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Lee M, Jeong H, Lee C, Lee MJ, Delmo BR, Heo WD, Shin JH, Park Y. High-resolution assessment of multidimensional cellular mechanics using label-free refractive-index traction force microscopy. Commun Biol 2024; 7:115. [PMID: 38245624 PMCID: PMC10799850 DOI: 10.1038/s42003-024-05788-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 01/03/2024] [Indexed: 01/22/2024] Open
Abstract
A critical requirement for studying cell mechanics is three-dimensional assessment of cellular shapes and forces with high spatiotemporal resolution. Traction force microscopy with fluorescence imaging enables the measurement of cellular forces, but it is limited by photobleaching and a slow acquisition speed. Here, we present refractive-index traction force microscopy (RI-TFM), which simultaneously quantifies the volumetric morphology and traction force of cells using a high-speed illumination scheme with 0.5-Hz temporal resolution. Without labelling, our method enables quantitative analyses of dry-mass distributions and shear (in-plane) and normal (out-of-plane) tractions of single cells on the extracellular matrix. When combined with a constrained total variation-based deconvolution algorithm, it provides 0.55-Pa shear and 1.59-Pa normal traction sensitivity for a 1-kPa hydrogel substrate. We demonstrate its utility by assessing the effects of compromised intracellular stress and capturing the rapid dynamics of cellular junction formation in the spatiotemporal changes in non-planar traction components.
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Affiliation(s)
- Moosung Lee
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
- KAIST Institute for Health Science and Technology, KAIST, Daejeon, 34141, South Korea
- Institute for Functional Matter and Quantum Technologies, Universität Stuttgart, 70569, Stuttgart, Germany
| | - Hyuntae Jeong
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Chaeyeon Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Mahn Jae Lee
- KAIST Institute for Health Science and Technology, KAIST, Daejeon, 34141, South Korea
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Benedict Reve Delmo
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Won Do Heo
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea.
- KAIST Institute for the BioCentury (KIB), KAIST, Jaejeo, Daejeon, 34141, South Korea.
| | - Jennifer H Shin
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea.
| | - YongKeun Park
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea.
- KAIST Institute for Health Science and Technology, KAIST, Daejeon, 34141, South Korea.
- Tomocube Inc., Daejeon, 34109, South Korea.
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Zhang Q, Wang W, Zhou S, Zhang R, Bischofberger I. Flow-induced periodic chiral structures in an achiral nematic liquid crystal. Nat Commun 2024; 15:7. [PMID: 38191525 PMCID: PMC10774319 DOI: 10.1038/s41467-023-43978-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 11/26/2023] [Indexed: 01/10/2024] Open
Abstract
Supramolecular chirality typically originates from either chiral molecular building blocks or external chiral stimuli. Generating chirality in achiral systems in the absence of a chiral input, however, is non-trivial and necessitates spontaneous mirror symmetry breaking. Achiral nematic lyotropic chromonic liquid crystals have been reported to break mirror symmetry under strong surface or geometric constraints. Here we describe a previously unrecognised mechanism for creating chiral structures by subjecting the material to a pressure-driven flow in a microfluidic cell. The chirality arises from a periodic double-twist configuration of the liquid crystal and manifests as a striking stripe pattern. We show that the mirror symmetry breaking is triggered at regions of flow-induced biaxial-splay configurations of the director field, which are unstable to small perturbations and evolve into lower energy structures. The simplicity of this unique pathway to mirror symmetry breaking can shed light on the requirements for forming macroscopic chiral structures.
