Methods of treating spinal cord injuries are disclosed. The method comprises implanting scaffolds comprising a protruding scaffold and a supporting scaffold, wherein at least a portion of the protruding scaffold is inserted into a lesioned area of the spinal cord so as to contact the injury or diseased site, wherein the supporting scaffold does not protrude into the injury or diseased site and is in contact with the rostral and/or caudal dura of the spinal cord.