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Yang S, Hu S. Perspectives on endoscopic functional photoacoustic microscopy. APPLIED PHYSICS LETTERS 2024; 125:030502. [PMID: 39022117 PMCID: PMC11251735 DOI: 10.1063/5.0201691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 06/27/2024] [Indexed: 07/20/2024]
Abstract
Endoscopy, enabling high-resolution imaging of deep tissues and internal organs, plays an important role in basic research and clinical practice. Recent advances in photoacoustic microscopy (PAM), demonstrating excellent capabilities in high-resolution functional imaging, have sparked significant interest in its integration into the field of endoscopy. However, there are challenges in achieving functional PAM in the endoscopic setting. This Perspective article discusses current progress in the development of endoscopic PAM and the challenges related to functional measurements. Then, it points out potential directions to advance endoscopic PAM for functional imaging by leveraging fiber optics, microfabrication, optical engineering, and computational approaches. Finally, it highlights emerging opportunities for functional endoscopic PAM in basic and translational biomedicine.
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Affiliation(s)
- Shuo Yang
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | - Song Hu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, USA
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2
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Wang J, Chen C, You W, Jiao Y, Liu X, Jiang X, Lu W. Honeycomb effect elimination in differential phase fiber-bundle-based endoscopy. OPTICS EXPRESS 2024; 32:20682-20694. [PMID: 38859444 DOI: 10.1364/oe.526033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 05/10/2024] [Indexed: 06/12/2024]
Abstract
Fiber-bundle-based endoscopy, with its ultrathin probe and micrometer-level resolution, has become a widely adopted imaging modality for in vivo imaging. However, the fiber bundles introduce a significant honeycomb effect, primarily due to the multi-core structure and crosstalk of adjacent fiber cores, which superposes the honeycomb pattern image on the original image. To tackle this issue, we propose an iterative-free spatial pixel shifting (SPS) algorithm, designed to suppress the honeycomb effect and enhance real-time imaging performance. The process involves the creation of three additional sub-images by shifting the original image by one pixel at 0, 45, and 90 degree angles. These four sub-images are then used to compute differential maps in the x and y directions. By performing spiral integration on these differential maps, we reconstruct a honeycomb-free image with improved details. Our simulations and experimental results, conducted on a self-built fiber bundle-based endoscopy system, demonstrate the effectiveness of the SPS algorithm. SPS significantly improves the image quality of reflective objects and unlabeled transparent scattered objects, laying a solid foundation for biomedical endoscopic applications.
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3
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Arora B, Kulkarni A, Markus MA, Ströbel P, Bohnenberger H, Alves F, Ramos-Gomes F. Label-free quantification of imaging features in the extracellular matrix of left and right-sided colon cancer tissues. Sci Rep 2024; 14:7510. [PMID: 38553551 PMCID: PMC10980747 DOI: 10.1038/s41598-024-58231-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 03/26/2024] [Indexed: 04/02/2024] Open
Abstract
The molecular pathogenesis of colorectal cancer is known to differ between the right and left side of the colon. Several previous studies have focussed on the differences in clinicopathological features, proteomic and genetic biomarkers, the composition of gut microbiota, response to therapy, and the characteristics of the tumour microenvironment. However, the morphology and density of collagen in the extracellular matrix (ECM) have not been studied intensively. In this study, we employed 2-photon laser scanning microscopy (2PLSM) to visualise the intrinsic second-harmonic generation (SHG) signal emitted by collagen fibres in the heterogeneous ECM of human colon tumour tissues. Through texture analysis of the SHG signal, we quantitatively distinguished the imaging features generated by structural differences of collagen fibres in healthy colon and cancers and found marked differences. The fibres inside of tumours exhibited a loss of organisation, particularly pronounced in right-sided colon cancer (RSCC), where the chaotic regions were significantly increased. In addition, a higher collagen content was found in left-sided colon cancer (LSCC). In future, this might aid in subclassification and therapeutic decisions or even in designing new therapy regimens by taking into account the differences between collagen fibres features between colon tumours located at different sides.
