Characterization of structural, mechanical and nano-mechanical properties of electrospun PGS/PCL fibers

Physical and mechanical studies of aligned nanofibers of poly (glycerol sebacate) (PGS)/poly (epsilon-caprolactone) (PCL) designed for application in cornea tissue engineering are investigated. The fibers were fabricated by electrospinning different weight ratios of PGS and PCL (1 : 1, 2 : 1, 3 : 1, and 4 : 1), and had diameters in the range of 300-550 nm. DSC and XRD measurements showed that the overall crystallinity decreased with increasing amount of amorphous PGS in the composition. Accordingly, the elastic modulus of the fibers was found to decrease with increasing PGS/PCL blend ratio. In contrast, the surface modulus of the nanofibers, measured by nanoindentation, exceeded the elastic modulus by two orders of magnitude and increased with weight ratio of PGS. It is assumed that this is caused by the increasing content of PGS forcing the fiber-forming PCL into confined and cross-linked domains near the fiber surface.