1
|
Lira RB, Dillingh LS, Schuringa JJ, Yahioglu G, Suhling K, Roos WH. Fluorescence lifetime imaging microscopy of flexible and rigid dyes probes the biophysical properties of synthetic and biological membranes. Biophys J 2024; 123:1592-1609. [PMID: 38702882 DOI: 10.1016/j.bpj.2024.04.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 03/22/2024] [Accepted: 04/30/2024] [Indexed: 05/06/2024] Open
Abstract
Sensing of the biophysical properties of membranes using molecular reporters has recently regained widespread attention. This was elicited by the development of new probes of exquisite optical properties and increased performance, combined with developments in fluorescence detection. Here, we report on fluorescence lifetime imaging of various rigid and flexible fluorescent dyes to probe the biophysical properties of synthetic and biological membranes at steady state as well as upon the action of external membrane-modifying agents. We tested the solvatochromic dyes Nile red and 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl) (ammonium salt) (NBD), the viscosity sensor Bodipy C12, the flipper dye FliptR, as well as the dyes 3,3'-dioctadecyloxacarbocyanine perchlorate (DiO), Bodipy C16, lissamine-rhodamine, and Atto647, which are dyes with no previous reported environmental sensitivity. The performance of the fluorescent probes, many of which are commercially available, was benchmarked with well-known environmental reporters, with Nile red and Bodipy C12 being specific reporters of medium hydration and viscosity, respectively. We show that some widely used ordinary dyes with no previous report of sensing capabilities can exhibit competing performance compared to highly sensitive commercially available or custom-based solvatochromic dyes, molecular rotors, or flipper in a wide range of biophysics experiments. Compared to other methods, fluorescence lifetime imaging is a minimally invasive and nondestructive method with optical resolution. It enables biophysical mapping at steady state or assessment of the changes induced by membrane-active molecules at subcellular level in both synthetic and biological membranes when intensity measurements fail to do so. The results have important consequences for the specific choice of the sensor and take into consideration factors such as probe sensitivity, response to environmental changes, ease and speed of data analysis, and the probe's intracellular distribution, as well as potential side effects induced by labeling and imaging.
Collapse
Affiliation(s)
- Rafael B Lira
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, the Netherlands.
| | - Laura S Dillingh
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, the Netherlands; Department of Hematology, Universitair Medisch Centrum Groningen & Rijksuniversiteit Groningen, Groningen, the Netherlands
| | - Jan-Jacob Schuringa
- Department of Hematology, Universitair Medisch Centrum Groningen & Rijksuniversiteit Groningen, Groningen, the Netherlands
| | | | - Klaus Suhling
- Department of Physics, King's College London, Strand, London, UK.
| | - Wouter H Roos
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, the Netherlands
| |
Collapse
|
2
|
Ma J, Luo F, Hsiung CH, Dai J, Tan Z, Ye S, Ding L, Shen B, Zhang X. Chemical Control of Fluorescence Lifetime towards Multiplexing Imaging. Angew Chem Int Ed Engl 2024; 63:e202403029. [PMID: 38641550 DOI: 10.1002/anie.202403029] [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: 02/12/2024] [Revised: 04/12/2024] [Accepted: 04/15/2024] [Indexed: 04/21/2024]
Abstract
Fluorescence lifetime imaging has been a powerful tool for biomedical research. Recently, fluorescence lifetime-based multiplexing imaging has expanded imaging channels by using probes that harbor the same spectral channels and distinct excited state lifetime. While it is desirable to control the excited state lifetime of any given fluorescent probes, the rational control of fluorescence lifetimes remains a challenge. Herein, we chose boron dipyrromethene (BODIPY) as a model system and provided chemical strategies to regulate the fluorescence lifetime of its derivatives with varying spectral features. We find electronegativity of structural substituents at the 8' and 5' positions is important to control the lifetime for the green-emitting and red-emitting BODIPY scaffolds. Mechanistically, such influences are exerted via the photo-induced electron transfer and the intramolecular charge transfer processes for the 8' and 5' positions of BODIPY, respectively. Based on these principles, we have generated a group of BODIPY probes that enable imaging experiments to separate multiple targets using fluorescence lifetime as a signal. In addition to BODIPY, we envision modulation of electronegativity of chemical substituents could serve as a feasible strategy to achieve rational control of fluorescence lifetime for a variety of small molecule fluorophores.
Collapse
Affiliation(s)
- Junbao Ma
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou, 310030, Zhejiang, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Feng Luo
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou, 310030, Zhejiang, China
| | - Chia-Heng Hsiung
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou, 310030, Zhejiang, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Jianan Dai
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou, 310030, Zhejiang, China
| | - Zizhu Tan
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou, 310030, Zhejiang, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Songtao Ye
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou, 310030, Zhejiang, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Lina Ding
- School of Pharmaceutical Sciences, Zhengzhou University, 100 Kexue Road, Zhengzhou, 450001, Henan, China
| | - Baoxing Shen
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Xin Zhang
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou, 310030, Zhejiang, China
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
- Westlake Laboratory of Life Sciences and Biomedicine, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| |
Collapse
|
3
|
Taimori A, Mills B, Gaughan E, Ali A, Dhaliwal K, Williams G, Finlayson N, Hopgood JR. A Novel Fit-Flexible Fluorescence Soft Imager: Tri-Sensing of Intensity, Fall-Time, and Life Profile. IEEE Trans Biomed Eng 2024; 71:1864-1878. [PMID: 38300773 DOI: 10.1109/tbme.2024.3354856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
Time-resolved fluorescence imaging techniques, like confocal fluorescence lifetime imaging microscopy, are powerful photonic instrumentation tools of modern science with diverse applications, including: biology, medicine, and chemistry. However, complexities of the systems, both at specimen and device levels, cause difficulties in quantifying soft biomarkers. To address the problems, we first aim to understand and model the underlying photophysics of fluorescence decay curves. For this purpose, we provide a set of mathematical functions, called "life models", fittable with the real temporal recordings of histogram of photon counts. For each model, an equivalent electrical circuit, called a "life circuit", is derived for explaining the whole process. In confocal endomicroscopy, the components of excitation laser, specimen, and fluorescence-emission signal as the histogram of photon counts are modelled by a power source, network of resistor-inductor-capacitor circuitry, and multimetre, respectively. We then design a novel pixel-level temporal classification algorithm, called a "fit-flexible approach", where qualities of "intensity", "fall-time", and "life profile" are identified for each point. A model selection mechanism is used at each pixel to flexibly choose the best representative life model based on a proposed Misfit-percent metric. A two-dimensional arrangement of the quantified information detects some kind of structural information. This approach showed a potential of separating microbeads from lung tissue, distinguishing the tri-sensing from conventional methods. We alleviated by 7% the error of the Misfit-percent for recovering the histograms on real samples than the best state-of-the-art competitor. Codes are available online.
Collapse
|
4
|
Kapitany V, Fatima A, Zickus V, Whitelaw J, McGhee E, Insall R, Machesky L, Faccio D. Single-sample image-fusion upsampling of fluorescence lifetime images. SCIENCE ADVANCES 2024; 10:eadn0139. [PMID: 38781345 PMCID: PMC11114222 DOI: 10.1126/sciadv.adn0139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 04/17/2024] [Indexed: 05/25/2024]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) provides detailed information about molecular interactions and biological processes. A major bottleneck for FLIM is image resolution at high acquisition speeds due to the engineering and signal-processing limitations of time-resolved imaging technology. Here, we present single-sample image-fusion upsampling, a data-fusion approach to computational FLIM super-resolution that combines measurements from a low-resolution time-resolved detector (that measures photon arrival time) and a high-resolution camera (that measures intensity only). To solve this otherwise ill-posed inverse retrieval problem, we introduce statistically informed priors that encode local and global correlations between the two "single-sample" measurements. This bypasses the risk of out-of-distribution hallucination as in traditional data-driven approaches and delivers enhanced images compared, for example, to standard bilinear interpolation. The general approach laid out by single-sample image-fusion upsampling can be applied to other image super-resolution problems where two different datasets are available.
Collapse
Affiliation(s)
- Valentin Kapitany
- School of Physics & Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
| | - Areeba Fatima
- School of Physics & Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
| | - Vytautas Zickus
- School of Physics & Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
- Department of Laser Technologies, Center for Physical Sciences and Technology, LT-10257 Vilnius, Lithuania
| | | | - Ewan McGhee
- School of Physics & Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
- Cancer Research UK, Beatson Institute, Glasgow, UK
| | | | | | - Daniele Faccio
- School of Physics & Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
| |
Collapse
|
5
|
Nguyen TD, Chen YI, Nguyen AT, Yonas S, Sripati MP, Kuo YA, Hong S, Litvinov M, He Y, Yeh HC, Grady Rylander H. Two-photon autofluorescence lifetime assay of rabbit photoreceptors and retinal pigment epithelium during light-dark visual cycles in rabbit retina. BIOMEDICAL OPTICS EXPRESS 2024; 15:3094-3111. [PMID: 38855698 PMCID: PMC11161359 DOI: 10.1364/boe.511806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 06/11/2024]
Abstract
Two-photon excited fluorescence (TPEF) is a powerful technique that enables the examination of intrinsic retinal fluorophores involved in cellular metabolism and the visual cycle. Although previous intensity-based TPEF studies in non-human primates have successfully imaged several classes of retinal cells and elucidated aspects of both rod and cone photoreceptor function, fluorescence lifetime imaging (FLIM) of the retinal cells under light-dark visual cycle has yet to be fully exploited. Here we demonstrate a FLIM assay of photoreceptors and retinal pigment epithelium (RPE) that reveals key insights into retinal physiology and adaptation. We found that photoreceptor fluorescence lifetimes increase and decrease in sync with light and dark exposure, respectively. This is likely due to changes in all-trans-retinol and all-trans-retinal levels in the outer segments, mediated by phototransduction and visual cycle activity. During light exposure, RPE fluorescence lifetime was observed to increase steadily over time, as a result of all-trans-retinol accumulation during the visual cycle and decreasing metabolism caused by the lack of normal perfusion of the sample. Our system can measure the fluorescence lifetime of intrinsic retinal fluorophores on a cellular scale, revealing differences in lifetime between retinal cell classes under different conditions of light and dark exposure.
Collapse
Affiliation(s)
- Trung Duc Nguyen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Yuan-I Chen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Anh-Thu Nguyen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Siem Yonas
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Manasa P Sripati
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Yu-An Kuo
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Soonwoo Hong
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Mitchell Litvinov
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Yujie He
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Hsin-Chih Yeh
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
- Texas Materials Institute, University of Texas at Austin, Austin, TX, USA
| | - H Grady Rylander
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| |
Collapse
|
6
|
Pitsch C, Walter D, Gasparini L, Bürsing H, Eichhorn M. A Method to Correct the Temporal Drift of Single-Photon Detectors Based on Asynchronous Quantum Ghost Imaging. SENSORS (BASEL, SWITZERLAND) 2024; 24:2578. [PMID: 38676195 PMCID: PMC11054488 DOI: 10.3390/s24082578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024]
Abstract
Single-photon detection and timing has attracted increasing interest in recent years due to their necessity in the field of quantum sensing and the advantages of single-quanta detection in the field of low-level light imaging. While simple bucket detectors are mature enough for commercial applications, more complex imaging detectors are still a field of research comprising mostly prototype-level detectors. A major problem in these detectors is the implementation of in-pixel timing circuitry, especially for two-dimensional imagers. One of the most promising approaches is the use of voltage-controlled ring resonators in every pixel. Each of these runs independently based on a voltage supplied by a global reference. However, this yields the problem that the supply voltage can change across the chip which, in turn, changes the period of the ring resonator. Due to additional parasitic effects, this problem can worsen with increasing measurement time, leading to drift in the timing information. We present here a method to identify and correct such temporal drifts in single-photon detectors based on asynchronous quantum ghost imaging. We also show the effect of this correction on recent quantum ghost imaging (QGI) measurement from our group.