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Affiliation(s)
- B Arora
- Translational Molecular Imaging, Max-Planck-Institute for Multidisciplinary Sciences, Hermann Rein-Straße 3, 37075, Göttingen, Germany
| | - A Kulkarni
- Translational Molecular Imaging, Max-Planck-Institute for Multidisciplinary Sciences, Hermann Rein-Straße 3, 37075, Göttingen, Germany
| | - M A Markus
- Translational Molecular Imaging, Max-Planck-Institute for Multidisciplinary Sciences, Hermann Rein-Straße 3, 37075, Göttingen, Germany
| | - P Ströbel
- Institute of Pathology, University Medical Center Göttingen, Robert-Koch-Straβe 40, 37075, Göttingen, Germany
| | - H Bohnenberger
- Institute of Pathology, University Medical Center Göttingen, Robert-Koch-Straβe 40, 37075, Göttingen, Germany
| | - F Alves
- Translational Molecular Imaging, Max-Planck-Institute for Multidisciplinary Sciences, Hermann Rein-Straße 3, 37075, Göttingen, Germany
- Clinic for Haematology and Medical Oncology, Institute of Interventional and Diagnostic Radiology, University Medical Center Göttingen, Robert-Koch-Straβe 40, 37075, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Goettingen, Göttingen, Germany
| | - F Ramos-Gomes
- Translational Molecular Imaging, Max-Planck-Institute for Multidisciplinary Sciences, Hermann Rein-Straße 3, 37075, Göttingen, Germany.
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Werner MP, Kučikas V, Voß K, Abel D, Jockenhoevel S, van Zandvoort MAMJ, Schmitz-Rode T. Multiphoton Imaging of Maturation in Tissue Engineering. Tissue Eng Part C Methods 2024; 30:38-48. [PMID: 38115629 DOI: 10.1089/ten.tec.2023.0141] [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: 12/21/2023] Open
Abstract
Donor cell-specific tissue-engineered (TE) implants are a promising therapy for personalized treatment of cardiovascular diseases, but current development protocols lack a stable longitudinal assessment of tissue development at subcellular resolution. As a first step toward such an assessment approach, in this study we establish a generalized labeling and imaging protocol to obtain quantified maturation parameters of TE constructs in three dimensions (3D) without the need of histological slicing, thus leaving the tissue intact. Focusing on intracellular matrix (ICM) and extracellular matrix (ECM) networks, multiphoton laser scanning microscopy (MPLSM) was used to investigate TE patches of different conditioning durations of up to 21 days. We show here that with a straightforward labeling procedure of whole-mount samples (so without slicing into thin histological sections), followed by an easy-to-use multiphoton imaging process, we obtained high-quality images of the tissue in 3D at various time points during development. The stacks of images could then be further analyzed to visualize and quantify the volume of cell coverage as well as the volume fraction and network of structural proteins. We showed that collagen and alpha-smooth muscle actin (α-SMA) volume fractions increased as normalized to full tissue volume and proportional to the cell count, with a converging trend to the final density of (4.0% ± 0.6%) and (7.6% ± 0.7%), respectively. The image analysis of ICM and ECM revealed a developing and widely branched interconnected matrix. We are currently working on the second step, that is, to integrate MPLSM endoscopy into a dynamic bioreactor system to monitor the maturation of intact TE constructs over time, thus without the need to take them out.
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Affiliation(s)
- Maximilian P Werner
- Department of Biohybrid & Medical Textiles (BioTex), Institute of Applied Medical Engineering (AME), Helmholtz Institute, RWTH Aachen University, Aachen, Germany
- Aachen-Maastricht-Institute for Biobased Materials (AMIBM), Maastricht University, Geleen, The Netherlands
| | - Vytautas Kučikas
- Institute of Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany
| | - Kirsten Voß
- Institute of Automatic Control (IRT), RWTH Aachen University, Aachen, Germany
| | - Dirk Abel
- Institute of Automatic Control (IRT), RWTH Aachen University, Aachen, Germany
| | - Stefan Jockenhoevel
- Department of Biohybrid & Medical Textiles (BioTex), Institute of Applied Medical Engineering (AME), Helmholtz Institute, RWTH Aachen University, Aachen, Germany
- Aachen-Maastricht-Institute for Biobased Materials (AMIBM), Maastricht University, Geleen, The Netherlands
| | - Marc A M J van Zandvoort
- Institute of Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany
- Department of Genetics and Cell Biology, Cardiovascular Research Institute Maastricht (CARIM), School for Oncology and Developmental Biology (GROW), Maastricht, The Netherlands
| | - Thomas Schmitz-Rode
- Department of Biohybrid & Medical Textiles (BioTex), Institute of Applied Medical Engineering (AME), Helmholtz Institute, RWTH Aachen University, Aachen, Germany
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Stark SL, Gross H, Reglinski K, Messerschmidt B, Eggeling C. Field curvature reduction in miniaturized high numerical aperture and large field-of-view objective lenses with sub 1 µm lateral resolution. BIOMEDICAL OPTICS EXPRESS 2023; 14:6190-6205. [PMID: 38420300 PMCID: PMC10898576 DOI: 10.1364/boe.499785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/09/2023] [Accepted: 10/10/2023] [Indexed: 03/02/2024]
Abstract
In this paper the development of a miniaturized endoscopic objective lens for various biophotonics applications is presented. While limiting the mechanical dimensions to 2.2 mm diameter and 13 mm total length, a numerical aperture of 0.7 in water and a field-of-view (FOV) diameter of 282 µm are achieved. To enable multimodal usage a wavelength range of 488 nm to 632 nm was considered. The performed broad design study aimed for field curvature reduction when maintaining the sub 1 µm resolution over a large FOV. Moreover, the usage of GRadient-INdex (GRIN) lenses was investigated. The resolution, field curvature improvement and chromatic performance of the novel device were validated by means of a confocal laser-scanning-microscope.
