Design of bicomponent electrospun conduits for peripheral nerve regeneration

This thesis deals with the potential of the electrospinning process to create substrates composed of synthetic and natural polymers for use as alternative scaffolds for peripheral nerve regeneration. In the first part, it has been estimated the influence of solvent permittivity, polymer/solvent thermodynamic affinity and other technological parameters (i.e., concentration, flow rate) on the morphology and on the physical properties of poly(?-caprolactone) (PCL) electrospun fibers in order to address cell response for nerve tissue engineering applications. Secondly, it has been evaluated the effect of gelatin protein integration into PCL fibers on morphology and physico-chemical properties to identify the contribution of biochemical cues and scaffolds topography on cells (hMSC and PC-12) response. Lastly, PCL and PCL/Gelatin electrospun conduits have been designed and optimized for in vivo implant in rat sciatic nerve model, in order to test them as artificial graft for peripheral nerve regeneration. Our experimental data showed that the PCL conduits gave good performance in resisting collapse and stretch forces in vivo, thus inducing a better recovery in comparison with PCL/Gelatin conduits. Despite the submicrometric size scale of fibers promotes a better in vitro response with primary cells, PCL/Gelatin electrospun scaffolds are less capable of sustaining nerve regeneration in vivo, due to lacks in mechanical response of the device.