Collapse
Affiliation(s)
- Carsten Pitsch
- Fraunhofer Institute of Optronics, System Technologies and Image Exploitation (IOSB), Gutleuthausstr. 1, 76275 Ettlingen, Germany
| | - Dominik Walter
- Fraunhofer Institute of Optronics, System Technologies and Image Exploitation (IOSB), Gutleuthausstr. 1, 76275 Ettlingen, Germany
| | - Leonardo Gasparini
- Fondazione Bruno Kessler, Center for Sensors & Devices, Integrated Readout ASICs & Image Sensors, Via Sommarive 18-Povo, 38123 Trento, Italy
| | - Helge Bürsing
- Fraunhofer Institute of Optronics, System Technologies and Image Exploitation (IOSB), Gutleuthausstr. 1, 76275 Ettlingen, Germany
| | - Marc Eichhorn
- Fraunhofer Institute of Optronics, System Technologies and Image Exploitation (IOSB), Gutleuthausstr. 1, 76275 Ettlingen, Germany
- Institute of Control Systems (IRS), Karlsruhe Institute of Technology, Fritz-Haber-Weg 1, 76131 Karlsruhe, Germany
| |
Collapse
|
7
|
Wang SY, Qu YC, Shao N, Niu LY, Yang QZ. Reversible Dual Fluorescence-Lifetime Imaging of Mitochondrial GSH and Microviscosity: Real-Time Evaluation of Ferroptosis Status. Anal Chem 2024; 96:4570-4579. [PMID: 38441542 DOI: 10.1021/acs.analchem.3c05430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Ferroptosis, as a new form of regulated cell death, is implicated in various physiological and pathological processes. Developing a single probe for an independent analysis of multiple analytes related to ferroptosis can provide more accurate information and simplify the detection procedures, but it faces great challenges. In this work, we develop a fluorescent probe for the simultaneous detection of GSH through ratiometric fluorescence response and microviscosity via a fluorescence lifetime model. Based on the reversible Michael addition reaction between GSH and unsaturated C═C bond, the probe responds reversibly to GSH with a ratiometric fluorescence variation and a fast response time (t1/2 = 4.7 s). At the same time, the probe is sensitive to environmental viscosity by changing its fluorescence lifetimes. The probe was applied to monitor the drug-induced ferroptosis process through both the classical Xc-/GSH/GPX4- and DHODH-mediated defense mechanisms. We hope that the probe will provide a useful molecular tool for the real-time live-cell imaging of GSH dynamics, which is benefit to unveiling related physiological and pathological processes.
Collapse
Affiliation(s)
- Si-Yu Wang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Yu-Chen Qu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Na Shao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Li-Ya Niu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Qing-Zheng Yang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| |
Collapse
|
8
|
Kakuda H, Akiba N, Hibino K, Tsuchiya K, Tanabe K, Shibasaki K. Visualization of latent fingerprints using fluorescence lifetime imaging on paper emitting strong fluorescence. J Forensic Sci 2024; 69:669-677. [PMID: 38263807 DOI: 10.1111/1556-4029.15461] [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: 09/04/2023] [Revised: 11/30/2023] [Accepted: 01/03/2024] [Indexed: 01/25/2024]
Abstract
Latent fingerprints were successfully visualized using fluorescence lifetime imaging (FLIM) on paper which emits strong fluorescence with a lifetime close to that of fingerprints and thus from which it is difficult for time-resolved spectroscopy to visualize fingerprints. Latent fingerprint samples on paper were excited using a 450 nm or 532 nm nanosecond pulsed-laser, and time-resolved fluorescence images were obtained at a delay time of 6-16 ns in intervals of 1 ns, to the excitation pulse. The excitation beam was expanded using a lens, and the fluorescence from the fingerprints was captured using an intensified CCD camera. Because of the large fluorescence intensity of the background paper of approximately two to four orders of magnitude larger than that of the fingerprint, the fingerprint was not visualized on each fluorescence image by time-resolved spectroscopy. However, the fingerprint was visualized in a FLIM image constructed using a series of the fluorescence images for the case with the fluorescence intensity of the background paper being four orders of magnitude larger than that of the fingerprint. The difference in fluorescence lifetime in the FLIM image of the visualized fingerprint and background paper was in the order of 0.1 ns, which was an order of magnitude smaller than the inherent fluorescence lifetime of a few nanoseconds for the fingerprints and paper. It was demonstrated that, at a background fluorescence intensity with a certain order of magnitude larger than that of fingerprints, FLIM has the potential to visualize latent fingerprints which cannot be visualized by time-resolved spectroscopy.
Collapse
Affiliation(s)
- Hidetoshi Kakuda
- Physics Section, National Research Institute of Police Science, Chiba, Japan
| | - Norimitsu Akiba
- Physics Section, National Research Institute of Police Science, Chiba, Japan
| | - Kazuhito Hibino
- Criminal Identification Division, National Police Agency, Tokyo, Japan
| | - Ken'ichi Tsuchiya
- Physics Section, National Research Institute of Police Science, Chiba, Japan
| | - Kosuke Tanabe
- Physics Section, National Research Institute of Police Science, Chiba, Japan
| | | |
Collapse
|
9
|
Ferrara V, Vetri V, Pignataro B, Chillura Martino DF, Sancataldo G. Phasor-FLIM analysis of cellulose paper ageing mechanism with carbotrace 680 dye. Int J Biol Macromol 2024; 260:129452. [PMID: 38228201 DOI: 10.1016/j.ijbiomac.2024.129452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 01/05/2024] [Accepted: 01/10/2024] [Indexed: 01/18/2024]
Abstract
Ageing of paper is a complex process of great relevance for application purposes because of its widespread use as support for information storage in books and documents, and as common low-cost and green packaging material, to name a few. A key factor in paper ageing is the oxidation of cellulose, a macromolecule of natural origin that constitutes the main chemical component of paper. Such a complex process results in changes in the cellulose polymeric chains in chemical and structural properties. The scope of this work is to explore the effects of oxidation of cellulose as one of the principal mechanisms of ageing of paper using a fluorescence-based approach. To this aim, fluorescence-lifetime imaging microscopy (FLIM) measurements on pure cellulose samples stained using Carbotrace 680 dye were performed, and data were analyzed by phasor approach. The comparison with results from conventional techniques allowed to map paper microstructure as a function of the sample oxidation degree correlating the fluorescence-lifetime changes to cellulose oxidation. A two-step oxidation kinetics that produced specific modification in paper organization was highlighted indicating that FLIM measurements using Carbotrace 680 dye may provide a simple tool to obtain information on the oxidation process also adding spatial information at sub-micrometric scale.
Collapse
Affiliation(s)
- Vittorio Ferrara
- Department of Physics and Chemistry - Emilio Segrè, University of Palermo, viale delle Scienze, Palermo 90128, Italy
| | - Valeria Vetri
- Department of Physics and Chemistry - Emilio Segrè, University of Palermo, viale delle Scienze, Palermo 90128, Italy
| | - Bruno Pignataro
- Department of Physics and Chemistry - Emilio Segrè, University of Palermo, viale delle Scienze, Palermo 90128, Italy
| | - Delia Francesca Chillura Martino
- Department of Biological, Chemical and Pharmaceutical Sciences (STeBiCeF), University of Palermo, viale delle Scienze, Palermo 90128, Italy.
| | - Giuseppe Sancataldo
- Department of Physics and Chemistry - Emilio Segrè, University of Palermo, viale delle Scienze, Palermo 90128, Italy.
| |
Collapse
|
10
|
Lin Y, Mos P, Ardelean A, Bruschini C, Charbon E. Coupling a recurrent neural network to SPAD TCSPC systems for real-time fluorescence lifetime imaging. Sci Rep 2024; 14:3286. [PMID: 38331957 PMCID: PMC10853568 DOI: 10.1038/s41598-024-52966-9] [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: 07/27/2023] [Accepted: 01/25/2024] [Indexed: 02/10/2024] Open
Abstract
Fluorescence lifetime imaging (FLI) has been receiving increased attention in recent years as a powerful diagnostic technique in biological and medical research. However, existing FLI systems often suffer from a tradeoff between processing speed, accuracy, and robustness. Inspired by the concept of Edge Artificial Intelligence (Edge AI), we propose a robust approach that enables fast FLI with no degradation of accuracy. This approach couples a recurrent neural network (RNN), which is trained to estimate the fluorescence lifetime directly from raw timestamps without building histograms, to SPAD TCSPC systems, thereby drastically reducing transfer data volumes and hardware resource utilization, and enabling real-time FLI acquisition. We train two variants of the RNN on a synthetic dataset and compare the results to those obtained using center-of-mass method (CMM) and least squares fitting (LS fitting). Results demonstrate that two RNN variants, gated recurrent unit (GRU) and long short-term memory (LSTM), are comparable to CMM and LS fitting in terms of accuracy, while outperforming them in the presence of background noise by a large margin. To explore the ultimate limits of the approach, we derive the Cramer-Rao lower bound of the measurement, showing that RNN yields lifetime estimations with near-optimal precision. To demonstrate real-time operation, we build a FLI microscope based on an existing SPAD TCSPC system comprising a 32[Formula: see text]32 SPAD sensor named Piccolo. Four quantized GRU cores, capable of processing up to 4 million photons per second, are deployed on the Xilinx Kintex-7 FPGA that controls the Piccolo. Powered by the GRU, the FLI setup can retrieve real-time fluorescence lifetime images at up to 10 frames per second. The proposed FLI system is promising and ideally suited for biomedical applications, including biological imaging, biomedical diagnostics, and fluorescence-assisted surgery, etc.
Collapse
Affiliation(s)
- Yang Lin
- Advanced Quantum Architecture Laboratory, École polytechnique fédérale de Lausanne, Neuchâtel, 2002, Switzerland
| | - Paul Mos
- Advanced Quantum Architecture Laboratory, École polytechnique fédérale de Lausanne, Neuchâtel, 2002, Switzerland
| | - Andrei Ardelean
- Advanced Quantum Architecture Laboratory, École polytechnique fédérale de Lausanne, Neuchâtel, 2002, Switzerland
| | - Claudio Bruschini
- Advanced Quantum Architecture Laboratory, École polytechnique fédérale de Lausanne, Neuchâtel, 2002, Switzerland
| | - Edoardo Charbon
- Advanced Quantum Architecture Laboratory, École polytechnique fédérale de Lausanne, Neuchâtel, 2002, Switzerland.
| |
Collapse
|
11
|
Gouzou D, Taimori A, Haloubi T, Finlayson N, Wang Q, Hopgood JR, Vallejo M. Applications of machine learning in time-domain fluorescence lifetime imaging: a review. Methods Appl Fluoresc 2024; 12:022001. [PMID: 38055998 PMCID: PMC10851337 DOI: 10.1088/2050-6120/ad12f7] [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: 06/30/2023] [Revised: 09/25/2023] [Accepted: 12/06/2023] [Indexed: 12/08/2023]
Abstract
Many medical imaging modalities have benefited from recent advances in Machine Learning (ML), specifically in deep learning, such as neural networks. Computers can be trained to investigate and enhance medical imaging methods without using valuable human resources. In recent years, Fluorescence Lifetime Imaging (FLIm) has received increasing attention from the ML community. FLIm goes beyond conventional spectral imaging, providing additional lifetime information, and could lead to optical histopathology supporting real-time diagnostics. However, most current studies do not use the full potential of machine/deep learning models. As a developing image modality, FLIm data are not easily obtainable, which, coupled with an absence of standardisation, is pushing back the research to develop models which could advance automated diagnosis and help promote FLIm. In this paper, we describe recent developments that improve FLIm image quality, specifically time-domain systems, and we summarise sensing, signal-to-noise analysis and the advances in registration and low-level tracking. We review the two main applications of ML for FLIm: lifetime estimation and image analysis through classification and segmentation. We suggest a course of action to improve the quality of ML studies applied to FLIm. Our final goal is to promote FLIm and attract more ML practitioners to explore the potential of lifetime imaging.
Collapse
Affiliation(s)
- Dorian Gouzou
- Dorian Gouzou and Marta Vallejo are with Institute of Signals, Sensors and Systems, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, EH14 4AS, United Kingdom
| | - Ali Taimori
- Tarek Haloubi, Ali Taimori, and James R. Hopgood are with Institute for Imaging, Data and Communication, School of Engineering, University of Edinburgh, Edinburgh, EH9 3FG, United Kingdom
| | - Tarek Haloubi
- Tarek Haloubi, Ali Taimori, and James R. Hopgood are with Institute for Imaging, Data and Communication, School of Engineering, University of Edinburgh, Edinburgh, EH9 3FG, United Kingdom
| | - Neil Finlayson
- Neil Finlayson is with Institute for Integrated Micro and Nano Systems, School of Engineering, University ofEdinburgh, Edinburgh EH9 3FF, United Kingdom
| | - Qiang Wang
- Qiang Wang is with Centre for Inflammation Research, University of Edinburgh, Edinburgh, EH16 4TJ, United Kingdom
| | - James R Hopgood
- Tarek Haloubi, Ali Taimori, and James R. Hopgood are with Institute for Imaging, Data and Communication, School of Engineering, University of Edinburgh, Edinburgh, EH9 3FG, United Kingdom
| | - Marta Vallejo
- Dorian Gouzou and Marta Vallejo are with Institute of Signals, Sensors and Systems, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, EH14 4AS, United Kingdom
| |
Collapse
|
12
|
Sarfraz N, Shafik LK, Stickelman ZR, Shankar U, Moscoso E, Braselmann E. Evaluating Riboglow-FLIM probes for RNA sensing. RSC Chem Biol 2024; 5:109-116. [PMID: 38333191 PMCID: PMC10849122 DOI: 10.1039/d3cb00197k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 01/03/2024] [Indexed: 02/10/2024] Open
Abstract
We recently developed Riboglow-FLIM, where we genetically tag and track RNA molecules in live cells through measuring the fluorescence lifetime of a small molecule probe that binds the RNA tag. Here, we systematically and quantitatively evaluated key elements of Riboglow-FLIM that may serve as the foundation for Riboglow-FLIM applications and further tool development efforts. Our investigation focused on measuring changes in fluorescence lifetime of representative Riboglow-FLIM probes with different linkers and fluorophores in different environments. In vitro measurements revealed distinct lifetime differences among the probe variants as a result of different linker designs and fluorophore selections. To expand on the platform's versatility, probes in a wide variety of mammalian cell types were examined using fluorescence lifetime imaging microscopy (FLIM), and possible effects on cell physiology were evaluated by metabolomics. The results demonstrated that variations in lifetime were dependent on both probe and cell type. Interestingly, distinct differences in lifetime values were observed between cell lines, while no overall change in cell health was measured. These findings underscore the importance of probe selection and cellular environment when employing Riboglow-FLIM for RNA detection, serving as a foundation for future tool development and applications across diverse fields and biological systems.
