Synovial mesenchymal stem cells from osteo- or rheumatoid arthritis joints exhibit good potential for cartilage repair using a scaffold-free tissue engineering approach  K. Koizumi, K. Ebina, D.A. Hart, M. Hirao, T. Noguchi, N. Sugita, Y. Yasui, R. Chijimatsu, H. Yoshikawa, N. Nakamura  Osteoarthritis and Cartilage  Volume 24, Issue 8, Pages 1413-1422 (August 2016) DOI: 10.1016/j.joca.2016.03.006 Copyright © 2016 Osteoarthritis Research Society International Terms and Conditions

Fig. 1 Relative gene expression levels of cell pellets composed of SMSCs at different passage number. Gene expression levels of cell pellets cultured in T-MEM for 2 weeks for (a) IL-1b, (b) IL-6, (c) IL-10, (d) MMP-3 and (e) ADAMTS-5, and of cell pellets cultured in C-MEM for 2 weeks for (f) COL2A1 (g) SOX9 and (h) ACAN normalized to GAPDH. Data are represented as mean ± 95% CI. (Bio(+)RA; N = 7, The other groups; N = 6). Osteoarthritis and Cartilage 2016 24, 1413-1422DOI: (10.1016/j.joca.2016.03.006) Copyright © 2016 Osteoarthritis Research Society International Terms and Conditions

Fig. 2 Proliferation assays for SMSCs derived from the four patient groups. Proliferation of SMSCs at passage 4 was assessed using the WST-1 assay and determination of PDT. (a) The margin between the absorbance values at 450 and 690 nm were normalized by the average margin at day 1 in each group. Data represent mean ± 95% CI. (b) PDT were calculated based on the cell number at passage 4 and 5, and the time between the passages. Data are represented as scatter plot. (Bio(+)RA; N = 7, The other groups; N = 6). Osteoarthritis and Cartilage 2016 24, 1413-1422DOI: (10.1016/j.joca.2016.03.006) Copyright © 2016 Osteoarthritis Research Society International Terms and Conditions

Fig. 3 Features of basic TEC composed of SMSCs from the four patient groups. (a) The WW and (b) wet mass of basic TEC comprised of the same number of SMSCs derived from the four patient groups, and at P5 cultured on 12-well culture dishes. Gene expression levels of basic TEC for (c) IL-1b, (d) IL-6, (e) IL-10, (f) MMP-3 and (g) ADAMTS-5 normalized to GAPDH are represented as scatter plot. (Bio(+)RA; N = 7, The other groups; N = 6). Osteoarthritis and Cartilage 2016 24, 1413-1422DOI: (10.1016/j.joca.2016.03.006) Copyright © 2016 Osteoarthritis Research Society International Terms and Conditions

Fig. 4 In vitro chondrogenic potential of basic TEC derived from SMSCs from the four patient groups. Macroscopic view of (a) basic TEC and (b) chondro-TEC. Chondro-TEC are a moderately transparent, thick and hard tissue (cartilage-like). (c) Low- and (d) high-magnification view of a typical chondro-TEC demonstrating cells with lacuna analogous to chondrocytes in cartilage, and with an abundant ECM strongly stained by Safranin O around them. Bar = 50 μm. (e) GAG content (data represent scatter plot, Bio(+)RA; N = 7, The other groups; N = 6) and gene expression levels for (f) COL2A1 (g) SOX9 (h) ACAN normalized to GAPDH (data represented in scatter plot, Bio(+)RA; N = 7, The other groups; N = 6). No significant differences between groups were detected. Osteoarthritis and Cartilage 2016 24, 1413-1422DOI: (10.1016/j.joca.2016.03.006) Copyright © 2016 Osteoarthritis Research Society International Terms and Conditions

Fig. 5 In vivo osteochondral repair in a rat model: implantation of basic TEC arising from SMSCs derived from the four patient groups. (a) Macroscopic view of the knees at sacrifice. There was no detectable apparent synovitis and inflammation. (b) Histology of the tissue after 8 weeks post-surgery stained with H&E, (c) Toluidine Blue (upper line; bar = 200 μm), their high-magnification images (lower line; bar = 30 μm) and (d) Immunohistochemical analysis of repair cartilage stained for type II collagen (Col II). The repair tissue arising from implantation with a TEC from any of the patient groups (N = 9 in each group) resulted in development of a hyaline cartilage-like repair with enriched ECM strongly stained by Toluidine Blue and expressing large quantities of Col II compared to the untreated group (N = 4). In some parts of repair tissue provided in the high-magnification images, the cells in the repair tissue contained lacuna (especially detected in the trauma group), clustering (presented in OA group), and arranged randomly or into columns (presented in intact and RA groups), which are found in articular cartilage tissue. (e) Immunohistochemical analysis of repair tissue stained for type I collagen (Col I) and (f) type X collagen (Col X) suggesting a deficiency of TEC-mediated cartilage in comparison to native articular cartilage. Osteoarthritis and Cartilage 2016 24, 1413-1422DOI: (10.1016/j.joca.2016.03.006) Copyright © 2016 Osteoarthritis Research Society International Terms and Conditions