Aggregates were made from TC-expanded cells as described previously (6 (link)). Briefly, 250,000 cells were dispensed into several wells of a sterilized (autoclaved) polypropylene v-shaped bottom 96-well plate (Phenix, Hayward, CA), centrifuged at 590 RCF for 10 min, and placed in chondrogenic medium (serum-free DMEM with 4.5g/L glucose, containing 1% sodium pyruvate, and 1% penicillin/streptomycin [all from Invitrogen], 1% ITS-premix [BD Bioscience], 100 nM dexamethasone [Sigma-Aldrich], and 37.5 µg/mL L-ascorbate-2-phosphate [Wako chemicals]. The aggregates were cultured under the same oxygen condition as that used in expansion, and medium was changed every other day. At 21 days, the aggregates were collected and processed for combined GAG and DNA analysis (3 aggregates from each group), for combined collagen and collagen cross-links analysis (3 aggregates from each group), for lysyl oxidase (LOX) activity assay (3 aggregates from each group), for LOX gene expression analysis (3 aggregates from each group, stored in RNA Later® [Qiagen] at −80°C), and fixed in neutral buffered formalin for histology (1 aggregate from each group). Wet weights of all aggregates were taken after blotting excess media using filter paper.