Nvision40 sem

In situ, freeze-fractured aerogel samples were imaged using a Zeiss NVision40 SEM at −140 °C, using an accelerating voltage of 3 keV and an in-lens energy and angle selective backscattered electron (EsB) detector.

Live cell staining was performed using 10 mg/mL Hoechst 33,342 and 5 μg/mL ethidium bromide (both Life Technologies, New York, NY, USA) in a supplemented cell growth medium to stain body and nucleus of cells in green and red, respectively. Cells with Hoechst 33,342 were incubated for 15 min at 37 °C, and then with ethidium bromide for 5 min at 37 °C. The live imaging was conducted at day in vitro (DIV) 1 and DIV 2. The fluorescence imaging was performed via a laser scanning microscope (LSM880, Carl Zeiss, Berlin, Germany) using the Zen software (Zen 2.3 SP 1 FP3 Black, Carl Zeiss Microscopy GmbH, Jena, Germany) (see Figure S2). In each case, three images were acquired. The SEM images were obtained on a NVision 40 SEM (Zeiss, Oberkochen, Germany).