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Matheson AB, Hopkinson C, Tanner MG, Henderson RK. Fluorescence lifetime imaging with distance and ranging using a miniaturised SPAD system. Sci Rep 2024; 14:13285. [PMID: 38858419 PMCID: PMC11164884 DOI: 10.1038/s41598-024-63409-w] [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: 03/08/2024] [Accepted: 05/28/2024] [Indexed: 06/12/2024] Open
Abstract
In this work we demonstrate a miniaturised imaging system based around a time-gated SPAD array operating in a "chip-on-tip" manner. Two versions of the system are demonstrated, each measuring 23 mm × 23 mm × 28 mm with differing fields of view and working distances. Initial tests demonstrate contrast between materials in widefield fluorescence imaging (WFLIm) mode, with frame rates of > 2 Hz achievable. Following this, WFLIm images of autofluorescence in ovine lung tissue are obtained at frame rates of ~ 1 Hz. Finally, the ability of the second system to perform simultaneous WFLIm and time of flight (aka Flourescence Lifetime Imaging Distance and Ranging, FLImDAR) is also tested. This shows that the system is capable of 4 mm resolution of object separation when tested on 3D printed samples. It is further demonstrated as being able to perform scene reconstruction on autofluorescent lung tissue. This system is, to date, the smallest chip on tip WFLIm system published, and is the first demonstration of the FLImDAR technique in a compact, portable system.
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Affiliation(s)
- Andrew B Matheson
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Edinburgh, EH9 3FF, UK.
| | - Charlotte Hopkinson
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Michael G Tanner
- School of Engineering and Physical Sciences, Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - Robert K Henderson
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Edinburgh, EH9 3FF, UK
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2
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Song J, Kang J, Kang U, Nam HS, Kim HJ, Kim RH, Kim JW, Yoo H. SNR enhanced high-speed two-photon microscopy using a pulse picker and time gating detection. Sci Rep 2023; 13:14244. [PMID: 37648768 PMCID: PMC10468500 DOI: 10.1038/s41598-023-41270-7] [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: 01/20/2023] [Accepted: 08/24/2023] [Indexed: 09/01/2023] Open
Abstract
Two-photon microscopy (TPM) is an attractive biomedical imaging method due to its large penetration depth and optical sectioning capability. In particular, label-free autofluorescence imaging offers various advantages for imaging biological samples. However, relatively low intensity of autofluorescence leads to low signal-to-noise ratio (SNR), causing practical challenges for imaging biological samples. In this study, we present TPM using a pulse picker to utilize low pulse repetition rate of femtosecond pulsed laser to increase the pulse peak power of the excitation source leading to higher emission of two-photon fluorescence with the same average illumination power. Stronger autofluorescence emission allowed us to obtain higher SNR images of arterial and liver tissues. In addition, by applying the time gating detection method to the pulse signals obtained by TPM, we were able to significantly reduce the background noise of two-photon images. As a result, our TPM system using the pulsed light source with a 19 times lower repetition rate allowed us to obtain the same SNR image more than 19 times faster with the same average power. Although high pulse energy can increase the photobleaching, we also observed that high-speed imaging with low total illumination energy can mitigate the photobleaching effect to a level similar to that of conventional illumination with a high repetition rate. We anticipate that this simple approach will provide guidance for SNR enhancement with high-speed imaging in TPM as well as other nonlinear microscopy.
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Affiliation(s)
- Jeonggeun Song
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-Ro, Daejeon, 34141, South Korea
| | - Juehyung Kang
- Department of Biomedical Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul, 04763, Republic of Korea
| | - Ungyo Kang
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-Ro, Daejeon, 34141, South Korea
| | - Hyeong Soo Nam
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-Ro, Daejeon, 34141, South Korea
| | - Hyun Jung Kim
- Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-Ro, Seoul, 08308, South Korea
| | - Ryeong Hyeon Kim
- Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-Ro, Seoul, 08308, South Korea
| | - Jin Won Kim
- Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-Ro, Seoul, 08308, South Korea
| | - Hongki Yoo
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-Ro, Daejeon, 34141, South Korea.
