Nanomechanical Characterization of Cell Walls

The cell wall material was prepared by grinding the AIR into powder. Next, the powder solution (0.1% w/w) was drop deposited onto microscope slides and left to dry for 72 hours. For each variant of sample, at least 250 nano-indentations were carried out. The Young modulus of cell wall material was estimated by means of the Hertz contact model^{52 (link)} using Nano Plot v1.1. software⁵³ . The nano-indentation was carried out using Bioscope Catalyst II (Bruker, Billerica, MA, USA), equipped with a silicon cantilever RTESPA-525 (Bruker, Billerica, MA, USA). The cantilever was calibrated prior to the experiments according to the protocols described by Zdunek and Kurenda^{52 (link)}.