Effect of surface morphology on orientating the NG108-15 cells applied in grooved nerve conduit

Introduction: Synthetic nerve guide conduits are extensively acknowledged as an alternative treatment for stimulating nerve regeneration. The aim of the study was to evaluate the influence of microgrooves, with three different designs, on the orientation of nerve cells and to assess the mechanical strength of films. Methods: Polycaprolactone and poly lactic acid (80/20 %) in dichloromethane (3% w/v) was cast onto the patterned silicon substrates. The substrates were fabricated with the groove dimension of 10-10-5µm, (space-width-depth), by microlithography and a) Wet etching to produce both “V” and slopped wall, b) Reactive ion etching to create an upright wall. A non-grooved film was used as a control. Films were imaged by scanning electron microscopy and tensile testing performed in the direction of the parallel to the length of the groove. Cell culture on the films was carried out with the 10,000 cells/sample. Results:Statistical analysis demonstrated that the maximum stress, Young’s Modulus and strain of the grooved films are not significantly different when compared to the non-grooved films. Assessment of cell orientation in relation to the grooves was observed after 2, 24 and 48 hrs from initial seeding. Cells on grooved film highly aligned in the grooved direction, specifically on “V” and slopped wall. Conclusion: This study has demonstrated that the presence of grooves affects the orientation of nerve cells and causes cell alignment. Cells’ are preferentially aligned when in contact with “V” wall and slopped wall grooves; which cells attachment occurred between the grooves ,however cells mostly attached on the groove spaces and grow in random direction, on the upright wall. This is a highly promising result as this guidance conferred from the grooves to the cells will assist with the directional re-growth of damaged nerves.