Abstract
Recent studies in mechanobiology have revealed the importance of cellular and extracellular mechanical properties in regulating cellular function in normal and disease states. Although it is established that cells should be investigated in a three-dimensional (3-D) environment, most techniques available to study mechanical properties on the microscopic scale are unable to do so. In this study, for the first time, we present volumetric images of cellular and extracellular elasticity in 3-D biomaterials using quantitative micro-elastography (QME). We achieve this by developing a novel strain estimation algorithm based on 3-D linear regression to improve QME system resolution. We show that QME can reveal elevated elasticity surrounding human adipose-derived stem cells (ASCs) embedded in soft hydrogels. We observe, for the first time in 3-D, further elevation of extracellular elasticity around ASCs with overexpressed TAZ; a mechanosensitive transcription factor which regulates cell volume. Our results demonstrate that QME has the potential to study the effects of extracellular mechanical properties on cellular functions in a 3-D micro-environment.
Highlights
The cell is subject to a range of physical forces that are intrinsically linked to the mechanical properties of both the cell and the extracellular matrix (ECM) [1]
A phantom was fabricated from Elastosil RT601, P7676, and AK50 Silicone oil (Wacker, Germany) that contained a stiff inclusion with dimensions of 50×45×44 μm, similar to a typical adipose-derived stem cells (ASCs) analyzed in this study [48]
The visualization of cell and extracellular elasticity provided by quantitative micro-elastography (QME) represents a new technique to study the influence of mechanical properties on cell physiology in 3-D biomaterials
Summary
The cell is subject to a range of physical forces that are intrinsically linked to the mechanical properties of both the cell and the extracellular matrix (ECM) [1]. Shear-flow techniques, such as microfluidics, have been used to characterize the effect of shear stress on cell physiology with an advantage of increased throughput [18] These techniques typically remain limited to surface measurements, or studying cells in isolation, making it challenging to study the influence of mechanical properties on cell physiology in 3-D biomaterials. Brillouin microscopy measures longitudinal modulus throughout a sample volume and has a number of attractive features, including its high spatial resolution (0.5–5 μm) and that it does not require an external mechanical load [21]. Cell imaging with Brillouin microscopy in scattering materials has a limited penetration depth (0.1–0.2 mm) compared to low-coherence interferometry techniques such as OCE (0.5–1 mm) [23]. Using QME to image the elasticity of cells in 3-D biomaterials has yet to be demonstrated and, the elasticity resolution of QME has been loosely defined, making its suitability for use in mechanobiology unclear
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
