Integrating mechanical sensor readouts into organ-on-a-chip platforms

Abstract

Organs-on-a-chip have emerged as next-generation tissue engineered models to accurately capture realistic human tissue behaviour, thereby addressing many of the challenges associated with using animal models in research. Mechanical features of the culture environment have emerged as being critically important in designing organs-on-a-chip, as they play important roles in both stimulating realistic tissue formation and function, as well as capturing integrative elements of homeostasis, tissue function, and tissue degeneration in response to external insult and injury. Despite the demonstrated impact of incorporating mechanical cues in these models, strategies to measure these mechanical tissue features in microfluidically-compatible formats directly on-chip are relatively limited. In this review, we first describe general microfluidically-compatible Organs-on-a-chip sensing strategies, and categorize these advances based on the specific advantages of incorporating them on-chip. We then consider foundational and recent advances in mechanical analysis techniques spanning cellular to tissue length scales; and discuss their integration into Organs-on-a-chips for more effective drug screening, disease modeling, and characterization of biological dynamics.

Integrated Closed-loop Control of Bio-actuation for Proprioceptive Bio-hybrid Robots

“…However, for use in bioengineering applications, the component materials, designs, and manufacturing approaches of mechanical sensors have to be optimized to improve the performance of the sensors ( i.e ., sensitivity, durability) within biological environments that feature complex architectures, soft materials, liquid milieu, and activity of living systems ( i.e ., cells) ( 29 , 30 ). Developing biocompatible, reliable, and minimally invasive sensors poses a significant challenge, limiting their application to natural or engineered biological systems ( 31 , 32 ).…”

From animal testing to in vitro systems: advancing standardization in microphysiological systems

“…The mechanical features of MPS contribute to stimulating realistic tissue formation and function as well as capturing integrative elements of tissue function in response to external insults and injuries and have emerged as a crucial consideration in the design of these systems. 26…”

“…The mechanical features of MPS contribute to stimulating realistic tissue formation and function as well as capturing integrative elements of tissue function in response to external insults and injuries and have emerged as a crucial consideration in the design of these systems. 26 Mechanical actuation using fluid flow and shear stress, is one of the most common forms of actuation and stimulation in MPS. The pumping and control system should be standardized to ensure the delivery of the appropriate flow rate for specific operations.…”

The Use of Sensors in Blood-Brain Barrier-on-a-Chip Devices: Current Practice and Future Directions

“…Mechanical properties of cells comprising the BBB play a fundamental role in determining the adaptability and vulnerability of the barrier subjected to external stimuli. The most commonly used methods of mapping the stress and strain fields associated to cell layers adapt one form or another of traction force microscopy, where the cells are grown on the surface of an elastic material (e.g., hydrogel or PDMS) doped with fluorescent microbeads or equipped with a micropillar-brushed surface [ 65 ]. If, however, only the overall principal components of the stress tensor are necessary to obtain, conductivity measurements across the elastic substrate doped with carbon nanotubes can also be used [ 66 ].…”