Auriga base

The morphology of nanoparticles was assessed by SEM (Auriga Base, Carl-Zeiss, Oberkochen, Germany) while associated EDX was performed in order to qualitatively investigate the sample compositions.

The PCL electrospun scaffolds were fabricated according to the protocols reported in our previous works [33 (link),78 (link)]. Briefly, the patterned and randomly oriented scaffolds were obtained by using the same polymeric solution. The solution for the electrospinning was prepared by dissolving PCL (average Mn 80,000) in glacial acetic acid (VWR, Darmstadt, Germany), with a concentration of 20% w/v, stirred overnight, and electrospun directly after immersion for 1 h in an ultrasound bath. The process parameters used for both scaffold types were kept constant, except for the use of a dedicated collector for the pattern. In detail, the applied voltage was set at 15 kV, the distance between the tip of the needle and the collector was 11 cm, the flow rate of the solution was 0.4 mL/h, and the needle diameter was 23 G. The used electrospinning device was equipped with a climate chamber, which allowed the setting and control of the temperature and relative humidity during the process (EC-CLI, IME Medical Electrospinning, Geldrop, The Netherlands).
The electrospun fiber morphology and scaffold topology were investigated by using a scanning electron microscope (SEM) (Auriga Base, Zeiss, Jena, Germany).

Scanning electron microscopy (SEM) (FE-SEM-EDS, Auriga Base, Carl-Zeiss, Jena, Germany) was conducted for examining the microstructure and morphology of the series of electrospun mats. Prior to SEM analysis, the samples were sputtered with gold using a sputter coater (Q150T, Quorum Technologies Ltd., Darmstadt, Germany). Magnification was varied in the range from 1000 to 45,000×. The average fiber diameter was calculated using the Fiji 1.51 s analysis software (NIH, Bethesda, MD, USA) [42 (link)]. The measurement of the diameter of 30 randomly chosen fibers was performed for each sample.
FTIR spectroscopy analysis was carried out in attenuated total reflectance mode (ATR) (IRAffinity-1S, Shimadzu, Japan). For the analysis, 40 spectral scans in absorbance mode were averaged across the wavenumber range of 4000 to 400 cm⁻¹ with a resolution of 4 cm⁻¹.