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Braun J, Bernarding J, Snellings J, Meyer T, Dantas de Moraes PA, Safraou Y, Wells RG, Guo J, Tzschätzsch H, Zappe A, Pagel K, Sauer IM, Hillebrandt KH, Sack I. On the relationship between viscoelasticity and water diffusion in soft biological tissues. Acta Biomater 2024:S1742-7061(24)00245-9. [PMID: 38729549 DOI: 10.1016/j.actbio.2024.05.007] [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] [Received: 01/24/2024] [Revised: 04/10/2024] [Accepted: 05/03/2024] [Indexed: 05/12/2024]
Abstract
Magnetic resonance elastography (MRE) and diffusion-weighted imaging (DWI) are complementary imaging techniques that detect disease based on viscoelasticity and water mobility, respectively. However, the relationship between viscoelasticity and water diffusion is still poorly understood, hindering the clinical translation of combined DWI-MRE markers. We used DWI-MRE to study 129 biomaterial samples including native and cross-linked collagen, glycosaminoglycans (GAGs) with different sulfation levels, and decellularized specimens of pancreas and liver, all with different proportions of solid tissue, or solid fractions. We developed a theoretical framework of the relationship between mechanical loss and tissue-water mobility based on two parameters, solid and fluid viscosity. These parameters revealed distinct DWI-MRE property clusters characterizing weak, moderate, and strong water-network interactions. Sparse networks interacting weakly with water, such as collagen or diluted decellularized tissue, resulted in marginal changes in water diffusion over increasing solid viscosity. In contrast, dense networks with larger solid fractions exhibited both free and hindered water diffusion depending on the polarity of the solid components. For example, polar and highly sulfated GAGs as well as native soft tissues hindered water diffusion despite relatively low solid viscosity. Our results suggest that two fundamental properties of tissue networks, solid fraction and network polarity, critically influence solid and fluid viscosity in biological tissues. Since clinical DWI and MRE are sensitive to these viscosity parameters, the framework we present here can be used to detect tissue remodeling and architectural changes in the setting of diagnostic imaging. STATEMENT OF SIGNIFICANCE: The viscoelastic properties of biological tissues provide a wealth of information on the vital state of cells and host matrix. Combined measurement of viscoelasticity and water diffusion by medical imaging is sensitive to tissue microarchitecture. However, the relationship between viscoelasticity and water diffusion is still poorly understood, hindering full exploitation of these properties as a combined clinical biomarker. Therefore, we analyzed the parameter space accessible by diffusion-weighted imaging (DWI) and magnetic resonance elastography (MRE) and developed a theoretical framework for the relationship between water mobility and mechanical parameters in biomaterials. Our theory of solid material properties related to particle motion can be translated to clinical radiology using clinically established MRE and DWI.
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Affiliation(s)
- Jürgen Braun
- Institute of Medical Informatics, Charité - Universitätsmedizin Berlin, Germany
| | | | - Joachim Snellings
- Department of Radiology, Charité - Universitätsmedizin Berlin, Germany
| | - Tom Meyer
- Department of Radiology, Charité - Universitätsmedizin Berlin, Germany
| | | | - Yasmine Safraou
- Department of Radiology, Charité - Universitätsmedizin Berlin, Germany
| | - Rebecca G Wells
- Perelman School of Medicine, University of Pennsylvania, PA, USA
| | - Jing Guo
- Department of Radiology, Charité - Universitätsmedizin Berlin, Germany
| | - Heiko Tzschätzsch
- Institute of Medical Informatics, Charité - Universitätsmedizin Berlin, Germany
| | - Andreas Zappe
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Germany
| | - Kevin Pagel
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Germany
| | - Igor M Sauer
- Department of Surgery, CCM | CVK, Experimental Surgery, Charité - Universitätsmedizin Berlin and Berlin Institute of Health, Berlin, Germany
| | - Karl H Hillebrandt
- Department of Surgery, CCM | CVK, Experimental Surgery, Charité - Universitätsmedizin Berlin and Berlin Institute of Health, Berlin, Germany; Berlin Institute of Health at Charité - Universitätsmedizin Berlin, BIH Biomedical Innovation Academy, BIH Charité Clinician Scientist Program, Charitéplatz 1, 10117 Berlin, Germany
| | - Ingolf Sack
- Department of Radiology, Charité - Universitätsmedizin Berlin, Germany.
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Snellings J, Keshi E, Tang P, Daneshgar A, Willma EC, Haderer L, Klein O, Krenzien F, Malinka T, Asbach P, Pratschke J, Sauer IM, Braun J, Sack I, Hillebrandt K. Solid fraction determines stiffness and viscosity in decellularized pancreatic tissues. Biomater Adv 2022; 139:212999. [PMID: 35882147 DOI: 10.1016/j.bioadv.2022.212999] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 04/15/2022] [Revised: 06/05/2022] [Accepted: 06/20/2022] [Indexed: 05/29/2023]
Abstract
The role of extracellular matrix (ECM) composition and turnover in mechano-signaling and the metamorphic fate of cells seeded into decellularized tissue can be elucidated by recent developments in non-invasive imaging and biotechnological analysis methods. Because these methods allow accurate quantification of the composition and structural integrity of the ECM, they can be critical in establishing standardized decellularization protocols. This study proposes quantification of the solid fraction, the single-component fraction and the viscoelasticity of decellularized pancreatic tissues using compact multifrequency magnetic resonance elastography (MRE) to assess the efficiency and quality of decellularization protocols. MRE of native and decellularized pancreatic tissues showed that viscoelasticity parameters depend according to a power law on the solid fraction of the decellularized matrix. The parameters can thus be used as highly sensitive markers of the mechanical integrity of soft tissues. Compact MRE allows consistent and noninvasive quantification of the viscoelastic properties of decellularized tissue. Such a method is urgently needed for the standardized monitoring of decellularization processes, evaluation of mechanical ECM properties, and quantification of the integrity of solid structural elements remaining in the decellularized tissue matrix.
