Chitosan Micro-Grooved Membranes with Increased Asymmetry for the Improvement of the Schwann Cell Response in Nerve Regeneration

Abstract

Peripheral nerve injuries are a common condition in which a nerve is damaged, affecting more than one million people every year. There are still no efficient therapeutic treatments for these injuries. Artificial scaffolds can offer new opportunities for nerve regeneration applications; in this framework, chitosan is emerging as a promising biomaterial. Here, we set up a simple and effective method for the production of micro-structured chitosan films by solvent casting, with high fidelity in the micro-pattern reproducibility. Three types of chitosan directional micro-grooved patterns, presenting different levels of symmetricity, were developed for application in nerve regenerative medicine: gratings (GR), isosceles triangles (ISO) and scalene triangles (SCA). The directional patterns were tested with a Schwann cell line. The most asymmetric topography (SCA), although it polarized the cell shaping less efficiently, promoted higher cell proliferation and a faster cell migration, both individually and collectively, with a higher directional persistence of motion. Overall, the use of micro-structured asymmetrical directional topographies may be exploited to enhance the nerve regeneration process mediated by chitosan scaffolds.

Insight and Recent Advances into the Role of Topography on the Cell Differentiation and Proliferation on Biopolymeric Surfaces

“…[ 18 , 19 , 20 , 21 ] and may include grooves [ 22 ], lines [ 23 , 24 , 25 ], squares [ 23 , 26 ] and other shapes [ 13 , 27 , 28 , 29 ] of various dimensions and functions widely used in applications related inclusively to cell culturing [ 30 , 31 , 32 , 33 , 34 , 35 ]. For instance, holes and pillars on gelatin-genipin substrates can be used for culturing human osteoblastic Saos-2 cells for developing better properties of surface dental implants [ 22 ], and the microgrooves on the chitosan membrane can be employed for enhancing nerve regeneration using Schwan cell cultures [ 36 ].…”

Mechanotransduction Impairment in Primary Fibroblast Model of Krabbe Disease

“…The two monolayers were separated by an empty gap with an averaged width of 497 ± 20 µm (mean ± SD, n = 18) at t = 0. The wound area was tracked as an ROI (delimited by the monolayer’s borders and the image borders) and measured at t = 0, t = 24 (T24), and t = 48 (T48) and reported as the percentage (%) of area closure [ 43 ]. The number of scattered cells in the wound at 24 h was also quantified and reported as number of scattered cells/wound, as in [ 41 ].…”

Platelet-Rich Plasma Gel-Loaded Collagen/Chitosan Composite Film Accelerated Rat Sciatic Nerve Injury Repair

“…Peripheral nerve injury (PNI) is a common clinical disease caused by severe limb trauma, congenital malformations, and tumor resection . It is estimated that about 5 million cases of peripheral nerve injury occur worldwide each year, resulting in severe disability and a reduction in their quality of life. − At present, the clinical treatment of PNI includes microsurgical suturing of the fractured nerves, autologous nerve grafts, and nonsurgical approaches such as pharmacological, electrical, and laser therapies . Nevertheless, the clinical outcome of these treatments is not optimistic because axon demyelination and degradation often occur in the distal stump of the injured nerve after PNI and result in muscle atrophy and loss of function .…”