Figure 1.

Chondrogenic differentiation induction and culture. Human bone marrow–derived mesenchymal stem cells (hBMSCs) were derived from bone marrow aspirates from the iliac crest of 3 male donors aged 21 (#1), 27 (#2), and 31 (#3) years. The bone mallow cells were seeded on flasks in media supplemented with 3 conditions: (1) 5% fetal bovine serum (FBS), (2) 10% FBS, and (3) 5% FBS + 10 ng/mL fibroblast growth factor 2 (FGF-2). The cells were subcultured at passage 1 (P1). Cell pellets were prepared using one of the following conditions: chondrogenic medium A that was chondrogenic differentiation media (i.e., no FBS). The trypsinized cell suspensions were manually counted using a hemocytometer, and population doublings were calculated using the equation shown. Cells from donor #1 were expanded to passage 3 (P3) in media from condition 3. Scaffold-free cartilage-like cell-sheets were prepared using two different conditions: one was A only and another was B, which was equal mixture of A and growth media 2 (i.e., includes FBS). The pellets and sheets were harvested and analyzed for glycosaminoglycan (GAG) and DNA contents and tissue matrix composition.