Jsm 5600lv sem

The micromorphological structure of the printed parts was observed by using SEM. All samples were gold-coated with 10 mA current using JEOL JFC-1600 Auto Fine Coater machine. The images were viewed and taken under 10 – 13 kV condition under a JEOL JSM-5600LV SEM.

Samples of PCL materials and alkaline etched materials were prepared to evaluate the surface roughness. To be observed under scanning electron microscope (SEM), the samples were dehydrated with gradient graded ethanol (50%, 70%, and 90%) for 30 min and then surface metalized by sputter coating with gold. The morphology of the PCL scaffold and the cellular morphology of the adherent BMSCs were observed by JSM5600LV SEM (JEOL Ltd., USA). To be observed under confocal laser scanning microscopy, the samples were also completely dried using gradient concentration ethanol aqueous solution and then imaged by laser reflection of the sample surface and pseudocolor processing.
The water contact angle test was also employed to evaluated the PCL scaffolds with M_w: 150,000 before and after NaOH treatment, which were performed on the produced PCL film. The film were then treated with NaOH as introduced before. Contact angles of deionized water drops were recorded and calculated with Image J software.

SEM and EDS-SEM were performed using a JSM-5600LV SEM (JEOL, Tokyo, Japan) with an acceleration voltage of 5 to 10 kV. Samples were initially coated with a thin layer of Au/Pd using a Hummer 6.2 sputtering system (Anatech, Battle Creek, MI, USA) and then imaged. EDS was performed in the dark field, and both SEM and EDS-SEM were performed at high vacuum settings. Samples for cross-sectional analysis were first frozen by liquid nitrogen and then cut under an optical microscope. Iron(II) sulfate heptahydrate (FeSO₄.7H₂O) was purchased from Sigma-Aldrich and dispensed (100 ng) into 4X-core particles using a cellenONE picoliter dispenser. Nanoresolution x-ray CT reconstructs (resolution, 0.38 to 0.45 μm) were obtained at the Biotechnology Resource Center of Cornell University. NanoCT imaging was performed using a ZEISS/Xradia Versa 520 x-ray microscope. The three cross sections depicted in Fig. 1 for each particle were selected to be equidistant (50 to 60 μm apart). Reconstruction of nanoCT scans was performed with Avizo software (Thermo Fisher Scientific, USA). All 2D image analysis including porosity measurements was performed by ImageJ.