(462d) Magnetic Stress Rheometer for Biological Fluid Characterization

The rheology of biological fluids plays a crucial role in a variety of biological processes, including the diagnosis and treatment of medical conditions. However, commercial rheometers are expensive and difficult to keep sterile. We present a novel magnetic stress rheometer platform that is portable, inexpensive, and disposable to ensure sterility, optimized for applications in clinical and hospital settings. The platform consists of a magnetic plate that rests on the surface of the sample, which is then subjected to a constant magnetic force generated by a pair of coils. The resulting plate motion relative to the applied force allows for the determination of the relative viscous and elastic contributions of the rheology of the material. The entire setup is compact and operated with a Raspberry Pi single-board computer, making it portable and easy to use in point-of-care applications.

We demonstrate the effectiveness of this new platform by analyzing a variety of biological materials, including abscess fluid and bioinks for 3D bioprinting. Abscesses caused by bacterial infections can occur in any part of the body and typically require drainage procedures, but there is currently no quantitative method to determine the optimal drainage parameters such as catheter size or potential chemical treatments to ease the drainage process. Our magnetic rheometer allows for a sterile and inexpensive way to analyze abscess fluid rheology in a hospital setting, and provides the first comprehensive rheological analysis of abscess fluid viscoelasticity.

Bioinks are an emerging class of materials used in 3D bioprinting, which allows for the creation of artificial tissue constructs that can be used for organ transplantation, drug testing, and tissue engineering. For the first time, our magnetic rheometer platform allows for the characterization of bioink rheology throughout diffusion-based crosslinking in situ, enabling better understanding of how to ensure print fidelity in setups containing bioink and support bath components.

Overall, our novel magnetic stress rheometer platform has broad applications in the biomedical field, enabling rapid, sterile, cost-effective, and comprehensive analysis of biological fluids in point-of-care applications. The ability to measure the rheology of abscess fluid and bioinks provides valuable insights for guiding personalized treatment plans and improving tissue engineering applications.