Collapse
Affiliation(s)
- Nadia Sarfraz
- Department of Chemistry, Georgetown University Washington District of Columbia USA
| | - Luke K Shafik
- Department of Chemistry, Georgetown University Washington District of Columbia USA
| | - Zachary R Stickelman
- Department of Chemistry, Georgetown University Washington District of Columbia USA
| | - Uma Shankar
- Department of Chemistry, Georgetown University Washington District of Columbia USA
| | - Emilia Moscoso
- Department of Chemistry, Georgetown University Washington District of Columbia USA
| | - Esther Braselmann
- Department of Chemistry, Georgetown University Washington District of Columbia USA
| |
Collapse
|
13
|
Nguyen TD, Chen YI, Nguyen AT, Chen LH, Yonas S, Litvinov M, He Y, Kuo YA, Hong S, Rylander HG, Yeh HC. Multiplexed imaging in live cells using pulsed interleaved excitation spectral FLIM. OPTICS EXPRESS 2024; 32:3290-3307. [PMID: 38297554 PMCID: PMC11018333 DOI: 10.1364/oe.505667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/30/2023] [Accepted: 12/30/2023] [Indexed: 02/02/2024]
Abstract
Multiplexed fluorescence detection has become increasingly important in the fields of biosensing and bioimaging. Although a variety of excitation/detection optical designs and fluorescence unmixing schemes have been proposed to allow for multiplexed imaging, rapid and reliable differentiation and quantification of multiple fluorescent species at each imaging pixel is still challenging. Here we present a pulsed interleaved excitation spectral fluorescence lifetime microscopic (PIE-sFLIM) system that can simultaneously image six fluorescent tags in live cells in a single hyperspectral snapshot. Using an alternating pulsed laser excitation scheme at two different wavelengths and a synchronized 16-channel time-resolved spectral detector, our PIE-sFLIM system can effectively excite multiple fluorophores and collect their emission over a broad spectrum for analysis. Combining our system with the advanced live-cell labeling techniques and the lifetime/spectral phasor analysis, our PIE-sFLIM approach can well unmix the fluorescence of six fluorophores acquired in a single measurement, thus improving the imaging speed in live-specimen investigation.
Collapse
Affiliation(s)
- Trung Duc Nguyen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Yuan-I Chen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Anh-Thu Nguyen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Limin H. Chen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Siem Yonas
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Mitchell Litvinov
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Yujie He
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Yu-An Kuo
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Soonwoo Hong
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - H. Grady Rylander
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Hsin-Chih Yeh
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
- Texas Materials Institute, University of Texas at Austin, Austin, TX, USA
| |
Collapse
|
14
|
Chang B, Chen J, Bao J, Sun T, Cheng Z. Molecularly Engineered Room-Temperature Phosphorescence for Biomedical Application: From the Visible toward Second Near-Infrared Window. Chem Rev 2023; 123:13966-14037. [PMID: 37991875 DOI: 10.1021/acs.chemrev.3c00401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Phosphorescence, characterized by luminescent lifetimes significantly longer than that of biological autofluorescence under ambient environment, is of great value for biomedical applications. Academic evidence of fluorescence imaging indicates that virtually all imaging metrics (sensitivity, resolution, and penetration depths) are improved when progressing into longer wavelength regions, especially the recently reported second near-infrared (NIR-II, 1000-1700 nm) window. Although the emission wavelength of probes does matter, it is not clear whether the guideline of "the longer the wavelength, the better the imaging effect" is still suitable for developing phosphorescent probes. For tissue-specific bioimaging, long-lived probes, even if they emit visible phosphorescence, enable accurate visualization of large deep tissues. For studies dealing with bioimaging of tiny biological architectures or dynamic physiopathological activities, the prerequisite is rigorous planning of long-wavelength phosphorescence, being aware of the cooperative contribution of long wavelengths and long lifetimes for improving the spatiotemporal resolution, penetration depth, and sensitivity of bioimaging. In this Review, emerging molecular engineering methods of room-temperature phosphorescence are discussed through the lens of photophysical mechanisms. We highlight the roles of phosphorescence with emission from visible to NIR-II windows toward bioapplications. To appreciate such advances, challenges and prospects in rapidly growing studies of room-temperature phosphorescence are described.
Collapse
Affiliation(s)
- Baisong Chang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, Hubei 430070, China
| | - Jie Chen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, Hubei 430070, China
| | - Jiasheng Bao
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, Hubei 430070, China
| | - Taolei Sun
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, Hubei 430070, China
| | - Zhen Cheng
- State Key Laboratory of Drug Research, Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
- Shandong Laboratory of Yantai Drug Discovery, Bohai Rim Advanced Research Institute for Drug Discovery, Yantai, Shandong 264000, China
| |
Collapse
|
15
|
Green MJ, Ge H, Flower SE, Pourzand C, Botchway SW, Wang HC, Kuganathan N, Kociok-Köhn G, Li M, Xu S, James TD, Pascu SI. Fluorescent naphthalimide boronates as theranostics: structural investigations, confocal fluorescence and multiphoton fluorescence lifetime imaging microscopy in living cells. RSC Chem Biol 2023; 4:1082-1095. [PMID: 38033726 PMCID: PMC10685793 DOI: 10.1039/d3cb00112a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/17/2023] [Indexed: 12/02/2023] Open
Abstract
New design and synthetic strategies were developed to generate functional phenyl boronic acid (BA)-based fluorescent probes incorporating the 1,8-naphthalimide (NI) tag. This fluorescent core was anchored onto the BA unit through small organic linkers consisting of nitrogen groups which can arrest, and internally stabilise the phenyl-boronate units. The newly synthesised fluorophores were characterised spectroscopically by NMR spectroscopy and mass spectrometry and evaluated for their ability to bind to a naturally occurring polysaccharide, β-d-glucan in DMSO and simultaneously as act as in vitro cell imaging reagents. The uptake of these new NI-boronic acid derivatives was studied living cancer cells (HeLa, PC-3) in the presence, and absence, of β-d-glucan. Time-correlated single-photon counting (TCSPC) of DMSO solutions and two-photon fluorescence-lifetime imaging microscopy (FLIM) techniques allowed an insight into the probes' interaction with their environment. Their cellular uptake and distributions were imaged using laser scanning confocal fluorescence microscopy under single- and two-photon excitation regimes (λmax 910 nm). FLIM facilitated the estimation of the impact of the probe's cellular surroundings using the fluorophore lifetime. The extent to which this was mediated by the β-d-glucan was visualised by 2-photon FLIM in living cells. The fluorescence lifetime observed under a range of temperatures varied appreciably, indicating that changes in the environment can be sensed by these probes. In all cases, the cellular membrane penetration of these new probes was remarkable even under variable temperature conditions and localisation was widely concentrated in the cellular cytoplasm, without specific organelle trapping: we conclude that these new probes show promise for cellular imaging in living cancer cells.
Collapse
Affiliation(s)
- Megan J Green
- Department of Chemistry, University of Bath Calverton Down Bath BA2 7AY UK
| | - Haobo Ge
- Department of Chemistry, University of Bath Calverton Down Bath BA2 7AY UK
| | - Stephen E Flower
- Department of Chemistry, University of Bath Calverton Down Bath BA2 7AY UK
| | - Charareh Pourzand
- Department of Life Sciences, University of Bath BA2 7AY UK
- Centre for Therapeutic Innovation, University of Bath BA2 7AY UK
| | - Stanley W Botchway
- STFC Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus Harwell Oxfordshire OX11 0QX UK
| | - Hui-Chen Wang
- Department of Chemistry, University of Bath Calverton Down Bath BA2 7AY UK
| | | | - Gabriele Kociok-Köhn
- Department of Chemistry, University of Bath Calverton Down Bath BA2 7AY UK
- Materials and Chemical Characterisation Facility (MC2), University of Bath Calverton Down Bath BA2 7AY UK
| | - Meng Li
- Department of Chemistry, University of Bath Calverton Down Bath BA2 7AY UK
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology Beijing 100029 P. R. China
| | - Suying Xu
- Department of Chemistry, University of Bath Calverton Down Bath BA2 7AY UK
- Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University Baoding 071003 P. R. China
| | - Tony D James
- Department of Chemistry, University of Bath Calverton Down Bath BA2 7AY UK
| | - Sofia I Pascu
- Department of Chemistry, University of Bath Calverton Down Bath BA2 7AY UK
- Centre for Therapeutic Innovation, University of Bath BA2 7AY UK
| |
Collapse
|
16
|
Khramtsov YV, Ulasov AV, Slastnikova TA, Rosenkranz AA, Lupanova TN, Georgiev GP, Sobolev AS. Modular Nanotransporters Delivering Biologically Active Molecules to the Surface of Mitochondria. Pharmaceutics 2023; 15:2687. [PMID: 38140028 PMCID: PMC10748074 DOI: 10.3390/pharmaceutics15122687] [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: 11/06/2023] [Revised: 11/23/2023] [Accepted: 11/24/2023] [Indexed: 12/24/2023] Open
Abstract
Treatment of various diseases, in particular cancer, usually requires the targeting of biologically active molecules at a selected subcellular compartment. We modified our previously developed modular nanotransporters (MNTs) for targeting mitochondria. The new MNTs are capable of binding to the protein predominantly localized on the outer mitochondrial membrane, Keap1. These MNTs possessing antiKeap1 monobody co-localize with mitochondria upon addition to the cells. They efficiently interact with Keap1 both in solution and within living cells. A conjugate of the MNT with a photosensitizer, chlorin e6, demonstrated significantly higher photocytotoxicity than chlorin e6 alone. We assume that MNTs of this kind can improve efficiency of therapeutic photosensitizers and radionuclides emitting short-range particles.
Collapse
Affiliation(s)
- Yuri V. Khramtsov
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology of Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; (Y.V.K.); (A.V.U.); (T.A.S.); (A.A.R.); (T.N.L.); (G.P.G.)
| | - Alexey V. Ulasov
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology of Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; (Y.V.K.); (A.V.U.); (T.A.S.); (A.A.R.); (T.N.L.); (G.P.G.)
| | - Tatiana A. Slastnikova
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology of Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; (Y.V.K.); (A.V.U.); (T.A.S.); (A.A.R.); (T.N.L.); (G.P.G.)
| | - Andrey A. Rosenkranz
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology of Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; (Y.V.K.); (A.V.U.); (T.A.S.); (A.A.R.); (T.N.L.); (G.P.G.)
- Faculty of Biology, Lomonosov Moscow State University, 1-12 Leninskie Gory St., 119234 Moscow, Russia
| | - Tatiana N. Lupanova
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology of Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; (Y.V.K.); (A.V.U.); (T.A.S.); (A.A.R.); (T.N.L.); (G.P.G.)
| | - Georgii P. Georgiev
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology of Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; (Y.V.K.); (A.V.U.); (T.A.S.); (A.A.R.); (T.N.L.); (G.P.G.)
| | - Alexander S. Sobolev
- Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology of Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; (Y.V.K.); (A.V.U.); (T.A.S.); (A.A.R.); (T.N.L.); (G.P.G.)
- Faculty of Biology, Lomonosov Moscow State University, 1-12 Leninskie Gory St., 119234 Moscow, Russia
| |
Collapse
|
17
|
Gottlieb D, Asadipour B, Kostina P, Ung TPL, Stringari C. FLUTE: A Python GUI for interactive phasor analysis of FLIM data. BIOLOGICAL IMAGING 2023; 3:e21. [PMID: 38487690 PMCID: PMC10936343 DOI: 10.1017/s2633903x23000211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 09/16/2023] [Accepted: 10/25/2023] [Indexed: 03/17/2024]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) is a powerful technique used to probe the local environment of fluorophores. The fit-free phasor approach to FLIM data is increasingly being used due to its ease of interpretation. To date, no open-source graphical user interface (GUI) for phasor analysis of FLIM data is available in Python, thus limiting the widespread use of phasor analysis in biomedical research. Here, we present Fluorescence Lifetime Ultimate Explorer (FLUTE), a Python GUI that is designed to fill this gap. FLUTE simplifies and automates many aspects of the analysis of FLIM data acquired in the time domain, such as calibrating the FLIM data, performing interactive exploration of the phasor plot, displaying phasor plots and FLIM images with different lifetime contrasts simultaneously, and calculating the distance from known molecular species. After applying desired filters and thresholds, the final edited datasets can be exported for further user-specific analysis. FLUTE has been tested using several FLIM datasets including autofluorescence of zebrafish embryos and in vitro cells. In summary, our user-friendly GUI extends the advantages of phasor plotting by making the data visualization and analysis easy and interactive, allows for analysis of large FLIM datasets, and accelerates FLIM analysis for non-specialized labs.
