Experimental and Computational Investigation of Mechanisms Governing Soft Tissue Interfaces

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

This grant will identify the mechanisms that govern mechanical behavior at soft tissue interfaces. Soft tissue interfaces are where two soft biological materials come together. These occur naturally, such as at the interface between muscle and tendon. These also occur in surgical and healing contexts, such as in focal cartilage repair. These interfaces are often spatially heterogeneous, which means that the stiffness and softness of the material varies with specific location. This has been shown using imaging techniques such as microscopy. How this heterogeneity affects the mechanical behavior across the interface is not known. When two soft tissues come together, their mechanical interactions can arise from friction, adhesion, and from the growth of new tissue across the interface. This work will first conduct experiments to measure spatial heterogeneity of the mechanical behavior at soft tissue interfaces. The work will then build computational models to identify the mechanisms governing this behavior. The results of this research will provide new fundamental insight into soft tissue interfaces. These insights can be used to improve surgical repair of soft tissue damage and can be used to design bio-inspired soft robotics. The results from this research will be shared with the broader public at outreach events, and will be shared with undergraduate and graduate students. Soft material interfaces are relevant to repair and regeneration of soft tissues, and to the application of soft robotics. The phenomena governing the mechanics at soft tissue interfaces is incompletely understood. This project will use a model system of in vitro cartilage-cartilage integration to experimentally and computationally probe those phenomena. The research team will conduct experiments to quantify spatially variant displacement at the cartilage-cartilage interface. In tandem, the research team will conduct experiments to quantify the bulk behavior, frictional behavior, adhesive behavior, swelling behavior and neocartilage material behavior. Subsequently, finite element models will be generated using the quantified behavior to interpret spatially variant displacement data. Models are expected to reveal the fundamental phenomena governing soft tissue interfaces. Results from this research will be integrated into K12, undergraduate, graduate, and broader public education. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.