Cellularized Thermoformed Scaffolds with Human Septal Chondrocytes Support In Vivo Cartilage Maturation for Auricular Reconstruction.

Introduction: The clinical translation of biomaterial-based strategies for ear reconstruction remains limited by several challenges, including scaffold design, selection of an optimal cell source, and stability of the new cartilage tissue. Most recent studies still rely on animal-derived cells and fail to demonstrate the long-term maintenance of the chondrogenic phenotype. Methods: In this study, we developed an off-the-shelf poly(lactide-b-ethylene glycol) (PLA-PEG) scaffold combined with clinical-grade alginate (Alg) and cellularized with human nasal chondrocytes for auricular cartilage engineering. Cellularized constructs were evaluated using histological and immunofluorescence analyses to assess extracellular matrix production and quality. In parallel, constructs retrieved after 12 weeks of in vivo implantation were mechanically characterized using a UniVert CellScale testing system to determine variations in compressive strength. Finally, the chondrogenic maturation of the new tissue was evaluated through bulk RNA transcriptomic profiling. Results: Histological, immunofluorescence, and transcriptomic analyses demonstrated robust cartilage matrix deposition with improved compressive properties and high expression of chondrogenic markers, such as ACAN, PRG4, and COL2A1. Furthermore, positive staining for the human-specific Ku80 antibody confirmed the presence of cells of human origin in the newly formed tissue after implantation. Conclusions: Overall, this study provides evidence that the combination of a PLA-PEG + Alg scaffold with human nasal septal chondrocytes represents a promising strategy for future reconstructive applications in auricular tissue engineering.