Comparison of Tracheal and Nasal Chondrocytes for Tissue Engineering of the Trachea

Background. This study was undertaken to evaluate the feasibility of creating engineered tracheal equivalents grown in the shape of cylindrical cartilaginous structures using sheep nasal cartilage-derived chondrocytes. We also tested sheep tracheal and nasal septum for cell yield and quality of the engineered cartilage each produced. Methods. Nasal septum and tracheal tissue were harvested from sheep. Chondrocytes from each were separately isolated from the tissues and suspended in culture media. Tracheal and nasal chondrocytes were seeded onto separate polyglycolic acid matrices. Cell-polymer constructs were cultured for 1 week and then wrapped around a 7-mm diameter x 30-mm length silicon tube and implanted subcutaneously on the back of nude mice for 8 weeks (each, n = 6). Both of the tissue-engineered tracheas (TET) were harvested and analyzed for histological, biochemical, and biomechanical properties. These values were compared with native sheep trachea. Results. The morphology and histology of both tracheal-chondrocyte TET and nasal-chondrocyte TET closely resembled that of native sheep trachea. Safranin-O staining showed that tissue-engineered cartilage was organized into lobules with round, angular lacunae, each containing a single chondrocyte. Chondrocytes from the trachea or nasal septum produced tissue with similar mechanical properties and had similar glycosaminoglycan and hydroxyproline content. Conclusions. This study demonstrates that the property of TET using nasal chondrocytes is similar to that obtained using tracheal chondrocytes. This has the potential benefit of facilitating an autologous approach for repair of segmental tracheal defects using an easily obtained chondrocyte population.