Researchers have identified focal adhesion tilting as a physical mechanism that allows cells to sense both curvature and stiffness, according to a peer-reviewed study published in Nature Communications. Co-lead authors Crescenzo Frascogna and Valeria Panzetta observed that the inclination of the focal adhesion plane relative to an underlying substrate directly adapts to mechanical forces.
Scientists used reverse cell imprinting alongside atomic force microscopy to track this structural behavior across different environments. Their measurements uncovered a strong inverse correlation between the focal adhesion tilting angle and substrate stiffness. A two-dimensional clutch model confirmed that the physical tilting emerges from force distribution across the interface between the focal adhesion and the substrate, directly guiding cellular mechanosensing.
The authors then engineered rigid substrates featuring precise, defined curvatures to test the effect without altering material stiffness. Imposing specific tilting angles changed the cellular mechanostate independently, establishing a curvature-stiffness mechanical equivalence principle. By tracking these shifts, the team constructed a correlation map that translates physical curvature values into equivalent stiffness levels for designing instructive biomaterials in tissue engineering.
The Italian Ministry of University and Research funded the work through the FIT4MEDROB medical robotics initiative and the Space It Up project. Investigators conducted the research across the Italian Institute of Technology's Center for Advanced Biomaterials for Healthcare, the University of Naples Federico II, and the University of Molise. The authors reported no competing financial interests, noting they used OpenAI's ChatGPT to assist in revising English phrasing across select sentences during manuscript preparation.
