Devices for use in the regeneration or repair of body tissue (such as nerves) comprise a multi-lumen scaffold and, optionally, an outer sheath. The tissue guidance conduits are preferably formed of biocompatible, biodegradable charged polymer hydrogels, particularly charged oligo-(polyethylene glycol)fumarate hydrogels. The outer sheath is formed of a stronger material than the scaffold and preferably comprises a region at each end for suturing the device in place. Methods for making tissue guidance conduits and for repairing tissue are also described.