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3
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Maloshenok LG, Abushinova GA, Ryazanova AY, Bruskin SA, Zherdeva VV. Visualizing the Nucleome Using the CRISPR–Cas9 System: From in vitro to in vivo. BIOCHEMISTRY (MOSCOW) 2023; 88:S123-S149. [PMID: 37069118 PMCID: PMC9940691 DOI: 10.1134/s0006297923140080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
One of the latest methods in modern molecular biology is labeling genomic loci in living cells using fluorescently labeled Cas protein. The NIH Foundation has made the mapping of the 4D nucleome (the three-dimensional nucleome on a timescale) a priority in the studies aimed to improve our understanding of chromatin organization. Fluorescent methods based on CRISPR-Cas are a significant step forward in visualization of genomic loci in living cells. This approach can be used for studying epigenetics, cell cycle, cellular response to external stimuli, rearrangements during malignant cell transformation, such as chromosomal translocations or damage, as well as for genome editing. In this review, we focused on the application of CRISPR-Cas fluorescence technologies as components of multimodal imaging methods for in vivo mapping of chromosomal loci, in particular, attribution of fluorescence signal to morphological and anatomical structures in a living organism. The review discusses the approaches to the highly sensitive, high-precision labeling of CRISPR-Cas components, delivery of genetically engineered constructs into cells and tissues, and promising methods for molecular imaging.
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Affiliation(s)
- Liliya G Maloshenok
- Bach Institute of Biochemistry, Federal Research Center for Biotechnology of the Russian Academy of Sciences, Moscow, 119071, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Gerel A Abushinova
- Bach Institute of Biochemistry, Federal Research Center for Biotechnology of the Russian Academy of Sciences, Moscow, 119071, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Alexandra Yu Ryazanova
- Bach Institute of Biochemistry, Federal Research Center for Biotechnology of the Russian Academy of Sciences, Moscow, 119071, Russia
| | - Sergey A Bruskin
- Bach Institute of Biochemistry, Federal Research Center for Biotechnology of the Russian Academy of Sciences, Moscow, 119071, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Victoria V Zherdeva
- Bach Institute of Biochemistry, Federal Research Center for Biotechnology of the Russian Academy of Sciences, Moscow, 119071, Russia.
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5
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Laine RF, Poudel C, Kaminski CF. A method for the fast and photon-efficient analysis of time-domain fluorescence lifetime image data over large dynamic ranges. J Microsc 2022; 287:138-147. [PMID: 35676768 PMCID: PMC9544871 DOI: 10.1111/jmi.13128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 11/29/2022]
Abstract
Fluorescence lifetime imaging (FLIM) allows the quantification of sub‐cellular processes in situ, in living cells. A number of approaches have been developed to extract the lifetime from time‐domain FLIM data, but they are often limited in terms of speed, photon efficiency, precision or the dynamic range of lifetimes they can measure. Here, we focus on one of the best performing methods in the field, the centre‐of‐mass method (CMM), that conveys advantages in terms of speed and photon efficiency over others. In this paper, however, we identify a loss of photon efficiency of CMM for short lifetimes when background noise is present. We subsequently present a new development and generalization of CMM that provides for the rapid and accurate extraction of fluorescence lifetime over a large lifetime dynamic range. We provide software tools to simulate, validate and analyse FLIM data sets and compare the performance of our approach against the standard CMM and the commonly employed least‐square minimization (LSM) methods. Our method features a better photon efficiency than standard CMM and LSM and is robust in the presence of background noise. The algorithm is applicable to any time‐domain FLIM data set.
