Peakforce hirs f a

OMVs produced from different E. coli MG1655 strains were adsorbed onto freshly cleaved mica for 15 min in DPBS buffer at room temperature. After adsorption, the sample was gently washed with fresh DPBS buffer for five times to remove non-adsorbed OMVs. Then OMVs were imaged using force-distance curve-based AFM (FD-based AFM) performed with an AFM (Nanoscope Multimode 8, Bruker) operated in PeakForce Tapping mode in buffer solution (DPBS) at room temperature^{59 (link)}. The AFM was equipped with a 120 μm piezoelectric J scanner and fluid cell. The images were recorded using two different AFM cantilevers: PEAKFORCE‐HiRs‐F‐A (Bruker) with a nominal spring constant of 0.4 N/m, a resonance frequency of ≈ 165 kHz in liquid, and a sharpened silicon tip with a nominal radius of ≈ 1 nm or SCANASYST-FLUID + (Bruker) with a nominal spring constant of 0.7 N/m, a resonance frequency of ≈ 150 kHz in liquid, and a sharpened silicon tip with a nominal radius of ≈ 2 nm. Before imaging, cantilevers were calibrated by ramping on the mica surface and the thermal tuning method. Images were recorded at 2 kHz oscillation frequency, by applying an imaging force of 100–120 pN with a vertical amplitude of 30 nm. The AFM was placed inside a home‐built acoustic isolated and temperature‐controlled box. Raw AFM images were processed using the AFM analysis software Nanoscope v.1.8 for levelling and flattening.

A Dimension FastScan Bio Icon Atomic Force Microscope (Bruker Nano, Santa Barbara, California, USA) with the “PeakForce QNM in Fluid” mode was used for both imaging and nanoindentation of the lehfilcon A CL, SiHy base substrate and the PAAm hydrogel samples. For imaging experiments, a PEAKFORCE- HIRS-F-A (Bruker) probe with a nominal tip radius of 1 nm was used to capture high-resolution images of the samples at a scan rate of 0.50 Hz. All imaging was conducted under aqueous solutions.