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Affiliation(s)
| | - Herbert Gross
- Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Albert-Einstein-Str. 7, 07745 Jena, Germany
| | - Katharina Reglinski
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien-Platz 4, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Str. 9, 07745 Jena, Germany
- University Hospital Jena, Bachstr. 18, 07743 Jena, Germany
| | | | - Christian Eggeling
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien-Platz 4, 07743 Jena, Germany
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Str. 9, 07745 Jena, Germany
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Vora N, Polleys CM, Sakellariou F, Georgalis G, Thieu HT, Genega EM, Jahanseir N, Patra A, Miller E, Georgakoudi I. Restoration of metabolic functional metrics from label-free, two-photon human tissue images using multiscale deep-learning-based denoising algorithms. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:126006. [PMID: 38144697 PMCID: PMC10742979 DOI: 10.1117/1.jbo.28.12.126006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/23/2023] [Accepted: 11/28/2023] [Indexed: 12/26/2023]
Abstract
Significance Label-free, two-photon excited fluorescence (TPEF) imaging captures morphological and functional metabolic tissue changes and enables enhanced understanding of numerous diseases. However, noise and other artifacts present in these images severely complicate the extraction of biologically useful information. Aim We aim to employ deep neural architectures in the synthesis of a multiscale denoising algorithm optimized for restoring metrics of metabolic activity from low-signal-to-noise ratio (SNR), TPEF images. Approach TPEF images of reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) and flavoproteins (FAD) from freshly excised human cervical tissues are used to assess the impact of various denoising models, preprocessing methods, and data on metrics of image quality and the recovery of six metrics of metabolic function from the images relative to ground truth images. Results Optimized recovery of the redox ratio and mitochondrial organization is achieved using a novel algorithm based on deep denoising in the wavelet transform domain. This algorithm also leads to significant improvements in peak-SNR (PSNR) and structural similarity index measure (SSIM) for all images. Interestingly, other models yield even higher PSNR and SSIM improvements, but they are not optimal for recovery of metabolic function metrics. Conclusions Denoising algorithms can recover diagnostically useful information from low SNR label-free TPEF images and will be useful for the clinical translation of such imaging.