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Affiliation(s)
- Romain F Laine
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, UK.,Medical Research Council Laboratory for Molecular Cell Biology (LMCB), University College London, Gower Street, London, WC1E 6BT
| | - Chetan Poudel
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, UK.,Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Clemens F Kaminski
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, UK
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6
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Sorrells JE, Iyer RR, Yang L, Chaney EJ, Marjanovic M, Tu H, Boppart SA. Single-photon peak event detection (SPEED): a computational method for fast photon counting in fluorescence lifetime imaging microscopy. OPTICS EXPRESS 2021; 29:37759-37775. [PMID: 34808842 PMCID: PMC8687103 DOI: 10.1364/oe.439675] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) characterizes samples by examining the temporal properties of fluorescence emission, providing useful contrast within samples based on the local physical and biochemical environment of fluorophores. Despite this, FLIM applications have been limited in scope by either poor accuracy or long acquisition times. Here, we present a method for computational single-photon counting of directly sampled time-domain FLIM data that is capable of accurate fluorescence lifetime and intensity measurements while acquiring over 160 Mega-counts-per-second with sub-nanosecond time resolution between consecutive photon counts. We demonstrate that our novel method of Single-photon PEak Event Detection (SPEED) is more accurate than direct pulse sampling and faster than established photon counting FLIM methods. We further show that SPEED can be implemented for imaging and quantifying samples that benefit from higher -throughput and -dynamic range imaging with real-time GPU-accelerated processing and use this capability to examine the NAD(P)H-related metabolic dynamics of apoptosis in human breast cancer cells. Computational methods for photon counting such as SPEED open up more opportunities for fast and accurate FLIM imaging and additionally provide a basis for future innovation into alternative FLIM techniques.
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Affiliation(s)
- Janet E. Sorrells
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Rishyashring R. Iyer
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Lingxiao Yang
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Eric J. Chaney
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Marina Marjanovic
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Haohua Tu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Stephen A. Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Cancer Center at Illinois, Urbana, IL 61801, USA
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Choppadandi M, Guduru AT, Gondaliya P, Arya N, Kalia K, Kumar H, Kapusetti G. Structural features regulated photoluminescence intensity and cell internalization of carbon and graphene quantum dots for bioimaging. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 129:112366. [PMID: 34579885 DOI: 10.1016/j.msec.2021.112366] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 07/28/2021] [Accepted: 08/09/2021] [Indexed: 11/17/2022]
Abstract
Carbon-based nanostructures with nanometer dimensions have been identified as potential photoluminescence probes for bioimaging due to their biocompatibility, tunable bandgap, and resistance to photobleaching. However, the influence of structural features of carbon quantum dots (CQDs) and graphene quantum dots (GQDs) in bioimaging has not been explored previously. In the present investigation, we elucidated the mechanism of higher PL in GQDs as compared to CQDs as a function of their structural features. TEM and AFM studies revealed that CQDs were spherical (size ~5 nm), while GQDs showed zigzag edges (size ~3 nm). Further, XRD and NMR studies confirmed that CQDs and GQDs show amorphous and crystalline structures with greater sp2 clusters, respectively. While both the QDs demonstrated multicolor fluorescence against variable excitations with similar lifetime, GQDs showed 7-fold higher QY than CQDs. Bioimaging studies in 2D cell culture, 3D tumoroids, and in vivo suggested a greater intensity of fluorescence in GQDs than CQDs. Additionally, rapid cell internalization was observed in GQDs owing to their positive surface potential by heterogeneous atomic (N and S) doping. Moreover, both CQDs and GQDs have demonstrated better time dependent stability for fluorescence properties. Taken together, the proposed mechanism elucidates the greater PL intensity in GQDs due to quantum confinement effect, crystallinity, and surface edge effects and is a better candidate for bioimaging amongst the carbon family.
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Affiliation(s)
- Mounika Choppadandi
- Department of Medical Devices, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, India
| | - Aditya Teja Guduru
- Department of Medical Devices, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, India
| | - Piyush Gondaliya
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, India
| | - Neha Arya
- Department of Medical Devices, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, India
| | - Kiran Kalia
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, India
| | - Hemant Kumar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, India
| | - Govinda Kapusetti
- Department of Medical Devices, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, India.
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8
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Ryu J, Kang U, Song JW, Kim J, Kim JW, Yoo H, Gweon B. Multimodal microscopy for the simultaneous visualization of five different imaging modalities using a single light source. BIOMEDICAL OPTICS EXPRESS 2021; 12:5452-5469. [PMID: 34692194 PMCID: PMC8515965 DOI: 10.1364/boe.430677] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 05/02/2023]
Abstract
Optical microscopy has been widely used in biomedical research as it provides photophysical and photochemical information of the target in subcellular spatial resolution without requiring physical contact with the specimen. To obtain a deeper understanding of biological phenomena, several efforts have been expended to combine such optical imaging modalities into a single microscope system. However, the use of multiple light sources and detectors through separated beam paths renders previous systems extremely complicated or slow for in vivo imaging. Herein, we propose a novel high-speed multimodal optical microscope system that simultaneously visualizes five different microscopic contrasts, i.e., two-photon excitation, second-harmonic generation, backscattered light, near-infrared fluorescence, and fluorescence lifetime, using a single femtosecond pulsed laser. Our proposed system can visualize five modal images with a frame rate of 3.7 fps in real-time, thereby providing complementary optical information that enhances both structural and functional contrasts. This highly photon-efficient multimodal microscope system enables various properties of biological tissues to be assessed.