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Affiliation(s)
- Qing Zhang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| | - Weiqiang Wang
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Shuang Zhou
- Department of Physics, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Rui Zhang
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China.
| | - Irmgard Bischofberger
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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Song S, Kim J, Moon T, Seong B, Kim W, Yoo CH, Choi JK, Joo C. Polarization-sensitive intensity diffraction tomography. LIGHT, SCIENCE & APPLICATIONS 2023; 12:124. [PMID: 37202421 PMCID: PMC10195819 DOI: 10.1038/s41377-023-01151-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 04/07/2023] [Accepted: 04/10/2023] [Indexed: 05/20/2023]
Abstract
Optical anisotropy, which is an intrinsic property of many materials, originates from the structural arrangement of molecular structures, and to date, various polarization-sensitive imaging (PSI) methods have been developed to investigate the nature of anisotropic materials. In particular, the recently developed tomographic PSI technologies enable the investigation of anisotropic materials through volumetric mappings of the anisotropy distribution of these materials. However, these reported methods mostly operate on a single scattering model, and are thus not suitable for three-dimensional (3D) PSI imaging of multiple scattering samples. Here, we present a novel reference-free 3D polarization-sensitive computational imaging technique-polarization-sensitive intensity diffraction tomography (PS-IDT)-that enables the reconstruction of 3D anisotropy distribution of both weakly and multiple scattering specimens from multiple intensity-only measurements. A 3D anisotropic object is illuminated by circularly polarized plane waves at various illumination angles to encode the isotropic and anisotropic structural information into 2D intensity information. These information are then recorded separately through two orthogonal analyzer states, and a 3D Jones matrix is iteratively reconstructed based on the vectorial multi-slice beam propagation model and gradient descent method. We demonstrate the 3D anisotropy imaging capabilities of PS-IDT by presenting 3D anisotropy maps of various samples, including potato starch granules and tardigrade.
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Affiliation(s)
- Seungri Song
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Jeongsoo Kim
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Taegyun Moon
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Baekcheon Seong
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Woovin Kim
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Chang-Hyuk Yoo
- Small Machines Company, Ltd., Seoul, 04808, Republic of Korea
| | - Jun-Kyu Choi
- Small Machines Company, Ltd., Seoul, 04808, Republic of Korea
| | - Chulmin Joo
- Department of Mechanical Engineering, Yonsei University, Seoul, 03722, Republic of Korea.
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Zhang Q, Zhou S, Zhang R, Bischofberger I. Dendritic patterns from shear-enhanced anisotropy in nematic liquid crystals. SCIENCE ADVANCES 2023; 9:eabq6820. [PMID: 36638169 PMCID: PMC9839321 DOI: 10.1126/sciadv.abq6820] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Controlling the growth morphology of fluid instabilities is challenging because of their self-amplified and nonlinear growth. The viscous fingering instability, which arises when a less viscous fluid displaces a more viscous one, transitions from exhibiting dense-branching growth characterized by repeated tip splitting of the growing fingers to dendritic growth characterized by stable tips in the presence of anisotropy. We controllably induce such a morphology transition by shear-enhancing the anisotropy of nematic liquid crystal solutions. For fast enough flow induced by the finger growth, the intrinsic tumbling behavior of lyotropic chromonic liquid crystals can be suppressed, which results in a flow alignment of the material. This microscopic change in the director field occurs as the viscous torque from the shear flow becomes dominant over the elastic torque from the nematic potential and macroscopically enhances the liquid crystal anisotropy to induce the transition to dendritic growth.
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Affiliation(s)
- Qing Zhang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Shuang Zhou
- Department of Physics, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Rui Zhang
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Irmgard Bischofberger
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Lee J, Shin S, Hugonnet H, Park Y. Spatially multiplexed dielectric tensor tomography. OPTICS LETTERS 2022; 47:6205-6208. [PMID: 37219208 DOI: 10.1364/ol.474969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 11/03/2022] [Indexed: 05/24/2023]
Abstract
Dielectric tensor tomography (DTT) enables the reconstruction of three-dimensional (3D) dielectric tensors, which provides a physical measure of 3D optical anisotropy. Herein, we present a cost-effective and robust method of DTT using spatial multiplexing. Exploiting two orthogonally polarized reference beams with different angles in an off-axis interferometer, two polarization-sensitive interferograms were multiplexed and recorded using a single camera. Then, the two interferograms were demultiplexed in the Fourier domain. By measuring the polarization-sensitive fields for various illumination angles, 3D dielectric tensor tomograms were reconstructed. The proposed method was experimentally demonstrated by reconstructing the 3D dielectric tensors of various liquid-crystal (LC) particles with radial and bipolar orientational configurations.
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