Human Adult, Pediatric and Microtia Auricular Cartilage harbor Fibronectin-adhering Progenitor Cells with Regenerative Ear Reconstruction Potential

Remaining challenges in auricular cartilage tissue engineering include acquiring
sufficient amounts of regeneration-competent cells and subsequent production of high
quality neocartilage. Progenitor cells are a resident subpopulation of native cartilage,
displaying a high proliferative and cartilage-forming capacity, yet their potential for
regenerative medicine is vastly understudied. In this study, human auricular cartilage
progenitor cells were newly identified in healthy cartilage and, importantly, in microtia-
impaired chondral remnants. Their cartilage repair potential was assessed via in vitro
3D culture upon encapsulation in a gelatin-based hydrogel, and subsequent
biochemical, mechanical and histological analyses. Auricular cartilage progenitor cells
demonstrate a potent ability to proliferate without losing their multipotent differentiation
ability and to produce cartilage-like matrix in 3D culture. As these cells can be easily
obtained through a non-deforming biopsy of the healthy ear or from the otherwise
redundant microtia remnant, they can provide an important solution for long-existing
challenges in auricular cartilage tissue engineering.