Photochromic proteins and photoswitching optoacoustics (OA) are a promising combination, that allows OA imaging of even small numbers of cells in whole live animals and thus can facilitate a more wide-spread use of OA in life-science and preclinical research. The concept relies on exploiting the modulation achieved by the photoswitching to discriminate the agents' signal from the non-modulating background. Here we share our analysis approaches that can be readily used on data generated with commercial OA tomography imaging instrumentation allowing-depending on the used photoswitching agent and sample-routine visualizations of as little as several hundreds of transgene labeled cells per imaging volume in the live animal.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/bs.mie.2021.06.031 | DOI Listing |
Nat Methods
November 2024
Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany.
Optoacoustic (photoacoustic) imaging advances allow high-resolution optical imaging much deeper than optical microscopy. However, while label-free optoacoustics have already entered clinical application, biological imaging is in need of ubiquitous optoacoustic labels for use in ways that are similar to how fluorescent proteins propelled optical microscopy. We review photoswitching advances that shine a new light or, in analogy, 'bring a new sound' to biological optoacoustic imaging.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2024
Department of Pharmacy, LMU Munich, Butenandtstrasse 7, Munich, 81377, Germany.
Optoacoustic (or photoacoustic) imaging promises micron-resolution noninvasive bioimaging with much deeper penetration (>cm) than fluorescence. However, optoacoustic imaging of enzyme activity would require loud, photostable, NIR-absorbing molecular contrast agents, which remain unknown. Most organic molecular contrast agents are repurposed fluorophores, with severe shortcomings of photoinstability or phototoxicity under optoacoustic imaging, as consequences of their slow S→S electronic relaxation.
View Article and Find Full Text PDFPhotoacoustics
March 2022
Institute of Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
Test-samples are necessary for the development of emerging imaging approaches such as optoacoustics (OA); these can be used to benchmark new labeling agents and instrumentation, or to characterize image analysis algorithms or the inversion required to form the three-dimensional reconstructions. Alginate beads (AlBes) loaded with labeled mammalian or bacterial cells provide a method of creating defined structures of controllable size and photophysical characteristics and are well-suited for both and use. Here we describe a simple and rapid method for efficient and reproducible production of AlBes with specific characteristics and show three example applications with multispectral OA tomography imaging.
View Article and Find Full Text PDFNat Biotechnol
April 2022
Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany.
Reversibly photo-switchable proteins are essential for many super-resolution fluorescence microscopic and optoacoustic imaging methods. However, they have yet to be used as sensors that measure the distribution of specific analytes at the nanoscale or in the tissues of live animals. Here we constructed the prototype of a photo-switchable Ca sensor based on GCaMP5G that can be switched with 405/488-nm light and describe its molecular mechanisms at the structural level, including the importance of the interaction of the core barrel structure of the fluorescent protein with the Ca receptor moiety.
View Article and Find Full Text PDFMethods Enzymol
August 2021
Institute of Biological and Medical Imaging (IBMI), Helmholtz Zentrum München (GmbH), Neuherberg, Germany. Electronic address:
Photochromic proteins and photoswitching optoacoustics (OA) are a promising combination, that allows OA imaging of even small numbers of cells in whole live animals and thus can facilitate a more wide-spread use of OA in life-science and preclinical research. The concept relies on exploiting the modulation achieved by the photoswitching to discriminate the agents' signal from the non-modulating background. Here we share our analysis approaches that can be readily used on data generated with commercial OA tomography imaging instrumentation allowing-depending on the used photoswitching agent and sample-routine visualizations of as little as several hundreds of transgene labeled cells per imaging volume in the live animal.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!