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Strachotová D, Holoubek A, Brodská B, Herman P. Two-photon lifetime-Based Photoconversion of EGFP for 3D-photostimulation in FLIM. Methods Appl Fluoresc 2023. [PMID: 37267995 DOI: 10.1088/2050-6120/acdb31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Enhanced green fluorescence protein (EGFP) is a fluorescent tag commonly used in cellular and biomedical applications. Surprisingly, some interesting photochemical properties of EGFP have remained unexplored. Here we report on two-photon-induced photoconversion of EGFP, which can be permanently converted by intense IR irradiation to a form with a short fluorescence lifetime and spectrally conserved emission. Photoconverted EGFP thus can be distinguished from the unconverted tag by the time-resolved detection. Nonlinear dependence of the two-photon photoconversion efficiency on the light intensity allows for an accurate 3D localization of the photoconverted volume within cellular structures, which is especially useful for kinetic FLIM applications. For illustration, we used the two photon photoconversion of EGFP for measurements of redistribution kinetics of nucleophosmin and histone H2B in nuclei of live cells. Measurements revealed high mobility of fluorescently tagged histone H2B in the nucleoplasm and their redistribution between spatially separated nucleoli.
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Affiliation(s)
- Dita Strachotová
- Institute of Physiscs, Charles University Faculty of Mathematics and Physics, Ke Karlovu 3, Praha 2, Praha, 121 16, CZECH REPUBLIC
| | - Aleš Holoubek
- Institute of Hematology and Blood Transfusion, U Nemocnice 2094/1, Praha, Praha, 128 20, CZECH REPUBLIC
| | - Barbora Brodská
- Institute of Hematology and Blood Transfusion, U Nemocnice 2094/1, Praha, Praha, 128 20, CZECH REPUBLIC
| | - Petr Herman
- Institute of Physiscs, Charles University Faculty of Mathematics and Physics, Ke Karlovu 3, Praha 2, Praha, 121 16, CZECH REPUBLIC
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Ahmed N, Gandhi D, Melhem ER, Frenkel V. MRI Guided Focused Ultrasound-Mediated Delivery of Therapeutic Cells to the Brain: A Review of the State-of-the-Art Methodology and Future Applications. Front Neurol 2021; 12:669449. [PMID: 34220679 PMCID: PMC8248790 DOI: 10.3389/fneur.2021.669449] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 05/14/2021] [Indexed: 12/24/2022] Open
Abstract
Stem cell and immune cell therapies are being investigated as a potential therapeutic modality for CNS disorders, performing functions such as targeted drug or growth factor delivery, tumor cell destruction, or inflammatory regulation. Despite promising preclinical studies, delivery routes for maximizing cell engraftment, such as stereotactic or intrathecal injection, are invasive and carry risks of hemorrhage and infection. Recent developments in MRI-guided focused ultrasound (MRgFUS) technology have significant implications for treating focal CNS pathologies including neurodegenerative, vascular and malignant processes. MRgFUS is currently employed in the clinic for treating essential tremor and Parkinson's Disease by producing precise, incisionless, transcranial lesions. This non-invasive technology can also be modified for non-destructive applications to safely and transiently open the blood-brain barrier (BBB) to deliver a range of therapeutics, including cells. This review is meant to familiarize the neuro-interventionalist with this topic and discusses the use of MRgFUS for facilitating cellular delivery to the brain. A detailed and comprehensive description is provided on routes of cell administration, imaging strategies for targeting and tracking cellular delivery and engraftment, biophysical mechanisms of BBB enhanced permeability, supportive proof-of-concept studies, and potential for clinical translation.
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Affiliation(s)
- Nabid Ahmed
- Department of Diagnostic Radiology and Nuclear Medicine, and Department of Neuroradiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Dheeraj Gandhi
- Department of Diagnostic Radiology and Nuclear Medicine, and Department of Neuroradiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Elias R Melhem
- Department of Diagnostic Radiology and Nuclear Medicine, and Department of Neuroradiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Victor Frenkel
- Department of Diagnostic Radiology and Nuclear Medicine, and Department of Neuroradiology, University of Maryland School of Medicine, Baltimore, MD, United States
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Rosenholm JM, Gulin-Sarfraz T, Mamaeva V, Niemi R, Özliseli E, Desai D, Antfolk D, von Haartman E, Lindberg D, Prabhakar N, Näreoja T, Sahlgren C. Prolonged Dye Release from Mesoporous Silica-Based Imaging Probes Facilitates Long-Term Optical Tracking of Cell Populations In Vivo. Small 2016; 12:1578-1592. [PMID: 26807551 DOI: 10.1002/smll.201503392] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 12/07/2015] [Indexed: 06/05/2023]
Abstract
Nanomedicine is gaining ground worldwide in therapy and diagnostics. Novel nanoscopic imaging probes serve as imaging tools for studying dynamic biological processes in vitro and in vivo. To allow detectability in the physiological environment, the nanostructure-based probes need to be either inherently detectable by biomedical imaging techniques, or serve as carriers for existing imaging agents. In this study, the potential of mesoporous silica nanoparticles carrying commercially available fluorochromes as self-regenerating cell labels for long-term cellular tracking is investigated. The particle surface is organically modified for enhanced cellular uptake, the fluorescence intensity of labeled cells is followed over time both in vitro and in vivo. The particles are not exocytosed and particles which escaped cells due to cell injury or death are degraded and no labeling of nontargeted cell populations are observed. The labeling efficiency is significantly improved as compared to that of quantum dots of similar emission wavelength. Labeled human breast cancer cells are xenotransplanted in nude mice, and the fluorescent cells can be detected in vivo for a period of 1 month. Moreover, ex vivo analysis reveals fluorescently labeled metastatic colonies in lymph node and rib, highlighting the capability of the developed probes for tracking of metastasis.