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Affiliation(s)
- Jiheun Ryu
- Massachusetts General Hospital, Wellman Center for Photomedicine, 55 Fruit Street, Boston, MA 02114, USA
- Contributed equally
| | - Ungyo Kang
- Korea Advanced Institute of Science and Technology, Department of Mechanical Engineering, 291 Daehak-ro, Daejeon 34141, Republic of Korea
- Contributed equally
| | - Joon Woo Song
- Korea University Guro Hospital, Cardiovascular Center, 148 Gurodong-ro, Seoul 08308, Republic of Korea
| | - Junyoung Kim
- Massachusetts General Hospital, Wellman Center for Photomedicine, 55 Fruit Street, Boston, MA 02114, USA
- Korea Advanced Institute of Science and Technology, Department of Mechanical Engineering, 291 Daehak-ro, Daejeon 34141, Republic of Korea
| | - Jin Won Kim
- Korea University Guro Hospital, Cardiovascular Center, 148 Gurodong-ro, Seoul 08308, Republic of Korea
| | - Hongki Yoo
- Korea Advanced Institute of Science and Technology, Department of Mechanical Engineering, 291 Daehak-ro, Daejeon 34141, Republic of Korea
| | - Bomi Gweon
- Sejong University, Department of Mechanical Engineering, 209 Neungdong-ro, Seoul 05006, Republic of Korea
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9
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Sorrells JE, Iyer RR, Yang L, Bower AJ, Spillman DR, Chaney EJ, Tu H, Boppart SA. Real-time pixelwise phasor analysis for video-rate two-photon fluorescence lifetime imaging microscopy. BIOMEDICAL OPTICS EXPRESS 2021; 12:4003-4019. [PMID: 34457395 PMCID: PMC8367245 DOI: 10.1364/boe.424533] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/28/2021] [Accepted: 05/28/2021] [Indexed: 05/06/2023]
Abstract
Two-photon fluorescence lifetime imaging microscopy (FLIM) is a widely used technique in biomedical optical imaging. Presently, many two-photon time-domain FLIM setups are limited by long acquisition and postprocessing times that decrease data throughput and inhibit the ability to image fast sub-second processes. Here, we present a versatile two-photon FLIM setup capable of video-rate (up to 25 fps) imaging with graphics processing unit (GPU)-accelerated pixelwise phasor analysis displayed and saved simultaneously with acquisition. The system uses an analog output photomultiplier tube in conjunction with 12-bit digitization at 3.2 GHz to overcome the limited maximum acceptable photon rate associated with the photon counting electronics in many FLIM systems. This allows for higher throughput FLIM acquisition and analysis, and additionally enables the user to assess sample fluorescence lifetime in real-time. We further explore the capabilities of the system to examine the kinetics of Rhodamine B uptake by human breast cancer cells and characterize the effect of pixel dwell time on the reduced nicotinamide adenine dinucleotide and reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H) autofluorescence lifetime estimation accuracy.
