1. A method for producing an engineered tissue scaffold for neural repair, the method comprising: i) providing a cell guide comprising a hydrogel matrix seeded with neural stem cells obtained from a stable stem cell line, or with differentiated cells obtained from said stable stem cell line to form a seeded hydrogel matrix, the seeded hydrogel matrix being tethered at opposed first and second ends to a frame; ii) incubating the seeded hydrogel matrix in culture medium, whereby the neural stem cells or the differentiated cells generate tension within the seeded hydrogel matrix, such that the cells self-align within the seeded hydrogel matrix; and iii) removing liquid from the seeded hydrogel matrix in order to at least partially dehydrate the seeded hydrogel matrix to form a sheet while retaining cells within the seeded hydrogel matrix; thereby providing an engineered tissue scaffold.