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Affiliation(s)
- Nilay Vora
- Tufts University, Department of Biomedical Engineering, Medford, Massachusetts, United States
| | - Christopher M. Polleys
- Tufts University, Department of Biomedical Engineering, Medford, Massachusetts, United States
| | | | - Georgios Georgalis
- Tufts University, Data Intensive Studies Center, Medford, Massachusetts, United States
| | - Hong-Thao Thieu
- Tufts University School of Medicine, Tufts Medical Center, Department of Obstetrics and Gynecology, Boston, Massachusetts, United States
| | - Elizabeth M. Genega
- Tufts University School of Medicine, Tufts Medical Center, Department of Pathology and Laboratory Medicine, Boston, Massachusetts, United States
| | - Narges Jahanseir
- Tufts University School of Medicine, Tufts Medical Center, Department of Pathology and Laboratory Medicine, Boston, Massachusetts, United States
| | - Abani Patra
- Tufts University, Data Intensive Studies Center, Medford, Massachusetts, United States
- Tufts University, Department of Mathematics, Medford, Massachusetts, United States
| | - Eric Miller
- Tufts University, Department of Electrical and Computer Engineering, Medford, Massachusetts, United States
- Tufts University, Tufts Institute for Artificial Intelligence, Medford, Massachusetts, United States
| | - Irene Georgakoudi
- Tufts University, Department of Biomedical Engineering, Medford, Massachusetts, United States
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Xiu D, Liu S, Li Y, Ju D, Zhao S, Luo M, Ma Z, Shen H. High NA and polarization-insensitive ultra-broadband achromatic metalens from 500 to 1050 nm for multicolor two-photon endomicroscopy imaging. OPTICS EXPRESS 2023; 31:30092-30107. [PMID: 37710559 DOI: 10.1364/oe.499585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 08/15/2023] [Indexed: 09/16/2023]
Abstract
Multicolor two-photon endomicroscopy has become a highly competitive tool for functional imaging in biomedical researches. However, to make the imaging system miniature and applicable for freely behaving animal brain activity, metalenses have received much attention in compact imaging systems. For high resolution multicolor imaging and maximizing fluorescence collection, there is a challenge metalenses faced to achieve large numerical aperture (NA) and focus the NIR excitation and VIS emission lights of multiple fluorophores to the same distance simultaneously because of the limitation of the group delay range of the meta-units. In this paper, we proposed a high NA and polarization-insensitive ultra-broadband achromatic metalens specifically for achromatically focusing the excitation and emission light of multiple fluorophores commonly used in neuroscience studies. TiO2 and Si meta-unit libraries composed of heights, widths and the corresponding phase and group delay were constructed, and the optimal meta-units were selected by particle swarm optimization algorithm to engineer the dispersion of metalens in the VIS band and NIR band, respectively. Combining dispersion engineering with spatial multiplexing, the proposed metalens achieved the maximal effective NA up to 0.8 and large achromatic bandwidth ranging from 500 nm to 1050 nm, which exhibited the coefficient of variation of focal lengths was only 3.41%. The proposed achromatic metalens could successfully achromatically focus different fluorescence with any polarization, which was suitable for most fluorophores. Our results firmly establish that the proposed metalens can open the door to high resolution and minimally invasive multicolor two-photon functional imaging in intravital deep brain.
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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.
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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
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Vora N, Polleys CM, Sakellariou F, Georgalis G, Thieu HT, Genega EM, Jahanseir N, Patra A, Miller E, Georgakoudi I. Restoration of metabolic functional metrics from label-free, two-photon cervical tissue images using multiscale deep-learning-based denoising algorithms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.07.544033. [PMID: 37333366 PMCID: PMC10274804 DOI: 10.1101/2023.06.07.544033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Label-free, two-photon imaging captures morphological and functional metabolic tissue changes and enables enhanced understanding of numerous diseases. However, this modality suffers from low signal arising from limitations imposed by the maximum permissible dose of illumination and the need for rapid image acquisition to avoid motion artifacts. Recently, deep learning methods have been developed to facilitate the extraction of quantitative information from such images. Here, we employ deep neural architectures in the synthesis of a multiscale denoising algorithm optimized for restoring metrics of metabolic activity from low-SNR, two-photon images. Two-photon excited fluorescence (TPEF) images of reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) and flavoproteins (FAD) from freshly excised human cervical tissues are used. We assess the impact of the specific denoising model, loss function, data transformation, and training dataset on established metrics of image restoration when comparing denoised single frame images with corresponding six frame averages, considered as the ground truth. We further assess the restoration accuracy of six metrics of metabolic function from the denoised images relative to ground truth images. Using a novel algorithm based on deep denoising in the wavelet transform domain, we demonstrate optimal recovery of metabolic function metrics. Our results highlight the promise of denoising algorithms to recover diagnostically useful information from low SNR label-free two-photon images and their potential importance in the clinical translation of such imaging.
