Dimethyl methylene blue dmmb

He Alphagaz 1 was purchased from Air Liquide and used as such. 300PEOT55PBT45 was received and stored in vacuum to avoid degradation (Polyactive®, PolyVation), (phosphate buffer saline solution) PBS, (Dulbecco’s modified eagle medium) DMEM F12, Fetal bovine serum (FBS) Insulin-Transferrin-Selenium (ITS), Penn/strep, Trypsin, ethidium bromide and calcein-AM were all purchased from Thermo-Fisher Scientific. Acrylic acid (used as such), ethanol 70%, HCl, methylene blue, dimethyl methylene blue (DMMB), chondroitin sulfate, proteinase K, iodoacetamine and Pepstatin A were purchased from Sigma-Aldrich.

rMSCs were suspended in medium and then seeded into scaffolds at a density of 1 × 10⁷ cells/mL. The tri-copolymer scaffold/rMSCs constructs were placed in a culture plate for 24 h for cell adhesion, then either cultured in static condition for seven days or cultured in the self-designed bioreactor system up to 21 days. After 24 h for cell adhesion, all the constructs were cultured with chondrogenic medium. The chondrogenic medium contained LG-DMEM, 10% FBS, 1x ITS liquid media supplement (Sigma-Aldrich, St. Louis, MO, USA), 50 µg/mL ascorbic acid (Sigma-Aldrich, St. Louis, MO, USA), 40 µg/mL proline (Sigma-Aldrich, St. Louis, MO, USA), 100 µg/mL sodium pyruvate (Sigma-Aldrich, St. Louis, MO, USA), and 0.1 µM or 1.0 µM of KGN (Merck, Darmstadt, Germany). At each time period, 5 mL of the medium were sampled for GAGs quantification (n = 3) via dimethylmethylene blue (DMMB, Sigma-Aldrich, St. Louis, MO, USA) assay.