Adhesion, alignment, and migration of cultured Schwann cells on ultrathin fibronectin fibres

Individual fibres of fibronectin (Fn-fibres), an extracellular matrix cell adhesion glycoprotein, were produced from a purified solution of fibronectin. These fibres range from 0.5-7 microm in width and have been engineered to produce mats (Fn-mats) by using a unidirectional shear force to orientate the fibres. Fn-fibres have been shown to promote alignment by contact guidance of human dermal fibroblasts, neurites, macrophages, and epitenon fibroblasts. Fn-mats have been used to orientate and enhance the regeneration of peripheral nerve components. We investigated cell spreading, orientation, formation of focal contacts, and the speed of cell movement on individual Fn-fibres, glass-covered with poly-L-lysine and poly-L-lysine/laminin/Fn. Fibronectin fibres significantly promoted cell spreading and the speed of cell migration with alignment of focal contacts and F-actin filaments to the axis of the fibres. The study reveals the potential of Fn-fibres to guide and direct cellular behaviour by contact guidance. The increase in migration and other behaviour exhibited by Schwann cells on Fn-fibres justifies the use of Fn-mats for peripheral nerve repair and is clinically important in that atrophy of the target organ, which is the most common failure of nerve repair, may be minimised.