Collapse
Affiliation(s)
- Dale Gottlieb
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Bahar Asadipour
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Polina Kostina
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Thi Phuong Lien Ung
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Chiara Stringari
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| |
Collapse
|
18
|
Fazel M, Jazani S, Scipioni L, Vallmitjana A, Zhu S, Gratton E, Digman MA, Pressé S. Building Fluorescence Lifetime Maps Photon-by-Photon by Leveraging Spatial Correlations. ACS PHOTONICS 2023; 10:3558-3569. [PMID: 38406580 PMCID: PMC10890823 DOI: 10.1021/acsphotonics.3c00595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) has become a standard tool in the quantitative characterization of subcellular environments. However, quantitative FLIM analyses face several challenges. First, spatial correlations between pixels are often ignored as signal from individual pixels is analyzed independently thereby limiting spatial resolution. Second, existing methods deduce photon ratios instead of absolute lifetime maps. Next, the number of fluorophore species contributing to the signal is unknown, while excited state lifetimes with <1 ns difference are difficult to discriminate. Finally, existing analyses require high photon budgets and often cannot rigorously propagate experimental uncertainty into values over lifetime maps and number of species involved. To overcome all of these challenges simultaneously and self-consistently at once, we propose the first doubly nonparametric framework. That is, we learn the number of species (using Beta-Bernoulli process priors) and absolute maps of these fluorophore species (using Gaussian process priors) by leveraging information from pulses not leading to observed photon. We benchmark our framework using a broad range of synthetic and experimental data and demonstrate its robustness across a number of scenarios including cases where we recover lifetime differences between species as small as 0.3 ns with merely 1000 photons.
Collapse
Affiliation(s)
- Mohamadreza Fazel
- Center for Biological Physics and Department of Physics, Arizona State University, Tempe, Arizona 85287, United States
| | - Sina Jazani
- Center for Biological Physics and Department of Physics, Arizona State University, Tempe, Arizona 85287, United States
| | - Lorenzo Scipioni
- Department of Biomedical Engineering, University of California Irvine, Irvine, California 92697, United States; Laboratory of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Alexander Vallmitjana
- Department of Biomedical Engineering, University of California Irvine, Irvine, California 92697, United States; Laboratory of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Songning Zhu
- Department of Biomedical Engineering, University of California Irvine, Irvine, California 92697, United States; Laboratory of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Enrico Gratton
- Department of Biomedical Engineering, University of California Irvine, Irvine, California 92697, United States; Laboratory of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Michelle A Digman
- Department of Biomedical Engineering, University of California Irvine, Irvine, California 92697, United States; Laboratory of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Steve Pressé
- Center for Biological Physics and Department of Physics, Arizona State University, Tempe, Arizona 85287, United States; School of Molecular Science, Arizona State University, Tempe, Arizona 85287, United States
| |
Collapse
|
19
|
Mo Y, Zhou H, Xu J, Chen X, Li L, Zhang S. Genetically encoded fluorescence lifetime biosensors: overview, advances, and opportunities. Analyst 2023; 148:4939-4953. [PMID: 37721109 DOI: 10.1039/d3an01201h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Genetically encoded biosensors based on fluorescent proteins (FPs) are powerful tools for tracking analytes and cellular events with high spatial and temporal resolution in living cells and organisms. Compared with intensiometric readout and ratiometric readout, fluorescence lifetime readout provides absolute measurements, independent of the biosensor expression level and instruments. Thus, genetically encoded fluorescence lifetime biosensors play a vital role in facilitating accurate quantitative assessments within intricate biological systems. In this review, we first provide a concise description of the categorization and working mechanism of genetically encoded fluorescence lifetime biosensors. Subsequently, we elaborate on the combination of the fluorescence lifetime imaging technique and lifetime analysis methods with fluorescence lifetime biosensors, followed by their application in monitoring the dynamics of environment parameters, analytes and cellular events. Finally, we discuss worthwhile considerations for the design, optimization and development of fluorescence lifetime-based biosensors from three representative cases.
Collapse
Affiliation(s)
- Yidan Mo
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Huangmei Zhou
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Jinming Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Xihang Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Lei Li
- School of Science, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China.
| | - Sanjun Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- NYU-ECNU Institute of Physics at NYU Shanghai, No. 3663, North Zhongshan Rd, Shanghai 200062, China.
| |
Collapse
|
20
|
Mao W, Bui HTD, Cho W, Yoo HS. Spectroscopic techniques for monitoring stem cell and organoid proliferation in 3D environments for therapeutic development. Adv Drug Deliv Rev 2023; 201:115074. [PMID: 37619771 DOI: 10.1016/j.addr.2023.115074] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 07/22/2023] [Accepted: 08/20/2023] [Indexed: 08/26/2023]
Abstract
Spectroscopic techniques for monitoring stem cell and organoid proliferation have gained significant attention in therapeutic development. Spectroscopic techniques such as fluorescence, Raman spectroscopy, and infrared spectroscopy offer noninvasive and real-time monitoring of biochemical and biophysical changes that occur during stem cell and organoid proliferation. These techniques provide valuable insight into the underlying mechanisms of action of potential therapeutic agents, allowing for improved drug discovery and screening. This review highlights the importance of spectroscopic monitoring of stem cell and organoid proliferation and its potential impact on therapeutic development. Furthermore, this review discusses recent advances in spectroscopic techniques and their applications in stem cell and organoid research. Overall, this review emphasizes the importance of spectroscopic techniques as valuable tools for studying stem cell and organoid proliferation and their potential to revolutionize therapeutic development in the future.
Collapse
Affiliation(s)
- Wei Mao
- Department of Biomedical Materials Engineering, Kangwon National University, Chuncheon 24341, Republic of Korea; Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Hoai-Thuong Duc Bui
- Department of Biomedical Materials Engineering, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Wanho Cho
- Department of Biomedical Materials Engineering, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Hyuk Sang Yoo
- Department of Biomedical Materials Engineering, Kangwon National University, Chuncheon 24341, Republic of Korea; Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Republic of Korea; Institue of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea; Kangwon Radiation Convergence Research Support Center, Kangwon National University, Chuncheon 24341, Republic of Korea.
| |
Collapse
|
21
|
Darvin ME. Optical Methods for Non-Invasive Determination of Skin Penetration: Current Trends, Advances, Possibilities, Prospects, and Translation into In Vivo Human Studies. Pharmaceutics 2023; 15:2272. [PMID: 37765241 PMCID: PMC10538180 DOI: 10.3390/pharmaceutics15092272] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/19/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023] Open
Abstract
Information on the penetration depth, pathways, metabolization, storage of vehicles, active pharmaceutical ingredients (APIs), and functional cosmetic ingredients (FCIs) of topically applied formulations or contaminants (substances) in skin is of great importance for understanding their interaction with skin targets, treatment efficacy, and risk assessment-a challenging task in dermatology, cosmetology, and pharmacy. Non-invasive methods for the qualitative and quantitative visualization of substances in skin in vivo are favored and limited to optical imaging and spectroscopic methods such as fluorescence/reflectance confocal laser scanning microscopy (CLSM); two-photon tomography (2PT) combined with autofluorescence (2PT-AF), fluorescence lifetime imaging (2PT-FLIM), second-harmonic generation (SHG), coherent anti-Stokes Raman scattering (CARS), and reflectance confocal microscopy (2PT-RCM); three-photon tomography (3PT); confocal Raman micro-spectroscopy (CRM); surface-enhanced Raman scattering (SERS) micro-spectroscopy; stimulated Raman scattering (SRS) microscopy; and optical coherence tomography (OCT). This review summarizes the state of the art in the use of the CLSM, 2PT, 3PT, CRM, SERS, SRS, and OCT optical methods to study skin penetration in vivo non-invasively (302 references). The advantages, limitations, possibilities, and prospects of the reviewed optical methods are comprehensively discussed. The ex vivo studies discussed are potentially translatable into in vivo measurements. The requirements for the optical properties of substances to determine their penetration into skin by certain methods are highlighted.
Collapse
|
22
|
Yahav G, Pawar S, Lipovsky A, Gupta A, Gedanken A, Duadi H, Fixler D. Probing Polarity and pH Sensitivity of Carbon Dots in Escherichia coli through Time-Resolved Fluorescence Analyses. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2068. [PMID: 37513079 PMCID: PMC10384995 DOI: 10.3390/nano13142068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/09/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023]
Abstract
Intracellular monitoring of pH and polarity is crucial for understanding cellular processes and functions. This study employed pH- and polarity-sensitive nanomaterials such as carbon dots (CDs) for the intracellular sensing of pH, polarity, and viscosity using integrated time-resolved fluorescence anisotropy (FA) imaging (TR-FAIM) and fluorescence lifetime (FLT) imaging microscopy (FLIM), thereby enabling comprehensive characterization. The functional groups on the surface of CDs exhibit sensitivity to changes in the microenvironment, leading to variations in fluorescence intensity (FI) and FLT according to pH and polarity. The FLT of CDs in aqueous solution changed gradually from 6.38 ± 0.05 ns to 8.03 ± 0.21 ns within a pH range of 2-8. Interestingly, a complex relationship of FI and FLT was observed during measurements of CDs with decreasing polarity. However, the FA and rotational correlation time (θ) increased from 0.062 ± 0.019 to 0.112 ± 0.023 and from 0.49 ± 0.03 ns to 2.01 ± 0.27 ns, respectively. This increase in FA and θ was attributed to the higher viscosity accompanying the decrease in polarity. Furthermore, CDs were found to bind to three locations in Escherichia coli: the cell wall, inner membrane, and cytoplasm, enabling intracellular characterization using FI and FA decay imaging. FLT provided insights into cytoplasmic pH (7.67 ± 0.48), which agreed with previous works, as well as the decrease in polarity in the cell wall and inner membrane. The CD aggregation was suspected in certain areas based on FA, and the θ provided information on cytoplasmic heterogeneity due to the aggregation and/or interactions with biomolecules. The combined TR-FAIM/FLIM system allowed for simultaneous monitoring of pH and polarity changes through FLIM and viscosity variations through TR-FAIM.
