Fabrication of uniaxially aligned 3D electrospun scaffolds for neural regeneration

Abstract

Nanofibrous scaffolds are very promising physical guidance substrates for regenerating nerves to traverse larger nerve gaps. In this study, we have attempted to develop 2D random and 3D longitudinally oriented nanofibers of poly(lactide-co-glycolide) (PLGA) by the modified electrospinning process and characterized the surface morphology, mechanical properties, porosity, degradation and wettability. The orientation of aligned fibers was optimized by varying the speed of the rotating mandrel in the electrospinning process. The mean diameter of random PLGA nanofibers was 197 ± 72 nm, whereas that of the aligned PLGA fiber was 187 ± 121 nm. The pore size of aligned PLGA nanofibers (3.5 ± 1.1 µm) was significantly lower than their respective random nanofibers (8.0 ± 2.0 µm) (p < 0.05). However, the percentage porosity of both scaffolds was comparable (p > 0.05). The mass loss percentage and molecular weight loss percentage due to degradation was higher in random PLGA fibers when compared to aligned PLGA after 5 weeks (p < 0.05). The tensile strength and Young's modulus of random PLGA fibers were significantly higher than those of the aligned PLGA nanofibers (p < 0.05). Both random and longitudinally aligned scaffolds were used for the in vitro culture of Schwann cells. Morphology and cell proliferation results demonstrated that the aligned fibers assist the direction of Schwann cells and a better proliferation rate than their random fibers. The results confirmed that aligned nanofibers have better deformability, slow degradation, comparable porosity and orientation cues than random nanofibers. Hence the longitudinally aligned nanofibers may be ideal scaffolds for nerve regeneration.