FIG. 2.

OC plug (3D biopaper) and 3D distribution of printed human chondrocytes in PEG gel. (A) An OC plug with full-thickness cartilage lesion 4 mm in diameter and 2 mm in depth. (B) Decalcified OC plug cut in half with printed hydrogel in the defect. (C) Printed cells maintained deposited positions with simultaneous photopolymerization in layer-by-layer assembly for multiple zonal cartilage printing. Bioink with different colors was printed in layers. (D) Cells accumulated to the interface of the mimicked cartilage zonal structure due to gravity when polymerized after cell deposition. Scale bars: (A, B)=2 mm; (C, D)=100 μm. PEG, poly(ethylene glycol); OC, osteochondral; 3D, three-dimensional. Color images available online at www.liebertonline.com/tea