1
|
Baines O, Sha R, Kalla M, Holmes AP, Efimov IR, Pavlovic D, O’Shea C. Optical mapping and optogenetics in cardiac electrophysiology research and therapy: a state-of-the-art review. Europace 2024; 26:euae017. [PMID: 38227822 PMCID: PMC10847904 DOI: 10.1093/europace/euae017] [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: 10/20/2023] [Revised: 12/07/2023] [Accepted: 01/12/2024] [Indexed: 01/18/2024] Open
Abstract
State-of-the-art innovations in optical cardiac electrophysiology are significantly enhancing cardiac research. A potential leap into patient care is now on the horizon. Optical mapping, using fluorescent probes and high-speed cameras, offers detailed insights into cardiac activity and arrhythmias by analysing electrical signals, calcium dynamics, and metabolism. Optogenetics utilizes light-sensitive ion channels and pumps to realize contactless, cell-selective cardiac actuation for modelling arrhythmia, restoring sinus rhythm, and probing complex cell-cell interactions. The merging of optogenetics and optical mapping techniques for 'all-optical' electrophysiology marks a significant step forward. This combination allows for the contactless actuation and sensing of cardiac electrophysiology, offering unprecedented spatial-temporal resolution and control. Recent studies have performed all-optical imaging ex vivo and achieved reliable optogenetic pacing in vivo, narrowing the gap for clinical use. Progress in optical electrophysiology continues at pace. Advances in motion tracking methods are removing the necessity of motion uncoupling, a key limitation of optical mapping. Innovations in optoelectronics, including miniaturized, biocompatible illumination and circuitry, are enabling the creation of implantable cardiac pacemakers and defibrillators with optoelectrical closed-loop systems. Computational modelling and machine learning are emerging as pivotal tools in enhancing optical techniques, offering new avenues for analysing complex data and optimizing therapeutic strategies. However, key challenges remain including opsin delivery, real-time data processing, longevity, and chronic effects of optoelectronic devices. This review provides a comprehensive overview of recent advances in optical mapping and optogenetics and outlines the promising future of optics in reshaping cardiac electrophysiology and therapeutic strategies.
Collapse
Affiliation(s)
- Olivia Baines
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
| | - Rina Sha
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
| | - Manish Kalla
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
| | - Andrew P Holmes
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
| | - Igor R Efimov
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
- Department of Medicine, Division of Cardiology, Northwestern University, Evanston, IL, USA
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
| | - Christopher O’Shea
- Institute of Cardiovascular Sciences, College of Medical and Dental Science, University of Birmingham, Edgbastion, Wolfson Drive, Birmingham B15 2TT, UK
| |
Collapse
|
2
|
Almasri RM, Ladouceur F, Mawad D, Esrafilzadeh D, Firth J, Lehmann T, Poole-Warren LA, Lovell NH, Al Abed A. Emerging trends in the development of flexible optrode arrays for electrophysiology. APL Bioeng 2023; 7:031503. [PMID: 37692375 PMCID: PMC10491464 DOI: 10.1063/5.0153753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/08/2023] [Indexed: 09/12/2023] Open
Abstract
Optical-electrode (optrode) arrays use light to modulate excitable biological tissues and/or transduce bioelectrical signals into the optical domain. Light offers several advantages over electrical wiring, including the ability to encode multiple data channels within a single beam. This approach is at the forefront of innovation aimed at increasing spatial resolution and channel count in multichannel electrophysiology systems. This review presents an overview of devices and material systems that utilize light for electrophysiology recording and stimulation. The work focuses on the current and emerging methods and their applications, and provides a detailed discussion of the design and fabrication of flexible arrayed devices. Optrode arrays feature components non-existent in conventional multi-electrode arrays, such as waveguides, optical circuitry, light-emitting diodes, and optoelectronic and light-sensitive functional materials, packaged in planar, penetrating, or endoscopic forms. Often these are combined with dielectric and conductive structures and, less frequently, with multi-functional sensors. While creating flexible optrode arrays is feasible and necessary to minimize tissue-device mechanical mismatch, key factors must be considered for regulatory approval and clinical use. These include the biocompatibility of optical and photonic components. Additionally, material selection should match the operating wavelength of the specific electrophysiology application, minimizing light scattering and optical losses under physiologically induced stresses and strains. Flexible and soft variants of traditionally rigid photonic circuitry for passive optical multiplexing should be developed to advance the field. We evaluate fabrication techniques against these requirements. We foresee a future whereby established telecommunications techniques are engineered into flexible optrode arrays to enable unprecedented large-scale high-resolution electrophysiology systems.
