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Abstract Tissue mimicking materials are designed to represent real tissue in applications such as medical device testing and surgical training. Thanks to progress in 3D‐printing technology, tissue mimics can now be easily cast into arbitrary geometries and manufactured with adjustable material properties to mimic a wide variety of tissue types. However, it is unclear how well 3D‐printable mimics represent real tissues and their mechanics. The objective of this work is to fill this knowledge gap using the Stratasys Digital Anatomy 3D‐Printer as an example. To this end, we created mimics of biological tissues we previously tested in our laboratory: blood clots, myocardium, and tricuspid valve leaflets. We printed each tissue mimic to have the identical geometry to its biological counterpart and tested the samples using identical protocols. In our evaluation, we focused on the stiffness of the tissues and their fracture toughness in the case of blood clots. We found that the mechanical behavior of the tissue mimics often differed substantially from the biological tissues they aim to represent. Qualitatively, tissue mimics failed to replicate the traditional strain‐stiffening behavior of soft tissues. Quantitatively, tissue mimics were stiffer than their biological counterparts, especially at small strains, in some cases by orders of magnitude. In those materials in which we tested toughness, we found that tissue mimicking materials were also much tougher than their biological counterparts. Thus, our work highlights limitations of at least one 3D‐printing technology in its ability to mimic the mechanical properties of biological tissues. Therefore, care should be taken when using this technology, especially where tissue mimicking materials are expected to represent soft tissue properties quantitatively. Whether other technologies fare better remains to be seen.
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Rheology in the Biological Sciences
Rheology is the science of how materials deform and flow and is a critical aspect of understanding the biomechanical functions of cell and tissue. Historically, scientists have designed simple often cost-effective instruments for assessing the mechanical properties of biological materials to inform their functionality. Cells and tissue are heterogeneous and possess complex mechanical properties. Yet, simple instruments such as falling ball viscometers and torsion pendulums, can often accurately capture and measure different aspects of how biological materials deform that are relevant to physiological conditions. Here, we review the application of simple, home-built instruments suitable for probing the viscoelastic properties of biological materials, underscoring the importance of creativity and innovation of experimental tool design in the field of biomechanics.
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- Award ID(s):
- 2238600
- PAR ID:
- 10568940
- Publisher / Repository:
- Rheology Bulletin
- Date Published:
- Format(s):
- Medium: X
- Institution:
- Rheology Bulletin
- Sponsoring Org:
- National Science Foundation
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