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Affiliation(s)
- Nilay Vora
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
| | | | | | | | - Hong-Thao Thieu
- Department of Obstetrics and Gynecology, Tufts University School of Medicine, Tufts Medical Center, Boston, MA 02111, USA
| | - Elizabeth M. Genega
- Department of Pathology and Laboratory Medicine, Tufts University School of Medicine, Tufts Medical Center, Boston, MA 02111, USA
| | - Narges Jahanseir
- Department of Pathology and Laboratory Medicine, Tufts University School of Medicine, Tufts Medical Center, Boston, MA 02111, USA
| | - Abani Patra
- Data Intensive Studies Center, Tufts University, Medford, MA 02155, USA
- Department of Mathematics, Tufts University, Medford, MA 02155, USA
| | - Eric Miller
- Department of Electrical and Computer Engineering, Tufts University, Medford, MA 02155, USA
- Tufts Institute for Artificial Intelligence, Tufts University, Medford, MA 02155, USA
| | - Irene Georgakoudi
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
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Lai C, Calvarese M, Reichwald K, Bae H, Vafaeinezhad M, Meyer-Zedler T, Hoffmann F, Mühlig A, Eidam T, Stutzki F, Messerschmidt B, Gross H, Schmitt M, Guntinas-Lichius O, Popp J. Design and test of a rigid endomicroscopic system for multimodal imaging and femtosecond laser ablation. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:066004. [PMID: 37388219 PMCID: PMC10306116 DOI: 10.1117/1.jbo.28.6.066004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 05/31/2023] [Accepted: 06/14/2023] [Indexed: 07/01/2023]
Abstract
Significance Conventional diagnosis of laryngeal cancer is normally made by a combination of endoscopic examination, a subsequent biopsy, and histopathology, but this requires several days and unnecessary biopsies can increase pathologist workload. Nonlinear imaging implemented through endoscopy can shorten this diagnosis time, and localize the margin of the cancerous area with high resolution. Aim Develop a rigid endomicroscope for the head and neck region, aiming for in-vivo multimodal imaging with a large field of view (FOV) and tissue ablation. Approach Three nonlinear imaging modalities, which are coherent anti-Stokes Raman scattering, two-photon excitation fluorescence, and second harmonic generation, as well as the single photon fluorescence of indocyanine green, are applied for multimodal endomicroscopic imaging. High-energy femtosecond laser pulses are transmitted for tissue ablation. Results This endomicroscopic system consists of two major parts, one is the rigid endomicroscopic tube 250 mm in length and 6 mm in diameter, and the other is the scan-head (10 × 12 × 6 cm 3 in size) for quasi-static scanning imaging. The final multimodal image accomplishes a maximum FOV up to 650 μ m , and a resolution of 1 μ m is achieved over 560 μ m FOV. The optics can easily guide sub-picosecond pulses for ablation. Conclusions The system exhibits large potential for helping real-time tissue diagnosis in surgery, by providing histological tissue information with a large FOV and high resolution, label-free. By guiding high-energy fs laser pulses, the system is even able to remove suspicious tissue areas, as has been shown for thin tissue sections in this study.
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Affiliation(s)
| | - Matteo Calvarese
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Member of the Leibniz Centre for Photonics in Infection Research, Jena, Germany
| | | | - Hyeonsoo Bae
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Member of the Leibniz Centre for Photonics in Infection Research, Jena, Germany
- Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Member of the Leibniz Centre for Photonics in Infection Research, Jena, Germany
| | - Mohammadsadegh Vafaeinezhad
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Member of the Leibniz Centre for Photonics in Infection Research, Jena, Germany
- Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Member of the Leibniz Centre for Photonics in Infection Research, Jena, Germany
| | - Tobias Meyer-Zedler
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Member of the Leibniz Centre for Photonics in Infection Research, Jena, Germany
- Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Member of the Leibniz Centre for Photonics in Infection Research, Jena, Germany
| | - Franziska Hoffmann
- Jena University Hospital, Department of Otorhinolaryngology, Jena, Germany
| | - Anna Mühlig
- Jena University Hospital, Department of Otorhinolaryngology, Jena, Germany
| | - Tino Eidam
- Active Fiber Systems GmbH, Jena, Germany
| | | | | | - Herbert Gross
- Fraunhofer Institute for Applied Optics and Precision Engineering, Jena, Germany
| | - Michael Schmitt
- Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Member of the Leibniz Centre for Photonics in Infection Research, Jena, Germany
| | | | - Jürgen Popp
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Member of the Leibniz Centre for Photonics in Infection Research, Jena, Germany
- Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Member of the Leibniz Centre for Photonics in Infection Research, Jena, Germany
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11
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Aghigh A, Bancelin S, Rivard M, Pinsard M, Ibrahim H, Légaré F. Second harmonic generation microscopy: a powerful tool for bio-imaging. Biophys Rev 2023; 15:43-70. [PMID: 36909955 PMCID: PMC9995455 DOI: 10.1007/s12551-022-01041-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 12/21/2022] [Indexed: 01/20/2023] Open
Abstract
Second harmonic generation (SHG) microscopy is an important optical imaging technique in a variety of applications. This article describes the history and physical principles of SHG microscopy and its more advanced variants, as well as their strengths and weaknesses in biomedical applications. It also provides an overview of SHG and advanced SHG imaging in neuroscience and microtubule imaging and how these methods can aid in understanding microtubule formation, structuration, and involvement in neuronal function. Finally, we offer a perspective on the future of these methods and how technological advancements can help make SHG microscopy a more widely adopted imaging technique.
