Applications of Light-Sheet Microscopy in Microdevices

Abstract

Light-sheet fluorescence microscopy (LSFM) has been present in cell biology laboratories for quite some time, mainly as custom-made systems, with imaging applications ranging from single cells (in the micrometer scale) to small organisms (in the millimeter scale). Such microscopes distinguish themselves for having very low phototoxicity levels and high spatial and temporal resolution, properties that make them ideal for a large range of applications. These include the study of cellular dynamics, in particular cellular motion which is essential to processes such as tumor metastasis and tissue development. Experimental setups make extensive use of microdevices (bioMEMS) that provide better control over the substrate environment than traditional cell culture experiments. For example, to mimic in vivo conditions, experiment biochemical dynamics, and trap, move or count cells. Microdevices provide a higher degree of empirical complexity but, so far, most have been designed to be imaged through wide-field or confocal microscopes. Nonetheless, the properties of LSFM render it ideal for 3D characterization of active cells. When working with microdevices, confocal microscopy is more widespread than LSFM even though it suffers from higher phototoxicity and slower acquisition speeds. It is sometimes possible to illuminate with a light-sheet microdevices designed for confocal microscopes. However, these bioMEMS must be redesigned to exploit the full potential of LSFM and image more frequently on a wider scale phenomena such as motion, traction, differentiation, and diffusion of molecules. The use of microdevices for LSFM has extended beyond cell tracking studies into experiments regarding cytometry, spheroid cultures and lab-on-a-chip automation. Due to light-sheet microscopy being in its early stages, a setup of these characteristics demands some degree of optical expertise; and designing three-dimensional microdevices requires facilities, ingenuity, and experience in microfabrication. In this paper, we explore different approaches where light-sheet microscopy can achieve single-cell and subcellular resolution within microdevices, and provide a few pointers on how these experiments may be improved.

ZeBraInspector, a platform for the automated segmentation and analysis of body and brain volumes in whole 5 dpf zebrafish following simultaneous visualization with identical orientations

“…Although being the most powerful method for live applications, we did not select light-sheet microscopy. Indeed, although their diversity has offered easier image acquisitions, many require a high degree of optical and informatics expertises that may not be available to many experimental biology groups (Albert-Smet et al, 2019). With such microscopes, mounting of zebrafish EE in agarose at large-scale is difficult, and may require sophisticated robotics, especially because of the side illumination, which precludes simply using plates as with upright microscopes.…”

Tissue Clearing and Expansion Methods for Imaging Brain Pathology in Neurodegeneration: From Circuits to Synapses and Beyond

“…and processes (interactions, synthesis, degradation, and aggregation) that can be imaged in fixed samples. On the other hand, recent advances in volumetric imaging of bio-microelectromechanical systems (bioMEMS microdevices) using LSFM opens a promising avenue for achieving 3D and sucellular imaging of in vitro model systems under highly controlled experimental conditions ( Albert-Smet et al, 2019 ). Computational developments, including neuropathology-optimized data analysis tools and implementation of standardized pipelines, data formats, and data-sharing platforms can further aid quantitative assessments and systems-biology level interpretation of the vast amount of brain/circuit-wide imaging data that can be generated, as well as integration with functional and cell-specific omics data ( Vandenberghe et al, 2018 ; Hériché et al, 2019 ).…”

Innovations in 3D Tissue Models of Human Brain Physiology and Diseases

“…[ 254 ] Future integration of light sheet microscopy in microdevices may allow for even greater spatial and temporal resolution, with lower phototoxicity than confocal microscopy. [ 255 ] While standard microscopes are still the most frequently used, continued development of compact microscope‐on‐a‐chip imaging systems will reduce costs and increase capabilities for automation and portability. [ 256 ] Future integration of smartphones, utilizing their high‐resolution complementary metal oxide semiconductor (CMOS) cameras, offers another alternative for optical biosensors, [ 257 ] with proof‐of‐concept already demonstrated in a microfluidic chip system.…”