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High-frequency quantitative ultrasound for the assessment of the acoustic properties of engineered tissues in vitro.
Sebastian, Joseph A; Strohm, Eric M; Chérin, Emmanuel; Mirani, Bahram; Démoré, Christine E M; Kolios, Michael C; Simmons, Craig A.
Afiliación
  • Sebastian JA; Institute of Biomedical Engineering, University of Toronto, Toronto, Canada; Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada. Electronic address: j.sebastian@mail.utoronto.ca.
  • Strohm EM; Department of Physics, Toronto Metropolitan University, Toronto, Canada; Institute of Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, Toronto, Canada; Keenan Research Centre for Biomedical Science, Li Ka Shing
  • Chérin E; Sunnybrook Research Institute, Toronto, Canada.
  • Mirani B; Institute of Biomedical Engineering, University of Toronto, Toronto, Canada; Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada; Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada.
  • Démoré CEM; Sunnybrook Research Institute, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada.
  • Kolios MC; Department of Physics, Toronto Metropolitan University, Toronto, Canada; Institute of Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, Toronto, Canada; Keenan Research Centre for Biomedical Science, Li Ka Shing
  • Simmons CA; Institute of Biomedical Engineering, University of Toronto, Toronto, Canada; Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, Canada; Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada. Electronic address: c.simmon
Acta Biomater ; 157: 288-296, 2023 02.
Article en En | MEDLINE | ID: mdl-36521676
ABSTRACT
Acoustic properties of biomaterials and engineered tissues reflect their structure and cellularity. High-frequency ultrasound (US) can non-invasively characterize and monitor these properties with sub-millimetre resolution. We present an approach to estimate the speed of sound, acoustic impedance, and acoustic attenuation of cell-laden hydrogels that accounts for frequency-dependent effects of attenuation in coupling media, hydrogel thickness, and interfacial transmission/reflection coefficients of US waves, all of which can bias attenuation estimates. Cell-seeded fibrin hydrogel disks were raster-scanned using a 40 MHz US transducer. Thickness, speed of sound, acoustic impedance, and acoustic attenuation coefficients were determined from the difference in the time-of-flight and ratios of the magnitudes of US signals, interfacial transmission/reflection coefficients, and acoustic properties of the coupling media. With this approach, hydrogel thickness was accurately measured by US, with agreement to confocal microscopy (r2 = 0.97). Accurate thickness measurement enabled acoustic property measurements that were independent of hydrogel thickness, despite up to 60% reduction in thickness due to cell-mediated contraction. Notably, acoustic attenuation coefficients increased with increasing cell concentration (p < 0.001), reflecting hydrogel cellularity independent of contracted hydrogel thickness. This approach enables accurate measurement of the intrinsic acoustic properties of biomaterials and engineered tissues to provide new insights into their structure and cellularity. STATEMENT OF

SIGNIFICANCE:

High-frequency ultrasound can measure the acoustic properties of engineered tissues non-invasively and non-destructively with µm-scale resolution. Acoustic properties, including acoustic attenuation, are related to intrinsic material properties, such as scatterer density. We developed an analytical approach to estimate the acoustic properties of cell-laden hydrogels that accounts for the frequency-dependent effects of attenuation in coupling media, the reflection/transmission of ultrasound waves at the coupling interfaces, and the dependency of measurements on hydrogel thickness. Despite up to 60% reduction in hydrogel thickness due to cell-mediated contraction, our approach enabled measurements of acoustic properties that were substantially independent of thickness. Acoustic attenuation increased significantly with increasing cell concentration (p < 0.001), demonstrating the ability of acoustic attenuation to reflect intrinsic physical properties of engineered tissues.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Acústica / Hidrogeles Idioma: En Revista: Acta Biomater Año: 2023 Tipo del documento: Article

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Acústica / Hidrogeles Idioma: En Revista: Acta Biomater Año: 2023 Tipo del documento: Article