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Affiliation(s)
- Arash Aghigh
- Centre Énergie Matériaux Télécommunications, Institut National de La Recherche Scientifique, Varennes, QC Canada
| | | | - Maxime Rivard
- National Research Council Canada, Boucherville, QC Canada
| | - Maxime Pinsard
- Institut National de Recherche en Sciences Et Technologies Pour L’environnement Et L’agriculture, Paris, France
| | - Heide Ibrahim
- Centre Énergie Matériaux Télécommunications, Institut National de La Recherche Scientifique, Varennes, QC Canada
| | - François Légaré
- Centre Énergie Matériaux Télécommunications, Institut National de La Recherche Scientifique, Varennes, QC Canada
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12
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Gibbs SL, Delikatny EJ. Editorial to the Special Issue Entitled "Optical Surgical Navigation". Mol Imaging Biol 2023; 25:1-2. [PMID: 36729349 DOI: 10.1007/s11307-023-01806-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Summer L Gibbs
- Biomedical Engineering Department, Knight Cancer Institute, Oregon Health & Science University, Portland, OR, 97201, USA.
| | - Edward J Delikatny
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
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Confocal laser endomicroscope with distal MEMS scanner for real-time histopathology. Sci Rep 2022; 12:20155. [PMID: 36418439 PMCID: PMC9684518 DOI: 10.1038/s41598-022-24210-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 11/11/2022] [Indexed: 11/25/2022] Open
Abstract
Confocal laser endomicroscopy is an emerging methodology to perform real time optical biopsy. Fluorescence images with histology-like quality can be collected instantaneously from the epithelium of hollow organs. Currently, scanning is performed at the proximal end of probe-based instruments used routinely in the clinic, and flexibility to control the focus is limited. We demonstrate use of a parametric resonance scanner packaged in the distal end of the endomicroscope to perform high speed lateral deflections. An aperture was etched in the center of the reflector to fold the optical path. This design reduced the dimensions of the instrument to 2.4 mm diameter and 10 mm length, allowing for forward passage through the working channel of a standard medical endoscope. A compact lens assembly provides lateral and axial resolution of 1.1 and 13.6 μm, respectively. A working distance of 0 μm and field-of-view of 250 μm × 250 μm was achieved at frame rates up to 20 Hz. Excitation at 488 nm was delivered to excite fluorescein, an FDA-approved dye, to generate high tissue contrast. The endomicroscope was reprocessed using a clinically-approved sterilization method for 18 cycles without failure. Fluorescence images were collected during routine colonoscopy from normal colonic mucosa, tubular adenomas, hyperplastic polyps, ulcerative colitis, and Crohn's colitis. Individual cells, including colonocytes, goblet cells, and inflammatory cells, could be identified. Mucosal features, such as crypt structures, crypt lumens, and lamina propria, could be distinguished. This instrument has potential to be used as an accessory during routine medical endoscopy.
