Existing and Potential Applications of Elastography for Measuring the Viscoelasticity of Biological Tissues In Vivo

Abstract

Mechanical tissue properties contribute to tissue shape change during development. Emerging evidence suggests that gradients of viscoelasticity correspond to cell movement and gene expression patterns. To accurately define mechanisms of morphogenesis, a combination of precise empirical measurements and theoretical approaches are required. Here, we review elastography as a method to characterize viscoelastic properties of tissue in vivo. We discuss its current clinical applications in mature tissues and its potential for characterizing embryonic tissues.

Multimodal mechano-microscopy reveals mechanical phenotypes of breast cancer spheroids in three dimensions

“…Furthermore, to reduce viscoelastic effects, the imaging protocol was carefully tailored by encapsulating cell spheroids into GelMA that exhibits low viscoelasticity [42], and the samples were deformed at a quasi-static loading frequency [11] to ensure the instantaneous elastic strain was measured. However, a more generalized mechanical model could be developed to account for viscoelasticity [43,44] of the sample to enable multiparametric quantitative characterization of spheroid mechanics.…”

Recent Methods for Modifying Mechanical Properties of Tissue-Engineered Scaffolds for Clinical Applications

“…The mechanical properties of biological materials are a product of a complex array of proteins, cells, and interstitial fluid flow, whose interactions characterise the response of their respective tissue under load [ 83 , 84 ]. As a product of their intricacy, biological tissues exhibit complex mechanical properties such as heterogeneity, viscoelasticity, and anisotropy [ 83 , 84 , 85 ]. Accurately assessing the mechanical properties of these tissues is therefore intrinsically challenging, with research groups often attaining a variety of results for the same tissue.…”

Viscoelasticity, Like Forces, Plays a Role in Mechanotransduction

“…The majority of approaches to query the viscoelastic behavior of cells utilize forced induced deformations or probes ( Wirtz, 2009 ) on relatively short time scales due to experimental requirement and feasibility. Efforts to gauge the elastic aspect of cell viscoelasticity involve atomic force microscopy (AFM) ( Haase and Pelling, 2015 ; Fischer et al, 2017 , Mierke et al, 2017 , Fischer et al, 2020 ), hydrodynamic stretching ( Gossett et al, 2012 ), optical cell stretcher ( Kunschmann et al, 2017 , Kunschmann et al, 2019 ; Mierke et al, 2020 ), optical laser tweezers ( Lincoln et al, 2004 ), magnetic tweezers ( Amblard et al, 1996 ; Aermes et al, 2020 , Aermes et al, 2021 ), microrheology ( Mason and Weitz, 1995 ; Crocker and Hoffman, 2007 ), magnetic resonance elastography ( Muthupillai et al, 1995 ; Zhang et al, 2021 ), micropipette suction ( Hochmuth, 2000 ) and uniaxial stretching rheometry ( Desprat et al, 2005 ) ( Figure 1 ). The viscous part of the reaction of cells to mechanical probing has been determined employing biophysical techniques encompassing microrheology ( Mason and Weitz, 1995 ; Crocker and Hoffman, 2007 ), micropipette suction ( Hochmuth, 2000 ), fluorescent rotor protein ( Kuimova et al, 2008 ), AFM ( Rebelo et al, 2013 ), electronic spin resonance ( Mastro and Keith, 1984 ) and optical laser tweezers ( Ługowski et al, 2002 ) ( Table 1 ).…”