Evaluating biomechanical properties of murine embryos using Brillouin microscopy and optical coherence tomography

Abstract

Embryogenesis is regulated by numerous changes in mechanical properties of the cellular microenvironment. Thus, studying embryonic mechanophysiology can provide a more thorough perspective of embryonic development, potentially improving early detection of congenital abnormalities as well as evaluating and developing therapeutic interventions. A number of methods and techniques have been used to study cellular biomechanical properties during embryogenesis. While some of these techniques are invasive or involve the use of external agents, others are compromised in terms of spatial and temporal resolutions. We propose the use of Brillouin microscopy in combination with optical coherence tomography (OCT) to measure stiffness as well as structural changes in a developing embryo. While Brillouin microscopy assesses the changes in stiffness among different organs of the embryo, OCT provides the necessary structural guidance.

Brillouin Light Scattering: Applications in Biomedical Sciences

“…Brillouin microscopy has been applied in combination with optical coherence tomography (Br-OCT) to map the stiffness of a developing murine embryo while assessing structural changes. 109 Structural imaging by OCT enables recognition of developing organs, whereas Brillouin microscopy gains spatially resolved stiffness through the measure of the mean Brillouin shift. It can be anticipated that this will be an area of further development in multimodal imaging.…”

Tissue biomechanics during cranial neural tube closure measured by Brillouin microscopy and optical coherence tomography

“…The configuration of the Brillouin microscope has been previously reported (Raghunathan et al, ; Scarcelli, Polacheck, et al, ). Briefly, a two‐stage VIPA spectrometer was used to acquire the Brillouin signal (Scarcelli, Kim, & Yun, ), and a spectral coronagraphy was integrated into the spectrometer to enhance its noise‐rejection capability (Edrei, Gather, & Scarcelli, ).…”

“…Brillouin microscopy has been recently used to characterize the mechanical properties of eye tissue (Besner, Scarcelli, Pineda, & Yun, ; Scarcelli, Besner, Pineda, Kalout, & Yun, ) in vivo, fibrous proteins of the extracellular matrix (Palombo et al, ), and cellular mechanics (Antonacci & Braakman, ; Elsayad et al, ; Scarcelli et al, ; Zhang, Nou, Kim, & Scarcelli, ). Very recently, we acquired the first mechanical images of a mouse embryo with the Brillouin microscope (Raghunathan et al, ), demonstrating that this technique had the promising capability of characterizing the biomechanics of embryonic tissue in situ .…”

Understanding the Mechanobiology of Early Mammalian Development through Bioengineered Models

“…Of these, we here highlight some that appear particularly suited to application for in vitro embryonic models and are generally responsive to criteria of high spatial resolution, scalability, and minimal invasiveness. One such technique is Brillouin microscopy (Scarcelli and Yun, 2007), already used to measure changes in local stiffness in late post-implantation mouse embryos (Raghunathan et al, 2017;Zhang et al, 2018a) as well as in simpler embryonic systems (Pukhlyakova et al, 2018). This type of microscopy exploits the so-called Brillouin scattering effect, originating from the interactions between light waves-illuminating the sample-and acoustic waves-originating from random thermal fluctuations of molecules within the sample and which can be related to the local viscoelastic properties of the tissue (see Prevedel et al, 2019).…”