Implants for repairing tissue defects, such as cartilage tissue defects, and methods of their preparation and use are disclosed. A mold of a tissue defect is prepared by pressing upon the defect a substrate having shape memory, such as aluminum foil. The mold, which has contours substantially conforming to those of the defect, is removed from the defect, and tissue particles are added to the mold ex vivo. A biological carrier such as biocompatible glue is also added to the mold. The combination of tissue particles and the biological carrier thereby form an implant, which retains its shape after separation from the mold. The implant can be transferred to the tissue defect, with contours of the mold matching corresponding contours of the defect.