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Affiliation(s)
- Janet E. Sorrells
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Rishyashring R. Iyer
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Lingxiao Yang
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Andrew J. Bower
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Darold R. Spillman
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Eric J. Chaney
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Haohua Tu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Stephen A. Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Cancer Center at Illinois, Urbana, IL 61801, USA
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Kang J, Kang U, Nam HS, Kim W, Kim HJ, Kim RH, Kim JW, Yoo H. Label-free multimodal microscopy using a single light source and detector for biological imaging. OPTICS LETTERS 2021; 46:892-895. [PMID: 33577541 DOI: 10.1364/ol.415938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/19/2021] [Indexed: 06/12/2023]
Abstract
Multimodal nonlinear microscopy has been widely applied in biology and medicine due to its relatively deep penetration into tissue and its label-free manner. However, current multimodal systems require the use of multiple sources and detectors, leading to bulky, complex, and expensive systems. In this Letter, we present a novel method of using a single light source and detector for nonlinear multimodal imaging of biological samples. Using a photonic crystal fiber, a pulse picker, and multimode fibers, our developed system successfully acquired multimodal images of swine coronary arteries, including two-photon excitation fluorescence, second-harmonic generation, coherent anti-Stokes Raman scattering, and backreflection. The developed system could be a valuable tool for various biomedical applications.
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Datta R, Heaster TM, Sharick JT, Gillette AA, Skala MC. Fluorescence lifetime imaging microscopy: fundamentals and advances in instrumentation, analysis, and applications. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-43. [PMID: 32406215 PMCID: PMC7219965 DOI: 10.1117/1.jbo.25.7.071203] [Citation(s) in RCA: 305] [Impact Index Per Article: 76.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 04/24/2020] [Indexed: 05/18/2023]
Abstract
SIGNIFICANCE Fluorescence lifetime imaging microscopy (FLIM) is a powerful technique to distinguish the unique molecular environment of fluorophores. FLIM measures the time a fluorophore remains in an excited state before emitting a photon, and detects molecular variations of fluorophores that are not apparent with spectral techniques alone. FLIM is sensitive to multiple biomedical processes including disease progression and drug efficacy. AIM We provide an overview of FLIM principles, instrumentation, and analysis while highlighting the latest developments and biological applications. APPROACH This review covers FLIM principles and theory, including advantages over intensity-based fluorescence measurements. Fundamentals of FLIM instrumentation in time- and frequency-domains are summarized, along with recent developments. Image segmentation and analysis strategies that quantify spatial and molecular features of cellular heterogeneity are reviewed. Finally, representative applications are provided including high-resolution FLIM of cell- and organelle-level molecular changes, use of exogenous and endogenous fluorophores, and imaging protein-protein interactions with Förster resonance energy transfer (FRET). Advantages and limitations of FLIM are also discussed. CONCLUSIONS FLIM is advantageous for probing molecular environments of fluorophores to inform on fluorophore behavior that cannot be elucidated with intensity measurements alone. Development of FLIM technologies, analysis, and applications will further advance biological research and clinical assessments.
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Affiliation(s)
- Rupsa Datta
- Morgridge Institute for Research, Madison, Wisconsin, United States
| | - Tiffany M. Heaster
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin, Department of Biomedical Engineering, Madison, Wisconsin, United States
| | - Joe T. Sharick
- Morgridge Institute for Research, Madison, Wisconsin, United States
| | - Amani A. Gillette
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin, Department of Biomedical Engineering, Madison, Wisconsin, United States
| | - Melissa C. Skala
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin, Department of Biomedical Engineering, Madison, Wisconsin, United States
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12
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Karpf S, Riche CT, Di Carlo D, Goel A, Zeiger WA, Suresh A, Portera-Cailliau C, Jalali B. Spectro-temporal encoded multiphoton microscopy and fluorescence lifetime imaging at kilohertz frame-rates. Nat Commun 2020; 11:2062. [PMID: 32346060 PMCID: PMC7188897 DOI: 10.1038/s41467-020-15618-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 03/18/2020] [Indexed: 12/21/2022] Open
Abstract
Two-Photon Microscopy has become an invaluable tool for biological and medical research, providing high sensitivity, molecular specificity, inherent three-dimensional sub-cellular resolution and deep tissue penetration. In terms of imaging speeds, however, mechanical scanners still limit the acquisition rates to typically 10-100 frames per second. Here we present a high-speed non-linear microscope achieving kilohertz frame rates by employing pulse-modulated, rapidly wavelength-swept lasers and inertia-free beam steering through angular dispersion. In combination with a high bandwidth, single-photon sensitive detector, this enables recording of fluorescent lifetimes at speeds of 88 million pixels per second. We show high resolution, multi-modal - two-photon fluorescence and fluorescence lifetime (FLIM) - microscopy and imaging flow cytometry with a digitally reconfigurable laser, imaging system and data acquisition system. These high speeds should enable high-speed and high-throughput image-assisted cell sorting.
