Figure 2.

(A) SEM investigations of the untreated and plasma-treated electrospun microfibers and the distribution of the fiber orientation. The SEM images showed that the CAP treatment did not affect the morphology neither the alignment of the electrospun microfibers (p > 0.05). The insets represent the histograms of each sample showing the angle distribution of the electrospun fibers on untreated and CAP treated PLGA samples. It can be noticed that fiber alignment after CAP treatment, by varying the plasma process’ parameters (exposure time and working distance), was maintained as the curves obtained from the analyses showed a sharp Gaussian curve confirming the aligned topography of the microfibers. Scale bars = 10 mm. (B) Infrared spectra for untreated and CAP treated PLGA microfibers at different exposure times (30, 60, and 90 s) and working distances (1.3 and 1.7 cm) reported in the 650 and 4000 cm⁻¹. (C) Molar mass distribution of untreated and CAP treated electrospun PLGA microfibers.