Figure 2.

Typical illustration of MACI operation for cartilage regeneration and MRI imaging. (A) Sagittal and transverse proton density-weighted image before surgery. A femoral trochlear cartilage in the right knee joint of a male patient is demonstrated; the arrows indicate the site of cartilage damage. (B) The process of MACI with combination of an ECM-derived scaffold and autologous chondrocytes. The arthroscopic surgery aims at assessing the site of injury and collecting autologous cartilage tissue from the non-weight-bearing area. After the proliferation of cells in vitro, the cells were implanted into the biomimetic cartilage scaffold at a concentration of 1 × 10⁷ cells per milliliter. About 24 h after the cells were loaded into the scaffolds, the tissue-engineered construct was transplanted to the cartilage damage area through stage II surgery to regenerate the cartilage. (C) T1 (left) and T2 (right) map images after 3 months