Abstract Introduction Pathologic tissue stiffening is a hallmark and driver of fibrotic lung disease, in which the altered extracellular matrix initiates a feedback loop that sustains fibroblast activation. A significant technological gap exists for user-friendly tools that can spatially map these mechanical changes to investigate the underlying mechanobiology. Here, we evaluated the utility of Brillouin microscopy as a quantitative method for measuring spatial stiffness variations in fibrotic lung tissue. Methods We utilized a label- and contact-free Brillouin microscopy platform to measure mechanical properties. The system’s precision was first confirmed by analyzing hydrogels with pre-defined stiffness. A methodology was then established for analyzing cryosectioned native murine lung tissue. This approach was employed to quantitatively compare mechanical stiffness in lung samples with various degrees of fibrosis against non-fibrotic controls. Results Initial validation experiments confirmed the system’s ability to accurately measure the stiffness of control hydrogels. Application of the workflow to biological samples yielded successful quantitative stiffness maps from lung tissue cryosections. The measurements clearly differentiated the elevated stiffness in fibrotic regions from the lower stiffness of control tissue, confirming the method’s sensitivity to pathological mechanical alterations. Conclusion Our findings establish Brillouin microscopy as a viable and robust tool for the quantitative, spatial mapping of lung tissue stiffness. Its operational simplicity allows for straightforward integration into existing biomedical research pipelines. Pairing this label-free mechanical imaging with complementary molecular techniques like immunofluorescence and spatial-omics holds substantial promise for advancing our understanding of the mechanobiology in pulmonary fibrosis and other diseases. This abstract is funded by: DFG Walter-Benjamin-Program Fellowship, Project number 490745655 to I.G.; •This work was supported by National Institutes of Health Grants 5R01 HL157384 and 5R01 HL147059 to B.D.M.
Ganzleben et al. (Fri,) studied this question.