Comparison of Human Costal-Derived Chondrocyte Donor Sites and Microtia-Derived Chondrocytes for Auricular Tissue...

ObjectiveTo compare microtia-derived chondrocytes (MCs) with costal cartilage-derived chondrocytes (CCs) and determine whether costal cartilage harvest location influences chondrocyte proliferative and chondrogenic potential for auricular cartilage tissue engineering.DesignExperimental laboratory study using native tissue analysis and in vitro cell culture.SettingSingle-center laboratory study.PatientsNative auricular and costal cartilage samples were collected from four paired pediatric patients undergoing autologous microtia reconstruction.Interventions: MCs and costal chondrocytes isolated from proximal/osteochondral (PCs), distal/sternal (DCs), and medial costal (CCs) regions, were expanded in normal cell culture and 3D pellet culture.Main Outcome MeasuresType II collagen, glycosaminoglycans, total collagen, proteoglycans, and Ki67 were evaluated via immunohistochemistry (IHC). Cell proliferation was measured using cell counting kit-8 (CCK8), and gene expression of chondrogenic, osteogenic, and proliferative markers was analyzed in monolayer and 3D pellet cultures.ResultsNative microtia and costal cartilage demonstrated similar type II collagen and proteoglycan content across regions. Native microtia tissue showed greater Ki67 staining than medial and proximal costal cartilage (p < 0.05 and p < 0.01, respectively), whereas glycosaminoglycan staining was greater in costal cartilage (p < 0.05). In normal cell culture, all cell types demonstrated similar proliferative activity. In 3D pellet culture, PCs had higher Ki67 staining than DCs and MCs (p < 0.01). In CC pellet cultures, Ki67 and COL2A1 expression was increased.ConclusionCostal CCs demonstrated distinct chondrogenic characteristics based on harvest site. These findings support a more targeted utilization of costal CCs for auricular cartilage tissue engineering.