• Biomateriali
• Biomaterials
• Chitosan
• Chitosano
• Regeneration
• Rigenerazione

Peripheral nerve injury is a critical problem that affects more than 1 million people worldwide every year and it represents a major challenge for reconstructive surgery. There are several strategies to reconstruct the nerve and to obtain a functional improvement. Today, the preferred treatment for short nerve gaps is the use of hollow nerve guidance conduits. They can be made of several biomaterials, and in this thesis, I decided to study the properties of chitosan.
Chitosan is approved by FDA for its use in biomedical devices and it represents an interesting material for regenerative medicine, thanks to its biocompatibility and biodegradability. This polymer has been already used to build nerve guidance conduits and the basic chitosan nerve guides have already been approved for clinical use.
However, it is known that the interaction between cells and the substrate does not depend only on the chemical composition of the material: cells can respond to topographies. Topographical modifications convey mechanical signals to the cell, causing changes in its morphology and guiding its migration. The design of nerve conduits should be thought to obtain a directional growth of the tissue and alignment of the growing axons. It has already been demonstrated that neural cells are able to recognize and interact with directional topographies, changing their neural type from multipolar to bipolar with aligned neurites. Moreover, Schwann cells cultured on a grating exhibited faster healing of wounds.
It has recently been shown that the speed of cell migration is also affected by the anisotropy of the pattern on which cells are cultured. This simple geometrical principle should be taken into account when designing scaffold for tissue engineering.
The aim of this work is to study chitosan properties as a material for nerve tissue regeneration. Chitosan membranes are developed and mechanically characterized. They are structured with patterns having different levels of anisotropy, to assess which topography is the most suitable for its application in regenerative medicine. These membranes are used as a scaffold on which Schwann cells are cultured, in order to analyze their migration and follow the healing of wounds.