Filbronectin tubes as tissue engineering devices for peripheral nerve repair

Fibronectin mats have proved to be successful guidance substrates for the outgrowth of neurites in models of neural damage. The overall aim of this investigation was to develop a tissue engineering conduit for surgical nerve reconstruction. In this study, fibronectin tubes were developed to provide global guidance for neural regrowth across a short gap. A viscous solution of concentrated plasma fibronectin was obtained from by-products of the human plasma fractionation process. The tube was formed by winding this material around an 18G hypodermic needle and allowing it to dry. The structure and physical properties of the tube were investigated. The spiral-wound material on the needles fused to form a durable tube, whose lumen remained patent after rehydration/swelling in buffer (swelling and stability were characterized). In vivo testing showed growth of axons through the tube 6 weeks post surgery in a rat sciatic nerve injury model. In conclusion, a tube has been developed from fibronectin which can be used to bridge gaps in damaged nerves. This could form the basis for the construction of a surgically implantable device for the tissue engineered repair of peripheral nerve injury.