2012] [Accepted: 11/23/2012] [Indexed: 11/11/2022]
Affiliation(s)
- Christina Holmes
- Department of Biomedical Engineering; McGill University; Montreal Canada
| | - Maryam Tabrizian
- Department of Biomedical Engineering; McGill University; Montreal Canada
- Faculty of Dentistry; McGill University; Montreal Canada
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Cheng NC, Hsieh TH, Wang YT, Lai CC, Chang CK, Lin MY, Huang DW, Tjiu JW, Huang SL. Cell death detection by quantitative three-dimensional single-cell tomography. BIOMEDICAL OPTICS EXPRESS 2012; 3:2111-20. [PMID: 23024905 PMCID: PMC3447553 DOI: 10.1364/boe.3.002111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 07/24/2012] [Accepted: 08/02/2012] [Indexed: 05/21/2023]
Abstract
Ultrahigh-resolution optical coherence tomography (UR-OCT) has been used for the first time to our knowledge to study single-cell basal cell carcinoma (BCC) in vitro. This noninvasive, in situ, label-free technique with deep imaging depth enables three-dimensional analysis of scattering properties of single cells with cellular spatial resolution. From three-dimensional UR-OCT imaging, live and dead BCC cells can be easily identified based on morphological observation. We developed a novel method to automatically extract characteristic parameters of a single cell from data volume, and quantitative comparison and parametric analysis were performed. The results demonstrate the capability of UR-OCT to detect cell death at the cellular level.
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Affiliation(s)
- Nai-Chia Cheng
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
| | - Tsung-Hsun Hsieh
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
| | - Yu-Ta Wang
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
| | - Chien-Chih Lai
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
| | - Chia-Kai Chang
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
| | - Ming-Yi Lin
- Department of Dermatology, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ding-Wei Huang
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
| | - Jeng-Wei Tjiu
- Department of Dermatology, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Sheng-Lung Huang
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
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Riehl BD, Park JH, Kwon IK, Lim JY. Mechanical stretching for tissue engineering: two-dimensional and three-dimensional constructs. TISSUE ENGINEERING PART B-REVIEWS 2012; 18:288-300. [PMID: 22335794 DOI: 10.1089/ten.teb.2011.0465] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Mechanical cell stretching may be an attractive strategy for the tissue engineering of mechanically functional tissues. It has been demonstrated that cell growth and differentiation can be guided by cell stretch with minimal help from soluble factors and engineered tissues that are mechanically stretched in bioreactors may have superior organization, functionality, and strength compared with unstretched counterparts. This review explores recent studies on cell stretching in both two-dimensional (2D) and three-dimensional (3D) setups focusing on the applications of stretch stimulation as a tool for controlling cell orientation, growth, gene expression, lineage commitment, and differentiation and for achieving successful tissue engineering of mechanically functional tissues, including cardiac, muscle, vasculature, ligament, tendon, bone, and so on. Custom stretching devices and lab-specific mechanical bioreactors are described with a discussion on capabilities and limitations. While stretch mechanotransduction pathways have been examined using 2D stretch, studying such pathways in physiologically relevant 3D environments may be required to understand how cells direct tissue development under stretch. Cell stretch study using 3D milieus may also help to develop tissue-specific stretch regimens optimized with biochemical feedback, which once developed will provide optimal tissue engineering protocols.
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Affiliation(s)
- Brandon D Riehl
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
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Dunkers JP, Lee YJ, Chatterjee K. Single cell viability measurements in 3D scaffolds using in situ label free imaging by optical coherence microscopy. Biomaterials 2011; 33:2119-26. [PMID: 22192538 DOI: 10.1016/j.biomaterials.2011.11.058] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 11/22/2011] [Indexed: 10/14/2022]
Abstract
The focus on creating tissue engineered constructs of clinically relevant sizes requires new approaches for monitoring construct health during tissue development. A few key requirements are that the technology be in situ, non-invasive, and provide temporal and spatial information. In this work, we demonstrate that optical coherence microscopy (OCM) can be used to assess cell viability without the addition of exogenous probes in three-dimensional (3D) tissue scaffolds maintained under standard culture conditions. This is done by collecting time-lapse images of speckle generated by sub-cellular features. Image cross-correlation is used to calculate the number of features the final image has in common with the initial image. If the cells are live, the number of common features is low. The number of common features approaches 100% if the cells are dead. In control experiments, cell viability is verified by the addition of a two-photon fluorescence channel to the OCM. Green fluorescent protein transfected human bone marrow stromal cells cultured in a transparent poly(ethylene glycol) tetramethacrylate hydrogel scaffold is used as the control system. Then, the utility of this approach is demonstrated by determining L929 fibroblast cell viability in a more challenging matrix, collagen, an optical scatterer. These results demonstrate a new technique for in situ mapping of single cell viability without any exogenous probes that is capable of providing continuous monitoring of construct health.
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Affiliation(s)
- Joy P Dunkers
- Polymers Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
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