Nanoindentation for Fibroblast Stiffness

Single fibroblast stiffness was assessed from nanoindentation measurements with AFM, as reported in [15 (link)]. In brief, a stand-alone AFM (Bioscope, Veeco, Plainview, NY, USA) was adapted to an optical microscope and provided with a low-spring constant (0.03 nN/nm) AFM cantilever (Veeco) was used to assess Young’s modulus (E) of single fibroblasts. For this purpose, three force versus displacement curves (F vs. z) were recorded on the perinuclear region of each fibroblast at a moderate loading force (<1 nN) and low speed (~5 µm/s). E of single fibroblasts was computed by fitting a suitable contact elastic model to each F vs. z curve and averaging it over three recordings. Final E for a fibroblast population for each donor and experimental condition was calculated from at least nine measurements as described [32 (link)].