Fig. 4.

Nanofiber topography analysis. a–c Scanning electron micrography (a), fiber alignment (b) and fiber diameter (c) in random poly (l-lactic acid) scaffolds. d–f Scanning electron micrography (d), fiber alignment (e) and fiber diameter (f) in aligned poly (l-lactic acid) scaffolds at 1175 rpm. Please note that the difference in topography of scaffolds with aligned nanofibers (d) corresponds to a higher percentage of fibers with the same alignment angle (e) in contrast to what it is observed in random scaffolds (a and b). The same pattern in fiber diameter distribution was observed in aligned and non-aligned scaffolds (c and f). Bars: 50 µm