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Affiliation(s)
- Sebastian Karpf
- Department of Electrical Engineering and Computational Science, University of California, Los Angeles (UCLA), Los Angeles, CA-90095, USA.
- Institute of Biomedical Optics (BMO), University of Luebeck, 23562, Luebeck, Germany.
| | - Carson T Riche
- Department of Bioengineering, University of California, Los Angeles (UCLA), Los Angeles, CA-90095, USA
| | - Dino Di Carlo
- Department of Bioengineering, University of California, Los Angeles (UCLA), Los Angeles, CA-90095, USA
| | - Anubhuti Goel
- Department of Neurology, University of California, Los Angeles (UCLA), Los Angeles, CA-90095, USA
| | - William A Zeiger
- Department of Neurology, University of California, Los Angeles (UCLA), Los Angeles, CA-90095, USA
| | - Anand Suresh
- Department of Neurology, University of California, Los Angeles (UCLA), Los Angeles, CA-90095, USA
| | - Carlos Portera-Cailliau
- Department of Neurology, University of California, Los Angeles (UCLA), Los Angeles, CA-90095, USA
| | - Bahram Jalali
- Department of Electrical Engineering and Computational Science, University of California, Los Angeles (UCLA), Los Angeles, CA-90095, USA
- Department of Bioengineering, University of California, Los Angeles (UCLA), Los Angeles, CA-90095, USA
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Poudel C, Mela I, Kaminski CF. High-throughput, multi-parametric, and correlative fluorescence lifetime imaging. Methods Appl Fluoresc 2020; 8:024005. [PMID: 32028271 PMCID: PMC8208541 DOI: 10.1088/2050-6120/ab7364] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 12/18/2019] [Accepted: 02/06/2020] [Indexed: 12/11/2022]
Abstract
In this review, we discuss methods and advancements in fluorescence lifetime imaging microscopy that permit measurements to be performed at faster speed and higher resolution than previously possible. We review fast single-photon timing technologies and the use of parallelized detection schemes to enable high-throughput and high content imaging applications. We appraise different technological implementations of fluorescence lifetime imaging, primarily in the time-domain. We also review combinations of fluorescence lifetime with other imaging modalities to capture multi-dimensional and correlative information from a single sample. Throughout the review, we focus on applications in biomedical research. We conclude with a critical outlook on current challenges and future opportunities in this rapidly developing field.
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Affiliation(s)
- Chetan Poudel
- Department of Chemical Engineering and Biotechnology,
Philippa Fawcett Drive, University of
Cambridge, Cambridge CB3 0AS, United
Kingdom
| | - Ioanna Mela
- Department of Chemical Engineering and Biotechnology,
Philippa Fawcett Drive, University of
Cambridge, Cambridge CB3 0AS, United
Kingdom
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology,
Philippa Fawcett Drive, University of
Cambridge, Cambridge CB3 0AS, United
Kingdom
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14
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Dumas JP, Jiang JY, Gates EM, Hoffman BD, Pierce MC, Boustany NN. FRET efficiency measurement in a molecular tension probe with a low-cost frequency-domain fluorescence lifetime imaging microscope. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-11. [PMID: 31884745 PMCID: PMC6935677 DOI: 10.1117/1.jbo.24.12.126501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 11/11/2019] [Indexed: 06/10/2023]
Abstract
We demonstrate the possibility of measuring FRET efficiency with a low-cost frequency-domain fluorescence lifetime imaging microscope (FD-FLIM). The system utilizes single-frequency-modulated excitation, which enables the use of cost-effective laser sources and electronics, simplification of data acquisition and analysis, and a dual-channel detection capability. Following calibration with coumarin 6, we measured the apparent donor lifetime in mTFP1-mVenus FRET standards expressed in living cells. We evaluated the system's sensitivity by differentiating the short and long lifetimes of mTFP1 corresponding to the known standards' high and low FRET efficiency, respectively. Furthermore, we show that the lifetime of the vinculin tension sensor, VinTS, at focal adhesions (2.30 ± 0.16 ns) is significantly (p < 10 - 6) longer than the lifetime of the unloaded TSMod probe (2.02 ± 0.16 ns). The pixel dwell time was 6.8 μs for samples expressing the FRET standards, with signal typically an order of magnitude higher than VinTS. The apparent FRET efficiency (<inline-formula>EFRETapp</inline-formula>) of the standards, calculated from the measured apparent lifetime, was linearly related to their known FRET efficiency by a factor of 0.92 to 0.99 (R2 = 0.98). This relationship serves as a calibration curve to convert apparent FRET to true FRET and circumvent the need to measure multiexponential lifetime decays. This approach yielded a FRET efficiency of 18% to 19.5%, for VinTS, in agreement with published values. Taken together, our results demonstrate a cost-effective, fast, and sensitive FD-FLIM approach with the potential to facilitate applications of FLIM in mechanobiology and FRET-based biosensing.
