Nature Materials 4, 518–524 (2005) doi: 10.1038/nmat1421

In this Progress Article, the caption for Figure 6 was incorrect; the correct wording is below.

Figure 6 Cartilage regeneration by chondrocyte delivery on designed Bioplotter-fabricated PEG/PBT scaffolds is superior to PEG/PBT scaffolds made by porogen leaching. a, PEG/PBT scaffold fabricated by porogen leaching. b, Bioplotter-fabricated PEG/PBT scaffold. c, Cartilage matrix (red areas) generation in Bioplotter scaffold after 21 days in a mouse. Insert shows scaffold implanted without chondrocytes. d, Cartilage matrix (red area) generation after 21 days in scaffold made by porogen leaching. Insert shows control scaffold implanted without chondrocytes. Reprinted from ref. 60. Copyright (2005), with permission from Elsevier.