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Affiliation(s)
- Joachim Snellings
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Radiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Eriselda Keshi
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Surgery, Campus Charité Mitte|Campus Virchow-Klinikum, Charitéplatz 1, 10117 Berlin, Germany
| | - Peter Tang
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Surgery, Campus Charité Mitte|Campus Virchow-Klinikum, Charitéplatz 1, 10117 Berlin, Germany
| | - Assal Daneshgar
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Surgery, Campus Charité Mitte|Campus Virchow-Klinikum, Charitéplatz 1, 10117 Berlin, Germany
| | - Esther C Willma
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Surgery, Campus Charité Mitte|Campus Virchow-Klinikum, Charitéplatz 1, 10117 Berlin, Germany
| | - Luna Haderer
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Surgery, Campus Charité Mitte|Campus Virchow-Klinikum, Charitéplatz 1, 10117 Berlin, Germany
| | - Oliver Klein
- Berlin Institute of Health at Charité - Universitätsmedizin Berlin, BIH Center for Regenerative Therapies, Charitéplatz 1, 10117 Berlin, Germany
| | - Felix Krenzien
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Surgery, Campus Charité Mitte|Campus Virchow-Klinikum, Charitéplatz 1, 10117 Berlin, Germany; Berlin Institute of Health, Germany at Charité - Universitätsmedizin Berlin, BIH Acadamy, Clinician Scientist Program, Charitéplatz 1, 10117 Berlin, Germany
| | - Thomas Malinka
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Surgery, Campus Charité Mitte|Campus Virchow-Klinikum, Charitéplatz 1, 10117 Berlin, Germany
| | - Patrick Asbach
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Radiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Johann Pratschke
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Surgery, Campus Charité Mitte|Campus Virchow-Klinikum, Charitéplatz 1, 10117 Berlin, Germany; Cluster of Excellence "Matters of Activity. Image Space Material" funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy - E.XC 2025, Germany
| | - Igor M Sauer
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Surgery, Campus Charité Mitte|Campus Virchow-Klinikum, Charitéplatz 1, 10117 Berlin, Germany; Cluster of Excellence "Matters of Activity. Image Space Material" funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy - E.XC 2025, Germany
| | - Jürgen Braun
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute for Medical Informatics, Charitéplatz 1, 10117 Berlin, Germany
| | - Ingolf Sack
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Radiology, Charitéplatz 1, 10117 Berlin, Germany; Cluster of Excellence "Matters of Activity. Image Space Material" funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy - E.XC 2025, Germany.
| | - Karl Hillebrandt
- Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Surgery, Campus Charité Mitte|Campus Virchow-Klinikum, Charitéplatz 1, 10117 Berlin, Germany; Berlin Institute of Health, Germany at Charité - Universitätsmedizin Berlin, BIH Acadamy, Clinician Scientist Program, Charitéplatz 1, 10117 Berlin, Germany; Cluster of Excellence "Matters of Activity. Image Space Material" funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy - E.XC 2025, Germany
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Eames I, Landeryou M, Greig A, Snellings J. Continuous flushing of contaminants from ballast water tanks. Mar Pollut Bull 2008; 56:250-260. [PMID: 18086479 DOI: 10.1016/j.marpolbul.2007.10.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 10/04/2007] [Accepted: 10/19/2007] [Indexed: 05/25/2023]
Abstract
The transport of non-indigenous species (NIS) with ship ballast water is a major environmental problem. The International Maritime Organisation (IMO) have recommended that ballast tanks are flushed through with sea water to remove NIS contaminants. The flushing efficiency is studied using mathematical models and a scaled experimental model of a ballast tank. The density contrast between the ballast water and water used for flushing is important when the Froude number Fr(w)=U(w)/sqr rt|g(')|H << 1 (defined in terms of average horizontal flow U(w), reduced buoyancy g', and H the vertical dimension in the tank). When denser water is used to flush a ballast tank, from below, it efficiently displaces lighter ballast water; but flushing through with light water creates a buoyant gravity current which effectively short circuits part of the tank. When Fr(w)>>1, the density contrast between the ballast water and water used for flushing is not important and flushing is controlled by a bulk Péclet number, Pe(w). For Pe(w)<<1 perfect mixing occurs, while for Pe(w)>>1 displacement flushing occurs. Laboratory experiments of flushing were performed using a model two-dimensional ballast tank employing dye attenuation to measure the whole concentration field and these experiments confirm the essential features of the mathematical models. The results of this study are discussed in the context of current IMO flushing protocols.
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Affiliation(s)
- I Eames
- Department of Mechanical Engineering, University College London, London, UK.
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