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Affiliation(s)
- John-Paul Dumas
- Rutgers University, Department of Biomedical Engineering, Piscataway, New Jersey, United States
- Thorlabs Inc., Newton, New Jersey, United States
| | | | - Evan M. Gates
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
| | - Brenton D. Hoffman
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
| | - Mark C. Pierce
- Rutgers University, Department of Biomedical Engineering, Piscataway, New Jersey, United States
| | - Nada N. Boustany
- Rutgers University, Department of Biomedical Engineering, Piscataway, New Jersey, United States
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15
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Bower AJ, Sorrells JE, Li J, Marjanovic M, Barkalifa R, Boppart SA. Tracking metabolic dynamics of apoptosis with high-speed two-photon fluorescence lifetime imaging microscopy. BIOMEDICAL OPTICS EXPRESS 2019; 10:6408-6421. [PMID: 31853407 PMCID: PMC6913390 DOI: 10.1364/boe.10.006408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/22/2019] [Accepted: 11/04/2019] [Indexed: 05/04/2023]
Abstract
Programmed cell death, or apoptosis, is an essential process in development and homeostasis, and disruptions in associated pathways are responsible for a wide variety of diseases such as cancer, developmental abnormalities, and Alzheimer's disease. On the other hand, cell death, in many cases, is the desired outcome of therapeutic treatments targeting diseases such as cancer. Recently, metabolic imaging based on two-photon fluorescence microscopy has been developed and shown to be highly sensitive to certain cell death processes, most notably apoptosis, thus having the potential as an advanced label-free screening tool. However, the typically low acquisition rates of this imaging technique have resulted in a limited throughput approach, allowing only a small population of cells to be tracked at well-separated time points. To address this limitation, a high-speed two-photon fluorescence lifetime imaging microscopy (2P-FLIM) platform capable of video-rate imaging is applied to study and further characterize the metabolic dynamics associated with cell death. Building upon previous work demonstrating the capabilities of this system, this microscope is utilized to study rapid metabolic changes during cell death induction, such as dose-dependency of metabolic response, response in invasive vs. noninvasive cancer cells, and response in an apoptosis-resistant cell line, which is further shown to undergo autophagy in response to toxic stimuli. Results from these experiments show that the early apoptosis-related metabolic dynamics are strongly correlated with important cellular parameters including responsiveness to apoptosis-inducing stimuli. The high speed and sensitivity of the presented imaging approach enables new investigations into this highly dynamic and complex process.
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Affiliation(s)
- Andrew J. Bower
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Janet E. Sorrells
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Joanne Li
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Marina Marjanovic
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Ronit Barkalifa
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Stephen A. Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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16
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Ranawat H, Pal S, Mazumder N. Recent trends in two-photon auto-fluorescence lifetime imaging (2P-FLIM) and its biomedical applications. Biomed Eng Lett 2019; 9:293-310. [PMID: 31456890 PMCID: PMC6694381 DOI: 10.1007/s13534-019-00119-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 05/30/2019] [Accepted: 06/27/2019] [Indexed: 02/07/2023] Open
Abstract
Two photon fluorescence microscopy and the numerous technical advances to it have served as valuable tools in biomedical research. The fluorophores (exogenous or endogenous) absorb light and emit lower energy photons than the absorption energy and the emission (fluorescence) signal is measured using a fluorescence decay graph. Additionally, high spatial resolution images can be acquired in two photon fluorescence lifetime imaging (2P-FLIM) with improved penetration depth which helps in detection of fluorescence signal in vivo. 2P-FLIM is a non-invasive imaging technique in order to visualize cellular metabolic, by tracking intrinsic fluorophores present in it, such as nicotinamide adenine dinucleotide, flavin adenine dinucleotide and tryptophan etc. 2P-FLIM of these molecules enable the visualization of metabolic alterations, non-invasively. This comprehensive review discusses the numerous applications of 2P-FLIM towards cancer, neuro-degenerative, infectious diseases, and wound healing.
