Super-resolution traction force microscopy with enhanced tracer density enables capturing molecular scale traction

Cell traction mediates the biochemical and mechanical interactions between the cell and its extracellular matrix (ECM). Traction force microscopy (TFM) is a powerful technique for quantitative cellular scale traction analysis. However, it is challenging to characterize macromolecular scale traction events with current TFM due to the limited sampling density and algorithmic precision. In this article, we introduce a super-resolution TFM by utilizing a novel substrate surface modification method. Our TFM technique achieved a spatial resolution comparable to fluorescence microscopy and precision comparable to the rupture force of an integrin-ligand bond. Correlated imaging of TFM with fluorescence microscopy demonstrated that the residing paxillin highly correlated with traction while alpha 5 integrin was located differently. Time-lapse TFM imaging captured a transient traction variation as the adhesion protein passed by. Thus, the novel super-resolution TFM benefits the studies on cellular biochemical and mechanical interactions.

Automated summary

Cell traction plays an important role in the biochemical and mechanical interactions between cell and extracellular matrix. Traction force microscopy (TFM) is a powerful technique for quantitative analysis at cellular scale. However, current TFM faces challenges in characterizing macromolecular scale traction events due to limited sampling density and algorithmic precision. This article introduces a super-resolution TFM using a novel substrate surface modification method, achieving spatial resolution comparable to fluorescence microscopy and precision comparable to the rupture force of an integrin-ligand bond. Correlated imaging with fluorescence microscopy reveals the high correlation between residing paxillin and traction, while alpha 5 integrin shows different localization. Time-lapse TFM imaging captures transient traction variation as the adhesion protein passes by. Therefore, the novel super-resolution TFM benefits the study of cellular biochemical and mechanical interactions.