Collapse
Affiliation(s)
- Gilad Yahav
- Institute of Nanotechnology and Advanced Materials, Faculty of Engineering, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Shweta Pawar
- Institute of Nanotechnology and Advanced Materials, Faculty of Engineering, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Anat Lipovsky
- Institute of Nanotechnology and Advanced Materials, Faculty of Engineering, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Akanksha Gupta
- Institute of Nanotechnology and Advanced Materials, Department of Chemistry, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Aharon Gedanken
- Institute of Nanotechnology and Advanced Materials, Department of Chemistry, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Hamootal Duadi
- Institute of Nanotechnology and Advanced Materials, Faculty of Engineering, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Dror Fixler
- Institute of Nanotechnology and Advanced Materials, Faculty of Engineering, Bar-Ilan University, Ramat Gan 52900, Israel
| |
Collapse
|
23
|
Wilda CB, Burnstock A, Suhling K, Mattioli Della Rocca F, Henderson RK, Nedbal J. Visualising varnish removal for conservation of paintings by fluorescence lifetime imaging (FLIM). HERITAGE SCIENCE 2023; 11:127. [PMID: 37333623 PMCID: PMC10276100 DOI: 10.1186/s40494-023-00957-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 05/17/2023] [Indexed: 06/20/2023]
Abstract
The removal of varnish from the surface is a key step in painting conservation. Varnish removal is traditionally monitored by examining the painting surface under ultraviolet illumination. We show here that by imaging the fluorescence lifetime instead, much better contrast, sensitivity, and specificity can be achieved. For this purpose, we developed a lightweight (4.8 kg) portable instrument for macroscopic fluorescence lifetime imaging (FLIM). It is based on a time-correlated single-photon avalanche diode (SPAD) camera to acquire the FLIM images and a pulsed 440 nm diode laser to excite the varnish fluorescence. A historical model painting was examined to demonstrate the capabilities of the system. We found that the FLIM images provided information on the distribution of the varnish on the painting surface with greater sensitivity, specificity, and contrast compared to the traditional ultraviolet illumination photography. The distribution of the varnish and other painting materials was assessed using FLIM during and after varnish removal with different solvent application methods. Monitoring of the varnish removal process between successive solvent applications by a swab revealed an evolving image contrast as a function of the cleaning progress. FLIM of dammar and mastic resin varnishes identified characteristic changes to their fluorescence lifetimes depending on their ageing conditions. Thus, FLIM has a potential to become a powerful and versatile tool to visualise varnish removal from paintings. Graphical Abstract
Collapse
Affiliation(s)
- Christine B. Wilda
- Department of Physics, King’s College London, Strand, London, WC2R 2LS United Kingdom
- The Courtauld, Somerset House, Strand, London, WC1X 0RN United Kingdom
- ConservArt, 6620 E Rogers Cir, Boca Raton, FL 33487 United States
| | - Aviva Burnstock
- The Courtauld, Somerset House, Strand, London, WC1X 0RN United Kingdom
| | - Klaus Suhling
- Department of Physics, King’s College London, Strand, London, WC2R 2LS United Kingdom
| | - Francesco Mattioli Della Rocca
- School of Engineering, University of Edinburgh, King’s Buildings, Edinburgh, EH9 3JL United Kingdom
- Europe Technology Development Centre, Sony Semiconductor Solutions - Sony Europe B.V., Trento, Italy
| | - Robert K. Henderson
- School of Engineering, University of Edinburgh, King’s Buildings, Edinburgh, EH9 3JL United Kingdom
| | - Jakub Nedbal
- Department of Physics, King’s College London, Strand, London, WC2R 2LS United Kingdom
| |
Collapse
|
24
|
Singh G, George G, Raja SO, Kandaswamy P, Kumar M, Thutupalli S, Laxman S, Gulyani A. A molecular rotor FLIM probe reveals dynamic coupling between mitochondrial inner membrane fluidity and cellular respiration. Proc Natl Acad Sci U S A 2023; 120:e2213241120. [PMID: 37276406 PMCID: PMC10268597 DOI: 10.1073/pnas.2213241120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 04/13/2023] [Indexed: 06/07/2023] Open
Abstract
The inner mitochondrial membrane (IMM), housing components of the electron transport chain (ETC), is the site for respiration. The ETC relies on mobile carriers; therefore, it has long been argued that the fluidity of the densely packed IMM can potentially influence ETC flux and cell physiology. However, it is unclear if cells temporally modulate IMM fluidity upon metabolic or other stimulation. Using a photostable, red-shifted, cell-permeable molecular-rotor, Mitorotor-1, we present a multiplexed approach for quantitatively mapping IMM fluidity in living cells. This reveals IMM fluidity to be linked to cellular-respiration and responsive to stimuli. Multiple approaches combining in vitro experiments and live-cell fluorescence (FLIM) lifetime imaging microscopy (FLIM) show Mitorotor-1 to robustly report IMM 'microviscosity'/fluidity through changes in molecular free volume. Interestingly, external osmotic stimuli cause controlled swelling/compaction of mitochondria, thereby revealing a graded Mitorotor-1 response to IMM microviscosity. Lateral diffusion measurements of IMM correlate with microviscosity reported via Mitorotor-1 FLIM-lifetime, showing convergence of independent approaches for measuring IMM local-order. Mitorotor-1 FLIM reveals mitochondrial heterogeneity in IMM fluidity; between-and-within cells and across single mitochondrion. Multiplexed FLIM lifetime imaging of Mitorotor-1 and NADH autofluorescence reveals that IMM fluidity positively correlates with respiration, across individual cells. Remarkably, we find that stimulating respiration, through nutrient deprivation or chemically, also leads to increase in IMM fluidity. These data suggest that modulating IMM fluidity supports enhanced respiratory flux. Our study presents a robust method for measuring IMM fluidity and suggests a dynamic regulatory paradigm of modulating IMM local order on changing metabolic demand.
Collapse
Affiliation(s)
- Gaurav Singh
- Institute for Stem Cell Science and Regenerative Medicine, 560065Bangalore, India
| | - Geen George
- Institute for Stem Cell Science and Regenerative Medicine, 560065Bangalore, India
| | - Sufi O. Raja
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, 500046Hyderabad, India
| | - Ponnuvel Kandaswamy
- Institute for Stem Cell Science and Regenerative Medicine, 560065Bangalore, India
| | - Manoj Kumar
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute of Fundamental Research, 560065Bangalore, India
| | - Shashi Thutupalli
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute of Fundamental Research, 560065Bangalore, India
- International Centre for Theoretical Sciences, Tata Institute for Fundamental Research, 560089 Bangalore, India
| | - Sunil Laxman
- Institute for Stem Cell Science and Regenerative Medicine, 560065Bangalore, India
| | - Akash Gulyani
- Institute for Stem Cell Science and Regenerative Medicine, 560065Bangalore, India
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, 500046Hyderabad, India
| |
Collapse
|
25
|
Chen P, Kang Q, Niu J, Jing Y, Zhang X, Yu B, Qu J, Lin D. Fluorescence lifetime tracking and imaging of single moving particles assisted by a low-photon-count analysis algorithm. BIOMEDICAL OPTICS EXPRESS 2023; 14:1718-1731. [PMID: 37078048 PMCID: PMC10110318 DOI: 10.1364/boe.485729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/06/2023] [Accepted: 03/06/2023] [Indexed: 05/03/2023]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) has been widely used in the field of biological research because of its high specificity, sensitivity, and quantitative ability in the sensing cellular microenvironment. The most commonly used FLIM technology is based on time-correlated single photon counting (TCSPC). Although the TCSPC method has the highest temporal resolution, the data acquisition time is usually long, and the imaging speed is slow. In this work, we proposed a fast FLIM technology for fluorescence lifetime tracking and imaging of single moving particles, named single particle tracking FLIM (SPT-FLIM). We used feedback-controlled addressing scanning and Mosaic FLIM mode imaging to reduce the number of scanned pixels and the data readout time, respectively. Moreover, we developed a compressed sensing analysis algorithm based on alternating descent conditional gradient (ADCG) for low-photon-count data. We applied the ADCG-FLIM algorithm on both simulated and experimental datasets to evaluate its performance. The results showed that ADCG-FLIM could achieve reliable lifetime estimation with high accuracy and precision in the case of a photon count less than 100. By reducing the photon count requirement for each pixel from, typically, 1000 to 100, the acquisition time for a single frame lifetime image could be significantly shortened, and the imaging speed could be improved to a great extent. On this basis, we obtained lifetime trajectories of moving fluorescent beads using the SPT-FLIM technique. Overall, our work offers a powerful tool for fluorescence lifetime tracking and imaging of single moving particles, which will promote the application of TCSPC-FLIM in biological research.
Collapse
|
26
|
Fluorescence lifetime imaging through scattering media. Sci Rep 2023; 13:3066. [PMID: 36810512 PMCID: PMC9944959 DOI: 10.1038/s41598-023-30055-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 02/15/2023] [Indexed: 02/24/2023] Open
Abstract
Fluorescence lifetime determination has proven to be useful, e.g. identification of molecules, quantitative estimation of species concentration and determination of temperatures. Lifetime determination of exponentially decaying signals is challenging if signals of different decay rates are being mixed, resulting in erroneous results. Such issues occur when the contrast of the measurement object is low, which can be limiting in applied measurements due to spurious light scattering. A solution is presented here where structured illumination is used to enhance image contrast in fluorescence lifetime wide-field imaging. Lifetime imaging determination was carried out using Dual Imaging Modeling Evaluation (DIME), and spatial lock-in analysis was used for removing spurious scattered signal to enable fluorescence lifetime imaging through scattering media.
Collapse
|
27
|
Humphries DC, O’Connor RA, Stewart HL, Quinn TM, Gaughan EE, Mills B, Williams GO, Stone JM, Finlayson K, Chabaud-Riou M, Boudet F, Dhaliwal K, Pavot V. Specific in situ immuno-imaging of pulmonary-resident memory lymphocytes in human lungs. Front Immunol 2023; 14:1100161. [PMID: 36845117 PMCID: PMC9951616 DOI: 10.3389/fimmu.2023.1100161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 01/30/2023] [Indexed: 02/12/2023] Open
Abstract
Introduction Pulmonary-resident memory T cells (TRM) and B cells (BRM) orchestrate protective immunity to reinfection with respiratory pathogens. Developing methods for the in situ detection of these populations would benefit both research and clinical settings. Methods To address this need, we developed a novel in situ immunolabelling approach combined with clinic-ready fibre-based optical endomicroscopy (OEM) to detect canonical markers of lymphocyte tissue residency in situ in human lungs undergoing ex vivo lung ventilation (EVLV). Results Initially, cells from human lung digests (confirmed to contain TRM/BRM populations using flow cytometry) were stained with CD69 and CD103/CD20 fluorescent antibodies and imaged in vitro using KronoScan, demonstrating it's ability to detect antibody labelled cells. We next instilled these pre-labelled cells into human lungs undergoing EVLV and confirmed they could still be visualised using both fluorescence intensity and lifetime imaging against background lung architecture. Finally, we instilled fluorescent CD69 and CD103/CD20 antibodies directly into the lung and were able to detect TRM/BRM following in situ labelling within seconds of direct intra-alveolar delivery of microdoses of fluorescently labelled antibodies. Discussion In situ, no wash, immunolabelling with intra-alveolar OEM imaging is a novel methodology with the potential to expand the experimental utility of EVLV and pre-clinical models.
Collapse
Affiliation(s)
- Duncan C. Humphries
- Translational Healthcare Technologies Group, Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom,Research & Development, Sanofi, Marcy L’Etoile, France
| | - Richard A. O’Connor
- Translational Healthcare Technologies Group, Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Hazel L. Stewart
- Translational Healthcare Technologies Group, Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Tom M. Quinn
- Translational Healthcare Technologies Group, Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Erin E. Gaughan
- Translational Healthcare Technologies Group, Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Beth Mills
- Translational Healthcare Technologies Group, Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Gareth O.S. Williams
- Translational Healthcare Technologies Group, Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - James M. Stone
- Translational Healthcare Technologies Group, Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom,Centre for Photonic and Physics, Bath University, Bath, United Kingdom
| | - Keith Finlayson
- Translational Healthcare Technologies Group, Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | | | | | - Kevin Dhaliwal
- Translational Healthcare Technologies Group, Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom,*Correspondence: Kevin Dhaliwal, ; Vincent Pavot,
| | - Vincent Pavot
- Research & Development, Sanofi, Marcy L’Etoile, France,*Correspondence: Kevin Dhaliwal, ; Vincent Pavot,
| |
Collapse
|
28
|
Lionetti MC, La Porta CAM. FLIM-FRET Investigation of Heterogeneous Huntingtin Aggregation in HeLa Cells. Methods Mol Biol 2023; 2551:595-604. [PMID: 36310227 DOI: 10.1007/978-1-0716-2597-2_36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Fluorescence lifetime imaging microscopy-fluorescence resonance energy transfer (FLIM-FRET) technique is a novel tool to study protein-protein interaction combining FRET detection, lifetime measurements, and high-resolution imaging. This chapter describes a FLIM-FRET protocol for the detection and quantification of heterogeneous huntingtin aggregates in HeLa cells co-transfected with huntingtin variants containing polyglutamine tracts of different lengths.
Collapse
Affiliation(s)
- Maria Chiara Lionetti
- Center for Complexity and Biosystems, Department of Environmental Science and Policy, University of Milan, Milano, Italy
| | - Caterina Anna Maria La Porta
- Center for Complexity and Biosystems, Department of Environmental Science and Policy, University of Milan, Milano, Italy.
| |
Collapse
|
29
|
Zhang G, Yang Y, Zhang C, Cao X, Liu L, Li L, Han X. Measurement of focal light spot at single-photon level with silicon photomultipliers. Sci Rep 2022; 12:15060. [PMID: 36064950 PMCID: PMC9445098 DOI: 10.1038/s41598-022-17759-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 07/30/2022] [Indexed: 11/09/2022] Open
Abstract
Focal spot (light spot) at single-photon level have important applications in many fields. This report demonstrates a method for measuring focal spot size at the single-photon level indirectly. This method utilizes Silicon Photomultiplier (SiPM) as the single-photon sensitive detectors, combined with a nano-positioning stage. The approach involves one- or two-dimensional space scanning and a deconvolution operation, which enable evaluations of the size and spatial distribution of the focal spot formed by a single-photon-level pulsed laser. The results indicate that the average full width at half maximum of the focal spot is about 0.657 μm, which is close to the nominal resolution of the objective lens of the microscope (i.e. 0.42 μm). The proposed method has two key advantages: (1) it can measure focal spot at the single-photon level, and (2) the focal spot can easily be aligned with the detector because the array area of the Geiger mode avalanche photodiode (Gm-APD) cells in SiPM is usually on the order of square millimeter, and there is no need to put an optical slit, knife edge, or pinhole in front of the detector. The method described herein is applicable in weak focal spot detection related fields.