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Carbon Nanoparticles Extracted from Date Palm Fronds for Fluorescence Bioimaging: In Vitro Study. J Funct Biomater 2022; 13:jfb13040218. [PMID: 36412859 PMCID: PMC9680435 DOI: 10.3390/jfb13040218] [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: 10/04/2022] [Revised: 10/25/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
Numerous studies have been reported on single- and multicolored highly fluorescent carbon nanoparticles (FCNPs) originating from various sources and their potential applications in bioimaging. Herein, multicolored biocompatible carbon nanoparticles (CNPs) unsheathed from date palm fronds were studied. The extracted CNPs were characterized via several microscopic and spectroscopic techniques. The results revealed that the CNPs were crystalline graphitic and hydrophilic in nature with sizes ranging from 4 to 20 nm. The unsheathed CNPs showed exemplary photoluminescent (PL) properties. They also emitted bright blue colors when exposed to ultraviolet (UV) light. Furthermore, in vitro cellular uptake and cell viability in the presence of CNPs were also investigated. The cell viability of human colon cancer (HCT-116) and breast adenocarcinoma (MCF-7) cell lines with aqueous CNPs at different concentrations was assessed by a cell metabolic activity assay (MTT) for 24 and 48 h incubations. The results were combined to generate dose-response curves for the CNPs and evaluate the severity of their toxicity. The CNPs showed adequate fluorescence with high cell viability for in vitro cell imaging. Under the laser-scanning confocal microscope, the CNPs with HCT-116 and MCF-7 cell lines showed multicolor fluorescence emissions, including blue, green, and red colors when excited at 405, 458, and 561 nm, respectively. These results prove that unsheathed CNPs from date palm fronds can be used in diverse biomedical applications because of their low cytotoxicity, adequate fluorescence, eco-friendly nature, and cheap production.
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Barry J, Peng A, Levine MS, Cepeda C. Calcium imaging: A versatile tool to examine Huntington's disease mechanisms and progression. Front Neurosci 2022; 16:1040113. [PMID: 36408400 PMCID: PMC9669372 DOI: 10.3389/fnins.2022.1040113] [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: 09/08/2022] [Accepted: 10/19/2022] [Indexed: 11/06/2022] Open
Abstract
Huntington's disease (HD) is a fatal, hereditary neurodegenerative disorder that causes chorea, cognitive deficits, and psychiatric symptoms. It is characterized by accumulation of mutant Htt protein, which primarily impacts striatal medium-sized spiny neurons (MSNs), as well as cortical pyramidal neurons (CPNs), causing synapse loss and eventually cell death. Perturbed Ca2+ homeostasis is believed to play a major role in HD, as altered Ca2+ homeostasis often precedes striatal dysfunction and manifestation of HD symptoms. In addition, dysregulation of Ca2+ can cause morphological and functional changes in MSNs and CPNs. Therefore, Ca2+ imaging techniques have the potential of visualizing changes in Ca2+ dynamics and neuronal activity in HD animal models. This minireview focuses on studies using diverse Ca2+ imaging techniques, including two-photon microscopy, fiber photometry, and miniscopes, in combination of Ca2+ indicators to monitor activity of neurons in HD models as the disease progresses. We then discuss the future applications of Ca2+ imaging to visualize disease mechanisms and alterations associated with HD, as well as studies showing how, as a proof-of-concept, Ca2+imaging using miniscopes in freely-behaving animals can help elucidate the differential role of direct and indirect pathway MSNs in HD symptoms.
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Yang M, Mahanty A, Jin C, Wong ANN, Yoo JS. Label-free metabolic imaging for sensitive and robust monitoring of anti-CD47 immunotherapy response in triple-negative breast cancer. J Immunother Cancer 2022; 10:jitc-2022-005199. [PMID: 36096527 PMCID: PMC9472253 DOI: 10.1136/jitc-2022-005199] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2022] [Indexed: 11/22/2022] Open
Abstract
Background Immunotherapy is revolutionizing cancer treatment from conventional radiotherapies and chemotherapies to immune checkpoint inhibitors which use patients’ immune system to recognize and attack cancer cells. Despite the huge clinical success and vigorous development of immunotherapies, there is a significant unmet need for a robust tool to identify responders to specific immunotherapy. Early and accurate monitoring of immunotherapy response is indispensable for personalized treatment and effective drug development. Methods We established a label-free metabolic intravital imaging (LMII) technique to detect two-photon excited autofluorescence signals from two coenzymes, NAD(P)H (reduced nicotinamide adenine dinucleotide (phosphate) hydrogen) and FAD (flavin adenine dinucleotide) as robust imaging markers to monitor metabolic responses to immunotherapy. Murine models of triple-negative breast cancer (TNBC) were established and tested with different therapeutic regimens including anti-cluster of differentiation 47 (CD47) immunotherapy to monitor time-course treatment responses using the developed metabolic imaging technique. Results We first imaged the mechanisms of the CD47-signal regulatory protein alpha pathway in vivo, which unravels macrophage-mediated antibody-dependent cellular phagocytosis and illustrates the metabolism of TNBC cells and macrophages. We further visualized the autofluorescence of NAD(P)H and FAD and found a significant increase during tumor growth. Following anti-CD47 immunotherapy, the imaging signal was dramatically decreased demonstrating the sensitive monitoring capability of NAD(P)H and FAD imaging for therapeutic response. NAD(P)H and FAD intravital imaging also showed a marked decrease after chemotherapy and radiotherapy. A comparative study with conventional whole-body bioluminescence and fluorescent glucose imaging demonstrated superior sensitivity of metabolic imaging. Flow cytometry validated metabolic imaging results. In vivo immunofluorescent staining revealed the targeting ability of NAD(P)H imaging mainly for tumor cells and a small portion of immune-active cells and that of FAD imaging mainly for immunosuppressive cells such as M2-like tumor-associated macrophages. Conclusions Collectively, this study showcases the potential of the LMII technique as a powerful tool to visualize dynamic changes of heterogeneous cell metabolism of cancer cells and immune infiltrates in response to immunotherapy thus providing sensitive and complete monitoring. Leveraged on ability to differentiate cancer cells and immunosuppressive macrophages, the presented imaging approach provides particularly useful imaging biomarkers for emerged innate immune checkpoint inhibitors such as anti-CD47 therapy.