Collapse
Affiliation(s)
- Reem M. Almasri
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
| | | | - Damia Mawad
- School of Materials Science and Engineering, UNSW, Sydney, NSW 2052, Australia
| | - Dorna Esrafilzadeh
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
| | - Josiah Firth
- Australian National Fabrication Facility, UNSW, Sydney, NSW 2052, Australia
| | - Torsten Lehmann
- School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052, Australia
| | | | | | - Amr Al Abed
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
| |
Collapse
|
3
|
Ling S, Chen J, Lapierre-Landry M, Suh J, Liu Y, Jenkins MW, Watanabe M, Ford SM, Rollins AM. Automated endocardial cushion segmentation and cellularization quantification in developing hearts using optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2022; 13:5599-5615. [PMID: 36733755 PMCID: PMC9872882 DOI: 10.1364/boe.467629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/17/2022] [Accepted: 08/22/2022] [Indexed: 06/18/2023]
Abstract
Of all congenital heart defects (CHDs), anomalies in heart valves and septa are among the most common and contribute about fifty percent to the total burden of CHDs. Progenitors to heart valves and septa are endocardial cushions formed in looping hearts through a multi-step process that includes localized expansion of cardiac jelly, endothelial-to-mesenchymal transition, cell migration and proliferation. To characterize the development of endocardial cushions, previous studies manually measured cushion size or cushion cell density from images obtained using histology, immunohistochemistry, or optical coherence tomography (OCT). Manual methods are time-consuming and labor-intensive, impeding their applications in cohort studies that require large sample sizes. This study presents an automated strategy to rapidly characterize the anatomy of endocardial cushions from OCT images. A two-step deep learning technique was used to detect the location of the heart and segment endocardial cushions. The acellular and cellular cushion regions were then segregated by K-means clustering. The proposed method can quantify cushion development by measuring the cushion volume and cellularized fraction, and also map 3D spatial organization of the acellular and cellular cushion regions. The application of this method to study the developing looping hearts allowed us to discover a spatial asymmetry of the acellular cardiac jelly in endocardial cushions during these critical stages, which has not been reported before.
Collapse
Affiliation(s)
- Shan Ling
- Department of Biomedical Engineering, School of Engineering and School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jiawei Chen
- Department of Biomedical Engineering, School of Engineering and School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Maryse Lapierre-Landry
- Department of Biomedical Engineering, School of Engineering and School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Junwoo Suh
- Department of Biomedical Engineering, School of Engineering and School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yehe Liu
- Department of Biomedical Engineering, School of Engineering and School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Michael W. Jenkins
- Department of Biomedical Engineering, School of Engineering and School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Pediatrics, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Michiko Watanabe
- Department of Pediatrics, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
- Division of Pediatric Cardiology, The Congenital Heart Collaborative, Rainbow Babies and Children’s Hospital, Cleveland, Ohio, USA
- Division of Neonatology, Rainbow Babies and Children’s Hospital, Cleveland, Ohio, USA
| | - Stephanie M. Ford
- Department of Pediatrics, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
- Division of Pediatric Cardiology, The Congenital Heart Collaborative, Rainbow Babies and Children’s Hospital, Cleveland, Ohio, USA
- Division of Neonatology, Rainbow Babies and Children’s Hospital, Cleveland, Ohio, USA
| | - Andrew M. Rollins
- Department of Biomedical Engineering, School of Engineering and School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| |
Collapse
|
4
|
Wan Y, McDole K, Keller PJ. Light-Sheet Microscopy and Its Potential for Understanding Developmental Processes. Annu Rev Cell Dev Biol 2019; 35:655-681. [PMID: 31299171 DOI: 10.1146/annurev-cellbio-100818-125311] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The ability to visualize and quantitatively measure dynamic biological processes in vivo and at high spatiotemporal resolution is of fundamental importance to experimental investigations in developmental biology. Light-sheet microscopy is particularly well suited to providing such data, since it offers exceptionally high imaging speed and good spatial resolution while minimizing light-induced damage to the specimen. We review core principles and recent advances in light-sheet microscopy, with a focus on concepts and implementations relevant for applications in developmental biology. We discuss how light-sheet microcopy has helped advance our understanding of developmental processes from single-molecule to whole-organism studies, assess the potential for synergies with other state-of-the-art technologies, and introduce methods for computational image and data analysis. Finally, we explore the future trajectory of light-sheet microscopy, discuss key efforts to disseminate new light-sheet technology, and identify exciting opportunities for further advances.
Collapse
Affiliation(s)
- Yinan Wan
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, USA;
| | - Katie McDole
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, USA;
| | - Philipp J Keller
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, USA;
| |
Collapse
|
5
|
Liu B, Hobson CM, Pimenta FM, Nelsen E, Hsiao J, O'Brien T, Falvo MR, Hahn KM, Superfine R. VIEW-MOD: a versatile illumination engine with a modular optical design for fluorescence microscopy. OPTICS EXPRESS 2019; 27:19950-19972. [PMID: 31503749 DOI: 10.1364/oe.27.019950] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 06/19/2019] [Indexed: 05/18/2023]
Abstract
We developed VIEW-MOD (Versatile Illumination Engine with a Modular Optical Design): a compact, multi-modality microscope, which accommodates multiple illumination schemes including variable angle total internal reflection, point scanning and vertical/horizontal light sheet. This system allows combining and flexibly switching between different illuminations and imaging modes by employing three electrically tunable lenses and two fast-steering mirrors. This versatile optics design provides control of 6 degrees of freedom of the illumination source (3 translation, 2 tilt, and beam shape) plus the axial position of the imaging plane. We also developed standalone software with an easy-to-use GUI to calibrate and control the microscope. We demonstrate the applications of this system and software in biosensor imaging, optogenetics and fast 3D volume imaging. This system is ready to fit into complex imaging circumstances requiring precise control of illumination and detection paths, and has a broad scope of usability for a myriad of biological applications.