Collapse
Affiliation(s)
- Guoqing Zhang
- School of Science, Xi'an Polytechnic University, Xi'an, 710048, China.
| | - Yaxian Yang
- School of Science, Xi'an Polytechnic University, Xi'an, 710048, China
| | - Chen Zhang
- School of Science, Xi'an Polytechnic University, Xi'an, 710048, China
| | - Xinyue Cao
- School of Science, Xi'an Polytechnic University, Xi'an, 710048, China
| | - Lina Liu
- School of Science, Xi'an University of Technology, Xi'an, 710048, China
| | - Lianbi Li
- School of Science, Xi'an Polytechnic University, Xi'an, 710048, China
| | - Xiaoxiang Han
- School of Science, Xi'an Polytechnic University, Xi'an, 710048, China
| |
Collapse
|
30
|
Alhibah M, Kröger M, Schanzer S, Busch L, Lademann J, Beckers I, Meinke MC, Darvin ME. Penetration Depth of Propylene Glycol, Sodium Fluorescein and Nile Red into the Skin Using Non-Invasive Two-Photon Excited FLIM. Pharmaceutics 2022; 14:pharmaceutics14091790. [PMID: 36145537 PMCID: PMC9506119 DOI: 10.3390/pharmaceutics14091790] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 11/30/2022] Open
Abstract
The stratum corneum (SC) forms a strong barrier against topical drug delivery. Therefore, understanding the penetration depth and pathways into the SC is important for the efficiency of drug delivery and cosmetic safety. In this study, TPT-FLIM (two-photon tomography combined with fluorescence lifetime imaging) was applied as a non-invasive optical method for the visualization of skin structure and components to study penetration depths of exemplary substances, like hydrophilic propylene glycol (PG), sodium fluorescein (NaFl) and lipophilic Nile red (NR) into porcine ear skin ex vivo. Non-fluorescent PG was detected indirectly based on the pH-dependent increase in the fluorescence lifetime of SC components. The pH similarity between PG and viable epidermis limited the detection of PG. NaFl reached the viable epidermis, which was also proved by laser scanning microscopy. Tape stripping and confocal Raman micro-spectroscopy were performed additionally to study NaFl, which revealed penetration depths of ≈5 and ≈8 μm, respectively. Lastly, NR did not permeate the SC. We concluded that the amplitude-weighted mean fluorescence lifetime is the most appropriate FLIM parameter to build up penetration profiles. This work is anticipated to provide a non-invasive TPT-FLIM method for studying the penetration of topically applied drugs and cosmetics into the skin.
Collapse
Affiliation(s)
- Mohammad Alhibah
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany
- Department of Mathematics, Physics and Chemistry, Berliner Hochschule für Technik, Luxemburger Straße 10, 13353 Berlin, Germany
| | - Marius Kröger
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Sabine Schanzer
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Loris Busch
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany
- Department of Pharmaceutics and Biopharmaceutics, Philipps University Marburg, 35037 Marburg, Germany
| | - Jürgen Lademann
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Ingeborg Beckers
- Department of Mathematics, Physics and Chemistry, Berliner Hochschule für Technik, Luxemburger Straße 10, 13353 Berlin, Germany
| | - Martina C. Meinke
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany
- Correspondence: ; Tel.: +49-30-450-518-244
| | - Maxim E. Darvin
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany
| |
Collapse
|
31
|
Morando MA, Venturella F, Sollazzo M, Monaca E, Sabbatella R, Vetri V, Passantino R, Pastore A, Alfano C. Solution structure of recombinant Pvfp-5β reveals insights into mussel adhesion. Commun Biol 2022; 5:739. [PMID: 35879391 PMCID: PMC9314366 DOI: 10.1038/s42003-022-03699-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 07/11/2022] [Indexed: 11/27/2022] Open
Abstract
Some marine organisms can resist to aqueous tidal environments and adhere tightly on wet surface. This behavior has raised increasing attention for potential applications in medicine, biomaterials, and tissue engineering. In mussels, adhesive forces to the rock are the resultant of proteinic fibrous formations called byssus. We present the solution structure of Pvfp-5β, one of the three byssal plaque proteins secreted by the Asian green mussel Perna viridis, and the component responsible for initiating interactions with the substrate. We demonstrate that Pvfp-5β has a stably folded structure in agreement with the presence in the sequence of two EGF motifs. The structure is highly rigid except for a few residues affected by slow local motions in the µs-ms time scale, and differs from the model calculated by artificial intelligence methods for the relative orientation of the EGF modules, which is something where computational methods still underperform. We also show that Pvfp-5β is able to coacervate even with no DOPA modification, giving thus insights both for understanding the adhesion mechanism of adhesive mussel proteins, and developing of biomaterials.
Collapse
Affiliation(s)
- Maria Agnese Morando
- Structural Biology and Biophysics Unit, Fondazione Ri.MED, 90133, Palermo, Italy
| | - Francesca Venturella
- Structural Biology and Biophysics Unit, Fondazione Ri.MED, 90133, Palermo, Italy
| | - Martina Sollazzo
- Structural Biology and Biophysics Unit, Fondazione Ri.MED, 90133, Palermo, Italy
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128, Palermo, Italy
| | - Elisa Monaca
- Structural Biology and Biophysics Unit, Fondazione Ri.MED, 90133, Palermo, Italy
| | - Raffaele Sabbatella
- Structural Biology and Biophysics Unit, Fondazione Ri.MED, 90133, Palermo, Italy
| | - Valeria Vetri
- Department of Physics and Chemistry-Emilio Segrè (DiFC), University of Palermo, 90128, Palermo, Italy
| | - Rosa Passantino
- Biophysics Institute, National Research Council, 90143, Palermo, Italy
| | - Annalisa Pastore
- European Synchrotron Radiation Facility, Ave des Martyrs, 38000, Grenoble, France
| | - Caterina Alfano
- Structural Biology and Biophysics Unit, Fondazione Ri.MED, 90133, Palermo, Italy.
| |
Collapse
|
32
|
Li B, Zhao M, Lin J, Huang P, Chen X. Management of fluorescent organic/inorganic nanohybrids for biomedical applications in the NIR-II region. Chem Soc Rev 2022; 51:7692-7714. [PMID: 35861173 DOI: 10.1039/d2cs00131d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biomedical fluorescence imaging in the second near-infrared (NIR-II, 100-1700 nm) window provides great potential for visualizing physiological and pathological processes, owing to the reduced tissue absorption, scattering, and autofluorescence. Various types of NIR-II probes have been reported in the past decade. Among them, NIR-II organic/inorganic nanohybrids have attracted widespread attention due to their unique properties by integrating the advantages of both organic and inorganic species. Versatile organic/inorganic nanohybrids provide the possibility of realizing a combination of functions, controllable size, and multiple optical features. This tutorial review summarizes the reported organic and inorganic species in nanohybrids, and their biomedical applications in NIR-II fluorescence and lifetime imaging. Finally, the challenges and outlook of organic/inorganic nanohybrids in biomedical applications are discussed.
Collapse
Affiliation(s)
- Benhao Li
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen 518060, China. .,Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and Faculty of Engineering, National University of Singapore, Singapore, 119074, Singapore. .,Clinical Imaging Research Centre, Centre for Translational Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore.,Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Mengyao Zhao
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and Faculty of Engineering, National University of Singapore, Singapore, 119074, Singapore. .,Clinical Imaging Research Centre, Centre for Translational Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore.,Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Jing Lin
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen 518060, China.
| | - Peng Huang
- Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen 518060, China.
| | - Xiaoyuan Chen
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and Faculty of Engineering, National University of Singapore, Singapore, 119074, Singapore. .,Clinical Imaging Research Centre, Centre for Translational Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore.,Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| |
Collapse
|
33
|
Kaeokhamloed N, Legeay S, Roger E. FRET as the tool for in vivo nanomedicine tracking. J Control Release 2022; 349:156-173. [PMID: 35779657 DOI: 10.1016/j.jconrel.2022.06.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/20/2022] [Accepted: 06/25/2022] [Indexed: 11/29/2022]
Abstract
Advanced drug delivery system utilizing a nanocarrier is the major application of nanotechnology on pharmacotherapeutics. However, despite the promising benefits and a leading trend in pharmaceutical research, nanomedicine development suffers from a poor clinical translation problem as only a handful of nanomedicine products reach the market yearly. The conventional pharmacokinetic study generally focuses only on monitoring the level of a free drug but ignores the nanocarrier's role in pharmacokinetics. One hurdle is that it is difficult to directly track intact nanocarriers in vivo to explore their pharmacokinetics. Although several imaging techniques such as radiolabeling, nuclear imaging, fluorescence imaging, etc., have been developed over the past few years, currently, one method that can successfully track the intact nanocarriers in vivo directly is by Förster resonance energy transfer (FRET). This review summarizes the application of FRET as the in vivo nanoparticle tracker for studying the in vivo pharmacokinetics of the organic nanocarriers and gives elaborative details on the techniques utilized.
Collapse
Affiliation(s)
| | - Samuel Legeay
- MINT, INSERM U1066, CNRS 6021, SFR-ICAT, University of Angers, 49333 Angers, France
| | - Emilie Roger
- MINT, INSERM U1066, CNRS 6021, SFR-ICAT, University of Angers, 49333 Angers, France.
| |
Collapse
|
34
|
Xiao D, Zang Z, Wang Q, Jiao Z, Rocca FMD, Chen Y, Li DDU. Smart Wide-field Fluorescence Lifetime Imaging System with CMOS Single-photon Avalanche Diode Arrays. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2022; 2022:1887-1890. [PMID: 36086288 DOI: 10.1109/embc48229.2022.9870996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Wide-field fluorescence lifetime imaging (FLIM) is a promising technique for biomedical and clinic applications. Integrating with CMOS single-photon avalanche diode (SPAD) sensor arrays can lead to cheaper and portable real-time FLIM systems. However, the FLIM data obtained by such sensor systems often have sophisticated noise features. There is still a lack of fast tools to recover lifetime parameters from highly noise-corrupted fluorescence signals efficiently. This paper proposes a smart wide-field FLIM system containing a 192×128 COMS SPAD sensor and a field-programmable gate array (FPGA) embedded deep learning (DL) FLIM processor. The processor adopts a hardware-friendly and light-weighted neural network for fluorescence lifetime analysis, showing the advantages of high accuracy against noise, fast speed, and low power consumption. Experimental results demonstrate the proposed system's superior and robust performances, promising for many FLIM applications such as FLIM-guided clinical surgeries, cancer diagnosis, and biomedical imaging.
Collapse
|
35
|
A layer-level multi-scale architecture for lung cancer classification with fluorescence lifetime imaging endomicroscopy. Neural Comput Appl 2022. [DOI: 10.1007/s00521-022-07481-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AbstractIn this paper, we introduce our unique dataset of fluorescence lifetime imaging endo/microscopy (FLIM), containing over 100,000 different FLIM images collected from 18 pairs of cancer/non-cancer human lung tissues of 18 patients by our custom fibre-based FLIM system. The aim of providing this dataset is that more researchers from relevant fields can push forward this particular area of research. Afterwards, we describe the best practice of image post-processing suitable per the dataset. In addition, we propose a novel hierarchically aggregated multi-scale architecture to improve the binary classification performance of classic CNNs. The proposed model integrates the advantages of multi-scale feature extraction at different levels, where layer-wise global information is aggregated with branch-wise local information. We integrate the proposal, namely ResNetZ, into ResNet, and appraise it on the FLIM dataset. Since ResNetZ can be configured with a shortcut connection and the aggregations by Addition or Concatenation, we first evaluate the impact of different configurations on the performance. We thoroughly examine various ResNetZ variants to demonstrate the superiority. We also compare our model with a feature-level multi-scale model to illustrate the advantages and disadvantages of multi-scale architectures at different levels.
Collapse
|
36
|
Becker L, Fischer F, Fleck JL, Harland N, Herkommer A, Stenzl A, Aicher WK, Schenke-Layland K, Marzi J. Data-Driven Identification of Biomarkers for In Situ Monitoring of Drug Treatment in Bladder Cancer Organoids. Int J Mol Sci 2022; 23:ijms23136956. [PMID: 35805961 PMCID: PMC9266781 DOI: 10.3390/ijms23136956] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 02/01/2023] Open
Abstract
Three-dimensional (3D) organoid culture recapitulating patient-specific histopathological and molecular diversity offers great promise for precision medicine in cancer. In this study, we established label-free imaging procedures, including Raman microspectroscopy (RMS) and fluorescence lifetime imaging microscopy (FLIM), for in situ cellular analysis and metabolic monitoring of drug treatment efficacy. Primary tumor and urine specimens were utilized to generate bladder cancer organoids, which were further treated with various concentrations of pharmaceutical agents relevant for the treatment of bladder cancer (i.e., cisplatin, venetoclax). Direct cellular response upon drug treatment was monitored by RMS. Raman spectra of treated and untreated bladder cancer organoids were compared using multivariate data analysis to monitor the impact of drugs on subcellular structures such as nuclei and mitochondria based on shifts and intensity changes of specific molecular vibrations. The effects of different drugs on cell metabolism were assessed by the local autofluorophore environment of NADH and FAD, determined by multiexponential fitting of lifetime decays. Data-driven neural network and data validation analyses (k-means clustering) were performed to retrieve additional and non-biased biomarkers for the classification of drug-specific responsiveness. Together, FLIM and RMS allowed for non-invasive and molecular-sensitive monitoring of tumor-drug interactions, providing the potential to determine and optimize patient-specific treatment efficacy.
