Efficiency of Human Epiphyseal Chondrocytes with Differential Replication Numbers for Cellular Therapy Products

Figure 7

Long-term observation at the P2 (PDL 18) cell-implanted sites. P2 (HEC #10) cell-implanted sites were analyzed at 9 weeks (a–e) and 17 weeks (f–j). Macroscopic examination of the P2 (PDL 18) cell-nodules (9 mg in weight) at 9 weeks showed light brown surface (a). Microscopic examination showed the cartilage with small chondrocytes with round or spindle nuclei and hypertrophic cells with lacunae (b) and thick perichondrium (c). Immunohistochemically, the cartilage was positive for COL II (d) and the perichondrium was positive for COL I (e). Macroscopic examination of the P2 (PDL 18) cell-implanted sites (32 mg in weight) at 17 weeks showed whitish surface with partly yellowish area (f). Microscopic examination showed the cartilage and irregularly thickened perichondrium (g) and the perichondrium with decrease of hypertrophic chondrocytes and increase of eosinophilic matrix (h), compared with nodules at 9 weeks. The cartilage was positive for COL II (i) and partially positive for COL I (j). The perichondrium was positive for COL I.