Collapse
|
6
|
Thomas K, Goudy J, Henley T, Bressan M. Optical Electrophysiology in the Developing Heart. J Cardiovasc Dev Dis 2018; 5:E28. [PMID: 29751595 PMCID: PMC6023508 DOI: 10.3390/jcdd5020028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 12/16/2022] Open
Abstract
The heart is the first organ system to form in the embryo. Over the course of development, cardiomyocytes with differing morphogenetic, molecular, and physiological characteristics are specified and differentiate and integrate with one another to assemble a coordinated electromechanical pumping system that can function independently of any external stimulus. As congenital malformation of the heart presents the leading class of birth defects seen in humans, the molecular genetics of heart development have garnered much attention over the last half century. However, understanding how genetic perturbations manifest at the level of the individual cell function remains challenging to investigate. Some of the barriers that have limited our capacity to construct high-resolution, comprehensive models of cardiac physiological maturation are rapidly being removed by advancements in the reagents and instrumentation available for high-speed live imaging. In this review, we briefly introduce the history of imaging approaches for assessing cardiac development, describe some of the reagents and tools required to perform live imaging in the developing heart, and discuss how the combination of modern imaging modalities and physiological probes can be used to scale from subcellular to whole-organ analysis. Through these types of imaging approaches, critical insights into the processes of cardiac physiological development can be directly examined in real-time. Moving forward, the synthesis of modern molecular biology and imaging approaches will open novel avenues to investigate the mechanisms of cardiomyocyte maturation, providing insight into the etiology of congenital heart defects, as well as serving to direct approaches for designing stem-cell or regenerative medicine protocols for clinical application.
Collapse
Affiliation(s)
- Kandace Thomas
- Department of Cell Biology and Physiology, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Julie Goudy
- Department of Cell Biology and Physiology, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Trevor Henley
- Department of Cell Biology and Physiology, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Michael Bressan
- Department of Cell Biology and Physiology, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| |
Collapse
|
7
|
Haslehurst P, Yang Z, Dholakia K, Emptage N. Fast volume-scanning light sheet microscopy reveals transient neuronal events. BIOMEDICAL OPTICS EXPRESS 2018; 9:2154-2167. [PMID: 29760977 PMCID: PMC5946778 DOI: 10.1364/boe.9.002154] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/15/2018] [Accepted: 01/18/2018] [Indexed: 05/02/2023]
Abstract
Light sheet fluorescence microscopy offers considerable potential to the cellular neuroscience community as it makes it possible to image extensive areas of neuronal structures, such as axons or dendrites, with a low light budget, thereby minimizing phototoxicity. However, the shallow depth of a light sheet, which is critical for achieving high contrast, well resolved images, adds a significant challenge if fast functional imaging is also required, as multiple images need to be collected across several image planes. Consequently, fast functional imaging of neurons is typically restricted to a small tissue volume where part of the neuronal structure lies within the plane of a single image. Here we describe a method by which fast functional imaging can be achieved across a much larger tissue volume; a custom-built light sheet microscope is presented that includes a synchronized galvo mirror and electrically tunable lens, enabling high speed acquisition of images across a configurable depth. We assess the utility of this technique by acquiring fast functional Ca2+ imaging data across a neuron's dendritic arbour in mammalian brain tissue.
Collapse
Affiliation(s)
- Peter Haslehurst
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
- these authors contributed equally to this work
| | - Zhengyi Yang
- SUPA, School of Physics & Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK
- these authors contributed equally to this work
| | - Kishan Dholakia
- SUPA, School of Physics & Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK
| | - Nigel Emptage
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
| |
Collapse
|
8
|
Abstract
Optical pacing (OP) uses pulsed infrared light to initiate heartbeats in electrically excitable cardiac tissues without employing exogenous agents. OP is an alternative approach to electrical pacing that may overcome some its disadvantages for some applications. In this review, we discuss the initial demonstrations, mechanisms, safety, advantages and applications of OP.
Collapse
Affiliation(s)
- S M Ford
- Rainbow Babies and Children's Hospital Divisions of Neonatology and Pediatric Cardiology, 11100 Euclid Ave, MS 6010, Cleveland, OH 44106, United States of America
| | | | | |
Collapse
|