Collapse
Affiliation(s)
- Lucas Becker
- Department for Medical Technologies and Regenerative Medicine, Institute of Biomedical Engineering, University of Tuebingen, 72076 Tuebingen, Germany; (L.B.); (K.S.-L.)
- Cluster of Excellence iFIT (EXC 2180) “Image-Guided and Functionally Instructed Tumor Therapies”, University of Tuebingen, 72076 Tuebingen, Germany
| | - Felix Fischer
- Institute of Applied Optics (ITO), University of Stuttgart, 70569 Stuttgart, Germany; (F.F.); (A.H.)
| | - Julia L. Fleck
- Mines Saint-Etienne, CNRS, UMR 6158 LIMOS, Centre CIS, Université Clermont Auvergne, 42270 Saint Jarez-en-Priest, France;
| | - Niklas Harland
- Department of Urology, University of Tuebingen Hospital, 72076 Tuebingen, Germany; (N.H.); (A.S.)
| | - Alois Herkommer
- Institute of Applied Optics (ITO), University of Stuttgart, 70569 Stuttgart, Germany; (F.F.); (A.H.)
| | - Arnulf Stenzl
- Department of Urology, University of Tuebingen Hospital, 72076 Tuebingen, Germany; (N.H.); (A.S.)
| | - Wilhelm K. Aicher
- Center of Medical Research, Department of Urology at UKT, University of Tuebingen, 72076 Tuebingen, Germany;
| | - Katja Schenke-Layland
- Department for Medical Technologies and Regenerative Medicine, Institute of Biomedical Engineering, University of Tuebingen, 72076 Tuebingen, Germany; (L.B.); (K.S.-L.)
- Cluster of Excellence iFIT (EXC 2180) “Image-Guided and Functionally Instructed Tumor Therapies”, University of Tuebingen, 72076 Tuebingen, Germany
- NMI Natural and Medical Sciences Institute at the University of Tueingen, 72770 Reutlingen, Germany
| | - Julia Marzi
- Department for Medical Technologies and Regenerative Medicine, Institute of Biomedical Engineering, University of Tuebingen, 72076 Tuebingen, Germany; (L.B.); (K.S.-L.)
- Cluster of Excellence iFIT (EXC 2180) “Image-Guided and Functionally Instructed Tumor Therapies”, University of Tuebingen, 72076 Tuebingen, Germany
- NMI Natural and Medical Sciences Institute at the University of Tueingen, 72770 Reutlingen, Germany
- Correspondence:
| |
Collapse
|
37
|
Dziuba D. Environmentally sensitive fluorescent nucleoside analogues as probes for nucleic acid - protein interactions: molecular design and biosensing applications. Methods Appl Fluoresc 2022; 10. [PMID: 35738250 DOI: 10.1088/2050-6120/ac7bd8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 06/23/2022] [Indexed: 11/12/2022]
Abstract
Fluorescent nucleoside analogues (FNAs) are indispensable in studying the interactions of nucleic acids with nucleic acid-binding proteins. By replacing one of the poorly emissive natural nucleosides, FNAs enable real-time optical monitoring of the binding interactions in solutions, under physiologically relevant conditions, with high sensitivity. Besides that, FNAs are widely used to probe conformational dynamics of biomolecular complexes using time-resolved fluorescence methods. Because of that, FNAs are tools of high utility for fundamental biological research, with potential applications in molecular diagnostics and drug discovery. Here I review the structural and physical factors that can be used for the conversion of the molecular binding events into a detectable fluorescence output. Typical environmentally sensitive FNAs, their properties and applications, and future challenges in the field are discussed.
Collapse
Affiliation(s)
- Dmytro Dziuba
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, 74 Route du Rhin, Illkirch-Graffenstaden, Grand Est, 67401, FRANCE
| |
Collapse
|
38
|
Giri D, Raut SK, Behera CK, Patra SK. Diketopyrrollopyrrole anchored carbazole-alt-thiophene based Fe3+-coordinated metallopolymer for the selective recognition of ATP. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.124951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
39
|
Xiao D, Zang Z, Xie W, Sapermsap N, Chen Y, Uei Li DD. Spatial resolution improved fluorescence lifetime imaging via deep learning. OPTICS EXPRESS 2022; 30:11479-11494. [PMID: 35473091 DOI: 10.1364/oe.451215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 03/12/2022] [Indexed: 06/14/2023]
Abstract
We present a deep learning approach to obtain high-resolution (HR) fluorescence lifetime images from low-resolution (LR) images acquired from fluorescence lifetime imaging (FLIM) systems. We first proposed a theoretical method for training neural networks to generate massive semi-synthetic FLIM data with various cellular morphologies, a sizeable dynamic lifetime range, and complex decay components. We then developed a degrading model to obtain LR-HR pairs and created a hybrid neural network, the spatial resolution improved FLIM net (SRI-FLIMnet) to simultaneously estimate fluorescence lifetimes and realize the nonlinear transformation from LR to HR images. The evaluative results demonstrate SRI-FLIMnet's superior performance in reconstructing spatial information from limited pixel resolution. We also verified SRI-FLIMnet using experimental images of bacterial infected mouse raw macrophage cells. Results show that the proposed data generation method and SRI-FLIMnet efficiently achieve superior spatial resolution for FLIM applications. Our study provides a solution for fast obtaining HR FLIM images.
Collapse
|
40
|
A near-infrared plasma membrane-specific AIE probe for fluorescence lifetime imaging of phagocytosis. Sci China Chem 2022. [DOI: 10.1007/s11426-021-1199-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AbstractPhagocytosis is a biological process that plays a key role in host defense and tissue homeostasis. Efficient approaches for realtime imaging of phagocytosis are highly desired but limited. Herein, an AIE-active near-infrared fluorescent probe, named TBTCP, was developed for fluorescence lifetime imaging of phagocytosis. TBTCP could selectively label the cell plasma membrane with fast staining, wash-free process, high signal-to-background ratio, and excellent photostability. Cellular membrane statuses under different osmolarities as well as macrophage phagocytosis of bacteria or large silica particles in early stages could be reported by the fluorescence lifetime changes of TBTCP. Compared with current fluorescence imaging methods, which target the bioenvironmental changes in the late phagocytosis stage, this approach detects the changes in the cell membrane, thus giving a faster response to phagocytosis. This article provides a functional tool to report the phagocytic dynamics of macrophages which may greatly contribute to the studies of phagocytic function-related diseases.
Collapse
|
41
|
Fazel M, Jazani S, Scipioni L, Vallmitjana A, Gratton E, Digman MA, Pressé S. High Resolution Fluorescence Lifetime Maps from Minimal Photon Counts. ACS PHOTONICS 2022; 9:1015-1025. [PMID: 35847830 PMCID: PMC9278809 DOI: 10.1021/acsphotonics.1c01936] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) may reveal subcellular spatial lifetime maps of key molecular species. Yet, such a quantitative picture of life necessarily demands high photon budgets at every pixel under the current analysis paradigm, thereby increasing acquisition time and photodamage to the sample. Motivated by recent developments in computational statistics, we provide a direct means to update our knowledge of the lifetime maps of species of different lifetimes from direct photon arrivals, while accounting for experimental features such as arbitrary forms of the instrument response function (IRF) and exploiting information from empty laser pulses not resulting in photon detection. Our ability to construct lifetime maps holds for arbitrary lifetimes, from short lifetimes (comparable to the IRF) to lifetimes exceeding interpulse times. As our method is highly data efficient, for the same amount of data normally used to determine lifetimes and photon ratios, working within the Bayesian paradigm, we report direct blind unmixing of lifetimes with subnanosecond resolution and subpixel spatial resolution using standard raster scan FLIM images. We demonstrate our method using a wide range of simulated and experimental data.
Collapse
Affiliation(s)
- Mohamadreza Fazel
- Center
for Biological Physics, Department of Physics, Arizona State University, Tempe, Arizona 85287, United States
| | - Sina Jazani
- Center
for Biological Physics, Department of Physics, Arizona State University, Tempe, Arizona 85287, United States
| | - Lorenzo Scipioni
- Department
of Biomedical Engineering, University of
California Irvine, Irvine, California 92697, United States
- Laboratory
of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Alexander Vallmitjana
- Department
of Biomedical Engineering, University of
California Irvine, Irvine, California 92697, United States
- Laboratory
of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Enrico Gratton
- Department
of Biomedical Engineering, University of
California Irvine, Irvine, California 92697, United States
- Laboratory
of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Michelle A. Digman
- Department
of Biomedical Engineering, University of
California Irvine, Irvine, California 92697, United States
- Laboratory
of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Steve Pressé
- Center
for Biological Physics, Department of Physics, Arizona State University, Tempe, Arizona 85287, United States
- School
of Molecular Science, Arizona State University, Tempe, Arizona 85287, United States
- E-mail:
| |
Collapse
|
42
|
Herrera-Ochoa D, Pacheco-Liñán PJ, Bravo I, Garzón-Ruiz A. A Novel Quantum Dot-Based pH Probe for Long-Term Fluorescence Lifetime Imaging Microscopy Experiments in Living Cells. ACS APPLIED MATERIALS & INTERFACES 2022; 14:2578-2586. [PMID: 35001616 PMCID: PMC8778634 DOI: 10.1021/acsami.1c19926] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 12/28/2021] [Indexed: 06/14/2023]
Abstract
The use of two nanoparticles for quantitative pH measurements in live cells by means of fluorescence lifetime imaging microscopy (FLIM) is investigated here. These nanoparticles are based on CdSe/ZnS quantum dots (QDs), functionalized with N-acetylcysteine (CdSe/ZnS-A) and with a small peptide containing D-penicillamine and histidine (CdSe/ZnS-PH). CdSe/ZnS-A has tendency to aggregate and nonlinear pH sensitivity in a complex medium containing salts and macromolecules. On the contrary, CdSe/ZnS-PH shows chemical stability, low toxicity, efficient uptake in C3H10T1/2 cells, and good performance as an FLIM probe. CdSe/ZnS-PH also has key advantages over a recently reported probe based on a CdSe/ZnS QD functionalized with D-penicillamine (longer lifetimes and higher pH-sensitivity). A pH(±2σ) of 6.97 ± 0.14 was determined for C3H10T1/2 cells by FLIM employing this nanoprobe. In addition, the fluorescence lifetime signal remains nearly constant for C3H10T1/2 cells treated with CdSe/ZnS-PH for 24 h. These results show the promising applications of this nanoprobe to monitor the intracellular pH and cell state employing the FLIM technique.
Collapse
Affiliation(s)
- Diego Herrera-Ochoa
- Departamento
de Química Física, Facultad de Farmacia, Universidad de Castilla-La Mancha, Av. Dr. José María
Sánchez Ibáñez, s/n, 02071 Albacete, Spain
| | - Pedro J. Pacheco-Liñán
- Departamento
de Química Física, Facultad de Farmacia, Universidad de Castilla-La Mancha, Av. Dr. José María
Sánchez Ibáñez, s/n, 02071 Albacete, Spain
| | - Iván Bravo
- Departamento
de Química Física, Facultad de Farmacia, Universidad de Castilla-La Mancha, Av. Dr. José María
Sánchez Ibáñez, s/n, 02071 Albacete, Spain
- Centro
Regional de Investigaciones Biomédicas (CRIB), Unidad Asociada de Biomedicina (UCLM-CSIC), C/Almansa, 14, 02008 Albacete, Spain
| | - Andrés Garzón-Ruiz
- Departamento
de Química Física, Facultad de Farmacia, Universidad de Castilla-La Mancha, Av. Dr. José María
Sánchez Ibáñez, s/n, 02071 Albacete, Spain
| |
Collapse
|
43
|
Chen YI, Chang YJ, Liao SC, Nguyen TD, Yang J, Kuo YA, Hong S, Liu YL, Rylander HG, Santacruz SR, Yankeelov TE, Yeh HC. Generative adversarial network enables rapid and robust fluorescence lifetime image analysis in live cells. Commun Biol 2022; 5:18. [PMID: 35017629 PMCID: PMC8752789 DOI: 10.1038/s42003-021-02938-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 11/24/2021] [Indexed: 11/09/2022] Open
Abstract
Fluorescence lifetime imaging microscopy (FLIM) is a powerful tool to quantify molecular compositions and study molecular states in complex cellular environment as the lifetime readings are not biased by fluorophore concentration or excitation power. However, the current methods to generate FLIM images are either computationally intensive or unreliable when the number of photons acquired at each pixel is low. Here we introduce a new deep learning-based method termed flimGANE (fluorescence lifetime imaging based on Generative Adversarial Network Estimation) that can rapidly generate accurate and high-quality FLIM images even in the photon-starved conditions. We demonstrated our model is up to 2,800 times faster than the gold standard time-domain maximum likelihood estimation (TD_MLE) and that flimGANE provides a more accurate analysis of low-photon-count histograms in barcode identification, cellular structure visualization, Förster resonance energy transfer characterization, and metabolic state analysis in live cells. With its advantages in speed and reliability, flimGANE is particularly useful in fundamental biological research and clinical applications, where high-speed analysis is critical.
