Chondrocyte harvest viability of auricular and nasal septal cartilage in a sheep model

Abstract Introduction: Autologous techniques for reconstruction of cartilaginous structures of the head and neck are limited by donor cartilage volume, donor site morbidity and inconsistent results. Bioprinting combines “bioinks” consisting of living cells, supporting structures and biological motifs with a scaffold to create customised implantable constructs. This animal study reports on the digestion and proliferation results of auricular and nasal septal chondrocytes with the aim of understanding the behavior of different donor sites for chondrocytes and its impact on clinical practice. Methods: Cartilage was harvested from the ear and nasal septum of six sheep. The cartilage was digested utilising a 0.15% w/v type II collagenase solution, then seeded at cell densities of 1.5x104 for 14 day proliferation, with cell counts calculated and recorded at days 1, 3, 7, 10 and 14. Results: Auricular and septal chondrocytes yielded an average of 6.09x106 and 5.48x106 cells per gram of cartilage respectively, with no statistically significant difference between total or viable chondrocyte counts between the sources. Septal chondrocyte cell counts expanded at a faster rate than auricular chondrocytes, though this rate plateaued and mean cell counts were not significantly different at day 14. Conclusion: Auricular and septal chondrocytes can be harvested without contamination. There was no significant difference between chondrocytes from the two sources following digestion and 14 day proliferation. Both auricular and septal cartilage are comparable cell sources for use in bioinks. It is important to consider the intended properties of the formed cartilage when deciding which donor source to utilise.