Functionalized nanostructured chitosan-based devices for peripheral nerve regeneration

Peripheral nerve injuries (PNIs) are a common global issue lacking definitive treatments. Regenerative medicine introduces promising methods to bridge nerve gaps, with a strong focus on biocompatible, biodegradable, and mechanically compliant materials. Chitosan, an FDA-approved biopolymer, stands out for its biocompatibility and biodegradability. Its regenerative potential improves with nano/micro-structuring, which guides cells through biomimetic topographical signals, and blending with other materials enhances its mechanical compatibility with host tissues.This thesis focuses on developing chitosan-based scaffolds for peripheral nerve regeneration. A method to create micro-structured chitosan films with reproducible patterns was designed, producing three directional micro-grooved patterns: gratings (GR), isosceles triangles (ISO), and scalene triangles (SCA). These structured films were tested in vitro with Schwann cells, showing variations in cell migration across the patterns.To address chitosan’s rigidity, soft chitosan membranes were created using glycerol as a bioplasticizer, reducing stiffness and enhancing suitability for clinical use. My work revealed that membrane flexibility and surface structures influence neural cell responses, with softer, micro-structured membranes leading to improved cell behavior compared to stiffer versions.Further evaluations employed an in vitro nerve model with primary Schwann cells and nociceptive neurons, developed in collaboration with the MERLN Institute (University of Maastricht) to study the effects of micro-structured glycerol-chitosan membranes. Additionally, these membranes were tested ex vivo with dorsal root ganglia (DRGs) from rats and in vivo in a cavernous nerve injury model in collaboration with the University of Turin.Finally, to develop even smaller features, glycerol-plasticized chitosan nanofibers were developed and characterized, demonstrating promising potential for use in nerve regeneration applications.In summary, this thesis highlights chitosan’s potential for peripheral nerve repair, showcasing its micro and nanostructurability, biocompatibility, and suitability in supporting nerve regeneration. This research demonstrates chitosan’s capacity to advance regenerative medicine, offering valuable biomaterials for peripheral nerve injury treatment.