Chondroitin sulfate c

Reduced glutathione (GSH), gelatin (from porcine skin), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and kojic acid (KA) was purchased from Sigma-Aldrich (St. Louis, MO, USA), sodium hyaluronate (100 k, HA) was purchased from SNVIA (Busan, Korea). Chondroitin sulfate (CS) was purchased from Wako Chemicals (Osaka, Japan). α-Melanocyte stimulating hormone (α-MSH) was purchased from TOCRIS (Bristol, UK), and apoptosis detection kit using FITC (fluorescein isothiocyanate)-labeled annexin V was purchased from BD Biosciences (Bedford, MA, USA). A liquid prepolymer (Sylgard 184A) and a curing agent (Sylgard 184B) for the polydimethylsiloxane (PDMS) molding were purchased from Dow Corning (Midland, MI, USA). All chemicals were used without further purification. Porcine skin (hair removed) was procured from a local butcher shop and kept at −20 °C until it was used in experiments.

Sodium heparin (heparin) was purchased from Nacalai Tesque. Chondroitin sulfate C sodium salt (chondroitin sulfate C) was purchased from Wako Pure Chemical Industries. Hyaluronic acid sodium salt (hyaluronan) was purchased from Sigma-Aldrich. Generally, heparin consists of uronic (glucuronic or iduronic) acid and glucosamine, both of which are linked by the 1,4-glycoside bond and are frequently sulfated and N-acetylated. Chondroitin sulfate C has a repeating disaccharide with the 1,3-glycosidic bond that is composed of glucuronic acid and N-acetyl-d-galactosamine with a sulfate group at the C6 position. Hyaluronan with no sulfate group is composed of glucuronic acid and N-acetyl-d-glucosamine, and shows a similar glycoside bond mode to chondroitin sulfate C. Nutrition-rich media, MRS and GAM, were purchased from BD Biosciences and the Nissui Pharmaceutical Co., respectively. Oligonucleotides were synthesised by Hokkaido System Science (Table S2). DNA-modifying enzymes were purchased from Toyobo. All other analytical grade chemicals used in this study were commercially available. Faeces were kind gifts from three Japanese volunteers in their 20’s, 40’s and 50’s. Informed consent was obtained from all subjects.