Figure 7.

Scheme for morphological events occurring during in vitro chondrogenesis of synovial MSCs with or without petaloid RCP. In the absence of petaloid RCP, synovial MSCs were condensed at the early phase, produced cartilage matrix at the middle phase, and then showed an increase in the size of the cartilage pellet at the late phase. With the inclusion of petaloid RCP, the framework of the pellet was constructed from petaloid RCP, and the cells were located in the spaces created by the petaloid RCP at the early phase. These spaces were filled with cartilage matrix, and the framework petaloid RCP formed was disrupted by production of cartilage matrix by the synovial MSCs during the middle phase. The cartilage pellet increased further in size at the late phase and showed diffuse petaloid RCP remaining.