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Affiliation(s)
- Jessica M Rosenholm
- Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland
| | - Tina Gulin-Sarfraz
- Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland
- Laboratory of Physical Chemistry, Faculty of Science and Engineering, Åbo Akademi University, FI-20500, Turku, Finland
| | - Veronika Mamaeva
- Department of Clinical Science, University of Bergen, Norway
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, P.O. Box 123, FI-20521, Turku, Finland
| | - Rasmus Niemi
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, P.O. Box 123, FI-20521, Turku, Finland
- Cell Biology, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland
| | - Ezgi Özliseli
- Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland
| | - Diti Desai
- Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland
| | - Daniel Antfolk
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, P.O. Box 123, FI-20521, Turku, Finland
- Cell Biology, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland
| | - Eva von Haartman
- Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland
- Laboratory of Physical Chemistry, Faculty of Science and Engineering, Åbo Akademi University, FI-20500, Turku, Finland
| | - Desiré Lindberg
- Laboratory of Physical Chemistry, Faculty of Science and Engineering, Åbo Akademi University, FI-20500, Turku, Finland
| | - Neeraj Prabhakar
- Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland
- Laboratory of Biophysics, Faculty of Medicine, University of Turku, FI-20520, Turku, Finland
| | - Tuomas Näreoja
- Laboratory of Biophysics, Faculty of Medicine, University of Turku, FI-20520, Turku, Finland
| | - Cecilia Sahlgren
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, P.O. Box 123, FI-20521, Turku, Finland
- Cell Biology, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland
- Department of Biomedical Engineering, Institute for Complex Molecular Systems, Technical University of Eindhoven, 2612, Eindhoven, The Netherlands
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Song HT, Jordan EK, Lewis BK, Gold E, Liu W, Frank JA. Quantitative T2* imaging of metastatic human breast cancer to brain in the nude rat at 3 T. NMR Biomed 2011; 24:325-334. [PMID: 20949637 PMCID: PMC3022951 DOI: 10.1002/nbm.1596] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 05/14/2010] [Accepted: 06/28/2010] [Indexed: 05/30/2023]
Abstract
This study uses quantitative T(2)* imaging to track ferumoxides--protamine sulfate (FEPro)-labeled MDA-MB-231BR-Luc (231BRL) human breast cancer cells that metastasize to the nude rat brain. Four cohorts of nude rats were injected intracardially with FEPro-labeled, unlabeled or tumor necrosis factor-related apoptosis-inducing ligand(TRAIL)-treated (to induce apoptosis) 231BRL cells, or saline, in order to develop metastatic breast cancer in the brain. The heads of the rats were imaged serially over 3-4 weeks using gradient multi-echo and turbo spin-echo pulse sequences at 3 T with a solenoid receive-only 4-cm-diameter coil. Quantitative T(2)* maps of the whole brain were obtained by the application of single-exponential fitting to the signal intensity of T(2)* images, and the distribution of T(2)* values in brain voxels was calculated. MRI findings were correlated with Prussian blue staining and immunohistochemical staining for iron in breast cancer and macrophages. Quantitative analysis of T(2)* from brain voxels demonstrated a significant shift to lower values following the intracardiac injection of FEPro-labeled 231BRL cells, relative to animals receiving unlabeled cells, apoptotic cells or saline. Quartile analysis based on the T(2)* distribution obtained from brain voxels demonstrated significant differences (p < 0.0083) in the number of voxels with T(2)* values in the ranges 10-35 ms (Q1), 36-60 ms (Q2) and 61-86 ms (Q3) from 1 day to 3 weeks post-infusion of labeled 231BRL cells, compared with baseline scans. There were no significant differences in the distribution of T(2)* obtained from serial MRI in rats receiving unlabeled or TRAIL-treated cells or saline. Histologic analysis demonstrated isolated Prussian blue-positive breast cancer cells scattered in the brains of rats receiving labeled cells, relative to animals receiving unlabeled or apoptotic cells. Quantitative T(2)* analysis of FEPro-labeled metastasized cancer cells was possible even after the hypointense voxels were no longer visible on T(2)*-weighted images.
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Affiliation(s)
- Ho-Taek Song
- Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA.
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