Characteristics of tissue-engineered cartilage from human auricular chondrocytes

This study was done to define the mechanical and histological properties of tissue-engineered cartilage (TEC) derived from human chondrocytes and to compare these findings with those of native cartilage. Chondrocytes were obtained from 10 human auricular cartilages and seeded onto a biodegradable template of polyglycolic acid and poly L-lactic acid. Each template was shaped into a 1 cm x 2 cm rectangle. The templates were implanted in athymic mice for 8 weeks. Eight human auricular cartilages were used for comparison. Mechanical analysis with a tensile testing device provided values of ultimate tensile strength (UTS), stiffness, and resilience. Statistical analysis was performed with the Student's t-test. Histological assessment was done with hematoxylin-eosin staining along with other special stains. The TEC had UTS of 2.07 MPa, stiffness of 3.7 MPa, and resilience of 0.37 J/m3. The control specimens had UTS of 2.18 MPa, stiffness of 5.11 MPa, and resilience of 0.42 J/m3. No statistical difference was found between the experimental and control groups for each of the three parameters. Histological analysis showed mature cartilage with characteristic collagen, glycosaminoglycans, and elastin in the TEC. The neo-cartilage showed slightly smaller size and more irregular distribution of chondrocytes and unique fibrous capsule formation with peripheral infiltration of fibrous tissue. This study showed that the mechanical qualities of TEC from human chondrocytes are similar to those of native auricular cartilage. It suggests that the engineered cartilage from human chondrocytes may have sufficient strength and durability for clinical uses. The histological findings revealed some differences with neo-cartilage.