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Affiliation(s)
- Minfeng Yang
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Arpan Mahanty
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Chunjing Jin
- The Affiliated Chuzhou Hospital of Anhui Medical University, The First People's Hospital of Chuzhou, Chuzhou, China
| | - Alex Ngai Nick Wong
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Jung Sun Yoo
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
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Wang C, Liu H, Cui H, Ma J, Li Y, Tian J, Jin C, Chen Y, Gao Y, Fu Q, Hu Y, Wu D, Yu F, Wu R, Wang A, Feng L. Two-photon endomicroscopy with microsphere-spliced double-cladding antiresonant fiber for resolution enhancement. OPTICS EXPRESS 2022; 30:26090-26101. [PMID: 36236806 DOI: 10.1364/oe.461325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 06/16/2022] [Indexed: 06/16/2023]
Abstract
We demonstrate a miniature fiber-optic two two-photon endomicroscopy with microsphere-spliced double-cladding antiresonant fiber for resolution enhancement. An easy-to-operate process for fixing microsphere permanently in an antiresonant fiber core, by arc discharge, is proposed. The flexible fiber-optic probe is integrated with a parameter of 5.8 mm × 49.1 mm (outer diameter × rigid length); the field of view is 210 µm, the resolution is 1.3 µm, and the frame rate is 0.7 fps. The imaging ability is verified using ex-vivo mouse kidney, heart, stomach, tail tendon, and in-vivo brain neural imaging.
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Septier D, Mytskaniuk V, Habert R, Labat D, Baudelle K, Cassez A, Brévalle-Wasilewski G, Conforti M, Bouwmans G, Rigneault H, Kudlinski A. Label-free highly multimodal nonlinear endoscope. OPTICS EXPRESS 2022; 30:25020-25033. [PMID: 36237042 PMCID: PMC9363033 DOI: 10.1364/oe.462361] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 06/16/2023]
Abstract
We demonstrate a 2 mm diameter highly multimodal nonlinear micro-endoscope allowing label-free imaging of biological tissues. The endoscope performs multiphoton fluorescence (3-photon, 2-photon), harmonic generation (second-SHG and third-THG) and coherent anti-Stokes Raman scattering (CARS) imaging over a field of view of 200 µm. The micro-endoscope is based on a double-clad antiresonant hollow core fiber featuring a high transmission window (850 nm to 1800 nm) that is functionalized with a short piece of graded-index (GRIN) fiber. When combined with a GRIN micro-objective, the micro-endoscope achieves a 1.1 µm point spread function (PSF). We demonstrate 3-photon, 2-photon, THG, SHG, and CARS high resolution images of unlabelled biological tissues.
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Affiliation(s)
- D. Septier
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | | | - R. Habert
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | - D. Labat
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | - K. Baudelle
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | - A. Cassez
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | | | - M. Conforti
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | - G. Bouwmans
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
| | - H. Rigneault
- Lightcore Technologies, Cannes, France
- Aix Marseille Univ., CNRS, Centrale Marseille, Institut Fresnel, Marseille, France
| | - A. Kudlinski
- Univ. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France
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