Dsa 1

Morphology was observed by scanning electron microscopy (SEM; Quanta 200; FEI, Eindhoven, the Netherlands).
Each specimen was examined for the structure of PLGA fibers with a transmission electron microscope (TEM; JEM-2100F; JOEL, Tokyo, Japan).
The water contact angles of different fibrous membranes were measured with a KRÜSS GmbH DSA 100 Mk 2 goniometer (Hamburg, Germany) followed by image processing of sessile drop with DSA 1.8 software (Krüss, Hamburg, Germany).
To test the mechanical properties, the dry fibrous membranes were punched into small strips (70.0×7.0×0.6 mm). Uniaxial tensile tests were performed using an all-purpose mechanical testing machine (5567; Instron, Norwood, MA, USA). The stress–strain curves of the fibrous membranes were constructed from the load deformation curves recorded at a stretching speed of 0.5 mm/s (n=3). Young’s modulus, tensile strength, and elongation at break of the fibrous membranes were derived from the stress–strain curves.

The micro-morphological features of the electrospun fibrous membranes were assessed with scanning electron microscopy (SEM, FEI Quanta 200, Netherlands) at an acceleration voltage of 21 ​kV, in at least five images per sample (10,000 ​× ​magnification). Final assessment was conducted with random views of each sample. The diameters of the nanofibers were calculated in ImageJ software (Bethesda, MD, USA). To investigate the tensile strength of fibrous membrane sections, we cut electrospun sections into similar dimensions of 1 ​cm ​× ​1 ​cm (length ​× ​width). The tensile strength of the fabricated fibrous membranes was evaluated with a mechanical machine (Instron 5567, Norwood, MA). In addition, stress-strain curves were established through documentation of load-deformation at a speed of 0.5 ​mm/s. A static contact angle measuring device with DSA 1.8 software (KRUSS, Hamburg, Germany) was used to determine the wettability of the electrospun membranes.