Collapse
Affiliation(s)
- Yuan-I Chen
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Yin-Jui Chang
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Shih-Chu Liao
- ISS, Inc., 1602 Newton Drive, Champaign, IL, 61822, USA
| | - Trung Duc Nguyen
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Jianchen Yang
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Yu-An Kuo
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Soonwoo Hong
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Yen-Liang Liu
- Master Program for Biomedical Engineering, China Medical University, Taichung, 406040, Taiwan
- Research Center for Cancer Biology, China Medical University, Taichung, 406040, Taiwan
| | - H Grady Rylander
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Samantha R Santacruz
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
- Institute for Neuroscience, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Thomas E Yankeelov
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
- Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Diagnostic Medicine, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Oncology, The University of Texas at Austin, Austin, TX, 78712, USA
- Livestrong Cancer Institutes, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Hsin-Chih Yeh
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA.
- Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA.
| |
Collapse
|
44
|
Farina S, Labanca I, Acconcia G, Ghezzi A, Farina A, D'Andrea C, Rech I. Above pile-up fluorescence microscopy with a 32 Mc/s single-channel time-resolved SPAD system. OPTICS LETTERS 2022; 47:82-85. [PMID: 34951886 DOI: 10.1364/ol.444815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/15/2021] [Indexed: 06/14/2023]
Abstract
One of the major drawbacks of time-correlated single-photon counting (TCSPC) is generally represented by pile-up distortion, which strongly bounds the maximum acquisition speed to a few percent of the laser excitation rate. Based on a previous theoretical analysis, recently we presented the first, to the best of our knowledge, low-distortion and high-speed TCSPC system capable of overcoming the pile-up limitation by perfectly matching the single-photon avalanche diode (SPAD) dead time to the laser period. In this work, we validate the proposed system in a standard fluorescence measurement by comparing experimental data with the reference theoretical framework. As a result, a count rate of 32 Mc/s was achieved with a single-channel system still observing a negligible lifetime distortion.
Collapse
|
45
|
Estrada H, Robin J, Özbek A, Chen Z, Marowsky A, Zhou Q, Beck D, le Roy B, Arand M, Shoham S, Razansky D. High-resolution fluorescence-guided transcranial ultrasound mapping in the live mouse brain. SCIENCE ADVANCES 2021; 7:eabi5464. [PMID: 34878843 PMCID: PMC8654306 DOI: 10.1126/sciadv.abi5464] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 10/19/2021] [Indexed: 05/28/2023]
Abstract
Understanding the physiological impact of transcranial ultrasound in rodent brains may offer an important preclinical model for human scale magnetic resonance–guided focused ultrasound methods. However, precision tools for high-resolution transcranial ultrasound targeting and real-time in vivo tracking of its effects at the mouse brain scale are currently lacking. We report a versatile bidirectional hybrid fluorescence-ultrasound (FLUS) system incorporating a 0.35-mm precision spherical-phased array ultrasound emission with a fiberscope-based wide-field fluorescence imaging. We show how the marriage between cortex-wide functional imaging and targeted ultrasound delivery can be used to transcranially map previously undocumented localized fluorescence events caused by reversible thermal processes and perform high-speed large-scale recording of neural activity induced by focused ultrasound. FLUS thus naturally harnesses the extensive toolbox of fluorescent tags and ultrasound’s localized bioeffects toward visualizing and causally perturbing a plethora of normal and pathophysiological processes in the living murine brain.
Collapse
Affiliation(s)
- Hector Estrada
- Institute of Pharmacology and Toxicology, University of Zurich, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Justine Robin
- Institute of Pharmacology and Toxicology, University of Zurich, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Ali Özbek
- Institute of Pharmacology and Toxicology, University of Zurich, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Zhenyue Chen
- Institute of Pharmacology and Toxicology, University of Zurich, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Anne Marowsky
- Institute of Pharmacology and Toxicology, University of Zurich, Switzerland
| | - Quanyu Zhou
- Institute of Pharmacology and Toxicology, University of Zurich, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Daniel Beck
- Institute of Pharmacology and Toxicology, University of Zurich, Switzerland
| | - Beau le Roy
- Institute of Pharmacology and Toxicology, University of Zurich, Switzerland
| | - Michael Arand
- Institute of Pharmacology and Toxicology, University of Zurich, Switzerland
| | - Shy Shoham
- Department of Ophthalmology and Tech4Health and Neuroscience Institutes, NYU Langone Health, New York, NY 10016, USA
| | - Daniel Razansky
- Institute of Pharmacology and Toxicology, University of Zurich, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| |
Collapse
|
46
|
Bao Y, Kornienko V, Lange D, Kiefer W, Eschrich T, Jäger M, Bood J, Kristensson E, Ehn A. Improved temporal contrast of streak camera measurements with periodic shadowing. OPTICS LETTERS 2021; 46:5723-5726. [PMID: 34780446 DOI: 10.1364/ol.438034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 09/25/2021] [Indexed: 06/13/2023]
Abstract
Periodic shadowing, a concept used in spectroscopy for stray light reduction, has been implemented to improve the temporal contrast of streak camera imaging. The capabilities of this technique are first proven by imaging elastically scattered picosecond laser pulses and are further applied to fluorescence lifetime imaging, where more accurate descriptions of fluorescence decay curves were observed. This all-optical approach can be adapted to various streak camera imaging systems, resulting in a robust technique to minimize space-charge induced temporal dispersion in streak cameras while maintaining temporal coverage and spatial information.
Collapse
|
47
|
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.
Collapse
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
| |
Collapse
|
48
|
Liu X, Skripka A, Lai Y, Jiang C, Liu J, Vetrone F, Liang J. Fast wide-field upconversion luminescence lifetime thermometry enabled by single-shot compressed ultrahigh-speed imaging. Nat Commun 2021; 12:6401. [PMID: 34737314 PMCID: PMC8568918 DOI: 10.1038/s41467-021-26701-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 10/13/2021] [Indexed: 11/13/2022] Open
Abstract
Photoluminescence lifetime imaging of upconverting nanoparticles is increasingly featured in recent progress in optical thermometry. Despite remarkable advances in photoluminescent temperature indicators, existing optical instruments lack the ability of wide-field photoluminescence lifetime imaging in real time, thus falling short in dynamic temperature mapping. Here, we report video-rate upconversion temperature sensing in wide field using single-shot photoluminescence lifetime imaging thermometry (SPLIT). Developed from a compressed-sensing ultrahigh-speed imaging paradigm, SPLIT first records wide-field luminescence intensity decay compressively in two views in a single exposure. Then, an algorithm, built upon the plug-and-play alternating direction method of multipliers, is used to reconstruct the video, from which the extracted lifetime distribution is converted to a temperature map. Using the core/shell NaGdF4:Er3+,Yb3+/NaGdF4 upconverting nanoparticles as the lifetime-based temperature indicators, we apply SPLIT in longitudinal wide-field temperature monitoring beneath a thin scattering medium. SPLIT also enables video-rate temperature mapping of a moving biological sample at single-cell resolution.
Collapse
Affiliation(s)
- Xianglei Liu
- Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, 1650 boulevard Lionel-Boulet, Varennes, Québec, J3X1S2, Canada
| | - Artiom Skripka
- Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, 1650 boulevard Lionel-Boulet, Varennes, Québec, J3X1S2, Canada
- Nanomaterials for Bioimaging Group, Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, 28049, Spain and The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yingming Lai
- Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, 1650 boulevard Lionel-Boulet, Varennes, Québec, J3X1S2, Canada
| | - Cheng Jiang
- Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, 1650 boulevard Lionel-Boulet, Varennes, Québec, J3X1S2, Canada
| | - Jingdan Liu
- Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, 1650 boulevard Lionel-Boulet, Varennes, Québec, J3X1S2, Canada
| | - Fiorenzo Vetrone
- Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, 1650 boulevard Lionel-Boulet, Varennes, Québec, J3X1S2, Canada.
| | - Jinyang Liang
- Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, 1650 boulevard Lionel-Boulet, Varennes, Québec, J3X1S2, Canada.
| |
Collapse
|
49
|
Wang Q, Hopgood JR, Vallejo M. Multi-Scale Aggregated-Dilation Network for ex-vivo Lung Cancer Detection with Fluorescence Lifetime Imaging Endomicroscopy. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:2918-2922. [PMID: 34891856 DOI: 10.1109/embc46164.2021.9630836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Multi-scale architectures at a granular level are characterised by separating input features into groups and applying multi-scale feature extractions to the split input features, and thus the correlations among the input features as global information are no longer retained. Moreover, they usually require more input features due to the separation, and therefore, more complexity is introduced. To retain the global information while utilising the advantages of feature-level hierarchical multi-scale architectures, we propose a multi-scale aggregated-dilation architecture (MSAD) to perform hierarchical fusion of features at a layer level, with the integration of dilated convolutions to overcome these issues. To evaluate the model, we integrate it into ResNet, and apply it to a unique dataset, containing over 60,000 fluorescence lifetime endomicroscopic images (FLIM) collected on ex-vivo lung normal/cancerous tissues from 14 patients, by a custom fibre-based FLIM system. To evaluate the performance of our proposal, we use accuracy, precision, recall, and AUC. We first compare our MSAD model with eight networks achieving a superiority over 6%. To illustrate the advantages and disadvantages of multi-scale architectures at layer and feature-level, we thoroughly compare our MSAD model with the state-of-the-art feature-level multiscale network, namely Res2Net, in terms of parameters, scales, and effective convolutions.
Collapse
|
50
|
Khaliduzzaman A, Omwange KA, Al Riza DF, Konagaya K, Kamruzzaman M, Alom MS, Gao T, Saito Y, Kondo N. Antioxidant assessment of agricultural produce using fluorescence techniques: a review. Crit Rev Food Sci Nutr 2021:1-12. [PMID: 34702101 DOI: 10.1080/10408398.2021.1992747] [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: 10/20/2022]
Abstract
The study of bioactive compounds like food antioxidants is getting huge attention and curiosity by researchers and other relevant stakeholders (e.g., food and pharmaceutical industries) due to their health benefits. However, the currently available protocols to estimate the antioxidant activity of foods are time-consuming, destructive, require complex procedures for sample preparation, need technical persons, and not possible for real-time application, which are very important for large-scale or industrial applications. On the other hand, fluorescence spectroscopy and imaging techniques are relatively new, fast, mostly nondestructive, and possible to apply real-time to detect the antioxidants of foods. However, there is no review article on fluorescence techniques for estimating antioxidants in agricultural produces. Therefore, the present review comprehensively summarizes the overview of fluorescence phenomena, techniques (i.e., spectroscopy and computer vision), and their potential to monitor antioxidants in fruits and vegetables. Finally, opportunities and challenges of fluorescence techniques are described toward developing next-generation protocols for antioxidants measurement. Fluorescence techniques (both spectroscopy and imaging) are simpler and faster than available traditional methods of antioxidants measurement. Moreover, the fluorescence imaging technique has the potential to apply in real-time antioxidant identification in agricultural produce such as fruits and vegetables. Therefore, this technique might be used as a next-generation protocol for qualitative and quantitative antioxidants measurement after improvements like new material technologies for sensor (detector) and light sources for higher sensitivity and reduce the cost of implementing real-world applications.
Collapse
Affiliation(s)
- Alin Khaliduzzaman
- Laboratory of Bio-sensing Engineering, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.,Department of Food Engineering and Technology, Sylhet Agricultural University, Sylhet, Bangladesh
| | - Ken Abamba Omwange
- Laboratory of Bio-sensing Engineering, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Dimas Firmanda Al Riza
- Department of Agricultural Engineering, Faculty of Agricultural Technology, University of Brawijaya, Malang, Indonesia
| | - Keiji Konagaya
- Faculty of Corroborative Regional Innovation, Ehime University, Matsuyama, Ehime, Japan
| | - Mohammed Kamruzzaman
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Md Siddik Alom
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio, USA
| | - Tianqi Gao
- Laboratory of Bio-sensing Engineering, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Yoshito Saito
- Laboratory of Bio-sensing Engineering, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Naoshi Kondo
- Laboratory of Bio-sensing Engineering, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| |
Collapse
|