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Affiliation(s)
- Harsh Ranawat
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104 India
| | - Sagnik Pal
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104 India
| | - Nirmal Mazumder
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104 India
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Mintz KJ, Zhou Y, Leblanc RM. Recent development of carbon quantum dots regarding their optical properties, photoluminescence mechanism, and core structure. NANOSCALE 2019; 11:4634-4652. [PMID: 30834912 PMCID: PMC6467229 DOI: 10.1039/c8nr10059d] [Citation(s) in RCA: 172] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Carbon quantum dots (CDs) are a relatively new class of carbon nanomaterials which have been studied very much in the last fifteen years to improve their already favorable properties. The optical properties of CDs have drawn particular interest as they display the unusual trait of excitation-dependent emission, as well as high fluorescence quantum yields (QY), long photoluminescence (PL) decay lifetimes, and photostability. These qualities naturally lead researchers to apply CDs in the field of imaging (particularly bio-imaging) and sensing. Since the amount of publications regarding CDs has been growing nearly exponentially in the last ten years, many improvements have been made in the optical properties of CDs such as QY and PL lifetime. However, a great deal of confusion remains regarding the PL mechanism of CDs as well as their structural properties. Therefore, presented in this review is a summary and discussion of the QYs and PL lifetimes reported in recent years. The effect of method as well as precursor has been evaluated and discussed appropriately. The current theories regarding the PL mechanism of CDs are discussed, with special attention to the concept of surface state-controlled PL. With this knowledge, the improvement of preparation and applications of CDs related to their optical properties will be easily accomplished. Further improvements can be made to CDs through the understanding of their structural and optical properties.
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Affiliation(s)
- Keenan J Mintz
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, USA.
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Bower AJ, Li J, Chaney EJ, Marjanovic M, Spillman DR, Boppart SA. High-speed imaging of transient metabolic dynamics using two-photon fluorescence lifetime imaging microscopy. OPTICA 2018; 5:1290-1296. [PMID: 30984802 PMCID: PMC6457362 DOI: 10.1364/optica.5.001290] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Two-photon fluorescence lifetime imaging microscopy (2P-FLIM) of autofluorescent metabolic coenzymes has been widely used to investigate energetic perturbations in living cells and tissues in a label-free manner with subcellular resolution. While the currently used state-of-the-art instruments are highly sensitive to local molecular changes associated with these metabolic processes, they are inherently slow and limit the study of dynamic metabolic environments. Here, a sustained video-rate 2P-FLIM imaging system is demonstrated for time-lapse lifetime imaging of reduced nicotinamide adenine dinucleotide, an autofluorescent metabolic coenzyme involved in both aerobic and anaerobic processes. This system is sufficiently sensitive to differences in metabolic activity between aggressive and nonaggressive cancer cell lines and is demonstrated for both wide field-of-view autofluorescence imaging as well as sustained video-rate image acquisition of metabolic dynamics following induction of apoptosis. The unique capabilities ofthis imaging platform provide a powerful technological advance to further explore rapid metabolic dynamics in living cells.
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Affiliation(s)
- Andrew J. Bower
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. MathewsAve, Urbana, Illinois 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Joanne Li
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. MathewsAve, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Eric J. Chaney
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. MathewsAve, Urbana, Illinois 61801, USA
| | - Marina Marjanovic
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. MathewsAve, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Carle-Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Darold R. Spillman
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. MathewsAve, Urbana, Illinois 61801, USA
| | - Stephen A. Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. MathewsAve, Urbana, Illinois 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Carle-Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Corresponding author:
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